A computed tomography score for assessment of mass effect in space-occupying cerebellar infarction

Background and Purpose. Patients with cerebellar infarction are threatened by infratentorial herniation and impaired circulation of cerebrospinal flui d if mass effect in posterior fossa develops. Clinical assessment is often impaired in patients with disturbances of consciousness. Therefore, compute d tomography (CT) examination is essential in the diagnosis of complication and decision for operative treatment. Methods. Mass effect of cerebellar i nfarction was quantitatively assessed using a 3-item CT score: width of fou rth ventricle, compression of quadrigeminal cistern, and width of lateral v entricle. Retest and interrater reliability was determined. Validity of ass essment of mass effect was examined using 185 CT scans from a cerebellar in farction study, and the effect of operative treatment on CT score was deter mined. Results. The correlation coefficients for retest and interrater reli ability were 0.94 and 0.75, respectively. The authors found a significant d ifference for the CT sum score and all CT items except "compression of the fourth ventricle" between patients with different levels of consciousness. Effect of operative treatment was documented by improvement of CT score. Co nclusions. The proposed CT score is of high interrater and retest reliabili ty. supplements the clinical assessment of the patient, and is able to moni tor the efficacy of decompressive treatment.