Tuberous sclerosis: differences between cerebral and cerebellar cortical tubers in a pediatric population.

BACKGROUND AND PURPOSE Histologic evidence of cortical tubers is pathognomonic of tuberous sclerosis (TS) disease. Cerebellar tubers, however, are uncommonly found. Our objective was to evaluate the prevalence and characteristics of cerebellar tubers in a large series of pediatric patients with TS studied with MR imaging. In particular, their relationship with volume loss and age will be analyzed. METHODS MR images of 34 children with TS and cortical tubers were reviewed. There were 17 female and 17 male patients. The mean age was 8.9+/-4.5 years (mean +/- SD), with a range from 2 to 14 years. The number and location (supratentorial, infratentorial) of tubers and volume loss of the underlying parenchyma were recorded. The relationship between tuber location, patient age, and number of tubers was studied using the Student's t test for independent samples. The relationship between tuber location and presence of volume loss was established using the Pearson chi2 test. RESULTS The mean number of cortical tubers was 14.3+/-8.5. Fifteen (44.1%) patients had cerebellar tubers associated with cerebral lesions. Patients with cerebellar and cerebral tubers had significantly more global cortical lesions than did patients with isolated cerebral tubers (17.9+/-8.9 versus 11.4+/-7.2 tubers, P = .026). Patients with cerebellar tubers were significantly older than those with isolated supratentorial tubers (11.3+/-3.4 versus 7.1+/-4.4 years, P = .005). In only four (11.8%) patients were tubers associated with focal parenchymal volume loss. The tubers in all of these cases were located in the cerebellum-indicating a significant relationship with volume loss (Pearson chi2 test, P = .017). CONCLUSION In this series, cerebellar tubers were frequent and were always present in association with cerebral cortical tubers. They were seen in older children with a larger total number of tubers. Cerebellar tubers may be associated with focal volume loss.