半側空間無視に対する低頻度反復経頭蓋磁気刺激(rTMS)の効果と局所脳血流量(rCBF)の変化について(教育-リハビリテーション医の教育の質的向上-, 第44回日本リハビリテーション医学会学術集会)  [in Japanese] The Effect of Low-frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Unilateral Spatial Neglect and Changes in Regional Cerebral Blood Flow (rCBF)(Education-Qualitative Improvement of Education for Physiatrists-, 44th Annual Meeting of the Japanese Association of Rehabilitation Medicine)  [in Japanese]

半側空間無視(USN)に対する1Hz反復経頭蓋磁気刺激(rTMS)の効果や,局所脳血流量(rCBF)の変化を調べてUSNの回復過程に関わる脳内機構について検討した.対象は,右大脳半球の血管障害22例(脳梗塞19例,脳出血3例)で,発症からrTMS開始までが70〜220日(平均128.3日)であった.rTMSは,左頭頂後部(P5)を運動閾値の90%の強度で,1Hz,500発刺激を隔日で計7セッション施行した(2例で2クール施行).評価は,Behavioural inattention test (BIT)や視覚的探索課題-反応時間,Xe-CT(cold法)などを用いて行った.結果では,抹消試験や模写試験,視覚探索反応時問は,rTMS施行1週〜2週後から改善を認め,その効果は終了2週後も持続していた.rCBFでは,ITMS施行後に右小脳半球で有意の増加を認めた.以上より,健側半球への低頻度rTMSはUSNに対して有効と思われ,USNの回復には小脳を含む脳内機構の改善が重要と考えられた.

Objective : To describe the effect of low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) on unilateral spatial neglect (USN) in 22 right handed stroke patients with right hemispheric damage and the corresponding change of regional cerebral blood flow (rCBF) before and after rTMS, speculating on the neural basis for recovery from USN. Methods : The time of onset to the initiation of rTMS was 70 to 220 days (mean : 128.3 days), on chronic stage in all patients. The therapeutic schedule consisted of 7 sessions of 1 Hz-rTMS delivered every other day for two weeks, with 14 sessions in two patients. Each session consisted of one train of 500 pulses applied over P5 (10/20 EEG system) at 90% motor threshold using a figure-eight-shaped coil. Assessment was made using the Japanese edition of the Behavioural Inattention Test (BIT) and a computed visual search task at four times as well as a cold-xenon CT (Xe-CT) at two times. Results : rTMS induced a significant improvement of USN patient performance in cancellation tasks and the BIT figure copy task as well as in visual search reaction time, an improvement which lasted 2 weeks after rTMS. Xe-CT showed a significant increase in rCBF in the right cerebellum after rTMS. Conclusions : It is conceivable that low frequency rTMS may be useful for improving USN and it is a promising therapeutic tool. Also, the cerebellum, by forming a neural network with the parietal and frontal lobe, may play an important role in patient recovery from spatial neglect.