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