Ataxia in childhood

The cerebellum is a servomechanistic unit that is dependent on input from many sources through many pathways. Lesions in the vermis and midline structures result primarily in the ataxic gait characterized by staggering, irregularity, unsteadiness, widebased lurching movement in any direction, and, in the case of hemispheric lesions, a tendency to veer in one lateral direction. Less severe forms of ataxia are observed by having the patient walk heel-to-toe along a straight line. The long list of conditions associated with ataxia necessitates a rather broad laboratory approach to the problem. CT and MRI scanning are necessary to exclude posterior fossa and hemispheral lesions. Toxicologic screening is often of major aid in diagnosis. Metabolic testing for specific leukodystrophies, mitochondrial diseases, amino acidopathies, and hyperammonemias are often required. Nerve conduction studies are necessary when the possibility of peripheral neuropathy induced ataxias is under consideration.