Sudden onset of paralysis in a twenty year-old male patient.

We report on a twenty year-old male patient who presented with sudden onset of flaccid paralysis. After exclusion of central nervous system involvement, marked hypokalemia pointed to the diagnosis of hypokalemic periodic paralysis, which was completely reversible on oral and parenteral potassium substitution. A provocation test with glucose and insulin administration leading to hypokalemia and incipient paralysis of the limbs confirmed the diagnosis. Pathogenetically, this syndrome is characterized by an excessive shift of potassium ions into the muscle cells. Therapeutic measures include potassium-sparing diuretics, beta blockers, acetazolamide or diclofenamide. In less severe cases, oral potassium may be sufficient to reverse the symptoms.