定位脳手術における微小電極による深部記録法の応用

Application of thaLamic recording technique with microelectrode for stereotaxic surgery

I．はじめに

　パーキンソン氏病の筋強剛や振戦，脳性麻痺の筋緊張亢進などに対し，現在われわれはsub-VLないしsub-Vim areaを破壊目標点とするいわゆるsubthalamotomyを施行することが多い^1,2）。

　手術目標部位を正確に決定する目的で，X-線フィルム上の第Ⅲ脳室，とくにIntercommissural（IC）lineおよび正中線を基準に計測する方法とともに，われわれは生理学的手段として視床内高頻度刺激により運動効果をみる方法および低頻度刺激による視床一皮質の誘発電位を利用する方法を開発してきた^3〜6）。

From our recent experiences of thalamic recording with microelectrode during stereotaxic surgeryin 84 cases, the following results were obtained and discussed from the practical point of view.

1. Upper limit of the thalamus, detected by sudden increase of cellular discharges, is between 13 mm and 21 mm from the intercommissural (IC) line in our anteroposterior approach.

2. Inferior margin of the thalamus which is important landmark for coagulation of sub-VL and/or sub-Vim area is identified by the reduction and/or disappearance of cellular discharges. In most of the cases it is within ±1 mm in relation to the IC line.