Rinsho Shinkeigaku (Clinical Neurology)

Case Report

A case of hyperkalemic periodic paralysis presenting progressive myopathy with tubular aggregates

Kenji Yoshimura, M.D.1)3), Hirokazu Morihata, M.D., Ph.D.1), Kiyoaki Takeda, M.D.1), Shunichi Sakoda, M.D.2), Jun-Hui Yuan, M.D., Ph.D.2) and Satoshi Nakano, M.D., Ph.D.1)

1)Department of Neurology, Osaka City General Hospital
2)Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
3)Present address: Department of Neurology, Graduate School of Medicine, Kyoto University

A 33-year-old man admitted to our hospital for the evaluation of progressive muscular atrophy of his left lower leg. From his childhood, he had suffered from transient attacks of limb paralysis and myalgia lasting about 1 hour. At age 30, the muscle weakness and atrophy of his left lower leg emerged and progressed gradually. Muscle MR images showed atrophy and fat replacement in left lower leg, and muscle biopsy revealed tubular aggregates (TA). Genetic analysis showed heterozygous c.2111C>T/p.T704M missense mutation of SCN4A gene, which causes hyperkalemic periodic paralysis (HyperPP). Although HyperPP is rare, it is quite critical for clinicians to recognize that the patients of HyperPP often present progressive myopathy. We emphasize the importance of paying attention to progressive myopathy and discuss the pathological mechanism of myopathy through this case report.
Full Text of this Article in Japanese PDF (572K)

(CLINICA NEUROL, 58: 663|667, 2018)
key words: hyperkalemic periodic paralysis, progressive myopathy, tubular aggregates, myotonia

(Received: 4-Jan-18)