Characterization of pain syndromes in patients with neuromyelitis optica.
Pain is common and refractory in spinal cord injury (SCI). Currently, most studies evaluated pain in male-predominant traumatic-SCI. Also, concomitant secondary pain syndromes and its temporal evolution were seldom reported. We aimed to prospectively describe the main and secondary pain and its associated factors in inflammatory-SCI evaluating neuromyelitis optica (NMO) patients. In-remission NMO patients underwent neurological, imaging and autoantibody evaluations. Questionnaires detailing main and secondary pains, functional state, mood, catastrophising, quality of life (QoL) and “non-motor symptoms” were used at two time points. Pain was present in 53(73.6%) of the 72 patients included. At-level neuropathic pain was the most common main pain syndrome, affecting 32 subjects (60.4% of those with pain). Over 70% (n=38) of this cohort reported two pain syndromes. Those without pain were significantly younger (26.1±12.7 y.o. in those without pain and 40.1±12.5, 37.2±11.4 y.o. in those whose main pain was neuropathic and non-neuropathic, respectively, p=0.001), and no differences in the inflammatory status were observed between groups. On follow-up, one-fifth (n=11) had a different main pain syndrome from the first visit. Pain impacted QoL as much as disability and motor strength. Pain is a prevalent and disabling non-motor symptom in NMO-SCI. Most patients experience more than one pain syndrome which can change in time even in the absence of clinical relapse. Age of the inflammatory-SCI was a major determinant of pain. Acknowledging temporal changes and multiplicity of pain syndromes in NMO-SCI may give insights into more precise designs of clinical trials and general management of pain in SCI.