[A case of parkinsonism due to pontine and extrapontine myelinolysis].

A 43-year-old man who presented parkinsonism due to pontine and extrapontine myelinolysis was reported. Late in February, 1990, the patient presented suffered from a flu-like illness and was seen at a community hospital. Physical finding showed the pigmentation on the whole body and hypotension, and laboratory examination revealed severe electrolyte imbalance (serum sodium 100 mEq/l, serum potassium 6.9 mEq/l, serum chloride 68 mEq/l) and hypoglycemia (postprandial serum glucose 78 mg/dl). Given these results, adrenal failure was strongly suspected. Prompt correction of electrocyte imbalance was performed by the infusion of sodium chloride, and four days later the serum sodium level reached 131 mEq/l. On the other hand, the patient was noticed lethargic and showed parkinsonism i.e., rest tremor, cog-wheel rigidity, and hypokinesia. Fourteen days after the onset of neurological abnormalities, the patient was referred to our hospital for further evaluation of parkinsonism. Additionally, neurological examination revealed dysphagia, mutism and positive pyramidal tract sign. On admission brain computed tomography was unremarkable, but on the 14th hospital day it showed low density area in the pons. Brain magnetic resonance imaging also showed a striking increase in T2-weighted signal from the pons, the midbrain, and the bilateral thalamus. Based on these findings, a diagnosis of parkinsonism due to pontine and extrapontine myelinolysis was made, and levodopa therapy was started. After the initiation of levodopa therapy, improvement of tremor, rigidity, and hypokinesia ensued with marked functional benefit, and the patient was discharged on the 49th hospital day. Levodopa was stopped three weeks after discharge but, all neurological abnormalities were not recurrent.(ABSTRACT TRUNCATED AT 250 WORDS)