Rinsho Shinkeigaku (Clinical Neurology)

Case Report

A case of thyrotoxic myopathy with generalized body muscular atrophy including the tongue muscle, lacking physical manifestations of Basedow disease

Sho Kitahara, M.D.1), Takahumi Tonouchi, M.D.1), Yutaka Otsu, M.D.1), Izumi Kawachi, M.D., Ph.D.2), Mutsuo Oyake, M.D., Ph.D.1) and Nobuya Fujita, M.D., Ph.D.1)

1) Department of Neurology, Nagaoka Red Cross Hospital
2) Department of Neurology, Niigata University Medical and Dental Hospital

We report a 74-year-old man with a 2-year history of proximal limb pain, body weight loss of 15 kg, and muscle weakness. Muscle atrophy was evident in the limbs and trunk, as well as the tongue. He was admitted to our hospital with suspected amyotrophic lateral sclerosis (ALS). Although he had no physical manifestations of Basedow disease such as palpitations, hyperhidrosis, hand tremor, exophthalmos, and an enlarged thyroid, he was diagnosed as having thyrotoxic myopathy as laboratory examinations indicated hyperthyroidism and positivity for TSH receptor antibody. The serum level of soluble IL-2 receptor was also elevated. Despite the severe muscle atrophy, the serum CK level was normal. A biopsy from the left quadriceps muscle revealed Type 1 fibers atrophy. Administration of anti-thyroid drugs normalized his thyroid function and the level of soluble IL-2 receptor, leading to improvement of the generalized muscle atrophy.
Full Text of this Article in Japanese PDF (4569K)

(CLINICA NEUROL, 60: 677|681, 2020)
key words: thyrotoxic myopathy, tongue atrophy, amyotrophic lateral sclerosis, Basedow disease, soluble IL-2 receptor

(Received: 5-Sep-19)