Quantitative Apparent Diffusion Coefficient Mapping May Predict Seizure Onset in Children with Sturge-Weber Syndrome

Abstract Background Sturge-Weber syndrome (SWS) is often accompanied by seizures, stroke-like episodes, hemiparesis, and visual field deficits. This study aims to identify early pathophysiological changes that exist prior to the development of clinical symptoms and evaluate if the Apparent Diffusion Coefficient (ADC) map is a candidate early biomarker of seizure risk in patients with SWS. Methods This is a prospective cross-sectional study using quantitative ADC analysis to predict later onset of epilepsy. Patient inclusion criteria were presence of the port wine birthmark, post contrast brain MRI with abnormal leptomeningeal capillary malformation and/or enlarged deep medullary veins and absence of seizures or other neurological symptoms. We used our recently developed normative, age-specific ADC atlases to quantitatively identify ADC abnormalities, and correlated pre-symptomatic ADC abnormalities with later onset of seizures. Results We identified 8 patients (3 girls) with SWS, age range of 40 days to 9 months, who met our study criteria. One patient had predominantly leptomeningeal capillary malformation (LCM), deep venous anomaly, and normal ADC values. This patient did not develop seizures. The remaining 7 patients had large regions of abnormal ADC values and all developed seizures; 1/7 with late onset seizures. Conclusions Larger regions of decreased ADC values in the affected hemisphere, quantitatively identified by comparison to age-matched normative ADC atlases, are common in young children with SWS and in this small study were associated with later onset of seizures. Our findings suggest that quantitative ADC maps, analyzed using standardized and objective atlases, may identify patients at high risk for seizures in SWS but larger prospective studies are needed to determine sensitivity and specificity.