びまん性軸索損傷後遺症における全般性脳室拡大の意義

Diffuse ventricular enlargement outlines the late outcome of diffuse axonal injury

I．はじめに

　われわれは，びまん性脳損傷，ことにびまん性軸索損傷，のあと次第に全般性脳室拡大を生じ，その程度はびまん性軸索損傷後遣症の程度に定性的に相関することを指摘した^20,22）．今回は，脳室拡大を定量的に測定した結果，びまん性軸索損傷後遺症との相関を確認できたので，改めて報告する．

Clinical significance of ventriculomegaly after severe head trauma has not been fully explored yet. We analyz-ed hospital records of 53 cases of diffuse axonal injury and 7 cases of brain concussion together. The follow-up periods ranged from 6 months to 8 years (average 25 months). Four patients underwent CSF shunting with-out noticeable effect. We classified their outcome according to our modification of the Glasgow outcome scale: vegetated, severe, moderate, mild, fair, and good. We reviewed initial (within 12 hours after injury) CT scans and late (3 to 6 months after injury) CT scans or MRI's. We measured the ratio of the third ventricular width to the inner diameter of the skull on the axial view. We computed the lateral ventricular volume by our newly-devised method which took the partial volume phenomenon into account. Temporary ex-tracerebral fluid accumulation was noted mostly within 3 months after injury in 25 of 39 cases in the mild level or above, and 2 of the 9 fair or good level cases. Ventri-culomegaly occurred early and stabilized around the 3 month period. We found the differences between the late and the initial values of the third ventricular width (%) and the lateral ventricular volume (cc) highly correlated with our outcome scale (Spearman's correla-tion coefficient rs=0.531, 0.676, respectively with p＜0.001 unanimously). We found the late values them-selves of the third ventricular width and the lateral ven-tricular volume highly correlated with our outcome scale (rs=0.575, 0.650, respectively with p＜0.001 unanimously). These 4 parameters were also highly correlated with the duration of the initial unconscious-ness (LOC). Thus, posttraumatic diffuse ventricu-lomegaly affecting the third ventricle as well should outline the late outcome of diffuse axonal injury. Both the ventriculomegaly and the late outcome should be roughly predicted by the duration of the initial uncon-sciousness.