Painful tonic spasm in neuromyelitis optica spectrum disorders: Prevalence, clinical implications and treatment options.

BACKGROUND

Painful tonic spasm (PTS) is a common symptom in patients with neuromyelitis optica spectrum disorders (NMOSD). This study aimed to obtain further insights into the prevalence, characteristics, and treatment of PTS in patients with NMOSD, and to systematically investigate and compare the clinical features and prognosis of NMOSD with and without PTS.

METHODS

We reviewed the medical records and prospectively interviewed patients with NMOSD who attended the West China Hospital of Sichuan University in Chengdu, China between September 2014 and December 2016.

RESULTS

In total, 52 of the 230 patients with NMOSD experienced PTS (22.61%). Patients with NMOSD and PTS were characterized by a higher age at onset (P = 0.017), higher annual relapse rate (ARR) (P = 0.003), higher ARR of myelitis (P = 0.011), and a tendency to experience pruritus (P = 0.025). Sodium channel blocking antiepileptic drugs (carbamazepine or oxcarbazepine) had higher efficacy than gabapentin in the treatment of PTS (P = 0.001). Although the progression index was higher in patients with PTS, this difference did not reach statistical significance (P = 0.05).

CONCLUSIONS

Our study suggested that immunosuppressors for the prevention of relapse should be administered without delay in patients with NMOSD and PTS. Owing to the side effects of carbamazepine, we recommend oxcarbazepine as the first-line of treatment for PTS in patients with NMOSD. Whether PTS is a marker of disease severity in NMOSD remains to be determined, requiring a long-term prospective observational study.