On four occasions since 1978, this 53 year-old woman presented with a right hemicorporal hypotonia, symptomatic of a hemispheric cerebellar syndrome. In 1981, she experienced the progressive development of a cervical dystonia. CT scan and RM scan showed a cavernous angioma in the right cerebellar hemisphere. The 18F-2-fluoro-2-deoxy-glucose PET scan revealed a right cerebellar and a contralateral cortical and striatal hypometabolism. This crossed cerebello-cortical diaschisis can be interpreted as a functional interruption of the cerebello-cerebral pathways. This case raises the question of the role played by a cerebellar lesion in the development of a focal dystonia.