Magnetic resonance imaging of cerebellar lesions in patients with tuberous sclerosis

Purpose: To characterize magnetic resonance imaging (MRI) features of lesions of tuberous sclerosis (TS) occurring in the cerebellum. Methods: All MRI studies obtained in patients with TS (n = 50) during a 6-year period were evaluated for cerebellar lesions. The following features were recorded: number, multiplicity, sidedness, depth of involvement, size, shape, signal characteristics, contrast enhancement, and associated lesions. The medical records of these patients also were reviewed, with special attention to signs and symptoms arising from the posterior fossa. Results: Of the 50 patients with TS who were studied, 8 patients had 10 cerebellar lesions: solitary lesions were found in 6 patients and multiple lesions were found in 2 cases. Six lesions were unilateral (five in the right hemisphere). Five lesions were larger than 2 cm in greatest dimension. All lesions involved the gray matter. Extension into the white matter was noted in five in-stances. All lesions were wedge shaped, and five extended to ward the fourth ventricle. All lesions were hypointense on T-1- and hyperintense on T-2-weighted sequences. Six patients received contrast medium; three lesions showed heterogenous enhancement in these patients. No patients had symptoms that were thought to be related to these lesions. Conclusion: Cerebellar lesions occurred in 16% of our patients. The lesions were incidental and asymptomatic. Lesions were devoid of mass effect and showed similar features to those described elsewhere for subcortical/cortical tubers arising in the cerebral hemispheres of patients with TS.