When you play the piano or hit a tennis ball you are activating the cerebellum. The cerebellum is the area of the brain that controls coordination and balance. Problems with the cerebellum include

• Cancer
• Genetic disorders
• Ataxias - failure of muscle control in the arms and legs that result in movement disorders
• Degeneration - disorders caused by brain cells decreasing in size or wasting away

Treatment of cerebellar disorders depends on the cause. In some cases, there is no cure but treatment may help with symptoms.

A genetic brain disorder is caused by a variation or a mutation in a gene. A variation is a different form of a gene. A mutation is a change in a gene. Genetic brain disorders affect the development and function of the brain.

Some genetic brain disorders are due to random gene mutations or mutations caused by environmental exposure, such as cigarette smoke. Other disorders are inherited, which means that a mutated gene or group of genes is passed down through a family. They can also be due to a combination of both genetic changes and other outside factors.

Some examples of genetic brain disorders include

• Leukodystrophies
• Phenylketonuria
• Tay-Sachs disease
• Wilson disease

Many people with genetic brain disorders fail to produce enough of certain proteins that influence brain development and function. These brain disorders can cause serious problems that affect the nervous system. Some have treatments to control symptoms. Some are life-threatening.

Friedreich's ataxia is an inherited disease that damages your nervous system. The damage affects your spinal cord and the nerves that control muscle movement in your arms and legs. Symptoms usually begin between the ages of 5 and 15. The main symptom is ataxia, which means trouble coordinating movements. Specific symptoms include

• Difficulty walking
• Muscle weakness
• Speech problems
• Involuntary eye movements
• Scoliosis (curving of the spine to one side)
• Heart palpitations, from the heart disease which can happen along with Friedreich's ataxia

People with Friedreich's ataxia usually need a wheelchair 15 to 20 years after symptoms first appear. In severe cases, people become incapacitated. There is no cure. You can treat symptoms with medicines, braces, surgery, and physical therapy.

Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical condition such as alcoholism, a tumor, or a stroke. Other causes may include toxins, chemicals, and viruses. Sometimes the cause is not known.

Degenerative nerve diseases include

• Alzheimer's disease
• Amyotrophic lateral sclerosis
• Friedreich's ataxia
• Huntington's disease
• Lewy body disease
• Parkinson's disease
• Spinal muscular atrophy

Degenerative nerve diseases can be serious or life-threatening. It depends on the type. Most of them have no cure. Treatments may help improve symptoms, relieve pain, and increase mobility.

Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body. Your nerves take in information from your senses and send it to the brain to be processed. Your brain and nerves also communicate to help you move and to control your body's functions.

When the brain is healthy, it works quickly and automatically. But when you have a brain disease, it may affect how well you can function and do your daily activities. Some common brain diseases include:

• Brain tumors, which can press on nerves and affect brain function.
• Degenerative nerve diseases, which can affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Types include Alzheimer's disease and Parkinson's disease.
• Encephalitis (inflammation in the brain), which can lead to problems such as vision loss, weakness, and paralysis.
• Genetic brain disorders, which are caused by changes in genes (also called variants or mutations). These disorders can affect the development and function of the brain.
• Strokes, which can cause a loss of brain cells and can affect your ability to think clearly.
• Traumatic brain injuries (TBIs), which can affect brain function. They may range from mild to severe. The effects of a TBI may be temporary or permanent.

The symptoms of brain diseases vary widely, depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines, or therapies such as physical, occupational, and speech therapies, may cure the disease or improve the symptoms.

Ataxia-telangiectasia (A-T) is a rare, inherited disease. It affects the nervous system, immune system, and other body systems. Symptoms appear in young children, usually before age 5. They include

• Ataxia - trouble coordinating movements
• Poor balance
• Slurred speech
• Tiny, red spider veins, called telangiectasias, on the skin and eyes
• Lung infections
• Delayed physical and sexual development

People with A-T have an increased risk of developing diabetes and cancers, especially lymphoma and leukemia. Although it affects the brain, people with A-T usually have normal or high intelligence.

A-T has no cure. Treatments might improve some symptoms. They include injections to strengthen the immune system, physical and speech therapy, and high-dose vitamins.

Diseases that affect the structure or function of the cerebellum. Cardinal manifestations of cerebellar dysfunction include dysmetria, GAIT ATAXIA, and MUSCLE HYPOTONIA.

Ataxia often occurs when parts of the nervous system that control movement are damaged. People with ataxia experience a failure of muscle control in their arms and legs, resulting in a lack of balance and coordination or a disturbance of gait. While the term ataxia is primarily used to describe this set of symptoms, it is sometimes also used to refer to a family of disorders. It is not, however, a specific diagnosis.

Most disorders that result in ataxia cause cells in the part of the brain called the cerebellum to degenerate, or atrophy. Sometimes the spine is also affected. The phrases cerebellar degeneration and spinocerebellar degeneration are used to describe changes that have taken place in a person's nervous system (neither term constitutes a specific diagnosis). Cerebellar and spinocerebellar degeneration have many different causes.

Many ataxias are hereditary and are classified by chromosomal location and pattern of inheritance:

• Autosomal dominant, in which the affected person inherits a normal gene from one parent and a faulty gene from the other parent
• Autosomal recessive, in which both parents pass on a copy of the faulty gene

Among the more common inherited ataxias are Friedreich's ataxia and Machado-Joseph disease. Sporadic ataxias can also occur in families with no prior history.

Ataxia also can be acquired. Conditions that can cause acquired ataxia include stroke, multiple sclerosis, tumors, alcoholism, peripheral neuropathy, metabolic disorders, and vitamin deficiencies.

There is no cure for the hereditary ataxias. If the ataxia is caused by another condition, that underlying condition is treated first. A variety of drugs may be used to either effectively prevent symptoms or reduce the frequency with which they occur. Physical therapy can strengthen muscles, while special devices or appliances can assist in walking and other activities of daily life. The prognosis for individuals with ataxia and cerebellar/spinocerebellar degeneration varies depending on its underlying cause.

Cerebellar degeneration is a process in which neurons (nerve cells) in the cerebellum—the area of the brain that controls coordination and balance—deteriorate and die. Diseases that cause cerebellar degeneration also can involve the spinal cord and other areas of the brain, including the medulla oblongata (which is involved in cardiac and respiratory systems), cerebral cortex (involved with thought consciousness, language, emotion, and other processes), and the brain stem.

Cerebellar degeneration may be the result of inherited genetic mutations that alter the normal production of specific proteins that are necessary for the survival of neurons. The disease also can be acquired (non-genetic). Symptoms may include:

• A wide-based, unsteady, lurching walk, often accompanied by a tremor in the trunk of the body
• Slow, unsteady and jerky movement of the arms or legs
• Slowed and slurred speech
• Rapid, small movements of the eyes (called nystagmus)

Diseases that are specific to the brain, as well as diseases that occur in other parts of the body, can cause neurons to die in the cerebellum. Neurological diseases that feature cerebellar degeneration include:

• Stroke, caused by a blood vessel that is either blocked or bleeding
• Cerebellar cortical atrophy, multisystem atrophy, and olivopontocerebellar degeneration – progressive disorders in which cerebellar degeneration is a key feature
• Friedreich ataxia and other spinocerebellar ataxias, which are caused by inherited genetic mutations that result in ongoing loss of neurons in the cerebellum, brain stem, and spinal cord
• Transmissible spongiform encephalopathies (such as Creutzfeldt-Jakob disease), in which abnormal proteins cause inflammation in the brain, including the cerebellum
• Multiple sclerosis, in which damage to the insulating membrane (myelin) that wraps around and protects nerve cells can involve the cerebellum

Acquired diseases that can cause cerebellar degeneration include:

• Chronic alcohol abuse that leads to temporary or permanent cerebellar damage
• Paraneoplastic disorders, in which cancer in a part of the body produces substances that cause immune system cells to attack neurons in the cerebellum.

There is no cure for hereditary forms of cerebellar degeneration. Treatment is usually supportive and is based on the person's symptoms or on disorders that may contribute to the cerebellar degeneration.

Cerebellar hypoplasia is a neurological condition in which the cerebellum—the part of the brain that coordinates movement—is smaller than usual or not completely developed. Cerebellar hypoplasia is a feature of a number of congenital (present at birth) brain malformation syndromes, inherited metabolic disorders and neurodegenerative disorders that begin in early childhood.

In an infant or young child, symptoms of a disorder that features cerebellar hypoplasia might include:

• floppy muscle tone
• developmental or speech delay
• problems with walking and balance
• seizures
• intellectual disability
• involuntary side to side movements of the eyes

In an older child, symptoms might include:

• headache
• dizzy spells
• clumsiness
• hearing difficulty

There is no standard course of treatment for cerebellar hypoplasia. Treatment depends upon the underlying disorder and the severity of symptoms. Generally, treatment is symptomatic and supportive.

Some of the disorders that are associated with cerebellar hypoplasia are progressive, which means the condition will worsen over time, and will most likely have a poor prognosis. Other disorders that feature cerebellar hypoplasia are not progressive, such as those that are the result of abnormal brain formation during fetal development and might have a better outcome.