The Location and Function of the Cerebellum in the Brain

The cerebellum (which is Latin for “little brain”) is a major structure of the hindbrain that is located near the brainstem.

The cerebellum is most directly involved in coordinating voluntary movements. It is also responsible for a number of functions including motor skills such as balance, coordination, and posture.

Where Is the Cerebellum Located?

The cerebellum is the largest structure of the hindbrain and can be found in the back portion of the skull below the temporal and occipital lobes and behind the brainstem.

When looking at the brain, the cerebellum looks much like a smaller structure separate from the brain, found beneath the hemispheres of the cerebral cortex. The cerebellum consists of a cortex covering white matter, as well as a ventricle filled with fluid. It is also divided into two hemispheres like the cerebral cortex.

There are two main parts of the cerebellum:

• Cerebellar cortex: A layer of folded tissue containing most of the cerebellum's neurons
• Cerebellar nuclei: The innermost part of the cerebellum containing nerve cells that communicate information from the cerebellum

What Are the Functions of the Cerebellum?

The cerebellum receives information from other regions of the brain and nervous system including the brain stem, spinal cord, and cerebrum. This incoming information is then used by the cerebellum to coordinate and control voluntary movements.

The cerebellum is like a “mini-brain” when it comes to movement and plays an important role in coordination, posture, and balance, as well as in speech and a number of important mental processes.

There are several key functions of the cerebellum, including:

• Balance and posture
• Mental function
• Movement
• Motor learning
• Vision

Impact of the Cerebellum

The cerebellum has an impact on a number of critical functions.

Coordinating the Body's Voluntary Movements

Movement is a complex process that requires a number of different muscle groups working together. Consider how many muscle groups are involved in the process of walking, running, or throwing a ball.

While the cerebellum is not thought to initiate movement, this part of the brain helps organize all of the actions of the muscle groups involved in a particular movement to ensure that the body is able to produce a fluid, coordinated movement. This includes eye movements and movements associated with speaking.

Mental Functions

Researchers believe the cerebellum plays a role in thinking, including processing language and mood, as well as attention, fear response, and pleasure or reward response.

Balance and Posture

In order to understand the important role that the cerebellum plays, it can be helpful to look at what happens when the function of this part of the brain is impaired.

Drinking alcohol, for example, has an immediate effect on the cerebellum and leads to disruptions in the body's coordination and movements. People who are severely intoxicated might find that they cannot even walk in a straight line or touch their own nose when instructed.

Motor Learning

When you learn to perform a new skill such as riding a bike or hitting a baseball, you often go through a trial-and-error process. As you fine-tune your motor movements, you eventually become better able to perform the skill, and eventually, you can perform the action seamlessly. The cerebellum plays a critical role in this motor learning process.

Causes of Cerebellum Damage

Damage to the cerebellum, or to its connection to other parts of the nervous system, can be a result of trauma, congenital condition, health conditions, medications, and other factors, including:

• Alcohol use disorder
• Brain tumor
• Head injury
• Huntington’s disease
• Infections
• Lead or mercury poisoning
• Medications, including benzodiazepines or barbiturates
• Multiple sclerosis
• Parkinson’s disease
• Stroke

Conditions That Affect the Cerebellum

When your cerebellum is damaged, nerve cells break down and die and can cause the following:

• Ataxia: The loss of control of voluntary movement (e.g., the ability to move your body the way you want)
• Cognitive impairment: A reduction in conscious mental activities, including thinking, learning, memory, and concentration
• Dystonia: Involuntary contraction of muscles that normally work in cooperation so that a body part is held in an unusual and often painful position as a result
• Tremors: Involuntary, rhythmic contraction of muscles that can lead to shaking movements in the hands, legs, face, head, or vocal cords
• Unsteady gait: Walking unsteadily or clumsily (A person with an unsteady gait may appear intoxicated even if that's not the case.)
• Vertigo: The dizziness sensation of spinning, swaying, or tilting, which is frequently associated with balance problems and often accompanied by nausea, vomiting, headache, or hearing loss

In addition, researchers are studying the link between cerebellum dysfunction and the following:

• Anxiety disorders: A category of disorders including panic disorder and social anxiety disorder that are marked by excessive or irrational anxiety or fear that is disproportionate to the actual threat
• Autism spectrum disorder: A developmental condition that causes impairments in social interactions and communication
• Dyslexia: A disorder that makes it difficult to process speech and results in problems with reading, writing, and spelling
• Schizophrenia: A psychotic disorder characterized by distorted perceptions, thoughts, emotions, and beliefs that are not connected to reality

Symptoms of Cerebellum Damage

The following may be signs of injury or damage to the cerebellum:

• Difficulty swallowing
• Difficulty walking or balancing
• Inability to control eye movements
• Trouble with speech (such as slurring your words)
  
• Trouble with tasks that require fine motor skills (like writing or eating)

See a doctor right away if you experience these or any other unusual symptoms.

How to Protect Your Cerebellum

While you can’t prevent many of the health conditions linked to cerebellum dysfunction, there are some steps you can take to keep your brain healthy and injury-free:

• Practice safety. Wear a seatbelt in the car and a helmet while bike riding or playing contact sports. Reduce the risks of falls in your home by securing rugs and organizing loose wires.
• Eat healthfully and exercise. A healthy diet and regular exercise routine is great for your body and brain, plus exercise can help stimulate blood flow to your brain and reduce your risk of stroke.
• Cut back on alcohol. Chronic, heavy drinking can result in alcohol use disorder and cause stroke—both factors in cerebellum damage.
• Stop smoking. Smoking cigarettes impacts brain function and is linked to an increased risk of stroke.

History of the Cerebellum

The distinct appearance of the cerebellum was first described thousands of years ago by philosophers. The Roman physician Galen gave the earliest written surviving descriptions of this part of the brain. 

It was not until the early 19th century, however, that physicians and researchers began to learn more about the functions of this region of the brain. Experimental work that involved ablating portions of the cerebellum in animals revealed that this part of the brain is important in the coordination of movement.