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.
Considering these definitions, paroxysmal manifestations are quite similar to epileptic attacks: positive signs, possible triggering, duration of a few seconds. Conversely, they are clearly different from the Uhthoff phenomenon and the exacerbations of the disease. In both of these instances, clinical manifestations are negative. The Uhthoff phenomenon is particular for being triggered by an increase in body temperature or warm atmosphere (hot bath test), or by muscular effort, and by having few minutes' duration, since the phenomenon disappears when physiological temperature returns to normal or physical effort stops. As for the exacerbations, they are spontaneous in most cases and their time-scale varies from a few days to a few weeks (Fig. 30.1).
Positive ± Induced (seconds)
Negative Induced (minutes)
Negative Spontaneous (days)
Figure 30.1 Comparison of the clinical characteristics of paroxysmal manifestations, epileptic seizures, Uhthoff phenomenon and exacerbations in multiple sclerosis.
Was this article helpful?
This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.