• Ependymoma
• Meningioma
• Astrocytoma
• Medulloblastoma
• Craniopharyngioma
• Oligodendroglioma
• Gliomas
• Brainstem Glioma
• Pituitary Adenoma
• Schwannoma
• Germ Cell Tumor
• Primitive Neuroectodermal Tumor
• Primary Central Nervous System Lymphoma
• Mixed Glioma
• Optic Nerve Glioma
• Chordoma
• Diffuse Astrocytomas
• Hemangioblastoma

1. What Is Ependymoma?

Ependymoma is a tumor that originates from ependymal cells which together form the ependyma.

The ependyma is a type of brain ciliated epithelium, known as neuroepithelium, which forms a thin membrane lining the brain cavities (ventricles) and the central canal of the spinal cord.

Ependymoma is caused by mutations in genes that control the growth of ependymal cells [1]. They are categorized as slow-growing (Low Grade which includes Grade I and Grade II) or fast-growing (High grade or Grade III) [2].

In the United States, about 1096 people are diagnosed with ependymoma each year with 13294 people living with this tumor [2].

2. What Is Meningioma?

Meningioma is a common type of brain tumor that originates from the membranes that cover the brain and spinal cord and is known as meninges.

The causes of meningioma are not well-known; however, mutations in genes that control the growth of the cells within the membranes of the meninges may be involved [3].

Meningioma is classified as low grade or slow-growing (Grade I; the most common), mid-grade or atypical meningiomas (Grade II), and fast-growing or anaplastic meningiomas (Grade III) [4].

In the United States, about 371 people are diagnosed with meningioma each year with 2692 people living with this type of tumor [4].

3. What Is Astrocytoma?

Astrocytoma is a brain tumor that originates from a type of brain cells, known as astrocytes. Astrocytes and oligodendrocytes (another type of brain cell) are also known as glial cells.

Astrocytes are star-shaped cells involved in supporting nerve cells (neurons) by providing nutrients, repairing nervous tissue following injury or infection, and regulating blood flow in the brain.

The causes of astrocytoma are not known but may involve genetic and immunologic anomalies.

Astrocytoma is categorized into the following grades:

• Astrocytoma Grade I, also known as Pilocystic Astrocytoma, is a low-grade tumor with slow growth.
• Astrocytoma Grade II, also known Low-Grade Astrocytoma, is a tumor also characterized by slow growth.
• Astrocytoma Grade III, also known as Anaplastic Astrocytoma, has a faster and more aggressive growth compared to Astrocytoma Grade III.
• Astrocytoma Grade IV, also known as Glioblastoma Multiforme, is the most aggressive and deadliest primary brain tumor [5].

In the United States and Europe, about 2 to 3 per 100,000 people are diagnosed with astrocytoma every year [5].

4. What Is Medulloblastoma?

Medulloblastoma is a brain tumor that arises from cells in the cerebellum whose functions have been altered by chromosomal abnormalities. However, the type of affected cells is not well-known and may involve cerebellar stem cells.

This type of brain tumor mostly affects children but can also affect adults but at a much lower frequency.

In the United States, about 1000 people are diagnosed with medulloblastoma each year [6].

5. What Is Craniopharyngioma?

Craniopharyngioma is a rare brain tumor that arises from epithelial cells located between the hypothalamus and the pituitary gland; however, the causes of this tumor formation are not known.

Craniopharyngioma is a very slow-growing tumor that affects children and adults over the age of 50. Craniopharyngioma has an incidence of about 0.13 to 2 per 100,000 people each year [7].

6. What Is Oligodendroglioma?

Oligodendroglioma is a tumor that originates from a type of glial cells known as oligodendrocytes. Although the causes are unknown, it mainly develops in the frontal and temporal lobes of the brain.

Oligodendrocytes are cells that provide support and insulation to the neurons’ axons through the production of myelin that covers the axons.

Oligodendrogliomas are categorized as Grade II (very slow-growing) and Grade III or anaplastic oligodendroglioma (very fast growing) [8].

In the United States, about 1271 people are diagnosed with oligodendroglioma each year with 11757 people living with this type of tumor [9].

7. What Are Gliomas?

Gliomas are brain tumors that arise from glial cells, including astrocytes, oligodendrocytes, and ependymal cells, leading to astrocytoma, oligodendroglioma, and ependymoma, respectively.

8. What Is Brainstem Glioma?

Brainstem Glioma is a tumor that is originated from glial cells (Astrocytes) in the brainstem which connects the cerebellum with the spinal cord and controls body functions such as heart rate, breathing, and swallowing [10].

Brainstem gliomas mostly affect children and young adults under the age of 20 years but can also affect adults [11]. Unfortunately, the causes of brainstem glioma are unknown.

Because brainstem gliomas are typically considered astrocytomas, they are categorized as astrocytomas grades I-IV [10].

9. What Is Pituitary Adenoma?

A pituitary adenoma is a tumor that develops from tissues in the pituitary gland which controls most of the functions of the endocrine system including growth, reproduction, metabolism, stress, and pain.

The pituitary gland controls these functions through the secretion of many hormones, including ACTH, GH, prolactin, FSH, LH, TSH, MSH, beta-endorphins, Vasopressin, and oxytocin.

Pituitary adenomas are categorized as benign adenomas, invasive adenomas, or carcinomas (epithelial tumors) but are also based on their ability to secrete hormones.

They affect about 1 in 5 people during their lifetime and are usually slow-growing, harmless, and less invasive [11].

10. What Is Schwannoma?

Schwannoma is a tumor that develops from Schwann cells that produce the myelin sheath which covers and insulate nerve cells in the peripherical nervous system.

Although the causes of Schwannoma are unknown, Schwannoma tumor cells are characterized by an abnormal growth compared to that of normal Schwann cells.

Depending on the affected peripheral nerves, schwannoma can affect different parts of the body (e.g., face, vestibule, or spinal cord root) through its compression effect on nerves.

Schwannoma is a rare tumor that affects around 200,000 people [12].

11. What Is Germ Cell Tumor?

Germ cell tumors are growths that originate from germ cells such as the gonads (ovaries or testes). They are categorized into benign germ cell tumors (e.g., mature teratoma) and malignant germ cell tumors (e.g., seminoma and dysgerminoma) [13].

In the United States, about 900 children and adolescents are diagnosed with germline tumors each year [14].

12. What Is Primitive Neuroectodermal Tumor?

A primitive neuroectodermal tumor (PNET) is a tumor that develops from the neuroectoderm during embryonic development affecting the brain and the spinal cord.

The neuroectoderm is an embryonic structure that later generates the hindbrain, the midbrain, and the forebrain.

Primitive neuroectodermal tumors (PNET) are fast-growing tumors (Grade IV) that mainly affect children and adults.

In the United States, about 129 people are diagnosed with PNET each year with 950 people living with this type of tumor [15].

13. What Is Primary Central Nervous System Lymphoma?

Primary central nervous system lymphoma (PCNSL) is a tumor that arises from the lymph node tissues in the brain and spinal cord.

Although the causes are unknown, PCNLCs are mostly large B-cell non-Hodgkin lymphomas and mainly affect patients with AIDS (Immunocompromised).

In the United States, about 1500 people are diagnosed with PCNL each year [16].

14. What Is Mixed Glioma?

Mixed gliomas are tumors that arise from more than one type of glial cells, including astrocytes, oligodendrocytes, and ependymal cells.

They are mostly originated from both astrocytes and oligodendrocytes resulting in oligoastrocytomas.

Mixed gliomas are categorized as Grade I and II (Slow-growing) or Grade III and IV (Fast-growing and likely invasive) [17].

15. What Is Optic Nerve Glioma?

Optic nerve glioma is a rare low-grade tumor that develops around the optic nerve causing vision problems [18]. It is mostly detected in children at the age of 5 years.

16. What Is Chordoma?

Chordoma is a slow-growing tumor originating from left-over cells, known as notochord cells, which role is associated with the formation of the spine during embryonic development.

Chordomas are mostly diagnosed in individuals in their 50s or 60s and in the sacral region (tailbone) or the region between the skull and the spine [19].

In the United States, about 300 people are diagnosed with chordoma each year, while 700 people are diagnosed with this type of tumor each year in Europe [20].

17. What Are Diffuse Astrocytomas?

Diffuse astrocytomas are grade II (slow-growing) tumors that develop from astrocytes in the cerebral hemispheres but are dispersed within the brain tissue instead of being well-defined within an area of the brain.

In the United States, about 1410 people were diagnosed with diffuse astrocytomas in 2017 [21].

18. What Is Hemangioblastoma?

Hemangioblastoma is a very rare benign vascular tumor that arises from cells lining the blood vessels in the cerebellum, brainstem, and spinal cord. The causes of hemangioblastoma are unknown.

In the United States, the incidence of hemangioblastoma was estimated at 0.014 per 100,000 people [22].

Conclusion

Brain tumors are classified based on the area or region of the brain tissue origin and how fast they grow. Depending on the affected tissues, brain tumors can affect brain function through compression or excess production of hormones.

The post What Are the Main Types of Brain Tumors? appeared first on .

1. What Activates the Reward System?

The reward system is activated every time we experience something rewarding. For instance, the reward system is triggered when eating something we really enjoy or meeting people we like. The result is a sensation of pleasure and joy.

2. What Part of the Brain Processes Rewards?

There are several parts of the brain that processes rewards, however, the main ones involve the ventral tegmental area (VTA), the nucleus accumbens, the prefrontal cortex, the amygdala, and the hippocampus.  

Rewards are controlled by the reward system through the neurotransmitter dopamine.

2.1. What Is the Ventral Tegmental Area (VTA) and Its Role in the Reward System?

The ventral tegmental area (VTA) is a brain structure located in the midbrain that contains the cell bodies of the dopaminergic neurons where dopamine is released.

2.2. What Is the Nucleus Accumbens and Its Role in the Reward System?

The nucleus Accumbens is a brain structure that is part of the ventral striatum in the basal ganglia. It contains nerve cells that are sensitive to dopamine.

The nerve cells of the nucleus accumbens express on their surface the dopamine receptors, the D1-like (D₁, and D₅) and the D2-like (D₂, D₃, and D₄) family of receptors where dopamine binds. Once activated by dopamine, these cells cause feelings of pleasure.

2.3. What Is the Amygdala and Its Role in the Reward System?

The amygdala is an almond-shaped brain structure located deep in the cerebrum. It is made of a cluster of neurons (Nucleus) responsible for memory including reward-related memory.

For instance, if we had a good experience that led to a feeling of pleasure, this information is stored in the amygdala in the form of desirable memory.

2.5. What Is the Hippocampus and Its Role in the Reward System?

The hippocampus is a brain structure located in the thalamus which is part of the diencephalon (forebrain).

It is made of several clusters of neurons (Nuclei) responsible for coordinating interactions between the nervous system and the endocrine system through the pituitary gland.

Like the amygdala, the hippocampus is also responsible for memory including reward-related memory.

2.6. What Is the Prefrontal Cortex and Its Role in the Reward System?

The prefrontal cortex is the part of the brain that covers up the front of the frontal lobe. It is involved in executive functions such as planning, decision making, and short-term memory.

Within the reward system, the prefrontal cortex coordinates all reward-related information and decides on the type of behavior in response to the information available.

3. What Is Dopamine in the Brain?

Dopamine is a neurotransmitter that is released by dopaminergic neurons to control movement and reward-motivated behavior, such as pleasure, craving, rewards-related decision making, associative learning (learning new things), and short-term memory [2].

Dopamine is synthesized through the metabolism of an essential amino acid known as Phenylalanine. Phenylalanine first generates tyrosine (another amino acid), then tyrosine produces DOPA which finally produces dopamine.

After dopamine synthesis by the dopaminergic neurons, it is transported from the cytoplasm of the neurons all the way to the synapses by a cellular transporter named VMAT2 (Vesicular Monoamine transporter 2), where it is released through vesicles known as synaptic vesicles.

The release of dopamine vesicles in the synaptic cleft is triggered by action potentials, and once released, dopamine binds to the dopamine receptors, the D1-like (D₁, and D₅) and the D2-like (D₂, D₃, and D₄) family of receptors, found on the surface of dendrites of postsynaptic neurons.

The binding of dopamine to its receptors initiates action potentials in the receiving neurons known as neurotransmission.

After the binding activation, dopamine is recycled back to the presynapse by the dopamine transporter until the next activity.

4. What Are the Disorders of the Reward System?

They are several disorders associated with dysfunctions of the reward system, including addiction, mood disorders, schizophrenia, and attention deficit hyperactivity disorder (ADHD).

4.1. What Is Addiction?

Addiction is a compulsive engagement in rewarding stimuli that have adverse consequences. The affected individual is incapable of stopping using a substance or engaging in a behavior. An example of this is drugs addiction.

4.2. Mood Disorders

Mood disorders are emotional states or moods characterized by inconsistency or swings in expressing emotions such as sadness, irritability, aggressivity, impulsivity, and excessive happiness.

Substance abuse such as alcoholism, cocaine, opioids (e.g., heroin) can cause mood disorders through addiction [3]. For instance, depression can be induced by substance abuse associated with an imbalance of neurotransmitters such as dopamine.

Besides addiction, mood disorders are also characterized by reduced motivation which may be associated with reduced activity of dopamine in the striatum [4].

4.3. Schizophrenia

Schizophrenia is a complex and severe mental health disorder that is classified as a type of psychosis. It is characterized by significant alterations in thoughts, perception, mood, and behaviors [5]. 

Like mood disorders, schizophrenia is also associated with a lack of motivation which may be due to abnormalities in the orbitofrontal cortex and striatum.

4.4. Attention Deficit Hyperactivity Disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) is a brain disorder that affects the behavior of affected individuals and is characterized by an impulsive and constant pattern of inattention and hyperactivity.

In ADHD individuals, there are alterations in motivation and reward which may be associated with the levels of dopamine [6].

These levels are high during the hyperactive phase which increases motivation and reward, while during the inattention phase the levels of dopamine decrease resulting in a lack of motivation and reward.

Conclusion

The reward system controls addictive behaviors, mood, feeding behaviors, positive emotions (e.g., pleasure), and learning.

It is a complex system that involves several brain structures, including the ventral tegmental area (VTA), the nucleus accumbens, the prefrontal cortex, the amygdala, and the hippocampus.

The neurotransmission of information with the reward system is ensured by the neurotransmitter, dopamine.

Dopamine is released by the dopaminergic neurons in the ventral tegmental and excites neurons in the nucleus accumbens. Memory related to reward is stored in the amygdala and the hippocampus. Finally, the behavior associated with motivation and reward is coordinated by the prefrontal cortex.

Anomalies of the reward system result in disorders including addiction, mood disorders, schizophrenia, and attention deficit hyperactivity disorder (ADHD).

The post What Is the Reward System of the Brain? appeared first on .

• Fungal Meningitis
• Fungal Meningoencephalitis
• Fungal Brain Abscess
• Rhino-cerebral Mucormycosis
• Fungal Skull Base Syndromes

1. What Is Fungal Meningitis and What Causes It?

Fungal meningitis is the inflammation of the membranes that cover the brain and spinal cord which is caused by the following genera of fungi:

• Cryptococcus
• Coccidioides
• Exserohilum
• Candida
• Histoplasma

Fungal meningitis manifest with the following symptoms:

• Severe Headaches
• Fever
• Confusion
• Stiff Neck
• Photophobia (sensitivity to light)
• Nausea
• Vomiting

2. What Is Fungal Meningoencephalitis and What Causes It?

Fungal meningoencephalitis is the inflammation of both the membranes that cover the brain and spinal cord, by the following genera of fungi:

• Cryptococcus
• Coccidioides
• Candida

Fungal meningoencephalitis manifest with the following symptoms:

• Severe Headaches
• Fever
• Confusion
• Stiff Neck
• Photophobia (sensitivity to light)
• Seizures
• Changes in Thinking, Behavior and Personality

3. What Is Fungal Brain Abscess and What Causes It?

A fungal brain abscess is an abscess that contains a collection of infected material and debris of brain cells resulting from a brain inflammation caused by the following genera of fungi:

• Aspergillus
• Coccidioides
• Mucoromycetes
• Candida
• Histoplasma
• Blastomyces

A fungal brain abscess manifests with the following symptoms:

• Headaches
• Fever
• Neurological problems associated with the abscess compression of the brain affected area (e.g., seizures, confusion, speech problems, drowsiness, weakness of one part of the body).

4. What Is Rhinocerebral Mucormycosis and What Causes It?

Rhinocerebral mucormycosis or zygomycosis is a rare disease that affects the nose, the sinuses, and the brain. It is caused by the following filamentous fungi [2]:

• Mucor
• Rhizopus
• Absidia
• Rhizomucor
• Syncephalastrum

Rhinocerebral mucormycosis manifests with the following symptoms:

• Facial and Nasal Deformity
• Brain Infarction (stroke)
• Neurological symptoms due to brain Hematoma or brain abscess which compresses brain areas or cranial nerves (e.g., vision loss, ptosis (dropping of the upper lids), cranial nerves palsies (paralysis with involuntary tremors).
• Meningitis symptoms

5. What Are Fungal Skull Base Syndromes and What Causes Them?

Fungal skull base syndromes are inflammations of the base of the skull and associated cranial nerves, caused by the fungus, Aspergillus.

They manifest neurological symptoms due to the damage caused to cranial nerves, including cranial nerve palsies and craniofacial pain.

6. How Do You Get Fungus in Your Brain?

You get fungi in the brain through the inhalation of fungi spores which reach the brain by spreading from the lungs. Below are environmental characteristics of some of the most common fungi:

6.1. Cryptococcus

Cryptococcus species are found worldwide where they are present in pigeon dropping and in eucalyptus and other tropical and subtropical trees found in Southern California, US pacific North-west regions, British Colombia, Mexico, part of Africa, and Australia [3].

In the USA, Cryptococcus neoformans is responsible for 30–66 infections per million population each year [4].

6.2. Candida

Candida species lives on the skin and inside the body without causing health issues; however, they are opportunistic and cause infections in immunosuppressed individuals (weak immune system).

In the USA, Candida species are responsible for 72 to 228 infections per million population each year [4]. 

6.3. Aspergillus

Aspergillus species are widely found in the environment with a high prevalence in the USA, Saudi Arabia, India, Pakistan, and Turkey [5].

6.4. Mucoromycetes

Mucoromycetes live in a natural and humid environment and causes infections, particularly in immunosuppressed individuals (weak immune system), such as AIDS patients.

The annual incidence of mucormycosis is estimated at 1.7 infections per 1 million inhabitants [6].

6.5. Coccidiosis

Coccidiosis is found in the soil in Central and South America and in the USA (south-central Washington State, southwest, and parts of Mexico) [7].

6.6. Histoplasma

Histoplasma mainly lives in soil rich in bat and pigeon droppings. In the USA, it is found in Central and Eastern states [7].

6.7. Blastomyces

Blastomyces live in decaying wood and leaves and in moist soil. In the USA, it is found in midwestern, south-central, and south-eastern states [7].

7. What Are the Risk Factors for Brain Fungal Infections?

Certain conditions, treatments, and medications can increase the risk for brain fungal infections including [8]:

• Weak immune system (e.g., individuals with AIDS or cancer)
• Steroid therapy
• Infants’ prematurity
• Neurosurgery
• Diabetic ketoacidosis
• Renal failure
• Necrotic burns
• Contact with birds

8. What’s the Mortality Rate for Fungal Meningitis?

The overall mortality of Fungal meningitis, and in particular candida meningitis, was estimated at 10-20%, and this percentage is about 31% for AIDS patients and 11% for individuals who have undergone neurosurgery [9].

9. What Are the Long-Term Effects of Fungal Meningitis?

10. Can You Have Candida in Your Brain?

Candida species live on the skin and inside the body without causing health issues; though, they can cause brain infections in immunosuppressed (weak immune system) individuals.

11. How Do You Test for Fungal Meningitis?

Testing for fungal meningitis involves collecting samples of blood or cerebrospinal fluid from patients to check for the presence and determine the type of fungus involved [7].

12. How Do You Get Rid of Brain Fungus?

Fungal infections are treated by high doses of antifungal drugs including Amphotericin B deoxycholate (AmBd), Voriconazole, Fluconazole, Flucytosine, and Isavuconazole [1].

These drugs have different effects and target the cell membrane of the fungus to induce their cell death such as Amphotericin B deoxycholate (AmBd), Voriconazole, Fluconazole, and Isavuconazole, while Flucytosine targets the metabolism of the fungus which weakens its DNA and RNA syntheses.

For instance, Amphotericin B deoxycholate (AmBd) is used in combination with Flucytosine for the treatment of cryptococcal meningoencephalitis.

A combination of Amphotericin B deoxycholate (AmBd) and Fluconazole is used for the treatment of candida infections.

Aspergillosis is treated with Voriconazole, while mucormycosis is treated with Amphotericin B deoxycholate (AmBd).

Conclusion

Fungal infections of the brain are characterized by high mortality rates which exceed those of viral, bacterial, or parasitic infections of the brain.

Individuals with a weak immune system such as AIDS or cancer patients are the most vulnerable, and therefore, preventive measures are necessary to prevent fungal infections.

Staying away from dusty areas such as construction sites, gardening (contact with soil), and ensuring cleaning of injured skin which can be a point of infection by fungi.

The post Can a Fungal Infection Cause Brain Lesions? appeared first on .

It is transmitted to humans through fecal-oral contamination or the consumption of pig meat infected with taenia cysts [1].

Neurocysticercosis results in the production of cysts in the brain parenchyma leading to headaches, seizures, cognitive abnormalities, and local nerve tissue damage.

Neurocysticercosis can also result in encephalitis when affecting other parts of the brain.

However, there are types of worms that can infect the brain including flatworms (cestodes) and roundworms (nematodes) causing diseases such as echinococcosis, or Schistosomiasis [2].

1. What Parasites Infect the Brain?

There are 2 types of parasites that can infect the brain: Protozoa and Metazoa parasites [1].

Protozoa parasites are single-cell parasites (made of 1 cell) that cause the following diseases:

• Cerebral Malaria
• American Trypanosomiasis (Chagas Disease)
• African Trypanosomiasis (Sleeping Sickness)
• Toxoplasmosis
• Leishmaniasis
• Amoebiasis
• Microsporidiasis

Metazoa parasites are multi-cellular parasites (worms) that cause the following diseases:

• Schistosomiasis
• Paragonimiasis
• Cysticercosis
• Coernurosis
• Echinococcosis
• Sparganosis
• Gnathostomiasis
• Angiostrongyliasis
• Toxocariasis
• Strongyloidiasis
• Baylisarcariasis
• Lagochilasarcariasis
• Onchocerciasis

1.1. Which Protozoan Parasites Infect the Brain?

1.1.1. What Is Cerebral Malaria?

Malaria of the brain is caused by Plasmodium falciparum which is transmitted to humans by insect bite (Anopheles mosquito) resulting in encephalitis (inflammation of the brain).

It mostly affects children in Africa and adults in Asia and manifests with symptoms including headaches, fatigue, muscle aches, fever, nausea, vomiting, and seizures [3].

These symptoms are due to the presence of schizonts (mature malaria parasites) in the brain venules which causes their damage.

1.1.2. What Is American Trypanosomiasis (Chagas Disease) of the Brain?

American Trypanosomiasis or Chagas disease is caused by Trypanosoma cruzi which is transmitted to humans by insect bite (Triatomine bug) resulting in meningoencephalitis particularly in immunoexpressed individuals such as individuals with HIV. It is mostly found in Latin America [4].

1.1.3. What Is African Trypanosomiasis (Sleeping Sickness) of the Brain?

African trypanosomiasis or sleeping sickness is caused by Trypanosoma brucei which is transmitted to humans by the Tsetse fly resulting in an infection of the brain parenchyma which if untreated early on leads to meningitis or meningoencephalitis with edema [5].

1.1.4. What Is Toxoplasmosis of the Brain?

Toxoplasmosis is caused by Toxoplasma gondii which is transmitted to humans through contaminated food with feces from cats, birds, or rodents.

Toxoplasmosis infection results in cysts within the brain, but also in cardiac muscle, and skeleton muscle, resulting in headaches, fever, confusion, and seizures [6].

1.1.5. What Is Leishmaniasis of the Brain?

Leishmaniasis of the brain is caused by Leishmania donovani which is transmitted to humans by dogs, resulting in seizures, paresis, meningoencephalitis, and cranial nerves dysfunction, and hemorrhagic stroke [7].

1.1.6. What Is Amoebiasis of the Brain?

Amoebiasis of the brain is caused by several species of amoeba, including Naegleria fowleri, Acanthamoeba species, and Balamuthia mandrillaris [8].

Naegleria fowleri is found in freshwater and is transmitted to humans while swimming in freshwater. It causes meningoencephalitis that manifests with headache, fever, nausea, and vomiting.

Acanthamoeba is found in water and can cause encephalitis in individuals with a weak immune system which manifests with headache, dizziness, nausea, vomiting, double vision, confusion, ataxia, and seizures.

Balamuthia mandrillaris is found in soil and its infection of the brain results in similar symptoms to those of acanthamoeba encephalitis.

1.1.7. What Is Cerebral Microsporidiosis?

Cerebral microsporidiosis is mainly caused Enterocytozoon bieneusi resulting in encephalitis and seizures [9].

1.2. Which Metazoan Parasites Infect the Brain?

Metazoan parasite infections involve flatworms (Trematoda and Cestodes) and roundworms (nematodes).

1.2.1. What Is Schistosomiasis?

Schistosomiasis is caused by the flatworms (Trematoda), Schistosoma mansoni, and Schistosoma haematobium that infect the spinal cord, and Schistosoma japonicum that mostly infects the brain.

These parasites are found in freshwater and infect humans through the skin resulting in immune-mediated hypersensitivity reaction (increased immune reaction) and acute encephalitis [10].

1.2.2. What is Paragonimiasis of the Brain?

Paragonimiasis is caused by the flatworm, Paragonimus westermani, which is transmitted to humans through fecal-oral contamination, or the consumption of uncooked contaminated crustaceans (e.g., crabs, shrimps, lobster).

Paragonimiasis infection causes an inflammation associated with a reaction to the parasite or its eggs and results in cerebral hemorrhage [11].

1.2.3. What is Cysticercosis Cellulosae?

Neurocysticercosis or Cysticercosis Cellulosae is caused by the flatworm (Cestode), Taenia solium, which is transmitted to humans through fecal-oral contamination, or the consumption of pig meat infected with taenia cysts [1].

Neurocysticercosis results in the production of cysts in the brain parenchyma leading to headaches, seizures, cognitive abnormalities, and local nerve tissue damage.

Neurocysticercosis can also result in encephalitis when affecting other parts of the brain.

1.2.4. Coernurosis

Coernurosis is caused by different Taenia species, including Taenia multiceps, T. serialis, T. brauni, and T. glomeratus [12]. 

These parasites infect humans through the consumption of contaminated food (by dogs or sheep feces) resulting in symptoms like those of neurocysticercosis, including headache, seizures, cognitive abnormalities, local nerve tissue damage, and encephalitis.

1.2.5. What is Hydatidosis or Echinococcosis?

Hydatidosis or echinococcosis is caused by Echinococcus granulosus and Echinococcus multilocularis which result in the formation of cysts in the brain.

The rupture of the cysts results in cerebral lesions and seizures [13].

1.2.6. What Is Sparganosis of the Brain?

Sparganosis is caused by the flatworms (cestodes), Spirometra mansoni, Spirometra ranarum, Spirometra mansonoides, Spirometra erinacei, and Sparganum proliferum, which infect humans through drinking water [14].

Brain sparganosis results in headaches, seizures, weakness, and abnormal skin sensations.

1.2.7. What Is Gnathostomiasis of the Brain?

Gnathostomiasis is caused by the roundworm (Nematode), Gnathostoma spinigerum, which is transmitted to humans through the consumption of undercooked birds’ meat and freshwater fish, eels, and frogs.

Although the gnasthostoma mainly infects the skin (under the skin), it can also infect the brain resulting in nerve pain, paralysis, coma, and death [15].

1.2.8. What Is Angiostrongyliasis of the Brain?

Angiostrongyliasis is caused by the roundworm (Nematode), Angiostrongylus cantonensis, which is transmitted to humans through the consumption of undercooked food such as shrimps, crabs, snails, and slugs [1].

Angiostrongyliasis results in meningitis (eosinophil meningitis) that manifests with headaches, neck stiffness, nausea, and vomiting.

1.2.9. What Is Toxocariasis of the Brain?

Toxocariasis is caused by the roundworms (Nematodes), Toxocara canis and Toxocara cati, transmitted to humans by dogs and cats, respectively.

Although infection of the brain is rare, toxocariasis can result in meningitis (eosinophil meningitis), seizures, meningomyelitis (inflammation of the myelin sheath), and optic neuritis (inflammation of the optic nerve) [16].

1.2.10. What Is Strongyloidiasis of the Brain?

Strongyloidiasis is caused by the roundworm (Nematode), Strongyloides stercoralis, which is transmitted to humans through contaminated soil.

Strongyloidiasis is often associated with sepsis due to the infiltration of bowel bacteria into the bloodstream following the parasite perforation of the bowel, resulting in bacterial meningitis and meningoencephalitis [17].

1.2.12. What Is Baylisarcariasis?

Baylisarcariasis is caused by the roundworm (Nematode), Baylisascaris procyonis, which is transmitted to humans by raccoons, resulting in meningoencephalitis and vision loss [18].

1.2.15. What Is Lagochilasarcariasis of the Brain?

Lagochilasarcariasis is caused by the roundworm (Nematode), Lagochilascaris minor Leiper, resulting in purulent abscesses in the different organs of the body, including the brain. It was mainly reported in Brazil.

The neurological lesions (cerebral hemispheres and cerebellum) results in encephalopathy, seizures, headache, motor alterations, paresthesia, cerebellar ataxia, mental confusion, and coma [19].

1.2.16. What Is Onchocerciasis?

Onchocerciasis is caused by the roundworm (Nematode), Onchocerca volvulus, which is transmitted to humans through repeated bites by blackflies of the genus Simulium.

Onchocerciasis can cause nodding syndrome and epileptic encephalopathy [20].

2. How Common Are Brain Parasites?

Although parasitic brain infections are less common in the United States, they are more common in developing countries [1]. The worldwide prevalence of parasitic diseases that can affect the brain is as follows:

• Malaria: 214 million
• Schistosomiasis: 207 million
• Cysticercosis: 50 million
• Onchocerciasis: 42 million
• American Trypanosomiasis: 10 million
• Echinococcosis: 1 million
• African Trypanosomiasis: 50,000 to 70,000

3. What Parasites Cause Neurological Symptoms?

There are many parasites that can infect the brain and cause neurological symptoms, including flatworms (cestodes) and roundworms (nematodes), causing diseases such as neurocysticercosis (Cysticercosis Cellulosae), echinococcosis, or Schistosomiasis [2].

4. Do Parasites Show Up on an MRI?

Parasites are usually detected by MRI and CT scans which allow visualizing their localization within the body of the infected individual [2].

5. Can You Have Worms in Your Brain?

There are several worms that can infect your brain including flatworms (cestodes) and roundworms (nematodes) causing diseases such as neurocysticercosis (Cysticercosis Cellulosae), echinococcosis, or Schistosomiasis [2].

6. Can Parasites Cause Mental Health?

Parasites can cause mental health issues, particularly by causing behavioral changes in the infected individual [21]. Parasites do this through the following actions:

• Interference with the immune-neuronal communication of the affected individual
• Secretion of substances that interfere with the brain activity of the affected individual
• Induction of changes in the brain gene and protein expression

7. How Do You Get Rid of Parasites in the Brain?

Some parasitic infections require surgery such as echinococcosis, or Coernurosis to remove the cysts; however, other parasitic infections require the use of drugs [1]:

• Neurocysticercosis is treated with Albendazole with corticosteroids, praziquantel with corticosteroids or a combination of the 2 drugs with corticosteroids.

• Schistosomiasis is treated with praziquantel

• Cerebral malaria is treated with artesunate and quinine dihydrochloride or quinine gluconate

• Onchocerciasis is treated with ivermectin and doxycycline

• American Trypanosomiasis is treated with benznidazole and nifurtimox

• African Trypanosomiasis is treated with different drugs depending on the species of Trypanosoma, including drugs such as pentamidine, suramin, eflornithine, nifurtimox, and melarsopol

Conclusion

Parasitic infections of the brain are less common in the United States but are more common in developing countries where they have significant health and economic burden.

These diseases have a neurological impact on the organs, mobility, and cognitive functions of the affected individuals resulting in lifelong disabilities, social shame, and a reduction in economic productivity.

The post What Is Called When You Have Worms in Your Brain? appeared first on .

• Nonopioid Analgesics
• Opioid Analgesics
• Adjuvant Analgesics

Nonopioid Analgesics include drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and dipyrone.

Opioid Analgesics or narcotic analgesics include drugs such as morphine, codeine, tramadol, and tapentadol.

Adjuvant Analgesics include drugs such as GABA agonists, neuroleptics, muscle relaxants, and anticholinergics.

Depending on the mechanism of action and usage, analgesics can be further divided into the following subcategories:

• Nonsteroidal Anti-Inflammatory Drugs
• Cox-2 Inhibitors
• Opioid Analgesics
• CGRP Inhibitors
• Miscellaneous Analgesics
• Adjuvant Analgesics

1. What Is the Mechanism of Action of Analgesics?

1.1. What Are Nonsteroidal Anti-Inflammatory Drugs?

NSAIDs are a group of drugs used to relieve pain, reduce inflammation, and fever by targeting the two cyclooxygenases (COX) enzymes, COX-1, and COX-2, responsible for the production of prostaglandins from the fatty acid arachidonic acid in the body [1].

Prostaglandins are lipid compounds that have hormone-like effects and are found in all tissues of our human body.

They are synthesized (produced) by the walls of the blood vessels and involved in the regulation of smooth muscle contraction and relaxation, including those of the blood vessels, uterus, gastrointestinal tract, and urinary bladder.

For example, prostaglandins are responsible for the vasoconstriction and vasodilatation of blood vessels.

They are also involved in inflammation through their role as proinflammatory mediators during the acute phase of inflammation.

Additionally, prostaglandins induce fever through their action on the thermoregulatory center in the hypothalamus.

Another function is associated with their role in platelets aggregation during coagulation, and therefore, are also involved in thrombosis (formation of blood clots in the blood vessels).

Thus, NSAIDs by inhibiting the enzymes COX-1 and COX-2, prevent the production of prostaglandins resulting in pain relief, reduction of inflammation, and fever, and prevention of thrombosis.

The most known NSAIDs are aspirin (acetylsalicylic acid), ibuprofen (Advil, Nurofen, Motrin), and naproxen (Aleve, Naprosyn).

• What Are NSAIDs Used to Treat?

NSAIDs are used for the relief of mild-to-moderate pain in conditions and disorders such as headaches, migraines, toothache, menstruation, muscle strains and sprains, rheumatoid arthritis, and osteoarthritis.

1.2. What Are Cox-2 Inhibitors?

COX-2 inhibitors are also NSAIDs used to relieve pain, reduce inflammation, and fever; however, these drugs selectively target COX-2, while the other NSAIDs target both COX-1 and COX-2.

The advantage of the COX-2 inhibitors is their reduced side effects on the gastrointestinal tract when compared with the other NSAIDs. However, some concerns were raised about the safety of some COX-2 drugs.

COX-2 inhibitors include drugs such as celecoxib (Celebrex) and rofecoxib (Vioxx), which were withdrawn from the market.

• What Are COX-2 Inhibitors Used to Treat?

Cox-2 inhibitors are used for the relief of mild-to-moderate pain in conditions and disorders such menstruation, hereditary polyps of the colon, ankylosing spondylitis, rheumatoid arthritis, and osteoarthritis.

1.3. What Are Opioid Analgesics?

Opioid analgesics or narcotic analgesics are used for the relief of moderate-to-severe acute or chronic pain.

This class of analgesics includes drugs such as morphine, codeine, tramadol, and tapentadol.

These drugs relieve pain through their binding to the opioid receptors (e.g., mu receptors) found in the brain, spinal cord, peripheral nerves, and gastrointestinal tract [2].

The increased prescriptions of opioid analgesics resulted in less effective therapy, and substance abuse [3].

• What Are Opioid Analgesics Used to Treat?

Opioid analgesics are used for the relief of mild-to-moderate pain associated with cancer, and for palliative care or end-of-life care. However, due to their oversubscription, they have been used for the relief of all types of pain.

1.4. What Are CGRP Inhibitors?

CGRP Inhibitors are drugs that relieve pain by targeting a peptide in the peptide known as Calcitonin gene-related peptide (CGRP) [4].

CGRP is stored in neurons of the brain, spinal cord, and peripheral nervous system, where it is involved in the transmission of pain.

CGRP Inhibitors include monoclonal antibodies that bind specifically to CGRP and block its action, including eptinezumab (Vyepti), galcanezumab (Emgality), and fremanezumab (Ajovy) and monoclonal antibodies that bind to the CGRP receptor such as erenumab (Aimovig).

• What Are CGRP Inhibitors Used to Treat?

CGRP Inhibitors are used to treat patients with frequent, episodic, or chronic migraine headaches.

1.5. What Are Miscellaneous Analgesics?

Miscellaneous Analgesics are a separate class of analgesics as they belong to neither nonsteroidal anti-inflammatory drugs (NSAIDs) nor opioid analgesics.

They include analgesics such as acetaminophen (Paracetamol, Tylenol), ziconotide, and dipyrone. However, in the United States, only acetaminophen and ziconotide are available.

• What Are Miscellaneous Analgesics Used to Treat?

Acetaminophen (Paracetamol, Tylenol) is used for reducing fever and relieving mild-to-moderate pain associated with conditions and disorders such as headaches, migraines, toothache, muscle strains, and sprains, rheumatoid arthritis, and osteoarthritis.

Ziconotide relieves severe pain by blocking N-type voltage-gated calcium channels found in the dendrites and nerve terminals and is involved in neurotransmission and pain transmission.

Dipyrone (Metamizole) is used as a pain killer, spasm reliever, and anti-inflammatory agent for the relief of acute and chronic forms of pain, high fever, acute injury, colic, and cancer pain; however, metamizole is banned in many countries including the United States.

1.6. Adjuvant Analgesics

Adjuvant analgesics are drugs that are not considered analgesics but are used for neuropathic pain, musculoskeletal pain, or cancer pain.

This group of drugs includes antidepressants, α₂-adrenergic agonists, corticosteroids, neuroleptics, muscle relaxants, and anticholinergics [2].

2. Do Analgesics Reduce Inflammation?

Analgesic drugs such as NSAIDs and COX-2 inhibitors are used to relieve pain and reduce fever, and inflammation.

The mechanism of action involves the inhibition of the production of the proinflammatory peptide prostaglandins.

3. Is Analgesic Good for Fever?

Analgesic drugs such as NSAIDs and COX-2 inhibitors are used to relieve pain and reduce inflammation, and fever.

The mechanism of action involves the inhibition of the production of prostaglandins which induce fever through their action on the thermoregulatory center in the hypothalamus.

4. Is Ibuprofen an Analgesic?

Ibuprofen (Advil, Nurofen, Motrin) is a nonsteroidal anti-inflammatory drug used to relieve pain, reduce inflammation, and fever by targeting COX-1, and COX-2 enzymes, responsible for the production of prostaglandins.

Conclusion

Analgesics are used for pain relief, and for the reduction of inflammation and fever. They are differently used depending on the severity of the pain; however, their oversubscription or misuse can result in disorders affecting the gastrointestinal tract (e.g., NSAIDs) or drug abuse (e.g., opioid analgesics).

The post What Does Analgesic Do to the Body? appeared first on .

In addition to its role in controlling touch, the somatosensory cortex is also involved in sensing temperature, pain, and body position and movement.

The somatosensory cortex is divided into 4 regions known as Brodmann’s areas 3a, 3b, 1, and 2. Area 3b is also known as the primary somatosensory cortex or S1 [1].

• The neurons in area 3b and 1 are involved processing tactile (touch) information.

• The neurons in the area 3a are involved in processing information associated with the stimulation of proprioceptors found in muscles, joints, and tendons.

Proprioceptors are receptors that detect the forces (in the form of sensations) that are exerted on muscles, tendons, and joints.

• The neurons in the area 2 are involved in sensing both tactile information and the stimulation of proprioceptors.

The somatosensory cortex receives tactile information from sensory neurons that are connected to sensory receptors found in the skin, muscle, tendons, and joints.

There are 3 types of sensory neurons that send tactile information to the somatosensory cortex:

• First-order neurons

These neurons have their cell body in the spinal cord with one axon extending to connect with proprioceptors (mechanoreceptors) and the other axon extending to connect with a second-order neuron through the synapse.

• Second-order neurons

These are generally sensory nerves such as cranial nerves or trigeminal ganglia (part of the trigeminal nerve) that have their cell body in the spinal cord or the brainstem.

• Third-order neurons

These neurons have their body in the ventral posterior nucleus of the thalamus and extend their axons to the somatosensory cortex.

The ventral posterior nucleus serves as a relay for the transmission of tactile information.

1. Where Does the Sense of Touch Takes Place?

The sense of touch takes place in the skin through sensory receptors found in the skin.

2. What Are the 4 Touch Receptors?

They are 4 types of touch receptors including Merkel’s Disks, Meissner’s Corpuscles, Ruffini Endings, and Pacinian Corpuscle [2].

Once activated by touch, the receptors convert the tactile information (mechanical stimuli) into action potential that is transmitted by neurotransmission through first-order, second-order, and third-order neurons

• Merkel’s Disks

Merkel’s Disks are receptors found in the basal layer of the epidermis of non-hairy skin (e.g., fingertips) and have the capacity to sense corners, curves, and edges.

• Meissner’s Corpuscles

These receptors are also known as Wagner-Meissner corpuscles or tactile corpuscles. They are found in the dermal papillae of the thick non-hairy skin (glabrous skin) such as the skin of the sole and palm.

They are neurons endings involved in sensing fine touch and low-frequency vibrations [3].

• Ruffini Endings

These receptors are found in hairy skin and are activated by the stretching of the skin.

• Pacinian Corpuscle

These receptors are also known as Vater-Pacini corpuscle and lamellar corpuscle. They are mechanoreceptors (mechanical sensations) found in hairy and non-hairy skins and involved in sensing vibrations.

Touch receptors are also classified based on their adaptability to dynamic changes in the skin.

Pacinian corpuscle receptors have very rapid adaptability, while Meissner’s Corpuscles have rapid adaptability and Ruffini corpuscle, Merkel disks have slow adaptability.

3. What Are the Different Types of Touch Senses?

The different types of touch senses are classified into light touch, pressure, pleasant touch, vibration, temperature, and pain.

This classification is based on the type of receptor involved and the intensity of their sensitivity

Light Touch

A light touch is also known as protective touch as it is immediately set something that brushes the skin such as tickling.

Pressure

These receptors are activated when there is pressure or squeeze of the skin.

Pleasant Touch

This type of touch differentiates between pleasant and unpleasant touch.

Vibration

This type of touch is associated with the sensing of low-frequency vibrations.

Temperature

This type of touch is associated with the sensing of cold, hot, or warm objects.

Pain

This is due to the stimulation of nerves ends by noxious stimuli such as prolonged pressure or chemicals.

4. Are There Disorders of the Sense of Touch?

Disorders of the sense of touch are associated with the loss of sensitivity, the intensity of the sensitivity, and the capacity of recognizing the objects being sensed by touch.

They are caused by lesions affecting the somatosensory pathways, neurological diseases such as dementia, and chronic diseases such as diabetes.

Below are some of the disorders associated with touch:

• Astereognosis

This disorder is characterized by the inability to identify objects by touch only. It is caused by lesions in the post-central gyrus [4].

• Hyperesthesia

Hyperesthesia is characterized by an increased sensitivity to stimuli associated with senses such as hearing, tasting, touch, smelling. It is caused by excessive stimulation of the nervous system such as overconsumption of caffeine.

• Allodynia

Allodynia is a pain that is caused by a stimulus that is not the one that initiated the pain, such as feeling pain after a gentle shake of hands or light touch on the back.

• Analgesia

Analgesia is characterized by the inability to feel the pain caused by a stimulus (cause) that should normally have caused pain.

• Paraesthesia

This disorder is characterized by an abnormal sensation of the skin such as numbness, tingling, burning, chilling.

• Hypoesthesia

This disorder is characterized by a decrease in the sensation of touch associated with nerve damage, ischemia (reduced blood supply to tissues).

• Hypoalgesia

Unlike analgesia that characterized by the inability to feel pain, hypoalgesia is associated with a reduced response to a painful stimulus.

• Hyperalgesia

Hyperalgesia is characterized by an abnormally increased sensitivity to pain due to the release of inflammatory hormone-like substances, known as prostaglandins, that increase the sensitivity of the nociceptors.

Hyperalgesia can be caused by fibromyalgia, diabetes, infection, trauma, postherpetic neuralgia, and complex regional pain syndrome.

Conclusion

The touch sensory system is very complex and sophisticated thanks to the presence of highly specialized touch receptors that have a wide range of sensitivity and intensity.

This system provides us with the capacity of sensing cold, warm, and hot objects but also shapes and curves, and vibrations’ frequencies.

The post What Part of the Brain Controls Touch? appeared first on .

• Odour sensing by receptors of the olfactory sensory neurons in the nose.
• The olfactory sensory neurons in the nose transmit the odour information (olfactory information) to the olfactory nerves through a process known as neurotransmission.
• The olfactory nerves transmit the olfactory information to the olfactory bulb, a neural structure responsible of olfaction (Smell).
• The olfactory bulb transmits the olfactory information to specific areas of the brain for processing and identification of the smell.

1. What Part of the Brain Is Most Responsible for Smell?

There are several and important parts of the brain that are responsible for smell; however, the olfactory bulb is responsible for transmitting the olfactory (smell) information from the olfactory nerves to the brain for processing.

This olfactory information is chemically identified and coded by a part of the olfactory bulb known as the glomeruli. This process is known as the odor map [1].

2. What Happens in the Brain When You Smell?

When the olfactory information is transmitted from the olfactory bulb to the brain, there are parts of the brain responsible for the processing of this information including the amygdala, the piriform cortex, and the entorhinal cortex [2].

• The Amygdala and Olfaction

The amygdala is the central hub for the management of fear within a network that involves other brain organs including the thalamus, the neocortex, the hypothalamus, the pituitary gland, the hippocampus, and the adrenal glands located on the top of the kidneys.

When the amygdala receives the olfactory information for processing it interrogates the memory siege, the hippocampus, for previous similar stimuli (e.g., olfactory stimuli).

Once the information is received from the hippocampus, the amygdala triggers the hypothalamus-pituitary-adrenal axis to initiate an adaptative reaction [3].

Depending on the nature of the smell which can be pleasant or unpleasant, associated or not with potential danger, a reaction such as robust approach (pleasant olfaction) or withdrawal if unpleasant or linked with potential danger (e.g., the smell of smoke due to fire) [4].

• The Olfactory Tubercle and Olfaction

The olfactory tubercle is part of the olfactory cortex found in the frontal lobe of the brain where is connected to the amygdala and the hippocampus.

It is involved in recognizing one’s body odor from the environment odors (sensory integration), motivated behaviors in response to odor (attractiveness or repulsion), and reward recognition [1].

• The Piriform Cortex and Olfaction

The piriform cortex is part of the brain known as the rhinencephalon located in the cerebrum. It is involved in odor perception and its differentiation from other odors and from a mixture of odors, and in odor memory [5].

• The Entorhinal Cortex and Olfaction

The Entorhinal cortex is part of the cerebral cortex where it plays a role as an interface between the hippocampus that is involved in memory and the neocortex involved in sensory perception (e.g., olfaction) spatial reasoning, and navigation, and cognition [6].

4. Can Smells Trigger Emotions?

There are common brain areas that are involved in both olfaction and emotion such as the amygdala, the hippocampus, the orbitofrontal cortex, the insula, and the cingulate cortex.

When the amygdala receives the olfactory information for processing it interrogates the memory siege, the hippocampus, for previous similar stimuli (e.g., olfactory stimuli).

Depending on the nature of the smell which can be pleasant or unpleasant, associated or not with potential danger, a reaction such as robust approach (pleasant olfaction) or withdrawal if unpleasant or linked with potential danger (e.g., the smell of smoke due to fire) [7].

The orbitofrontal cortex is involved in the reward value of taste but also in the reward value of odors which initiate an emotion [8].

The insula is a part of the cerebral cortex involved in emotion and in the processing of unpleasant odors [9].

The cingulate cortex is also part of the cerebral cortex that is involved in the formation and processing of emotions related to pleasant and unpleasant odors [10].

5. Does Smell Affect Memory?

Olfaction requires the involvement of the hippocampus, the brain part that controls memory. The amygdala processing of the olfactory information involves interrogating the hippocampus about previous experiences with the olfactory information.

6. What Is It Called When a Smell Triggers a Memory?

This effect is known as the Proustian effect based on the name of the novelist Marcel Proust.

7. Why Do Smells Make Me Angry?

The smell can trigger anger if that smell was associated with a past situation that caused anger to an individual.

The amygdala processing of the olfactory information involves interrogating the hippocampus about previous experiences with the olfactory information.

The olfactory information can also trigger emotions of anger through parts of the brain such as the amygdala, the hippocampus, the orbitofrontal cortex, the insula, and the cingulate cortex.

8. What Causes Loss of Smell?

The loss of smell can be complete and is known as anosmia or diminished and is known as hyposmia. These alterations in olfaction are due to physical or mental health disorders, viral infections, inflammation, environmental exposure, or aging [2].

Disorders or conditions such as Alzheimer’s disease, Parkinson’s disease, meningiomas, facial trauma or schizophrenia, may affect the function of the olfactory system leading to a loss of smell.

Upper respiratory viral infections and neurotropic viruses can also cause a loss of smell.

Neurotoxins found in some industrial workplaces such as solvents, metals, and particulate matter can cause a loss of smell [11].

9. What Is Aromatherapy and Its Benefits?

Aromatherapy is the use of plant essential oils through skin application or olfaction for the management of chronic pain, anxiety, some cognitive disorders, depression, insomnia, and stress-related disorders [12].

However, the clinical evidence is limited, and further research and clinical trials are required.

These are some of the essential plant oils that were used in different studies:

• Bergamot
• Chamomile-Roman
• Geranium
• Jasmine
• Juniper
• Lavender
• Lemon
• Mandarin
• Marjoram
• Melissa
• Neroli
• Patchouli
• Rose
• Rosemary
• Sage
• Spearmint
• Ylang-Ylang
• Vetiver

Conclusion

Olfaction is a complex process that involves the transmission of the olfactory information (smell) by specialized sensory neurons in the nose, the olfactory nerves, the olfactory bulb, and its processing by several regions of the brain.

Meanwhile, let’s enjoy the smell of a nice dish of food and a delicate perfume.

The post How Does Smell Get from the Nose to the Brain? appeared first on .

• Mental health disorders such as schizophrenia, bipolar disorder, or psychosis
• Central nervous system disorders
• Neurological disorders
• Toxic and metabolic disorders and conditions
• Sleep deprivation or disorders
• Physical disorders such as diseases of vision and hearing organs
• Drugs such as some medications, alcohol, and hallucinogens (e.g., plant hallucinogens)
• Stroke
• Post-traumatic stress disorder (PTSD)

More information on the different types of hallucinations and their causes are provided below.

1- How Do You Know If You Hallucinate?

If an individual is hearing, seeing, smelling, tasting, and feeling (touch) things that are not real or do not exist outside their mind, this individual is likely to be experiencing hallucinations.

2- Is It Normal to Hallucinate?

Hallucinations can be a sign of mental health, neurological, and physical disorders. They can also be a sign of drugs consumption such as alcohol and hallucinogens.

3- What Are the 5 Types of Hallucinations?

There are 5 types of hallucinations that are not all due to psychotic disorders. Hallucinations can be caused by psychiatric and physical disorders [1].

3.1. What Are Auditory Hallucinations?

An auditory hallucination is the perception of sounds that are not real or do not exist outside of the mind of an individual [2]. They can be due to the following causes:

• Schizophrenia

Schizophrenia is a complex and severe mental health disorder that is classified as a type of psychosis. It is characterized by significant alterations in thoughts, perception, mood, and behaviors [3].

• Central Nervous System (CNS) Disorders

These are disorders that affect the brain known as encephalopathies or the spinal cord which are known as myelopathies.

• Psychotic Depression

Psychotic depression is a major depression associated with symptoms such as delusions, hallucinations, sleep issues, reduced motivation, and the capacity to experience a pleasure. It is often associated with bipolar disorder and major depression.

• Mania

Mania is a mood disorder characterized by an excessive level of energy, arousal, and enthusiasm.

• Post-Traumatic Stress Disorder (PTSD)

PTSD is an anxiety disorder associated with extremely stressful or distressing situations.

• Peripheral Lesions

Peripheral lesions are lesions that affect sensory or motor neurons of the peripheral nervous system (outside the brain and the spinal cord).

• Middle and Inner Ear Diseases

There are many diseases that affect tissues and organs of the middle and inner ear causing dizziness, inflammation, discharge, or hearing loss.

• Auditory Nerve Disease

This disorder affects the auditory nerve responsible for transmitting sound to the brain.

• Stroke

Stroke is a condition characterized by a very low blood supply to the brain which prevents its proper function.

• Arterio-vascular malformations

These are malformations that affect arteries and vessels responsible for blood supply to organs involved in hearing.

• Delirium

Delirium is a state of mental confusion lasting hours or days with alterations in consciousness, cognition, and attention.

• Dissociative Identity Disorder

Dissociative identity disorder or multiple personality disorder is a mental disorder characterized by the presence of at least two states of personality.

• Pontine Lesions

These are lesions that affect the pons region of the brainstem part of the brain which controls hearing, balance, involuntary actions, taste, and facial sensations.

• Temporal Lobe Epilepsy

Temporal lobe epilepsy is seizures that began in the temporal lobe and spread to other areas of the brain.

• Hallucinogens

Hallucinogens are chemical substances that modify the function of the nervous system causing cognitive, behavioral, perception, and consciousness changes. The most known hallucinogen is LSD (D-Lysergic acid diethylamide).

• Alcohol Hallucinosis

Alcohol Hallucinosis is a chronic state of alcoholic intoxication that affects the auditory system causing hallucinations.

• Syncope

Syncope or fainting is associated with low blood pressure resulting in a loss of consciousness and muscle strength.

3.2. What Are Visual Hallucinations?

A visual hallucination is the perception of images that are not real or do not exist outside of the mind of an individual such as crawling insects or small animals [4]. They can be due to the following causes:

• Neurologic Disorders

Neurologic Disorders are diseases that affect the nervous system including the central nervous system (brain and spinal cord) and the peripheric nervous system.

• Epilepsy

Epilepsy is associated with seizures that are due to abnormal electrical activity in the brain.

• Migraine

A migraine is a severe form of headache that manifests as an excruciating pain on one side of the head accompanied by a feeling of sickness and an increased sensitivity to light and sound.

• Glaucoma

Glaucoma is due to an excessive increase in the intraocular pressure within the eye that leads to damages including vision loss.

• Optic Nerve Disorders

This disorder affects the optic nerves responsible for transmitting visual information to the brain.

• Toxic Metabolic Disorders

Toxic metabolic disorders are characterized by the accumulation of products of metabolism (metabolites) in the tissues of the body leading to their damage. When affecting the eyes, it can cause damages that lead to anomalies with vision, such as visual hallucinations.

• Toxic Metabolic Encephalopathy

Toxic metabolic encephalopathy is also associated with the accumulation of metabolites in the brain leading to damages. If damaging parts of the brain involved in vision, it can cause anomalies with the vision such as visual hallucinations

• Schizophrenia

Schizophrenia is a complex and severe mental health disorder that is classified as a type of psychosis. It is characterized by significant alterations in thoughts, perception, mood, and behaviors [3].

• Hallucinogens

Hallucinogens are chemical substances that modify the function of the nervous system causing cognitive, behavioral, perception, and consciousness changes. The most known hallucinogen is LSD (D-Lysergic acid diethylamide).

• Sleep deprivation

Sleep deprivation is associated with insufficient (not enough) sleep that can be acute or chronic leading to reduced alertness, performance, and health issues.

• Drug and Alcohol Withdrawal Syndromes

These withdrawal syndromes are due to the changes in neurotransmission mediated by GABA.

• Retinal Diseases

Retinal diseases are disorders that affect the retina of the eye such as macular degeneration, intraocular tumors, retinal tear, and macular edema [5].

• Affective Disorders

Affective disorders are mental conditions characterized by changes in mood and emotions such as major depressive disorder.

• Conversion Disorders

Conversion disorders are mental conditions that cannot be explained by the presence of a disease or injury and which are characterized by paralysis, blindness, or other symptoms of the nervous system [6].

• Cataract Formation

A cataract is the clouding of the lenses of the eyes that help focus on objects at different distances.

• Enucleation

Surgical removal of the entire eye from its socket.

• Narcolepsy

Narcolepsy is a chronic disorder associated with the reduction in the ability to regulate the sleep-wake cycles.

• Choroidal Disorder

The choroidal disorder is due to damages to blood vessels in the eye known as choroid causing anomalies in vision.

• Sensory Deprivation

Sensory deprivation is an intentional reduction in the perception of one or more senses.

• Intense Emotional Experiences

These are life experiences that had significant emotional effects on the affected individuals such as a loss of a loved one, sexual abuse, or traumatic experiences.

3.3. What Are Olfactory Hallucinations?

An olfactory hallucination is the perception of smell that is not real or does not exist outside of the mind of an individual [7]. They can occur with several mental health disorders such as:

• Schizophrenia

Schizophrenia is a complex and severe mental health disorder that is classified as a type of psychosis. It is characterized by significant alterations in thoughts, perception, mood, and behaviors [3].

• Bipolar Disorder

Bipolar Disorder is a mood disorder characterized by mood swings between periods of depression (depressive episodes), and elevated mood that can be severe known as mania (manic episode) or less severe known as hypomania.

• Substance Abuse

Abusive consumption of drugs

• Eating Disorders

Eating disorders are characterized by unusual habits of excessive eating (e.g., binge eating disorder) or insufficient eating (e.g., anorexia).

3.4. What Are Gustatory Hallucinations?

A gustatory hallucination is the perception of taste (often metallic taste) that is not real or does not exist outside of the mind of an individual [8].

• Temporal Lobe Diseases

Temporal Lobe Disease causes seizures that began in the temporal lobe and spread to other areas of the brain. They can be caused by tumors, injury to the head, stroke, brain infections, or brain lesions

• Parietal Operculum Lesions

These are lesions that affect a part of the cerebral cortex causing the absence of speech.

3.5. What Are Tactile Hallucinations?

A tactile hallucination is the perception of touch that is not real or does not exist outside of the mind of an individual [7]. They can be due to the following causes:

• Substance Abuse

Abusive consumption of drugs

• Drug and Alcohol Withdrawal Syndromes

These withdrawal syndromes are due to the changes in neurotransmission mediated by GABA.

4- Can Stress Cause Hallucinations?

Auditory hallucinations have been associated with Post-Traumatic Stress Disorder (PTSD). PTSD is an anxiety disorder associated with extremely stressful or distressing situations.

6- What Causes Hallucinations in the Elderly?

Most of the hallucinations in the elderly are visual or auditory which can be due to the following causes:

• Side effects of Medications
• Diseases such as brain cancer, kidney, or liver failure.
• Dementia and Alzheimer Disease
• Grieving
• Impairment in hearing and vision
• Delirium

Conclusion

Hallucinations are very complex and their treatment depends on the cause of the hallucination.

The post What Causes the Brain to Hallucinate? appeared first on .

1- What Are Omega 3 Fatty Acids?

Lipids or fats are made from saturated and unsaturated fatty acids. Omega 3 fatty acids are a type of fatty acids known as polyunsaturated fatty acids.

Omega 3 Fatty Acids are also divided into docosahexaenoic acid (DHA), linolenic acid (ALA), and eicosapentaenoic acid (EPA).

Docosahexaenoic Acid (DHA) is the principal constituent of the plasma membrane of neurons found in the brain and cerebral cortex. It is also found in the retina and skin.

Eicosapentaenoic Acid (EPA) is essential for the synthesis of the vasodilator, anticoagulant, and inflammatory hormone, Prostaglandin (PG). It is also essential critical for the synthesis of the pro-coagulation and thrombosis factor, thromboxane, and the inflammation mediators, leukotrienes.

Linolenic Acid (ALA) is involved in the regulation of blood lipids and endothelial (Vessels) function. It has also significant anti-inflammatory and anti-thrombotic effects.

2- Which Types of Omega-3 Fatty Acids Are Found in Fish?

Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA) are found in fatty fish such as salmon, tuna, herring, mackerel, sardine, and fish oils,

Linolenic Acid (ALA) is found in fish but in flaxseed, chia, walnuts, hemp, and vegetable oils.

3- Omega 3 Benefits for the Brain

Omega 3 fatty acids are present in the membrane of brain cells (neurons) and are protecting factors of the nervous system [1]. These are some of the functions of omega 3 fatty acids in the brain:

• Omega 3 Fatty Acids and Neurotransmission

Neurotransmission is the process of transmission of information between the brain and the other parts of the body.

This transmission is carried out by neurotransmitters, such as dopamine, serotonin, glutamate, GABA, along the neurons.

Neurotransmitters travel from one neuron to another through synapses; however, to do so they must be transported by membranous vesicles that are made essentially made of omega 3 fatty acids [2].

• Omega 3 Fatty Acids and Neurogenesis

Neurogenesis is a process of making neurons and other types of brain cells that begins during embryonic life and that continue in certain parts of the adult brain such as the hippocampus and the subventricular zone of the cerebral cortex.

The hippocampus is the part of the brain that is involved in memory and the subventricular zone is implicated in olfaction (sensation of smell).

Omega 3 fatty acids are necessary for the production of new hippocampal neurons and olfactory neurons as they are essential for the formation of the membranes of the new neurons.

• Omega 3 Fatty Acids and Membrane Receptor Function

Omega 3 fatty acids have been shown to regulate the activity of the adenosine A_2A and dopamine D₂ receptors that are found on neurons, and which modulate the function of the neurotransmitters, glutamate, and dopamine [3].

• Omega 3 Fatty Acids and Synaptic Plasticity

Neurotransmission is performed through the transfer of neurotransmitters from one neuron to another through synapses.

The changes in strength or weakness of the synapses are known as synaptic plasticity. These changes can regulate the number of neurotransmitter receptors that bind neurotransmitters, and therefore, control the excitation of neurons.

Omega 3 fatty acids are involved in changing the strength or efficacy of synaptic plasticity and inducing the growth of new synaptic connections [4].

• Omega 3 Fatty Acids and Neuroinflammation

Neuroinflammation is an inflammation that happens within the central nervous system (brain and spinal cord) following injury.

Omega 3 fatty acids have been shown to have anti-inflammatory properties through their involvement in the synthesis of pre-resolving mediators, such as resolvins, protectins, and maresins. These mediators are involved in the resolution of inflammation [5].

4- Omega-3 Fatty Acids and Neuropsychiatric Disorders

• Omega-3 Fatty Acids and Schizophrenia

A study found that the blood levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are significantly lower in schizophrenia patients compared to healthy control individuals.

It also found that schizophrenia patients who consume more omega 3 fatty acids have an improvement in schizophrenia symptoms [6].

• Omega-3 Fatty Acids and Mood Disorders

Mood disorders have been associated with abnormalities in the composition and concentration of omega 3 fatty acids.

Patients with major depression have significantly lower omega 3 fatty acids in the blood cells and the severity of the depression correlated with the concentration of 3 fatty acids [7] [8].

5- Omega-3 Fatty Acids and Alzheimer’s Disease (AD)

Several studies have shown a correlation between Alzheimer’s disease (AD) and the decrease in the levels of omega 3 fatty acids in the hippocampus and cortex [9][10].

However, further clinical trials are required to confirm the beneficial role of omega 3 fatty acids for patients with Alzheimer’s disease.

6- Omega-3 Fatty Acids and Attention Deficit Hyperactivity Disorder (ADHD)

Although the effect was modest, a study reported that supplementation with omega 3 fatty acids improved the symptoms of attention deficit hyperactivity disorder (ADHD) [11].

7- Omega-3 Fatty Acids and Acute Neuronal Injury

Excess or chronic neuroinflammation can cause damage and death of nerve cells. Through their neuroprotective and anti-inflammatory properties, Omega 3 fatty acids can prevent the induction of acute neuronal injury that is can be caused by neuroinflammation [12].

8- Omega-3 Fatty Acids and Traumatic Brain Injury

Traumatic brain injury can result in sensory and motor disabilities and post-traumatic inflammation that limit the regeneration of neuronal axons.

An experimental study showed a significant increase in locomotor performance and survival neurons following the administration of Omega 3 fatty acids [13].

Conclusion

Fish is rich in omega 3 fatty acids and specifically in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Omega 3 fatty acids have many roles in brain function, cognition, the generation of new neurons in the hippocampus and the cerebral cortex, and in neuroinflammation.

Omega 3 fatty acids also have neuroprotective properties that can help with the treatment of mental health disorders such as schizophrenia and major depression, Alzheimer’s disease, brain injury, ADHD, neuronal injury, and protection against neuroinflammation.

Therefore, to the question “Is It True That Fish Is Brain Food?”, the answer is an absolute, yes, and I will always have fish as part of my diet.

The post Is It True That Fish Is Brain Food? appeared first on .

• Exercise
• Diet
• Brain Activity
• Preventing Brain Injury
• Social Interactions
• Stopping or Limiting Alcohol Consumption
• Preventing Hyperglycemia
• Preventing Hypertension
• Reducing Cholesterol level
• Promoting Emotional Well-Being
• Keeping Out of Drug Consumption

1- Exercise

Physical activity has been shown to inversely correlate with the risk of dementia and Alzheimer’s disease.

A study that investigated data from 163797 individuals (without dementia) compared the risk of dementia between individuals that had a high physical activity and those with a lower physical activity [1].

They found that physical activity reduces the risk of dementia by 28% and the risk of Alzheimer’s disease by 45%.

Another study investigated the correlation between aerobic exercise and cognition and found that aerobic exercise improves attention, processing speed, and memory [2].

How does exercise Improve Brain Function?

• Exercise increases heart rate and blood flow which provide the brain with more oxygen and nutrients that are necessary for its metabolism and energy production.

• Exercise reduces or slows down cognitive deficits by promoting the production of new neurons in the hippocampus, a process known as hippocampal neurogenesis [3].

• Exercise increases the secretion of the growth factor BDNF (Brain-Derived Neurotrophic Factor) that promotes the differentiation, survival, and plasticity (connections) of neurons [4].

2- Diet

A healthy diet provides nutrients that are essential for brain function, for the generation and maintenance of existing and new neurons.

• Glucose

Glucose is essential for the metabolism of the brain as it is required for the production of energy (ATP). However, too much glucose can have negative effects on the brain but also lead to chronic diseases such as diabetes and cardiovascular diseases.

• Amino Acids

Amino acids are the building block for proteins that are necessary for the maintenance and activity of neurons which involves connecting with other neurons (neuronal plasticity) and for neurotransmission of information between the brain and the rest of the body.

• Vitamins

Vitamins work as coenzymes (help the activities of enzymes) in the metabolism of carbohydrates, lipids, and amino acids.

Vitamins are also involved in the synthesis of neurotransmitters necessary for the nervous system’s functions.

• Essential Minerals

Essential minerals also work as coenzymes in many enzymatic reactions and are involved in neurotransmission.

Iron is essential for the production of energy (ATP) in the brain. As a coenzyme, Iron is involved in the synthesis of the neurotransmitters, serotonin, dopamine, norepinephrine, and epinephrine.

Magnesium has an essential role in neurotransmission and neuromuscular transduction through its protective function against excitotoxicity (excessive transmission by neurotransmitters)

• Fatty Acids

Fatty acids are essential compounds of the membrane of cells, including neurons.

The omega 3 fatty acid, Docosahexaenoic Acid (DHA) is the principal constituent of the plasma membrane of neurons found in the brain and cerebral cortex.

• Plant-Based Antioxidants

Plant-Based Antioxidants such as flavones, polyphenols, flavonoids, phytoestrogens, and catechins, prevent oxidative stress damage to neurons that causes their death. They perform this action by neutralizing free radicals.

3- Brain Activity

Activities such as puzzles, crosswords, painting, drawing, video games, and problem-solving games, stimulate brain function by increasing the connectivity of the neurons’ connectivity (plasticity).

4- Preventing Brain Injury

Individuals that survive a moderate to severe traumatic injury are more likely to experience long-lasting cognitive deficits [5]. The seriousness of the cognitive deficits depends on the severity of the injury, the location of the lesion, and the cause of the injury.

5- Social Interactions

Meaningful social interaction through family, friends and social support can significantly reduce the risk of diseases such as neurodegenerative diseases (e.g., dementia), cardiovascular diseases, strokes, respiratory diseases, and other pathologies [6] [7].

6- Stopping or Limiting Alcohol Consumption

Alcohol is a stimulator of the central nervous system through the induction of the release of the neurotransmitter, dopamine, which results in a feeling of pleasure.

However, excessive consumption of alcohol (quantity and duration) was associated with brain damage and neurocognitive deficits that significantly affect learning, and intellectual development [8].

7- Preventing Hyperglycaemia

An excessive level of glucose in the blood (Hyperglycaemia) can cause brain injuries through damaging brain blood vessels which prevent the brain from obtaining the necessary nutrients (Ischemia).

A prolonged state of hyperglycemia can also cause vascular cognitive impairment, also known as vascular dementia [9].

8- Preventing Hypertension

Hypertension or a high level of blood pressure can significantly affect the function of blood vessels which limits nutrients supply to the brain and causes white matter lesions, and therefore, cognitive deficit.

Hypertension can also cause dementia, and other diseases such as cardiovascular diseases, stroke, and kidney disease [10].

9- Reducing Cholesterol level

Cholesterol is an essential component of the membrane of cells, including neurons, and is necessary for the production of steroid hormones and the acids of the bile.

However, excessive levels of cholesterol in the body can cause atherosclerosis (narrowing of the blood vessels), and neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS) [11].

10- Promoting Emotional Well-Being

Stress and anxiety can develop into depression. This transition affects brain function through alterations in the transmission of information that is managed by the brain neurotransmitters [12].

Therefore, reducing stress, anxiety, and depression can significantly improve brain function and a state of well-being.

11- Keeping Out of Drug Consumption

Recreational use of brain stimulants such as psychomotor stimulants can result in neurotoxicity that significantly damages the brain neurons due to the excessive activation of neurotransmitters in the brain (Excitotoxicity).

Conclusion

To improve the function of the brain, changes in lifestyle are necessary. Consuming healthy foods that contain enough glucose, amino acids, minerals, fatty acids, and antioxidants, provides the brain with the necessary nutrients for its function.

A balanced diet that has the right amount of cholesterol can also promote brain function without causing chronic diseases that can significantly reduce longevity.

In addition to its euphoric effect, exercising helps blood flow and delivery of nutrients to the brain, reducing stress, anxiety, depression, and hypertension.

The post How to Improve the Brain Function? appeared first on .