Paroxysmal symptoms in neuromyelitis optica spectrum disorder: Results from an online patient survey

Background: Paroxysmal symptoms (PS), defined as short-lasting, recurrent, and stereotyped neurological symptoms, are frequently reported by patients with Neuromyelitis Optica Spectrum Disorder (NMOSD). Their prevalence and spectrum of presentations in NMOSD have not been fully characterized. Methods: Patients with NMOSD, who were members of a closed international Facebook Group, were recruited to complete an anonymous survey on REDCap. Participants were queried regarding demographic and NMOSD-related characteristics and PS history. Results: The sample consisted of 219 responders with self-reported NMOSD, of whom 134 (63.8%) reported testing positive for AQP4 Antibody. 156 responders (71.9%) reported ≥1 type of PS during the disease course. The most common PS were intermittent tingling/numbness sensation (N=106, 67.9%), followed by involuntary muscle contractions/abnormal posture (N=95, 60.9%), hot/cold/burning sensations (N=87, 55.8%), and shock-like sensations along the spine or limbs (N=77, 49.4%). 150 responders (96% of those with PS) reported that PS were painful; in 82 responders (54.6%), the pain intensity reached ≥ 8/10 and in 40 responders (26.0%) - 10/10 level. PS were most commonly aggravated by fatigue (105 responders, 70.0%), physical activity (N=86, 57.3%), and neck flexion (N=39 responders, 26.0%). 82 patients (52.5% of those with PS) reported having been prescribed one or more medications for PS. Less than 50% reported them to be 'very helpful.' Conclusions: This survey highlights that PS occurs commonly in NMOSD patients. The symptomatology of PS is diverse. PS are often painful and not adequately treated. Our study represents a novel method to learn more about a rare disease from the patient's perspective. Given the fact that the study was conducted using an anonymous questionnaire and the diagnosis of NMOSD was self-reported by the survey participants, its’ results should be regarded as a first step towards the understanding of PS in NMOSD, which should be further validated in a larger, controlled study.