Secondary hypokalemic paralysis with bulbar weakness and reversible electrophysiologic abnormalities: A case report and systematic review

Abstract

Hypokalemic periodic paralysis secondary to distal renal tubular acidosis presenting with prominent bulbar symptoms is extremely rare. The exact pathophysiology by which hypokalemia causes weakness is yet to be elucidated though muscle and nerve membrane hyperpolarization have been hypothesized. The pathophysiology of bulbar involvement in this condition is even more unclear. We report a case presenting as acute flaccid quadriplegia with prominent bulbar symptoms that reversed once potassium levels returned to normal. Serial nerve conduction studies were performed at various potassium levels revealing electrophysiologic abnormalities that corrected with potassium repletion. A systematic review of the literature was also conducted focusing on bulbar symptoms and electrophysiologic findings in hypokalemic periodic paralysis. Nerve conduction abnormalities in this condition are seldom documented, but reports have shown reduced amplitudes of compound motor action potentials and abnormal F-waves during acute attacks of hypokalemic paralysis.