Painful tonic spasm in Chinese patients with neuromyelitis optica spectrum disorder: Prevalence, subtype, and features

Abstract Objectives : Painful tonic spasm (PTS) is a common symptom in patients with neuromyelitis optica spectrum disorder (NMOSD). We herein aimed to explore the prevalence, subtype, and features of PTS in Chinese Han patients with NMOSD. Methods : We retrospectively reviewed medical records and interviewed patients with NMOSD who were admitted to Huashan Hospital and the Jing'an District Centre Hospital of Fudan University in Shanghai, China, from February 2017 to May 2019. The primary questionnaires included a Numerical Rating Scale (NRS), Spinal Cord Injury Health Questionnaire (SCI-HQ), Penn Spasm Frequency Scale (PSFS), and Patient Global Impression of Improvement (PGI-I). Results : Sixty-seven of 153 (43.79%) patients with NMOSD showed PTS, only when spinal cord was involved. PTS had a negative impact on daily life in 97.01% (65/67) of the patients, and 92.54% (62/67) of the patients needed symptomatic treatment. Pain intensity and frequency of PTS were significantly different (P=0.018 with NRS, P=0.045 with PSFS) among flexor tonic spasm, extensor tonic spasm, isometric tonic spasm and complex tonic spasm subtype. Forty patients (59.71%) manifested complex tonic spasms, which indicated more severe pain and frequent spasms comparing to other subtypes. The locations of PTS were significantly different among the 5 subtypes (P Conclusions : PTS was associated with myelitis, and was a common symptom in NMOSD. Intensity, frequency and location were different among the PTS subtypes. Complex tonic spasm was the most common and serious subtype.