Ataxia is unsteady and clumsy motion of the limbs or trunk due to a failure of the fine coordination of muscle movements. The cerebellum is the center of the fine coordination of muscle movements, while the information emerging from it is carried to the muscles by the spinal cord and peripheral nerves, respectively. Therefore a disorder in either the spinal cord or in the peripheral nerves can cause ataxia.
Ataxia may be caused by a congenital disease (for example Friedreich's ataxia), a viral infection (chicken pox), encephalitis, diseases and lesions of the central nervous system or spinal cord (including abscess, trauma, stroke etc.) or by various toxic substances, including drugs such as alcohol.
Resources
National Ataxia Foundation