Fisher症候群—とくにその3主徴の発現機序に関する神経生理学的考察

ELECTROPHYSIOLOGICAL STUDY OF A PATIENT WITH FISHER'S SYNDROME

I．はじめに

　1956年Fisher^1）が多発性神経炎のunusual variantformとして動眼神経麻痺，失調症，深部反射消失を3主徴とする3症例を報告して以来同様の症例報告が散見される^2〜3）。感染後神経炎として髄液での蛋白細胞解離現象を示すことが多くGuillain-Barré症候群との異同が問題となつている^14〜19）。我々は最近Fisher症候群と診断した症例を経験し，その特異な3主徴について若干の神経生理学的検索を行ない，その発現機序に関して考察を加えた。

A 41-year-old bus driver developed headache,double vision and staggering gait, preceded bycommon cold like symptoms for one week. Onadmission neurological examination revealed ptosis,dilated pupils, absent light reflex, almost totallyimpaired external ocular movement, cerebellardiscoordination, ataxic gait and absent DTRs. Alsotransient paresthesia was noted on face and handsat the initial stage. The csf protein increased ashigh as 98 mg/dl with normal cell count. Thepatient had classical triad of Fisher's syndrome,which were total ophthalmoplegia, ataxia andareflexia. The improvement of clinical symptomswas very slow and repeated electrophysiological ex-amination of the characteristic triad was performed,and the following conclusion was obtained: 1)concerning with the ophthalmoplegia, the site oflesions was supposed to be adjacent to the oculo-motor nuclei and was accompanied by some peri-pheral involvement, because of concomitant recoveryof the voluntary and the reflactory eye movementsand the presence of saccadation at the stage ofrecovery. 2) ataxia was supposed to be cerebellarin origin and the possibility was pointed out thatthe spinocerebellar tract was partly involved to theataxia. 3) at the stage of recovery H reflex of theevoked myogram was high in threshold and theposttetatic potentiation was observed but minimal.4) according to the examination of the spinal rootaction potentials GIa and α-motoneurons weremaintained functionally normal, which was evi-denced clinically by no weakness and hypotonia ofthe muscles. These findings indicated that areflexiawas mainly due to disturbance of the synaptictransmission with a slight possibility of the supra-spinal influences to the synaptic pathways.