Tuberous sclerosis is an autosomal dominant disease with variable expression and a predilection for diffuse hamartomatous development. Multiple organ systems are often involved. The exact etiology is not known, but is felt to represent abnormal migration of neurons. There are four major intracranial findings consisting of cortical tubes, white matter abnormalities, subependymal nodules and giant cell astrocytomas. In adults, these lesions are generally hypointense on T1 weighted images and hyperintense on T2 weighted images.
Enhancement is rare, but calcifications are common.
White matter lesions are believed to represent dysplastic white matter or abnormal migration. The MRI findings generally consist of a variety of appearances with most abnormalities being hypointense on T1 and hyperintense on T2. The signal characteristics are variable, but most commonly are hypointense on T1 and hyperintense on T2. They often calcify and the majority will demonstrate some enhancement. Subependymal giant cells develop near the foramen of Monroe.