Cerebellar Examination

The cerebellum coordinates voluntary movement, maintains balance and posture, and modulates motor learning. It processes proprioceptive, visual, and vestibular inputs to produce smooth, accurate, coordinated movements. Three functional divisions: vestibulocerebellum (flocculonodular lobe — balance, eye movements; lesion causes truncal ataxia, nystagmus), spinocerebellum (vermis and intermediate zone — limb coordination, gait; lesion causes appendicular ataxia, dysmetria), and cerebrocerebellum (lateral hemispheres — motor planning, timing; lesion causes intention tremor, dysarthria). Cerebellar signs are IPSILATERAL to the lesion (uncrossed — unlike cortical motor signs which are contralateral). Key cerebellar findings: ataxia (limb and gait), dysmetria (overshooting/undershooting targets), dysdiadochokinesia (impaired rapid alternating movements), intention tremor (worsens approaching target), dysarthria (scanning/staccato speech), nystagmus, and hypotonia.