頭内爆発音症候群（exploding head syndrome）の1例

A Case of Exploding Head Syndrome

はじめに

　頭内爆発音症候群は夜間，うとうとしている際に頭の中で急激な爆発音を感じるもしくは頭蓋内で爆発が起こった感覚を持つという病態で，通常痛みは伴わない良性の疾患とされる^1）。睡眠関連疾患国際診断分類第2版（International Classification of Sleep Disorders 2nd ed, ICSD-2）ではパラソムニア（睡眠随伴症）の1つに分類されており，診断基準をTable1に示す^2）。最近片頭痛患者での報告がみられ^3，4），何らかの関係も示唆されるがその病因については不明な点が多い。睡眠センターにおいて患者が受診することは稀で，われわれの施設においては1998年4月より2009年3月までの初診患者数15,585人のうち2例のみである。今回本疾患と考えられる症例を経験したので，終夜睡眠ポリグラフ検査をあわせ報告する。

Abstract

　Exploding head syndrome (EHS) attacks are characterized by the sensation of sudden loud banging noises, and are occasionally accompanied by the sensation of a flash light.　Although these attacks in themselves are usually not painful, it is reported that EHS attacks may precede migraines and may be perceived as auras.

　A 53-year-old woman, with a 40-year history of fulgurating migraines, experienced 2 different types of EHS attacks.　During most of the attacks, which were not painful, she heard sounds like someone yelling or cars passing by.　Only 1 episode was accompanied with the sensation of a flash light and of sounds similar to those of an electrical short circuit.　On the video-polysomnography, video-polysomnography showed 11 EHS attacks occurred during stage N1 and stage N2; these attacks were preceded by soft snoring.　She also had moderate obstructive sleep apnea syndrome (Apnea Hypopnea Index: 16.7) for which an oral appliance was prescribed; the EHS attacks did not recur after this treatment.

　The pathophysiology of EHS is still unclear.　A detailed analysis of PSG data may help in understanding the pathophysiology of this syndrome and also in the selection of therapeutic strategies.

（Received: July 22,2009,Accepted: September 2,2009)