排尿筋外括約筋協調不全を呈したウェルニッケ脳症の1例

A Case of Wernicke's Encephalopathy with Detrusor-sphincter Dyssynergia

意識障害，外眼筋麻痺，小脳性運動失調そして尿閉を呈した54歳のアルコール性ウェルニッケ脳症の1例を報告した。ビタミンB₁投与で意識障害と外眼筋麻痺は速やかに改善したが尿閉は遷延し，膀胱内圧測定において排尿筋外括約筋協調不全が認められた。3カ月後に尿閉は消失し，排尿筋外括約筋協調不全もみられなくなった。ウェルニッケ脳症は中脳水道周囲灰白質および第四脳室底を障害する。尿排出に関わる長経路反射において，中脳水道周囲灰白質は青斑核近傍に存在する橋排尿中枢へ線維投射する。したがって，中脳水道周囲灰白質あるいは橋背外側部の病変が本例の排尿障害に深く関わっていると考えられた。

Abstract

We report a case of a 54-year-old man with alcoholic Wernicke's encephalopathy. Neurological examination showed unconsciousness, absence of the oculocephalic reflex, generalized hyporeflexia, and urinary retention. The patient immediately regained consciousness after the administration of thiamine, but amnesia and cerebellar ataxia became apparent. The urinary retention persisted, and an urodynamic study showed detrusor-sphincter dyssynergia. Three months after the treatment, the urinary retention resolved, and a second urodynamic study showed disappearance of the detrusor-sphincter dyssynergia. Wernicke's encephalopathy involves the periaqueductal gray matter and the floor of the fourth ventricle. For the voiding reflex, the periaqueductal gray matter neurons project to the pontine micturition center, which seems to be located adjacent to the locus coeruleus. We concluded that lesions of the periaqueductal gray matter and/or the dorsolateral portion of the pons were responsible for the micturitional disturbance in the patient.

(Received July 22, 2014; Accepted September 11, 2014; Published March 1, 2015)