[Central pontine myelinolysis with cerebellar ataxia and dystonia]

Abstract

A 46-year-old alcoholic woman presented with dementia, chronic cerebellar ataxia and diffuse dystonia. Neurological examination also demonstrated emotional lability and a pyramidal signs on the four limbs. CT showed mild cerebellar and frontal atrophy. The diagnosis of central pontine myelinolysis was confirmed by MRI. The centropontine lesion gave an hyposignal on T1-weighted sequences and a hypersignal on T2-weighted sequences. It was shaped as a trident and symmetrical, sparing the tegmentum and the ventro-lateral regions of the pons. Cerebellar ataxia was related to cerebellar atrophy and extension of myelinolysis to the middle cerebellar peduncles. Dystonia, rarely reported in central pontine myelinolysis, was not associated with striatal lesions on MRI. The pathophysiology of these movement disorders in central pontine myelinolysis remains unclear. This case shows that central pontine myelinolysis is a rare cause of dystonia and can be diagnosed by MRI.