Wernicke's encephalopathy is a syndrome characterized by ataxia, ophthalmoplegia, and confusion with thiamine deficiency. We reported on two Japanese brothers with a newly discovered recessively inherited syndrome similar to Wernicke's encephalopathy that developed in the second decade of life; this syndrome was manifested clinically as thiamine-responsive diplopia, ataxia and confusion without serum thiamine deficiency. The patients had complex partial seizure. The administration of high-dose thiamine improved these symptoms. MRI of the brain showed high-intensity signals in the bilateral medial thalamus and periaqueductal region on fluid-attenuated inversion recovery images; these signals were characteristic of findings in Wernicke's encephalopathy. There was no history of chronic alcoholism. The clinical and images features resembling Wernicke's encephalopathy in these patients suggested that the syndrome was caused by a genetic disorder of thiamine metabolism. Genomic analysis of SLC10A3 encoding human thiamine transporter 2 revealed that the patients were compound heterozygotes for the K44E and E320Q mutations. Gene-expression analyses of mammalian culture cells showed that intracellular thiamine uptake activities were decreased significantly. High expression of SLC19A3 RNA in the thalamus may explain the selective thalamic lesions on MRI. The identification of this syndrome proves insight into the thiamine metabolism associated with Wernicke's encephalopathy in humans.

Frontal Assessment Battery（FAB）をもちいて筋萎縮性側索硬化症（ALS）の前頭葉機能を評価した．対象はMMSEが24点以上で，発語と上肢の運動が十分に保たれ，呼吸困難をみとめない孤発性ALSの24例である．FABの結果を健常対照群と比較するとともに，ALS Functional Rating Scale（ALSFRS）および呼吸機能との相関の有無を検討した．ALS群ではFABの点数が健常対照群と比較して有意に低下しており，とくに類似性の理解と語の流暢性の低下が明らかであった．また，FABの点数はALSFRSおよび呼吸機能との間に相関をみとめなかった．以上よりALSには前頭葉機能障害が存在すると考えられた．