Ataxia: Overview

Ataxia is a disorder of movement and coordination. Symptoms may include clumsy movements, gait disorders, staggering (balance difficulty), vertigo, or speech difficulty. The underlying cause of ataxia is often a serious disorder of the brain (e.g. stroke) or central nervous system (e.g. multiple sclerosis). Ataxia is a particular type of movement disorder, and needs to be distinguished from other types, such as: apraxia, chorea, dystonia, seizures, asterixis, athetosis, and other types of movement symptoms (or speech disorders).

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Back to: « Ataxia

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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 personís nervous system; neither term constitutes a specific diagnosis. Cerebellar and spinocerebellar degeneration have many different causes. The age of onset of the resulting ataxia varies depending on the underlying cause of the degeneration.

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; and autosomal recessive, in which both parents pass on a copy of the faulty gene. Among the more common inherited ataxias are Friedreichís ataxia and Machado-Joseph disease. Sporadic ataxias can also occur in families with no prior history.

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

Source: NINDS (NIH)1

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Ataxia: Failure of muscular coordination; irregularity of muscle action.

Source: RDCRN (NCATS/NIH)2

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Summary

A type of ataxia characterized by the impairment of the ability to smoothly perform the elements of a voluntary movement in the appropriate order and speed. With dyssynergia, a voluntary movement appears broken down into its component parts. [from HPO]

Source: GTR (NCBI/NIH)3

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Ataxia is a term for a group of disorders that affect co-ordination, balance and speech.

Source: NHS Choices UK4

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Ataxia: Lack of coordination of muscle movements resulting in the impairment or inability to perform voluntary activities. Causes include peripheral nerve disorders, posterior column injuries, cerebral and cerebellar disorders, basal ganglia disorders, and thalamic disorders.5

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Ataxia: Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or Peripheral Nerve Diseases. Motor ataxia may be associated with Cerebellar Diseases; Cerebral Cortex diseases; Thalamic Diseases; Basal Ganglia Diseases; injury to the Red Nucleus; and other conditions.6

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Ataxia: Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- oder overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).

Ataxia can be differentiated into dyssynergy, asynergy, dysmetria (hypometria, hypermetria), dysdiadochokinesis, gait ataxia, truncal ataxia, limb ataxia, and dysarthria). Note: This term does not include sensory ataxia.7

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Ataxia: Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or PERIPHERAL NERVE DISEASES. Motor ataxia may be associated with CEREBELLAR DISEASES; CEREBRAL CORTEX diseases; THALAMIC DISEASES; BASAL GANGLIA DISEASES; injury to the RED NUCLEUS; and other conditions.8

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References

  1. Source: NINDS (NIH): ninds.nih.gov/ disorders/ ataxia/ ataxia.htm
  2. Source: RDCRN (NCATS/NIH): rarediseasesnetwork.org/ cms/ stair/ Learn-More/ Glossary
  3. Source: GTR (NCBI/NIH): ncbi.nlm.nih.gov/ gtr/ conditions/ C0004134/ 
  4. Source: NHS Choices UK: nhs.uk/ conditions/ Ataxia/ 
  5. Source: NCI Thesaurus
  6. Source: MeSH (U.S. National Library of Medicine)
  7. Source: Human Phenotype Ontology
  8. Source: Monarch Initiative

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.