Klippel-Trenaunay syndrome: frequency of cerebral and cerebellar hemihypertrophy on MRI.

We examined 11 patients, clinically and radiographically diagnosed as having the Klippel-Trenaunay syndrome (KTS) by MRI. There were four females and seven males, aged 3-51 years (mean 21 years). Two had clear asymmetry of the cerebral and cerebellar hemispheres. The thickness of the grey matter was normal, without sulcation abnormalities, but the thickness of the white matter was increased; the size of the ipsilateral ventricle was normal. These patients had hypertrophy of the leg and a cutaneous haemangioma on the same side as the brain abnormality. No patient had an intracranial vascular malformation, unilateral megalencephaly, cerebral atrophy or hydrocephalus. The prevalence of cerebral hemihypertrophy in our series of patients with KTS was thus 18%.