What Are the Functions of The Cerebellum-HealthQM

What Are the Main Functions of the Cerebellum?

The cerebellum is situated at the base of the brain in the posterior cranial fossa (the most posterior part of the skull base) and has the following functions:

  • Regulation of motor movements (directed movements and reflexes)
  • Balance control

However, functional imaging studies indicated its potential involvement in cognition, including working memory, executive functioning (e.g., attention, reasoning, and problem-solving), time perception, language, and emotional processing [1].

1. What Is the Structure of the Cerebellum?

The cerebellum contains almost 80% of the brain neurons and consists of two lateral hemispheres involved in the control of quick and finely coordinated movements of the arms.

The lateral hemispheres are separated by a narrow midline zone, known as the vermis, involved in coordinating the movements of the trunk and legs [2].

The cerebellum is divided into 3 lobes, the anterior lobe, the posterior lobe, and the flocculonodular lobe.

The anterior lobe is separated from the posterior lobe by the primary fissure and the posterior fissure from the flocculonodular lobe by the posterior fissure.

the flocculonodular lobe is involved in maintaining equilibrium and coordinating the movements of the eye, head, and neck.

The cerebellum has an outer layer of intricately folded grey matter (accordion-like structure) known as the cerebellum cortex that surrounds a layer of white matter known as the arbor vitae.

Lateral View of the Brain-HealthQM

The arbor vitae surrounds 3 pairs of nuclei (compact groups of specialized neurons) that form the center of the white matter.

These pairs of nuclei are known as fastigial (deep nuclei), interposed, and dentate nuclei.

The cerebellar cortex is made of 3 layers: the molecular layer (outer layer), the Purkinje layer (middle layer), and the granular layer (deep layer).

The molecular layer is made of dendritic arborizations from the Purkinje cells in the Purkinje layer and fibers from the granule layer.

The Purkinje layer is made of neurons known as Purkinje cells involved in movement coordination.

The granule layer is made of granule neurons which role is unknown.

2. What Causes Cerebellum Disorders?

They are several disorders that can affect the cerebellum:

3. What Are Some of the Cerebellum Disorders?

Cerebellum disorders can be due to congenital malformations associated with inherited genetic mutations or acquired after birth [3].

3.1. Congenital Malformations

3.1.1. What Is Joubert Syndrome?

Joubert Syndrome is an inherited disorder of brain development that affects the cerebellar vermis and the brainstem.

This disorder may manifest with the following symptoms:

  • Low muscle tone resulting in muscle weakness
  • Intellectual disability
  • Abnormal eye movements
  • Ataxia (difficulty coordinating movements)
  • Episodic breathing anomalies
  • Distinctive facial features.

3.1.2. What Is Dandy-Walker Malformation?

Dandy-Walker malformation is a congenital malformation that affects the development of the cerebellum and the 4th ventricle (space around the cerebellum).

This malformation during embryonic development results in the underdevelopment of the cerebellar vermis, cystic expansion of the 4th ventricle, and an enlargement of the base of the skull.

This disorder may manifest with the following symptoms:

  • Ataxia
  • Muscle weakness due to low muscle tone
  • Mental retardation
  • Seizures
  • Enlarged head circumference

3.1.3. What Is Rhombencephalosynapsis?

Rhombencephalosynapsis is a congenital abnormality of the cerebellum characterized by the absence of the vermis.

This disorder may manifest with the following symptoms:

  • Truncal and/or limb ataxia
  • Head stereotypies (e.g., body rocking, head banging)
  • Abnormal eye movements
  • Delayed motor development

3.1.4. What Is Pontocerebellar Hypoplasia?

Pontocerebellar hypoplasia is a group of inherited degenerative disorders characterized by the underdevelopment (hypoplasia) of the pons and cerebellum.

This disorder may manifest with the following symptoms:

  • Mental retardation
  • Slow development
  • Ataxia
  • Nystagmus (involuntary eye movement)

3.1.5. What Is Cerebellar Hypoplasia?

Cerebellar hypoplasia is a congenital malformation characterized by the underdevelopment (hypoplasia) of the cerebellum.

This disorder may manifest with the following symptoms:

  • Intellectual disability
  • Seizures
  • Bilateral spastic cerebral palsy (stiff and tight muscles reducing movement ability)
  • Microcephaly
  • Loss of hearing

3.1.6. What Are Spinocerebellar Ataxias?

Spinocerebellar Ataxias (SCA) are a group of genetic diseases (over 25 SCA) characterized by the degeneration of the spinal cord and cerebellum.

These disorders may manifest with the following symptoms:

  • Poor coordination of the eyes
  • Poor speech coordination
  • Progressive Gait incoordination
  • Poor hand coordination

3.2. Acquired Cerebellum Disorders

Acquired cerebellum disorders are characterized by cerebellar degeneration associated with ischemic or hemorrhagic stroke, which limits blood flow or oxygen to the cerebellum.

These acquired disorders can also be associated with Multisystem atrophy, cerebellar cortical atrophy, and olivopontocerebellar degeneration.

Transmissible spongiform encephalopathies, such as Creutzfeldt-Jakob disease, can cause inflammation in the brain, including the cerebellum.

Damages to the neurons’ myelin sheath during diseases, such as multiple sclerosis can also affect nerve cells of the cerebellum.

Chronic alcohol abuse can lead to temporary or permanent cerebellar damage that can cause cerebellar degeneration.

Finally, paraneoplastic disorders that are triggered by the body’s own immune system in response to cancers (e.g., lung, ovarian, lymphatic, or breast cancer) can result in the production of substances that cause immune system cells to attack neurons in the cerebellum leading to cerebellar degeneration.


Although the cerebellum plays an important role in the regulation of motor movements and balance control, little is known about its development.

Little is also known about the role of the cerebellum in cognition. Interestingly, using advanced imaging techniques, some studies indicated the cerebellum may have a potential role in working memory, executive functioning, time perception, language, and emotional processing.

This potential role of the cerebellum in cognition is less surprising when we consider that it is interconnected with brain networks involved in cognition such as the cerebrum, the thalamus, and the cerebral cortex.

However, more research on this topic will certainly uncover more details about the mechanisms by which the cerebellum contributes to cognition.

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