Neuropathic pain and constipation coexisted in 43.5% of the survey participants, and approximately one-third of patients with both symptoms reported a possible link between the two.
Itay Lotan, MD
Using data from an anonymously surveyed group of patients with neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD), findings showed that neuropathic pain (NP) and constipation may be associated with each other, as the majority of patients reported increased NP severity with worsened constipation.1
Of the 317 participants who completed the survey, 213 (67.2%) reported a diagnosis of aquaporin-4 (AQP4) positive NMOSD, 93 (29.4%) MOGAD, and 11 (3.4%) double-seronegative NMOSD. In total, 138 participants (43.5%) had both NP and constipation. Of these, 47 participants (34.1%) reported that the 2 symptoms were related, with over one-third (36.2%) claiming that when their constipation is increased, it makes NP worse. Additionally, 6 (12.8%) of the participants reported that when their NP is increased, it makes constipation worse.
"The possible link between constipation and NP suggested by our survey should be validated by a prospective study,” the study investigators wrote. "The preliminary evidence generated by our survey provides motivation to initiate a prospective interventional study on the effects on NP of bowel regimen in patients with constipation."
Lead author Itay Lotan, MD, neurology department, Massachusetts General Hospital, and colleagues explored the possible association between NP and constipation among patients with NMOSD and MOGAD, who were queried about the presence and severity of their symptoms. NP remains one of the most chronic symptoms in both conditions and has been shown to be a major determinant of quality of life. Bowel and bladder disfunction, also common in both NMOSD and MOGAD, are even more frequent in those with a history of transverse myelitis.
In a subgroup of patients (n = 198) with a reported history of myelitis, investigators found an increased risk of suffering from both NP and constipation. Stratified by history of myelitis and diagnosis, 112 participants with NMOSD (73.2% of those with a history of myelitis) and 29 participants with MOGAD (76.4% of those with a history of myelitis) reported NP (P = .8373). In comparison, 60.6% of those with a history of myelitis reported constipation vs 38.3% of those without (P = .001).
In the overall cohort, NP was reported by 226 participants (65%), while constipation was reported in 167 participants (52.7%). There was no statistically significant difference in the rate of NP between the AQP4-positive NMOSD and MOGAD groups (P = .0659). Of those with NP, 133 participants (64.6%) were treated with 1 or more symptomatic medications, the most frequent being gabapentrin (40.1%; n = 54). As for constipation, 67 participants (40.2%) were treated with at least 1 medication, 100 (59.9%) were not treated, and 1 (0.06%) was unsure. The effectiveness of the various treatments for constipation defined as "very helpful” ranged from 75% for "other measures" to 28% for lifestyle measures.
As for quality of life, 36 participants (42.9%) rated their quality of life as “good,” 49 (15.5%) rated as very good, 77 (24.3%) as neither poor nor good, 52 (16.4%) reported poor quality of life, and 3 (0.9%) reported very poor quality of life. When asked how satisfied they were about their health, 90 participants (28.4%) felt they were satisfied, 11 (3.5%) were reportedly very satisfied, 74 (23.4%) were neither satisfied nor dissatisfied, 114 (36%) were dissatisfied, and 28 (8.9%) were very dissatisfied.