Abstract
A case of central pontine myelinolysis (CPM) caused by hyponatremia in a patient on regular hemodialysis (HD) is reported. A 51-year-old woman with a history of diabetes mellitus for 15 years started HD in July 1995. There were no serious clinical problems, except for intermittent diarrhea due to a previous operation for a thrombus of the supraintestinal artery and a poorly controlled blood glucose level. General fatigue occurred around August 10, 1996. A few days later, gait disturbance and dysarthria appeared, while a brain computerized tomography revealed no abnormalities. Additional intake of salt was recommended, because hyponatremia of 125mEq/l was also found. Magnetic resonance imaging on August 21 revealed a low intensity area in the central pons. Several lines of evidence led to the diagnosis of CPM. The deliberate slow correction of serum sodium concentration by administration of sodium (170mEq/day), reinforcement of medication for diarrhea, control of water volume and strict correction of the blood glucose level improved the neurological disorders. It was considered that loss of sodium due to intermittent severe diarrhea and anorexia as well as water excess due to inadequate dry weight and hyperosmolarity with high blood glucose level were the main causes of her hyponatremia. There was also a possibility that unexpected rapid correction of her serum sodium concentration by the normal dialysate composition (Na; 140mEq/l) during HD caused or exacerbated the CPM. In conclusion, it is necessary to diagnose immediately and to treat deliberately a case of CPM, because HD therapy has a tendency to bring on an imbalance and unexpected rapid correction of electrolyte concentration.
