Cerebellar lesions are associated with TSC2 mutations in tuberous sclerosis complex: a retrospective record review study.

AIM: Cerebellar lesions are present in approximately 30% of patients with tuberous sclerosis complex. Although several prior studies have characterized these lesions, our study provides the first description of the specific distribution of these lesions within the cerebellum and the first genotype-phenotype correlation yet to be published.

METHOD: We retrospectively reviewed magnetic resonance images from 220 paediatric and adult patients with tuberous sclerosis complex (95 males, 125 females; mean age 22.7y, range 9mo-81y). Sex, age, and genotype of patients with cerebellar lesions were recorded and specific characteristics, including signal intensity, number, shape, presence of enhancement, calcification or haemorrhage, and location within the cerebellar lobules were noted.

RESULTS

Fifty-eight patients (26.4%) had 106 cerebellar lesions (62 right, 44 left). The mean number of cerebellar lesions per patient was 1.8 (range 1-6). Enhancement was present in 42.4% of lesions and folial retraction in 84%. Calcification was detected in 86.8% of lesions. Patients with calcified lesions were older (mean age 21.6y) than patients without calcification (11.5y). TSC2 mutations were detected in 41/42 (97.6%) of patients with cerebellar tubers who had genetic testing and one patient had no mutation identified. None of the patients had TSC1 mutation.

INTERPRETATION: We provide new information regarding cerebellar lesions in tuberous sclerosis complex: cerebellar lesions are significantly much more frequent in patients with TSC2 mutations than TSC1 mutations or patients with no mutation identified, and Crus II is the most frequent location of cerebellar lesions. New studies are needed to assess the clinical significance of these lesions.