Primary cerebellar hemorrhage. Quadrigeminal cistern obliteration on CT scans as a predictor of outcome.

The authors studied a consecutive series of 75 patients with cerebellar hemorrhage diagnosed by computerized tomography (CT) scanning, and assessed the relationship of outcome to the CT appearance of the quadrigeminal cistern, which in some cases was obliterated by rostral displacement of the vermis resulting from the cerebellar mass. Obliteration of the quadrigeminal cisterns was classified on the CT scans into three grades: normal (Grade I), compressed (Grade II), or absent (Grade III). There were 43 patients with Grade I, 16 with Grade II, and 16 with Grade III cisterns. Of the 75 patients, 38 (88.4%) of those with Grade I, 11 (68.8%) of those with Grade II, and none of those with Grade III cisterns returned to their previous activities at 6 months or more after onset. A Grade I cistern predicted a good outcome whether the hematoma was evacuated or not, as long as obstructive hydrocephalus, if present, was relieved early. However, a Grade II cistern was not predictive of a good outcome unless the hematoma was evacuated within 48 hours after onset of the hemorrhage. A Grade III cistern invariably predicted an unfavorable outcome. It is concluded that the CT grade of quadrigeminal cistern obliteration is an accurate indicator of outcome and is highly useful in selecting appropriate treatment for patients with cerebellar hemorrhage.