Isolated trigeminal nerve palsy with motor involvement as a presenting manifestation of multiple sclerosis in an equatorial region – a case report

INTRODUCTION: Isolated cranial nerve palsies are considered to be an uncommon presenting feature of multiple sclerosis. Involvement of the trigeminal nerve, particularly its motor component as part of a clinically isolated syndrome of multiple sclerosis has rarely been reported in equatorial regions and no cases have been described in Sri Lanka thus far. CASE PRESENTATION: We report a case of isolated right sided trigeminal nerve palsy (Motor and Sensory) in a 34 year old previously well lady from urban Sri Lanka who was found to have characteristic lesions on Magnetic Resonance Imaging highly suggestive of multiple sclerosis. CONCLUSIONS: Multiple sclerosis should be considered in the differential diagnosis of patients who present with isolated cranial nerve palsies. Clinicians should have a high index of suspicion when evaluating such patients especially in low prevalence regions close to the equator. Early recognition and treatment of such a “Clinically Isolated Syndrome” may prevent early relapse.