[Crossed cerebellar diaschisis and crossed cerebellar atrophy in a patient with a lesion in brain stem].

We report a 54-year-old woman who revealed right hemiparesis and ataxia in her right extremities due to a lesion which was suggested to be cavernous hemangioma located in the left side of pons in 1971, and showed remarkable crossed cerebellar atrophy (CCA) by computed tomography and magnetic resonance imaging in 1985 and 1989. Angiography showed no abnormality but made iatrogenic embolism in left thalamus which developed severe pain in her right side. Single-photon-emission-computed-tomography (SPECT) with I123-IMP in 1989 showed reduction of right cerebellar hemispheric blood flow (crossed cerebellar diaschisis: CCD) and left cerebral hemispheric blood flow. Our case was thought to have revealed persisting CCD. Although there are many reports about CCD and CCA following cerebral damage, CCD and CCA due to brain stem lesion has not been described yet. This might be explained by the persisting functional depression of cerebro-ponto-cerebellar pathways at the pons' level by cavernous hemangioma. It was assumed that the left cortical hypometabolism was result from damage to thalamo-cortical pathways due to ipsilateral thalamic lesion.