[Degenerative diseases of the extrapyramidal and spinocerebellar system--differential diagnostic references]

Degenerative disorders of the extrapyramidal and spinocerebellar system often have a genetic cause; however, pathogenesis usually is still unknown. Disturbance of neurotransmitter metabolism in Parkinson disease or in some dystonic syndromes offers new therapeutic approaches; in choreatic or athetoid syndromes biochemical factors are only known in some parts. Clinical and neurophysiological differentiation of various dyskinetic disorders is essential to reach better understanding. In children early signs and symptoms are seen which may be caused by different factors and are difficult to diagnose. Similar problems are to be seen in hereditary ataxias which sometimes begin in childhood: Clinical findings are essential to plan for additional investigations.