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

Abstract 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.