What Is the Cerebellum and What Does It Do?

The cerebellum can be found just below your cerebrum and behind the upper portion of your brain stem. This is the area at the base of your skull where your head meets your neck.

The cerebellum is divided up into three different parts called lobes. These lobes are separated from each other by deep grooves called fissures. There are two major components of the cerebellum:

• Cerebellar cortex: This is a layer of thin, heavily folded tissue that contains most of the nerve cells in the cerebellum.
• Cerebellar nuclei: Found deep within the cerebellum, the nerve cells of the cerebellar nuclei are primarily involved in sending information from the cerebellum.

The cerebellum only accounts for about 10 percent of your brain’s total size. Although it’s much smaller than the cerebrum, it contains significantly more nerve cells.

Some estimates say that the cerebellum contains about 50 percent of the nerve cells that make up your brain. Others put the number as high as 80 percent.

Your cerebellum receives input from other areas of your nervous system, including:

• the cerebrum
• brain stem
• spinal cord

It then uses this information to regulate and coordinate voluntary movements. Voluntary movements are movements that you can control, such as walking or throwing a baseball.

In addition to voluntary movements, the cerebellum is also involved in coordination of the following:

• Balance and posture: Your cerebellum works with sensory input from your eyes and ears to keep you upright and steady.
• Motor learning: This involves the learning and fine-tuning of various movements. Examples include the specific, precise movements used for writing or for riding a bicycle.
• Speech: The cerebellum is also involved in the movements associated with speaking.

The cerebellum may also play a role in other cognitive functions. Research into this area is ongoing, and there’s still so much more to learn. From what we know so far, the cerebellum’s functions can include:

• language
• processing of emotions
• attention
• pleasure or reward response
• fear response

Disruption of the cerebellum or its connections to other parts of the nervous system can happen in a variety of ways. For instance, the cerebellum can sustain damage due to:

• a head injury
• stroke
• a brain tumor
• autoimmune conditions, such as multiple sclerosis
• neurodegenerative conditions, such as Parkinson’s disease or Huntington’s disease
• infections
• some medications, such as benzodiazepines or barbiturates
• alcohol use disorder
• heavy metal poisoning, such as due to lead or mercury

When the cerebellum is damaged, movement and balance can be affected. You may have trouble trying to move in a coordinated way. Or you may have difficulty with balance, or experience involuntary muscle contractions. Damage to the cerebellum can result in conditions such as:

• Ataxia: Ataxia is characterized by uncoordinated movement, trouble with fine motor tasks, and changes in speech.
• Dystonia: With dystonia, your muscles contract, or spasm, involuntarily. These spasms can occur in any part of the body and lead to twisting or repetitive motions.
• Tremors: Tremors are involuntary muscle contractions that occur in a rhythmic manner. This leads to a shaking movement that can disrupt fine motor tasks and speech.
• Vertigo: Vertigo is the sensation of spinning. You may feel as if you’re spinning or that your surroundings are spinning. Many cases of vertigo are caused by inner ear problems. But there are instances where vertigo can be caused by damage to the cerebellum or brain stem.

Imaging studies of the brain have given us more insight into the cerebellum’s connections to other areas of the brain. While research is ongoing, cerebellar dysfunction may also play a role in some of the following conditions:

• Autism spectrum disorder (ASD): ASD is a developmental condition characterized by impairments in communication and social interaction as well as repetitive or restricted behaviors.
• Dyslexia: Dyslexia is a learning disorder in which a person has difficulty reading, spelling, or writing due to trouble processing how speech sounds relate to words or parts of words.
• Anxiety disorders: Anxiety disorders comprise a group of emotional disorders involving excessive levels of anxiety or fear.
• Schizophrenia: Schizophrenia is a mental illness that has a variety of symptoms, such as hallucinations or delusions, a lack of emotion, and disorganized speech and movement.

Keeping your cerebellum and the rest of your brain healthy and free of injury is key to your physical and emotional health and overall sense of well-being. Here are some tips to keep in mind for good brain health:

• Protect your head: Lower your risk of a head injury by wearing your seatbelt in the car; removing fall hazards from your home, like loose wires and slippery rugs; and wearing a helmet while biking or playing contact sports.
• Exercise regularly: Not only is exercise good for your overall health, but it also helps to stimulate blood flow to your brain.
• Eat a healthy diet: All parts of your body can benefit from a healthy diet. Focus on fresh fruits and vegetables, whole grains, nuts, seeds, fish, and lean meat.
• Limit alcohol consumption: Drinking too much alcohol can damage your cerebellum. It can also increase your risk of stroke.
• Avoid smoking: Smoking is associated with many health conditions, including high blood pressure and stroke.

Your cerebellum, although small in size, is a crucial part of your brain. It’s associated with coordination of movement and balance. However, according to ongoing research, it can also be involved in other functions, such as emotions and language.

If the cerebellum is damaged, it can result in issues like uncoordinated movement, tremors, or muscle spasms. Damage to this part of the brain is most often caused by a head injury or stroke.

You can take care of your cerebellum by making some lifestyle changes. Protecting your head, exercising regularly, limiting alcohol, and not smoking can all help lower your risk of injury or disease that can affect the cerebellum and the rest of your brain.