I was not familiar with this term but I have just read that in relation to ms it describes a very wide range of symptoms that come on suddenly, briefly (seconds or minutes) and then disappear as suddenly. They are often frequent e.g could occur as much as several times in the course of a day, and are apparently triggered by movement or sensory stimuli. They do not indicate a relapse. One suggestion is that these symptoms are ‘due to a transmission of nerve impulses across sites where they do not normally occur and where there has been previous damage, so not a true exacerbation of MS or cause a loss of myelin in the CNS. This can apparently be caused by some sort of stimulation, such as irritating clothing or movement.’
Example symptoms: ‘paroxysmal diplopia, facial paresthesia, trigeminal neuralgia, ataxia, and dysarthria, . . . . pain, trunk and limb paresthesia, weakness, ataxia, pruritus, akinesia, and seizures. Motor system involvement may result in dystonia characterized by painful tonic contractions of muscles of one or two (homolateral) limbs, trunk, and occasionally the face.’
Paroxysmal symptoms can also be the initial manifestations of MS in a patient.
I have quoted info from:
http://ms.about.com/od/signssymptoms/a/paroxysmal_utd.htm
I think one of the big difficulties presented by these kind of symptoms, especially if they are the only kind currently being experienced is that they are by no means guaranteed to show up on a clinical examination and this may possibly induce/explain cynicism in the doc or lead him to believe the patient is exaggerating or imagining it, especially if knowing little about this pattern of manifestation.
Another useful source of info is at:
http://www.chemvistasolutions.org/multiple-sclerosis/clinical-diversity.html