The word "ataxia" means lack of coordination. People with ataxia have problems with muscle control causing a lack of balance and coordination when performing voluntary movements. The word "ataxia" is not the name of a specific disease. Rather, ataxia is a symptom that can result from a number of different diseases. These diseases damage a part of the brain in the back of the head called the cerebellum that normally controls balance and coordination.
Types of Ataxias
Hereditary or Genetic Forms of Ataxia
These forms occur when abnormal genes are passed on in families. The most common forms of hereditary ataxias are the spinocerebellar ataxias (SCAs) and Friedreich's ataxia.
- SCAs (spinocerebellar ataxias): Currently there are 26 types of SCAs with more types being discovered through research. Each subtype of SCA is characterized by a different set of symptoms that may be difficult to tell apart on the basis of a physical exam alone. Therefore, the only definitive way to identify what type of SCA affects a particular patient is through genetic testing. SCAs typically present in adulthood.
- Friedreich's ataxia: This type of ataxia is the most common form of recessively inherited ataxia. This means that both parents must carry the abnormal gene in order to pass it on. Children of two carriers of the gene have a 25 percent chance of developing the disease. Friedreich's generally presents during childhood.
Non-genetic Forms of Ataxia
- Sporadic (Degenerative) Ataxia: People with sporadic (degenerative) ataxia have no family history of this disease. Diagnosis may be difficult, as no specific test is available. Patients may have additional symptoms such as Parkinsonian features (stiffness, slow movements, tremor at rest) or autonomic neuropathy (difficulty controlling blood pressure and bladder and bowel function. Sporadic (degenerative) ataxia generally presents in adulthood.
- Secondary Ataxia: Ataxia can be a symptom of another medical or neurological condition.
Signs & Symptoms
Ataxia can affect people in many different ways. Depending on the underlying disease, patients may have some symptoms but not others. The severity of the symptoms is different from person to person.
Common symptoms include:
- Unsteady walking
- Poor balance and tendency to fall
- Wide-based gait with feet spread far apart
- Poor coordination of hands, feet, and legs (clumsiness)
- Difficulty with fine motor tasks such as writing and buttoning clothing
- Slurred speech
Some forms of ataxia are characterized by other symptoms, including:
- Loss of feeling, numbness or tingling in feet or legs (neuropathy)
- Muscle cramps
- Tremor when reaching for or holding objects
- Difficulty swallowing
- Visual problems such as blurred vision and eye movement abnormalities
- Cardiac complications
- Orthopedic complications.
Ataxia occurs when the underlying disease damages a part of the brain in the back of the head called the cerebellum. There are many conditions that might cause ataxia.
- Vascular injury (stroke)
- Metabolic problems, such as hypothyroidism, and vitamin E or B12 deficiency
- Exposure to certain drugs or toxins, such as chronic alcohol exposure, heavy metals, some seizure or cancer drugs.
- Infectious diseases, such as HIV, syphilis, or after a viral infection of the brain
- Cancer, either in the brain or in other areas of the body
- Multiple Sclerosis
- Head trauma
- Cerebral Palsy
- Congenital malformations