b'Medicine & ResearchRX Update:M S a n d Pa i nM S a n d Pa i nFour categories can be IDd, addressed by treatments By Caroline Stevens, Pharm.D. candidate, and Ellen Whipple, Pharm.D.Pain is a common symptom in manyIntermittent central neuropathic pain can neurological diseases, including multiplebe classied as trigeminal neuralgia (i.e., facial sclerosis. According to Dr. Ben Thrower, directorpain), Lhermittes sign (i.e., electric sensations of the MS Institute at the Shepherd Center,originatingfromflexingoftheneck),or pain can affect up to 85 percent of patientsglossopharyngeal neuralgia (i.e., pain in the with MS. Dr. Thrower went on to explain thatthroat).the common presenting symptoms usuallyTrigeminal neuralgia is the most widely include chronic headaches and neuropathicrecognized neuropathic syndrome in MS, with pain. Less commonly, pain may present inprevalence ranging from 1.9 to 6.3 percent. the limbs, back, organs, or eyes. The presenceTypical trigeminal neuralgia results in episodes of pain generally correlates with disability,of severe and sudden shock-like pain on the disease course, duration, and age. Symptomsside of the face. This type of pain may be of pain may be present at any point in theexperienced in the ear, eyes, lips, nose, scalp, course of the disease and may be secondaryforehead, teeth, and/or jaw. Patients with to other symptoms such as spasticity, fatigue,trigeminal neuralgia often describe the presence and mood disorders. of a trigger area on the face so sensitive to the MS pain can be classied into four categories:slightest touch or pressure that it can precipitateContinuous central neuropathic painintense pain. Treatment for trigeminal neuralgiaIntermittent central neuropathic painprimarilyincludesantiepileptics.SurgicalMusculoskeletal paininterventions may also be necessary. Mixed neuropathic and musculoskeletal pain Lhermittes sign is a suggestive symptom ofMS,transversemyelitis,vitaminB12 Continuous central neuropathic pain isdeciency, or cervical cord compression. The due to the demyelinating lesions in areas ofsymptom is a short and sudden sensation the central nervous system involved in painoriginating in the back of the neck, which perception. This common pain syndrome maytravels to the lower back and may descend be present in up to 50 percent of patientsfurther into the lower extremities. Severity with MS. Classic signs of central neuropathicand duration of Lhermittes sign are variable. pain include hyperalgesia and allodynia.Theonlyrecommendedtreatmentforthe Hyperalgesia is an enhanced response to paindisease is carbamazepine in severe cases. that many patients describe as diffuse or spreading. Allodynia is pain due to a stimulusGlossopharyngeal neuralgia is an uncommon, that usually would not provoke pain, such asbut painful syndrome, that affects patients with combing ones hair. Treatment of central neuro-MS. Symptoms include unilateral, paroxysmal, pathic pain includes tricyclic antidepressants,sharp,andstabbingpainfulattacksthat antiepileptic medications, baclofen, opioidradiate to the back of the throat, tongue, tonsils, analgesics, and cannabinoidsand/or middle ear. Episodes may occur up to msfocusmagazine.org 60'