CYST-LIKE WHITE-MATTER LESIONS IN TUBEROUS SCLEROSIS

PURPOSE: To investigate the presence of small cystlike structures in t he cerebral hemispheric white matter on MR images of patients with tub erous sclerosis. METHODS: The MR images of 18 consecutive patients wit h tuberous sclerosis were reviewed retrospectively. RESULTS: Eight of the 18 patients were found to have cystlike structures in the cerebral white matter. The signal intensity of these lesions was isointense wi th cerebrospinal fluid on T1-, proton density-, and T2-weighted images . Four patients were imaged with a fluid-attenuated inversion recovery sequence, which in each case also showed fluid-type signal in these a reas. Three of the patients had CT for correlation, and these scans su pported the diagnosis of cystic lesions. Cysts ranged in number from o ne to 12 per patient and were usually smaller than 1 cm. The most comm on location was adjacent to the occipital horn or trigone of the later al ventricle (six of eight patients). Less frequent sites were near th e frontal horns, in the corpus callosum, and in the deep white matter near the body of the lateral ventricle. Cysts in Five patients were ei ther immediately adjacent to a cortical tuber or in the center of a wh ite matter dysplastic lesion. A cyst in one patient had septa, and non e of the cysts enhanced. CONCLUSIONS: Cystlike structures in the cereb ral hemispheric white matter were seen on the MR images of 44% of 18 p atients with tuberous sclerosis. Whether these findings represent cyst ic degeneration of dysplastic tissue or are unrelated to the disease p rocess of tuberous sclerosis is unknown. More than one pathogenesis ma y exist.