自己免疫疾患における神経筋障害

NEUROMUSCULAR DISORDERS IN COLLAGEN DISEASES AND ALLIED DISEASES

緒言

　膠原病はKlempererにより提唱された病理組織学的概念である。その疾患の主座は，（1）血管病変（2）結合織病変であり現在では血管炎を根底に置く結合織の反応性変化と理解されている。この概念に抱括される疾患には，（1）結節性動脈周囲炎（以下P．N．と略す）（2）皮膚筋炎（以下D．M．）（3）全身性紅斑性狼蒼（以下S．L．E．）（4）汎発性皮膚硬化症（以下P．S．S）（5）リウマチ様関節炎（以下R．A．）などがある。これらの典型的症例を診断することは困難ではないが，実際の個々の症例の鑑別診断のむずかしさは我々臨床医のしばしば経験するところである。その理由の一つは診断基準の不確定なことであり，他の一つには血管結合織が共通の病変の場となるため臨床症状が極めて類似しているためと考えられる。類似し易いこれらの疾患を臨床的に区別するものは，（1）主要障害部位の差（2）病変の進行速度の差，（3）障害を受ける血管の大きさ，部位の差である。しかし，この基準すら絶対的でなく，たとえばSLEの血管病変は細小血管のみならず，中等大血管にもおよび，程度も軽微な血管炎からP．N．様血管炎にまでおよびうる。近年"膠原病のオーバーラッピング"^1）として各種膠原病間の合併あるいは移行型の存在が議論される所以でもある。我々は特にP．N，．S．L．E．，P．S．S．，R．A．とそれにBehçet症候群を加えてこれら疾患による神経筋症状の類似点と相違点を検討した。

1) The authors studied the clinical pictures and laboratory investigations of the neuromuscular dis-orders in patients with various collagen diseases.

The subjects consist of 5 with polyarteritis nodosa (P. N.), 5 with dermatomyositis (D. M.), 8 with pro-gressive systemic sclerosis (P. S. S.), 29 with sys-temic lupus erythematosus (S. L. E.), 9 with rheu-matoid arthritis (R. A.) and 14 with Behcet's syn-drome. Upon each group of patients the frequency of neuromuscular disorders, the sites of involvement and onset of disorders were surveyed. Laboratory investigation includes serum creatine .phosphokinase (CPK), electromyography and muscular biopsy.

2) The clinical manifestations of the neuromus-cular disorder were divided into the followingcategories ; CNS involvement, peripheral neuropathy and myopathy with a sub-category of steroid myo-pathy. CNS involvement includes psychosis, severe headache, vascular accident, encephalopathy and myolopathy. Neuropathy consisted of polyneuro-pathy and monouenritis multiplex. Four of five cases with P. N. showed CNS involvement and for neuropathy, which were highly frequent, compared with other diseases. The initial sympform of all cases with D. M. was myopathy, complicated with polyneuropathy in two out of five cases. One fourth of patients with P. S. S. showed neuropathy and myopathy. The frequency of CNS involve-ment, neuropathy and myopathy in S. L. E. were 17.2, 10.4 and 3.4% respectively, where CNS in-volvement consisted of psychosis, headache, vascular accident and encephalopathy. Frequency of the neuromuscular disorders in R. A. was low.

3) Moderate to mild elevation of CPK was ob-served in all 5 cases of D. M., in 4 out of 7 cases of P. S. S. and one out of 8 cases of S. L. E., while in R. A. all patients did not show any increased CPK. In EMG study fibrillation was found only in one cases of D. M.. Muscular biopsy done in 6 cases revealed various myopathic changes. Remark-able changes such as basophilic regeneration and cell infiltration were seen in 3 cases of D. M.. How-ever, similar changes in milder grade were seen in cases with S. L. E. and P. S. S..

4) Two cases with diagnosis of D. M. were presended to show overlapping features in collagen diseases.

5) It was concluded that there exist supple-mentary disagnostic findings of serum enzymes, EMG and muscle biopsy in patients with D. M., corresponding to its acute and extensive muscular involvement, although similar findings can be seen in S. L. E. or P. S. S. in milder forms.