脳幹吻側部と眼球運動—定位脳手術時の刺激経験

THE UPPER BRAIN STEM AND OCULAR MOVEMENTS:RESULTS FROM THE STIMULATION OF THE MESENCEPHALO-DIENCEPHALON DURING THE STEREOTAXIC OPERATIONS

序論

　脳幹吻側部は古来，眼球運動の核上性中枢及至，繊維集合部として注目された，動物による刺激，破壊実験などが種々行なわれている。

　人間に於てはこの部の腫瘍，血管障害の臨床例が報告されているが狭い範囲に種々の核繊維が集合しており，眼球運動中枢の解析は必ずしも容易でない。

1) Fifty five patients with the violent, aggresive behaviour underwent the stereotaxic postero-medial hypothalamotomy and 13 with the spasmodic torti-collis underwent the interstitalnucleotomy.

2) More than 300 points in and around the hy-pothalamus and the upper mesencephalon are stimu-lated under the local or general anesthesia, in these operations. Besides the autonomic reactions vari-ous ocular movements are observed.

3) In and around this area, the inward, infero-medial or downward movements of the eye on the stimulated side or both sides were observed. Theconjugated deviation or the upward movement ofthe eye was rare.

4) The downward movements of the eye or eyeswere elicited from the stimulations in the hypotha-lamus, Forel H₁, H₂, Field H and rarely in thethalamus. It may be due to the stimulation of thecorticifugal fibers which come down directly fromthe frontal cortex to the mesencephalon.

5) The horizontal inward movements were usua-lly seen by the stimulation in the hypothalamus, themesencephalic central gray, the medial part of thered nucleus and the brachium conjunctivum, whichmay be due to the stimulation of the descendingfibers from the oculomoter nucleus.

6) In the supine position, when the patient'shead was not fixed firmly, ocular movements wereoften accompanied by the lateral flexion or the re-troflexion of the neck. There may be an intimaterelationship between the ocular and the extrapyra-midal motor system.

7) The pupillary dilatation was observed by thestimulation of the posteromedial hypothalamus,where the ergotropic reactions are marked, whilepupillary constriction was obtained from the stimul-tion in the medial, periventricular hypothalamusfollowed by the parasympathetic reactions.

8) Considering the results of the stimulation ofthe oculomotor nucleus itself, the distribution ofcenters for the individual ocular muscles of the manis the same as that of the monkey confirmed byWarwick.