Headache disorders in multiple sclerosis: Is there an association? A systematic review and meta-analysis.

OBJECTIVE

To look for any potential association of headache disorders with multiple sclerosis (MS).

BACKGROUND

The prevalence of headache disorders has been found to be increased in people with MS (pwMS), however, an association has not been established. Existing studies have provided conflicting results mostly because of methodological differences.

METHODS

PubMed, Embase and Scopus were searched to identify eligible studies. Studies were included if they were cross-sectional, case-control or cohort. Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias of the included studies. Case-control, cross sectional or cohort studies that used the International Classification of Headache Disorders (ICHD)-2 or-3 criteria for headache diagnosis and Mc Donald or Poser criteria for MS diagnosis were included. Data were extracted using standardized data collection form. Meta-analysis was conducted by calculating the overall prevalence of headache disorders in pwMS as well as the association of headache disorders with MS. The Newcastle-Ottawa Scale (NOS), a tool for assessing the quality of non-randomized studies, was used to assess the quality of the included studies.

RESULTS

Twenty-three studies were included yielding a total of 5,440 MS patients and 28,0958 controls. The majority of them scored a NOS score between 5 and 6 (max 9), which indicates that they did not rank high in terms of quality, because most studies were cross-sectional and uncontrolled, and only one was prospective, controlled, and longitudinal, but with small population size. Pooled prevalence for all headache disorders, migraine and tension-type headache (TTH) in pwMS was 58 % (95 % CI 0.54-0.61), 30 % (95 % CI 0.25-0.34) and 19 % (95 % CI 0.15-0.23) respectively. A significant association between migraine and MS was found (OR = 2.02, 95 % CI = 1.14-3.57).

CONCLUSION

PwMS are twice as likely to experience migraine as controls, but the results need to be translated with caution since most of the studies included in the meta-analysis were of low or moderate quality. Larger prospective cohort, controlled, longitudinal studies are needed to confirm whether there is indeed an association between MS and migraine.