Is there a link between neuropathic pain and constipation in NMOSD and MOGAD? Results from an online patient survey and possible clinical implications.

BACKGROUND

Neuropathic pain (NP) and constipation are common among people with neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and have a negative impact on quality-of-life measures. The possible association between the two symptoms has not been explored.

METHODS

Patients with NMOSD and MOGAD, who were members of a closed international Facebook group, were recruited to complete an anonymous survey on REDCap. Participants were queried regarding demographic and disease-related characteristics, the presence and severity of NP and constipation, and whether they believe there is a relationship between the two symptoms.

RESULTS

Of the 317 participants who completed the survey, 213 (67.2%) reported a diagnosis of aquaporin-4 (AQP-4) positive NMOSD, 93 (29.4%) - MOGAD, and 11 (3.4%) - double-seronegative NMOSD. The mean age was 43.9 ± 16.4 years; 259 were female (81.7%). 206 participants (65%) reported NP, of whom 133 (64.6%) were being treated for it with one or more medications. 167 participants (52.7%) reported constipation, of whom 67 (40.2%) received one or more medications. 137 of 206 participants with NP (66%) also had constipation. Both symptoms were significantly more common among patients with a history of myelitis. Among patients with NP and constipation, 47 participants (34.3%) thought there was a relationship between the two conditions, with the majority reporting increased severity of NP when constipation severity was increased and, conversely, alleviation of NP when constipation lessened.

CONCLUSIONS

NP and constipation were seen in the majority of NMOSD and MOGAD patients with a history of myelitis. Interestingly, one-third of patients with both symptoms reported a link between them, with the majority reporting that NP severity was increased with worse constipation. The possible association opens a possibility of a new approach to managing NP, which tends to be poorly responsive to symptomatic therapies and is associated with worse quality of life in NMOSD and MOGAD. Further studies are warranted to confirm our results.