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 fluid if mass effect in posterior fossa develops. Clinical assessment is often impaired in patients with disturbances of consciousness. Therefore, computed tomography (CT) examination is essential in the diagnosis of complication and decision for operative treatment. Methods. Mass effect of cerebellar infarction was quantitatively assessed using a 3-item CT score: width of fourth ventricle, compression of quadrigeminal cistern, and width of lateral ventricle. Retest and interrater reliability was determined. Validity of assessment of mass effect was examined using 185 CT scans from a cerebellar infarction study, and the effect of operative treatment on CT score was determined. Results. The correlation coefficients for retest and interrater reliability were 0.94 and 0.75, respectively. The authors found a significant difference 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. Conclusions. The proposed CT score is of high interrater and retest reliability. supplements the clinical assessment of the patient, and is able to monitor the efficacy of decompressive treatment.