A 28-year-old woman was hospitalized with dysarthria and oro-mandibular and upper limb dystonia. Approximately 8 years prior to the current admission, the woman became severely hyponatremic due to traumatic subarachnoid hemorrhage-related SIADH. Brain MRIs showed a signal increase in the central pons, thalamus and striatum on T2 weighted images compatible with central pontine and extrapontine myelinolysis. From a few months after that event, dystonia progressed slowly over the subsequent 8 years. We speculate that the particular damage chiefly to the myelin structures by myelinolytic process may have caused an extremely slow plastic reorganization of the neural structures, giving rise to progressive dystonia.