Predictive value of the prolonged exercise test in hypokalemic paralytic attack

✍ Scribed by Yumiko Arimura; Kimiyoshi Arimura; Shugo Suwazono; Hidehito Imamura; Yoshito Sonoda; Yoshikazu Maruyama; Kazushi Nakano; Mitsuhiro Osame

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 229 KB
• Volume: 18
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/mus.880180418

✦ Synopsis

H ypokalemic paralytic attack has multiple etiologies manifested in a characteristic manner: primary hypokalemic periodic paralysis (HypoPP), which is usually autosomal dominant inheritance (sporadic in some cases); and secondary paralytic attack or periodic paralysis (PP), associated with hyperthyroidism and induced hypokalemic conditions. McManis et aL6 devised a prolonged exercise (PE) test based on the principle that the gradual decline of the elicited compound muscle action potential (CMAP) amplitude after exercise is abnormally large in PP. An electrophysiological in vitro study has shown decreases in the excitability of the muscle membrane with HypoPP.' An abnormal PE test therefore is considered to be correlated with abnormal excitability of the muscle membrane. Clinically, it may be difficult to diagnose HypoPP if the attack is the first one and the family history is not known. In this situation, the PE test may serve as a predictive factor in the study of abnormal excitability of the muscle membrane. We therefore used the PE test to test patients who had suffered paralytic attack.