Severe Bilateral Kinetic Tremor Due to Unilateral Midbrain Lesions

BACKGROUND: The dentatothalamic tract connects the dentate nucleus of the cerebellum with the contralateral thalamus and plays a major role in the pathogenesis of tremor. Unilateral lesions of the dentatothalamic pathway may affect its ipsilateral predecussational or its contralateral postdecussational course, which results either in ipsilateral or in contralateral tremor. CASE REPORT: Here, we present two patients with a unilateral midbrain lesion resulting in bilateral tremor. Both patients presented with severe kinetic tremor. DISCUSSION: The corresponding unilateral mesencephalic lesion affected both the ipsilateral predecussational and the ipsilateral postdecussational dentatothalamic tract originating from the contralateral dentate nucleus, which is very unusual and has not been outlined clearly before.