[Pain in multiple sclerosis: prevalence, mechanisms, types and treatment].
BACKGROUND
Pain is a frequent symptom in multiple sclerosis (MS), although its prevalence and its importance vary from one study to another.


OBJECTIVE
To analyse the prevalence, types, mechanisms and treatments of the different painful syndromes that affect patients with MS.


METHODS
The work includes a non-systematic review of the literature on the above-mentioned aspects in patients with MS. The prevalence of pain in this disease is higher than what was initially supposed and some series estimate it to be up to 86%. It has important effects on patients' quality of life, limiting both their daily activities and their working life. It is associated with advanced age, duration of the disease, degree of disability, fatigue and depression. There are different types of pain in patients with MS and several different classifications have been proposed. Examples of such systems of classification include dysesthesias in the extremities, complex regional pain, L'Hermitte's sign, trigeminal neuralgia, pain associated to optic neuritis, painful tonic spasms, low back pain and headache. Treatments used are the same as those employed with patients who do not have MS, since few studies have been conducted in patients with this disease.


CONCLUSIONS
Pain affects a high percentage of patients with MS, its pathophysiology is unknown and there are no specific treatments. We therefore recommend that further studies should be carried out to investigate the pain experienced by patients with MS.
Bermejo
Pedro E
PE
UAM. Universidad Autonoma de Madrid. Hospital Universitario La Paz, 28046 Madrid, Espana. pedro.bermejo.v@gmail.com
Oreja-Guevara
Celia
C
Díez-Tejedor
Exuperio
E
D000203:Activities of Daily Living; D000700:Analgesics / Q000627:therapeutic use; D000818:Animals; D002186:Cannabinoids / Q000627:therapeutic use; D006261:Headache / Q000503:physiopathology; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy; D009902:Optic Neuritis / Q000503:physiopathology; D010146:Pain / Q000453:epidemiology / Q000503:physiopathology; D059408:Pain Management; D010147:Pain Measurement; D011788:Quality of Life
D000700:Analgesics; D002186:Cannabinoids