- 著者
- Takamichi Kanbayashi Shunsuke Kobayashi Yuki Hatanaka Jun Shimizu Masahiro Sonoo
- 出版者
- The Japanese Society of Internal Medicine
- 雑誌
- Internal Medicine (ISSN:09182918)
- 巻号頁・発行日
- vol.62, no.22, pp.3397-3400, 2023-11-15 (Released:2023-11-15)
- 参考文献数
- 14
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.