The prevalence, associations, and natural history of pain in multiple sclerosis (MS) are poorly understood. The objective of this work was to study the prevalence of pain syndromes in MS both cross-sectionally, and longitudinally during the MS disease course. We systematically identified prospective studies detailing pain prevalence in definite MS. We used pooled prevalence estimates, explored heterogeneity using meta-regression, and analysed prevalence during the disease course using both estimates at disease milestones and longitudinal studies. Twenty-eight articles (7101 subjects) describing overall pain, or pain syndromes, met inclusion criteria. Pooled overall pain prevalence (17 studies, 5319 subjects) was 63% (95% confidence interval [CI] 55–70%). Marked heterogeneity in this estimate was not significantly explained by selected study design variables (use of outpatient sample, timeframe prior to study over which pain was assessed) or sample demographic variables (mean Expanded Disability Status Scale, mean disease duration, proportion of female sex, and proportion with progressive MS). We quantified prevalence of headache (43%; 95% CI 33–52%), neuropathic extremity pain (26%; 95% CI 7–53%), back pain (20%; 95% CI 13–28%), painful spasms (15%; 95% CI 8.5–23%), Lhermitte sign (16%; 95% CI 10–25%), and trigeminal neuralgia (3.8%; 95% CI 2–6%) in included studies. Prevalence of pain at MS disease milestones (prior to onset, at onset, and at relapse) and during longitudinal follow-up was poorly described. Pain is common in MS, as are specific pain syndromes. The clinical associations and natural history of pain in MS require clarification. Future study could be enhanced by standardised study design.
Financial disclosure: Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
aDivision of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK
bDepartment of Palliative Medicine, Edinburgh Cancer Research Centre, University of Edinburgh, Edinburgh, UK
cEuropean Palliative Care Research Centre (PRC), Norwegian University of Science and Technology, Trondheim, Norway
dThe Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Heidelberg, Australia
eDepartment of Anaesthesia and Pain Medicine, University of Edinburgh, Edinburgh, UK
*Corresponding author. Address: Bramwell Dott Building, Department of Clinical Neurosciences, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK. Tel.: +44 131 537 2922; fax: +44 131 332 5150.
Article history: Received 17 September 2012; Received in revised form 30 November 2012; Accepted 4 December 2012.