Clinical symptoms of cerebellar dysfunction and their topodiagnostical significance

The clinical symptoms of cerebellar dysfunction are reviewed in relation to modern concepts of cerebellar physiology. Special attention is given to their topodiagnostical significance. Hypotonia, hyporeflexia, asthenia, delayed onset and offset as well as slowing of voluntary movement, ataxia, dysmetria, tremor and myoclonus result from damage of the lateral cerebellar hemispheres and the dentate nucleus. Three different key patterns of postural ataxia result from lesions of the anterior lobe, the vermal part of the vestibular cerebellum and dysfunction of cerebellar afferences respectively. The long latency response (M3) is significantly prolonged in patients with anterior lobe atrophy. Oculomotor symptoms mainly result from either lesions of the cerebellar flocculus, causing dysfunction of retinal-image stabilization or from damage to the dorsal vermis (VI and VII) and the fastigial nuclei, resulting in saccadic dysmetria.