Clinical and pathological study on hypokalemic periodic paralysis

Objective To investigate the clinical and pathological features of hypokalemic periodic paralysis.Methods The clinical manifestations in 42 patients and pathological features of biopsied muscle specimens from 3 patients were analyzed and summarized.Results The lower was the serum kalemia level,the severer of the clinical symptoms and the worse was the cure effect. However,there is no association between the level of the serum kalemia and myoasthenia. The muscle weakness may not be symmetric. Respiratory paralysis was found in two patients and in one of them cranial nerve innervated muscles were affected. Subjective sensation disturbance was complained by 11 cases. Increased serum CPK was detected in 18 cases. In pathological examination,the rimmed vacuoles and tubular aggregates in muscle fibers were observed.Conclusion There should be no correlation between the level of serum kalemia and muscle weakness. Sensation disturbance,increased serum CPK and prolonged healing time might be related to the muscular pathological changes. Atypical hypokalemic periodic paralysis should be distinguished from Guillain-Barre syndrome and polymyositis. In some cases,pathological examination of biopsied muscles is needed.