Department of Neurology, Teikyo University School of Medicine, Japan.
Department of Neurology, Graduate School of Medicine, University of Tokyo, Japan.
Intern Med. 2023 Nov 15;62(22):3397-3400. doi: 10.2169/internalmedicine.1545-22. Epub 2023 Apr 7.
Grip myotonia can be a clue for the diagnosis of myotonic disorders. However, several clinical conditions cause delayed finger opening mimicking grip myotonia. We herein report a 44-year-old man with idiopathic inflammatory myopathy who presented with delayed finger opening resembling grip myotonia. The delayed finger opening differed from grip myotonia given the absence of the warm-up phenomenon and percussion myotonia, relative sparing of the thumb extension, and pronounced weakness of the extensor digitorum. Focusing on the extension of the thumb and other fingers may aid in the differentiation between delayed finger opening and true grip myotonia.
握力性肌强直可能是肌强直性疾病诊断的线索。然而，有几种临床情况会导致手指张开延迟，类似于握力性肌强直。本文报告一例特发性炎性肌病患者，表现为类似于握力性肌强直的手指张开延迟。由于缺乏预热现象和叩击性肌强直、拇指伸展相对保留、以及伸指肌明显无力，这种手指张开延迟与真正的握力性肌强直不同。关注拇指和其他手指的伸展有助于区分手指张开延迟和真正的握力性肌强直。
