Learn More - Overview of Ataxia

What is ataxia?

The word "ataxia" means without coordination. People with ataxia have problems with coordination because parts of the nervous system that control movement and balance are affected. Ataxia may affect the fingers, hands, arms, legs, body, speech, and eye movements. The word ataxia is often used to describe a symptom of incoordination which results from damage to a part of the brain called the cerebellum due to infections, injuries, strokes, other diseases such as multiple sclerosis or degenerative changes in the cerebellum. The word "Ataxia" is also used to denote a group of specific degenerative diseases of the nervous system affecting the cerebellum and called the hereditary and sporadic ataxias. These ataxias result from progressive shrinkage (atrophy) of the cerebellum from various reasons. At this web site, the word Ataxia means a degenerative condition affecting the cerebellum.
Spinocerebellar Ataxias and Friedreich’s ataxia are hereditary forms of Ataxia. The cerebellum and/or spinal cord are affected in these conditions, resulting in imbalance, poor coordination, speech difficulties and ultimately a wheelchair bound existence.

Who gets ataxia?

Ataxia can affect children and adults of all ages and occurs in both men and women.

What causes ataxia?

There are different causes for Ataxia and many forms of the disease. As already pointed out before, ataxia as a symptom, can result from other diseases that may damage the cerebellum, such as strokes, tumors, infections and multiple sclerosis. Degenerative ataxias may be either due to a genetic cause (hereditary or inherited ataxia) or occur in a "sporadic" form with no family history of the disease and no identifiable genetic cause (this type of ataxia is called sporadic or idiopathic ataxia).

Some types of ataxia and some conditions that cause ataxia are hereditary. Probably close to half the patients seen in many of the Ataxia Clinics have this form of ataxia. There are many different genetic diseases that result in ataxia. When an ataxia is transmitted in a dominant fashion it is usually called Spinocerebellar ataxia (SCA). Dominant inheritance results in the disease being passed on from one generation to the next.

The many different genetic causes of SCA are indicated by the number following the SCA; thus SCA 1,2,3, etc are each caused by a different genetic defect. SCA 3 is also called Machado-Joseph disease. Most SCA’s have onset in young to middle adult life. A different form dominantly inherited ataxia results in brief, self-limited episodes of ataxia with a normal appearance between episodes; these are called episodic ataxias or EA’s. Ataxias resulting from recessive inheritance have different names: Friedreich’s ataxia (FA) is the most common of these. Other types of recessive ataxias include ataxia teleangiectasia, ataxia with oculomotor apraxia types 1 and 2 and many other rare ataxias. Recessive ataxias result by inheriting an abnormal copy of the gene from both the father and mother who are "carriers". Thus, in this type of ataxia, many siblings may be affected but the parents do not have ataxia. In small families, a recessive ataxia can occur in a single individual. Most of the recessive ataxias have onset in childhood or young adult life. In this age group, ataxia can also result from other types of inherited metabolic diseases such as vitamin E deficiency, mitochondrial diseases, adrenomyeloneuropathy etc; thus ataxia in a young person like this requires a very detailed evaluation by expert physicians to be sure of the diagnosis. Rarely a genetic defect on the X chromosome (the female sex chromosome) causes ataxia. A recently recognized form of X-linked ataxia is called fragile X tremor ataxia syndrome (FXTAS). Since there are many causes of Ataxia, only a trained physician can help you with an accurate diagnosis.

How is ataxia diagnosed?

Diagnosis is based on a person's medical history, family history, and a complete neurological evaluation including an MRI scan of the brain. A good clinical evaluation and MRI scan alone can establish that a patient’s motor difficulties result from ataxia; but often, this is not sufficient to find the underlying cause. Various blood tests and other laboratory procedures are performed to diagnose one of the  disorders which may present with ataxia. Genetic tests are now available for many types of hereditary ataxia to confirm a diagnosis. Gene analysis can be used as a predictive test to determine if someone has inherited an ataxia gene that is known to affect other family members.

What is the treatment for ataxia?

The treatment depends on the cause of the Ataxia. If a definite cause can be established, it may be possible to eliminate the damaging agent and allow improvement.

Most genetic forms of Ataxia do not have any treatment that will correct the gene defect. Many symptoms associated with Ataxia may be amenable to treatment.