Clinical epidemiology and analysis of pathomechanisms of optic-spinal form of multiple sclerosis

我们研究了日本多发性硬化（MS）的临床特征和病理机制，特别是视脊髓型MS（OSMS）。（1）对1970-1998年发病的86例MS进行临床分型。与20世纪70年代相比，20世纪80年代和90年代MS伴急性横肌萎缩（ATM）的病例频率有所下降。与此相反，无ATM和传统MS的OSMS在20世纪80年代有所增加。环境因素的变化可能导致了日本MS临床表现的这些变化。本文分析了66例MS患者的脑干、小脑症状、体征及MRI表现，其中65%有上述症状、体征。30%有小脑征。此外，MRI上小脑病变仅占6.4%，明显低于西方国家的数字（50-90%）。（2）4-氨基吡啶（4-AP）通过阻断钾通道解除脱髓鞘神经的传导阻滞。静脉注射4-AP，记录治疗前后运动诱发电位（MEP）。4-AP治疗后，MEP振幅明显增加，MEP潜伏期平均连续差明显减少。4-AP可能引起更多肌纤维的协调收缩。(3)细小病毒819（B19）感染与自身免疫有关。本文对46例MS患者进行了血清、脑脊液（CSF）中B19抗体及CSF中B19 DNA的检测。MS组B19 IgG阳性率（65%）明显高于对照组（40%），而血清819 IgM和CSF中B19 DNA均为阴性。

We studied clinical features and pathomechanisms of multiple sclerosis (MS) in Japan, especially optic-spinal form of MS (OSMS). (l)Eighty six cases of MS whose onset of disease were during 1970-1998 were clinically classified. Frequency of cases of MS with acute transverse myelitis (ATM) decreased in 1980s and 1990s compared with 1970s. In contrast, OSMS without ATM and conventinal MS increased in 1 980s. Changes of environmental factors might have caused these changes of clinical picture of MS in Japan. Brainstem and cerebellar symptoms and signs and MRI findings were analyzed in 66 consecutive cases of MS, and 65% had those symptoms and signs. Cerebellarsigns were seen in 30%. Moreover, cerebellar lesions on MRI were seen in only 6.4%, which was significantly lower than the figures in Western countries (50-90%). (2)4-aminopyridine (4-AP) relieves conductionlock in demyelinated nerves by blocking K channels. 4-AP was administered intravenously and motor evoked potentials (MEP) were recorded before and after 4-AP therapy. After 4-AP therapy, MEP amplitudes increased significantly and mean consecutive difference of MEP latency decreased significantly. 4-AP probably caused coordinated contraction of more muscle fibers. (3) Parvovirus 819 (B19) infection is associated with autoimmunity. B19 antibodies in sera and cerebrospinal fluid (CSF) and B19 DNA in CSF were studied in 46 MS patients. Frequency of B19 lgG in MS (65%) was significantly higher than that in controls (40%), but serum 819 lgM and B19 DNA in CSF were consistently negative in excerbation of MS.