Paroxysmal dystonia and pathological laughter as a first manifestation of multiple sclerosis

Paroxysmal dystonia is an uncommon but well- established feature of multiple sclerosis ( MS). Attacks can occur in established MS and may even occasionally be the initial symptom of this disorder. Pathological laughter is usually seen as a pseudobulbar palsy in some diffuse neurological diseases, but cases have been described, mostly in ischaemic attacks or tumours, where it is presented as bursts of laughter of variable duration. The pathogenesis of neither of the two phenomena has been fully established but both have been reported as being positive phenomena resulting from ectopic activation with ephaptic spread. We describe the first reported case of a paroxysmal hemidystonia together with bursts of pathological laughter as the first manifestation of MS.