脊髄ならびに脳幹における痛覚伝導路切截術の検討

Clinical Evaluation on the Anterolateral Cordotomy and Intra-Medullary Tractotomy for the Relief of Intractable Pain

I．緒言

　頑痛に対する外科的除痛法については現在まで幾多の手段方法が講ぜられてきている。これらのうち，中枢神経系に対する除痛手術としてもつともよく知られ，行なわれてきているものは前側索切截術である。本法は1912年にSpiller ＆ Martin^63）によりはじめて行なわれたものであるが，その後脳神経外科学の発達とともにSjöqvist^59）が1938年三叉神経痛に対する延髄位での三叉神経脊髄路切截術を報告し，1941年Schwarz ＆ O'Leary^58），翌1942年^29）久留が延髄内外側脊髄視床路切截術を発表している。一方これと時を同じくしてWalker^69）70）が中脳位での痛覚伝導路遮断術を発表するにいたつている。これらの除痛手術は多数の脳神経外科医によつて追試施行され，その効果がみとめられている。

　最近White^76）は頑痛に対して前側索切截を行なつたもの131例について良好な遠隔成績をあげ，またNathan^51）はMcKissockらの前側索切載例104例についての遠隔成績を発表している。久留^{27）〜37）}らは多年にわたり，脊髄脳幹の上行路について研究を行なつてきたが，癌研究会付属康楽病院，金沢大学，大阪大学および国立がんセンターにおいて，1934年より1964年までに，脊髄脳幹において痛覚伝導路の遮断を行なつた頑痛症例64例について，その除痛効果をまとめ，ここに報告する。

　The preseat paper deals with the clinical evaluation of result of the anterolateral cordotomy and intramedullary tractotomy for the relief ofintractable pain. These operations were carried out by the authors on 64 patients in Koraku Hospital, Kanazawa University Hospital, Osaka University Hospital and National Cancer Center Hospital during the peroid from 1934 to 1964. They consist of 46 cases of cordotomy (bilateral 37 cases, unilateral 9 cases) and 18 cases of medullary tractotomy. In 36 cases of them the extent of the cut was determined histologically and in 21 cases the ascending and descending degenerations were traced by Marchi technique. The results were compared with those obtained by experimental studies in animals (especially in cats) and with the related literature. The conclusions are as follows.

　Five long ascending pathways can be distinguished in the human spinal cord. Two of them, tractus spinothalamicus lateralis and tractus spinobulbaris seem to be concerned with conduction of pain sensation. They participate in the anterolateral ascending fascicle of Gowers. The lateral spinothalamic tract mediates the pain and temperature sensation of the body surface and terminates in the nuclei vcntralis posterolateralis intralaminalis and centre médian -of the thalamus. The lateral spinobulbar tract mediates the visceral sensation including visceral pain and terminates in the nuclei of paraalaris, juxtasolitarius and paratrigeminalis, which locate close to the vagal nuclei in the medulla. The centripetal connections of the latter tract are comprised in the tegmental fascicle of Forel and terminate in the nuclei of intralaminalis and centre médian.

　Close to the both ascending tracts in the anterolateral fascicle, the tractus reticulospinalis ventralis and lateralis descend, the former participates in the vesical contraction and the latter in the vesical relaxation.

　It is reasonable to classify the central pathways of trigeminal nerve into four categories. Two of them are termed tractus quintothalamicus tenuiss. paralemniscalis, and tractus quintothalamicus juxtagrisealis. The former tract corresponds to the lateral spinothalamic tract and seems to mediate sensations of pain and temperature of the face. The latter tract is comprised in Forel's tegmental fascicle and mediates visceral sensation including gustatory. The other two are classical trigeminothalamic tracts, i.e. dorsal tract of Wal lenberg and trigeminal lemniscus (i.e. ventral tegmental fascicle) of Spitzer.

　The topographical arrangement of these tracts in the various level of the brain stem and spinal cord are described in detail.

　Based on these findings it is recommended to interrupt both tractus spinobulbaris lateralis and spinothalamicus lateralis at the spinal level in order to palliate effectively the somatic and visceral pain of the body below the neck simultaneously.

　Interruption of these two tracts was attempted in 46 cases. Complication was proved to be less than the classical anterolateral cordotomy. Nine of them died within one week, so that 37 cases of bilateral cordotomy and 9 cases of unilateral cordotomy could be analyzed as to the effect and following results were obtained: excellent in 3, good in 19, fair in 13 and poor in 2, As to the relation of the site of the pain to the effect, it can be concluded that this operation is less effective for the pain of the upper body (e.g. caused by the cancer of the lung or breast) than for the pain in the lower body half.

　Intramedullary tractotomies, such as trigeminal, spinothalmic and spinobulber tractotomy were carried out on 18 cases. Indication was chosen not only for trigeminal neuralgia, but also for the tabtic crises and for the intractable pain due to cancer of the face and neck. Much better results was obtained by this operation for the former two indications, especially for tabetic crises. Intramedullary tractotomies were carried out on 7 cases bilaterally and on 11 cases unilaterally.