Acute transverse myelopathy in multiple sclerosis: clinical and laboratory analyses.

Seventy-three consecutive patients with clinically definite multiple sclerosis (MS) were classified into 2 subgroups: group A, consisting of 21 patients who had shown acute transverse myelopathy (ATM) during the course of illness; and group B, 52 patients without ATM. The clinical features of these 2 groups were analysed prospectively, and MRI findings, trimodal evoked potentials (EPs), CSF analyses and HLA profiles were compared between 2 groups, and some significant differences were found. Clinical analyses showed later onset, less frequent occurrence of brainstem, cerebellar and cerebral symptoms, and more frequent and severe involvements of the optic nerve in group A compared with group B, and the clinical features of group B were quite similar to those of previous western series. On MRI findings, the degree of cerebral white matter and periventricular lesions were higher in group B, the moderate, large, ovoid or confluent lesions were lower in number in group A, and brainstem lesions were less common in group A. The number of the patients with abnormal findings on brainstem auditory EPs (BAEPs) were smaller in group A. HLA-DRw8 was significantly increased and DR9 was significantly decreased in group B compared with controls. HLA-DQw7 and DR4 were raised in group A and group B, respectively, and the frequency of DQW7 and DR4 were different between these 2 groups. The patients in group A may be different clinically, genetically and possibly pathologically from those in group B, and seem to constitute a distinct subgroup in patients with MS.