Differing clinical pictures may be seen with pathology in different parts of the cerebellum. Broadly speaking, a midline cerebellar syndrome (involving the vermis) may be distinguished from a hemispheric cerebellar syndrome (involving the hemispheres). Their clinical characteristics are:
- Midline cerebellar syndrome:
- Gait ataxia but with little or no limb ataxia, hypotonia, or nystagmus (because the vestibulocerebellum is spared), or Dysarthria; causes include alcoholic cerebellar degeneration, tumor of the midline (e.g., medulloblastoma), paraneoplastic cerebellar degeneration.
- Hemispheric cerebellar syndrome:
- Limb ataxia (e.g., ataxia on finger-nose and/or heel-shin testing), dysdiadochokinesia, dysmetria, dysarthria, nystagmus; usual causes are infarcts, hemorrhages, demyelination, and tumors.
- Pancerebellar syndrome:
- Affecting all parts of the cerebellum, and showing a combination of the above signs (e.g., cerebellar degenerations).
Holmes G. The Croonian lectures on the clinical symptoms of cerebellar disease and their interpretation. Lancet 1922: i: 1177-1182; 12311237; ii: 59-65; 111-115