ABSTRACT
Paroxysmal manifestations in multiple sclerosis share several clinical characteristics. They correspond to positive symptoms or signs related to hyperactivity of the central nervous system. They occur suddenly, at any time or place. Their duration is short, a few seconds to 1 or 2 min. They often recur from a few times per day to several times an hour. Their semiological expression may vary considerably from one patient to another, but, as shown on the occasion of the frequent recurrences, remains stereotyped for a given patient. Paroxysmal manifestations may either occur spontaneously or be triggered by external stimuli. Typical examples are neck flexion for Lhermitte sign, tactile stimuli for trigeminal neuralgia, and limb movements for kinesigenic choreoathetosis. Eye movements have also been described at the origin of phosphenes in
optic neuritis. Paroxysmal manifestations may recur in a given patient for several days, weeks or months until remission appears. This time-scale of the cluster is similar to that of exacerbations of the disease. A dramatic response to carbamazepine is another characteristic of paroxysmal manifestations.
