Can a Fungal Infection Cause Brain Lesions?
Fungal infections of the brain become more common over the past 2 decades and can cause the following syndromes [1]:
- 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:
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.
