Certain other epidemiologic data have a bearing on this subject. There are, in the United States, 250,000 to 350,000 cases of physician-diagnosed MS (Anderson et al). Also, a study from the National Center for Health Statistics has determined that trauma sufficiently severe to be recalled at a periodic health examination occurs in one-third of the population of the United States (some 83 million persons) each year. Moreover, MS patients suffer physical injuries 2 or 3 times more often than normal persons (Sibley et al). In light of these data, it is perhaps not surprising that a traumatic event and an exacerbation should sometimes coincide, quite by chance. The current authoritative view on this subject is that the coincidence of trauma and new or exacerbated MS is incidental.
Variants of Multiple Sclerosis
Several variants of MS present special problems that are addressed in this and later sections.
Rarely, MS takes a rapidly progressive and highly malignant form; Marburg’s name has been attached to this variant. A combination of cerebral, brainstem, and spinal manifestations evolves over a few weeks, rendering the patient stuporous, comatose, or decerebrate with prominent cranial nerve and corticospinal abnormalities. Death may end the illness within a few weeks to months without any remission having occurred, or there may be partial recovery, as noted below. At autopsy the lesions are of macroscopic dimensions, in essence very large acute plaques of MS. The only difference from the usual form of MS is that many plaques are of the same age and the confluence of many perivenous zones of demyelination is more obvious. Two of our most striking examples of this rapidly fatal form were in a 6-year-old girl and a 16-year-old boy, both of whom died within 5 weeks of the onset of symptoms. Another was a 30-year-old man who lived 2 months. In none of them had there been a preceding exanthem or inoculation or any symptoms suggestive of demyelinating disease. Usually the CSF shows a cellular response but no oligoclonal bands. Some have made an astonishing recovery after several months, and a few have then remained well for 25 to 30 years. Others have relapsed, and the subsequent clinical course was typical of MS.
Among these cases are occurrences of large acute plaques with associated mass effect and enhancement that simulate a tumor on imaging (tumefactive MS, as described in the series by Kepes and shown in Fig. 35-2). The tumefactive lesion also occurs independently in cases of new or established disease that evolve in a manner that is more consistent with typical MS.
The concentric sclerosis of Balo has as its distinguishing feature the occurrence of alternating bands of destruction and preservation of myelin in roughly a series of concentric rings that represent alternating areas of myelin loss, and preservation. The configuration of lesions in this pattern suggests the centrifugal diffusion of some factor that is damaging to myelin. While usually a part of an acute illness, a similar pattern of lesions, although less extensive, is seen in occasional cases of chronic relapsing MS. Some studies have found a high incidence in the Philippines.