アルコール性Wernicke脳症の臨床経過—自験5症例の観察から

THE ALCOHOLIC WERNICKE'S ENCEPHALOPATHY : OBSERVATION OF CLINICAL COURSE AND RESPONSIVENESS TO THIAMINE IN FIVE CASES

　1881年，Carl Wernicke^19）は意識障害，眼筋麻痺，運動失調などの臨床症状と，第3,4脳室近傍および中脳水道周囲に限局した出血性病変を示した3症例を，ひとつの疾患単位として記載した。それ以来1世紀が経過し，欧米では多数の臨床および剖検例が集積され，本症がthiamine欠乏によつて惹起される栄養障害性脳症であり，慢性アルコール中毒者に多発することは良く知られている。しかし，本邦では臨床的，病理学的症例報告は散見されるが，本疾患に関する包括的報告はきわめて少ない^9,10,12）。今回，著者らは過去3年間に経験したアルコール性Wernicke脳症の5症例を呈示し，特にその臨床症状，検査所見と，thiamine投与に対する反応について検討を加えたので報告する。

The Wernicke's encephalopathy has been only infrequently described in Japan and comprehensive clinical studies lacking. We reported five consecu-tive cases of alcoholic Wernicke's encephalopathy during three-year period and described the clinical course, laboratory findings and responsiveness to intravenous thiamine administration. All of them displayed ocular motor abnormalities, namely, the bilateral conjugate gaze palsy or abducens nerve palsy with or without nystagmus. Some degree of locomotor ataxia was noted in four and evidences of polyneuropathy in all. Global confusional state was noted initially in two and moderate to severe recent memory loss in four. One of them showed rather profound anterograde as well as retrograde amnesia associated with confabulatory tendency.

Laboratory studies revealed one of them to be jaundiced due to fatty liver and the other one had liver cirrhosis with esophageal varices. Another one showed markedly enlarged heart with evidence of high output failure, all of which were compati-ble with beri-beri heart disease. The nerve con-duction studies disclosed some degree of conduction delay in all. Blood thiamine level and erythrocyte transketolase activity were measured in two, both of whom revealed abnormally decreased thiamine and enzyme activities with enhanced thiamine pyrophosphate effect.

Following administration of intravenous thiamine, four of them responded promptly with reversal of extraocular motor palsy and gait ataxia in hours to days. The mental symptoms improved as well but not to the degree of full recovery. Upon dis-charge, four of them displayed difficuly in regis-tering new informations as a serious sequela of Wernicke's encephalopathy.

Five cases described here confirmed the Werni-cke's encephalopathy to be an important nutritional complication of alcoholism in Japan. Because of high prevalence of beri-beri syndrome in young generations of Japan, it is speculated that we are by no means immune to CNS thiamine deficiency disease, namely the Wernicke's encephalopathy.