Abstracts

Rationale: The objective of our study was to correlate the extent of the leptomeningeal angiomatosis with electroclinical features in Sturge-Weber syndrome (SWS). Methods: All patients undergoing an EEG at Cleveland Clinic during the last 10 years were reviewed for Sturge-Weber syndrome. Clinical, MRI and EEG data were analyzed. Results: Eleven patients with complete clinical, EEG and MRI data were identified (9 males) aged 9 months to 13 years with unilateral SWS and pharmacologically intractable epilepsy. MRI revealed leptomeningeal angiomatosis in all (6 right) and involved the complete hemisphere in four and was localized to the posterior quadrant in seven patients. Clinical seizures started on average at 25 months (range 0 - 120 months) and presented with one to four different clinical seizure types per patient including unilateral clonic (9), hypomotor (2), staring (dialeptic, 1), tonic, versive (1), atonic (1), and automotor seizures (1). In two patients, seizures were preceded by auras (somatosensory and visual). Versive and clonic seizures were always contralesional. Hemiparesis was present in eight out of eleven (73%). Patients with hemispheric SWS had significantly earlier onset of seizures (p<0.05). Interictal EEG revealed background asymmetry in ten and lateralized or regional slowing in eight out of eleven. Three additional patients presented with generalized EEG slowing. Interictal epileptiform discharges were recorded in eight patients and were always concordant with the MRI lesion. Additionally, two patients had ipsilesional frontal and frontocentral sharp waves but only posterior quadrant leptomeningeal involvement. One additional patient presented also with generalized polyspikes. EEG-seizures were documented in six patients (parieto-occipital in five and temporo-parietal in one) and were ipsilateral to the MRI findings. Conclusions: SWS is a rare neurocutaneous syndrome presenting with seizures early in life. In our series, lateralizing semiology with clonic and versive seizure types was always contralesional. Ictal and interictal EEG findings were almost always concordant with radiological disease extent in our patient population, although additional generalized or ipsilesional frontal discharges were occasionally seen. Patients with hemispheric involvement of SWS presented with earlier seizure onset than patients with SWS of the posterior quadrant. Further study is needed to determine whether hemispheric and posterior quadrant SWS represent distinct entities.