右被殻出血におけるDiaschisis—血腫進展度・血腫量との相関

Diaschisis in Right Putaminal Hemorrhage:Correlation with the degree of the extension to the internal capsule and the volume of hematoma

I．はじめに

　神経線維が破壊されると，その神経線維と結合している遠隔部の神経細胞の活動が低下する現象があり，これはtransneuronal depressionあるいはdiaschisisなどという表現で知られている^{2,4,8,17,21,25）}．このdiaschisisにおいては，神経細胞のdeactivationによる代謝の低下とcouplingして局所脳循環も低下することが知られている^2,16,17）．

　一方，脳内出血は基本的には脳実質の破壊が局所に止まっており，原病巣の障害度と遠隔部に出現するdi—aschisisとの関係を知るのには有用な病態と考えられる．そこで今回われわれは，右被殻出血症例のみを対象にそのdiaschisisの程度を亜急性期に施行したN-iso—propyl-p—〔123I〕iodo-amphetamine（IMP）　SPECTによる脳循環の測定から知り，血腫進展度・血腫量と比較検討したので報告する．

Local cerebral lesions may cause depression of func-tion in remote areas of the brain presumably by a transneural mechanism. This has been called “diaschi-sis”. In the present study, regional brain blood flow in hypertensive right putaminal hemorrhage was studied in 33 patients (mean age, 55 year; 22 men, 11 women) to investigate the relationship between the degree in damage of the original lesions and “diaschisis”. The hematoma was treated conservatively in 8 patients, aspirated stereotaxically in 9 patients, and evacuated through craniotomy in 16 patients. The regional blood flow in bilateral motor cortices and bilateral cerebellar hemispheres was measured by a single photon emission CT with N-isopropyl-p- 〔123 I〕 iodo-amphetamine in-travenous injection, and was evaluated by the RI count on early image/the decay-corrected RI count on de-layed image (E/D). The regional brain blood flow was measured for 29 to 35 days from the onset. There was a negative correlation between the degree of the exten-sion to the internal capsule and the regional blood flow of the right motor cortex and the bilateral cerebellar hemispheres. There was also a negative correlation be-tween the volume of the hematoma and the regional blood flow of the right motor cortex and the bilateral cerebellar hemispheres. The regional blood flow of the left motor cortex correlated with neither the degree of the extension to the internal capsule nor the volume of the hematoma. On the other hand, there was a positive correlation in the regional blood flow between the bi-lateral motor cortices. The results of the present study suggest that in right putaminal hemorrhage the original lesions, in proportion to the degree- of the damage, may have direct influence on the right motor cortex and the bilateral cerebellar hemispheres, and indirect influence on the left motor cortex through the right motor cortex.