Locked-in Syndrome due to Central Pontine Myelinolysis: Case Report.

Central pontine myelinolysis (CPM) classically occurs in alcoholics, malnourished individuals, chronic liver diseases, and rapid correction of hyponatremia. This report presents locked-in syndrome due to CPM following rapid correction of hyponatremia. A 44-year-old male came to the hospital due to a short period of loss of consciousness. He was alert and had no focal neurological abnormalities at admission. The serum sodium concentration was 118 mEq/L and was corrected to 134 mEq/L in the first 18 hours. One week later, progressive weakness in limbs developed and he progressed to a complete quadriplegic state and bulbar palsy, with only eye blinking preserved. Brain magnetic resonance imaging revealed a characteristic hyperintense signal abnormality in both pons, so he was diagnosed to locked-in syndrome caused by CPM. The patient gradually improved following continuous intensive rehabilitation for more than 2 years. He was able to move all joint muscles against gravity in generally and he could gait under supervision.