A perfusion-metabolic mismatch in Sturge-Weber syndrome: A multimodality imaging study

Abstract

OBJECTIVE We combined perfusion weighted imaging (PWI) with 2-deoxy-2[18F]fluoro-D-glucose (FDG) positron emission tomography (PET) to study the relationship between regional metabolic and perfusion abnormalities and their clinical correlates in children with Sturge-Weber syndrome (SWS). METHODS Fifteen children (age: 0.9-10 years) with unilateral SWS underwent high-resolution PWI and FDG PET prospectively. Regional (lobar) asymmetry indices (AIs) of subcortical white matter (WM) cerebral blood flow (CBF) were correlated with corresponding cortical FDG uptake asymmetries, extent of leptomeningeal vascular malformation and clinical seizure variables. RESULTS Abnormal cortical glucose metabolism and/or subcortical WM CBF were seen in all lobes affected by vascular malformation and extended to lobes not affected by abnormal pial vessels in 6 patients. Lower CBF was associated with lower cortical glucose metabolism in the temporal, parietal and occipital lobes (p≤0.02). While decreased perfusion was associated with hypometabolism in most cases, increased regional CBF (found in 6 patients) was commonly associated with relatively mild or no hypometabolism. Ten of 24 cerebral lobes with normal glucose metabolism in the affected hemisphere showed abnormal perfusion. High seizure frequency was associated with severe parieto-occipital hypoperfusion (p≤0.03), while long duration of epilepsy was related to frontal lobe hypometabolism (p=0.015). CONCLUSIONS Regional perfusion and cortical metabolic abnormalities can extend beyond lobes affected by leptomeningeal vascular malformations and are related to epilepsy in SWS. Despite a general correlation between perfusion and metabolism, increased WM perfusion with preserved cortical metabolism in overlying cortex is a common pattern of a perfusion/metabolic mismatch. This may represent a disease stage where cortical function is preserved while increased WM perfusion provides collateral drainage of cortex via the deep vein system.

Neuroimaging of phakomatoses: overview and advances

“…A recent study has demonstrated a general correlation between cerebral perfusion and metabolism; however, increased white matter perfusion with preserved cortical metabolism and overlying cortex was a common pattern of perfusion/metabolic mismatch [34]. This mismatch was theorized to represent a disease stage where cortical function is preserved while increased white matter perfusion provides collateral drainage of the cortex via the deep vein system.…”

Posterior quadrant disconnection surgery for Sturge‐Weber syndrome

“…Relative findings leading to surgical decision are progressive atrophy and transient increase of glucose metabolism in the affected cerebral cortex on fluorodeoxyglucose–positron emission tomography (FDG‐PET) study. Transient hypermetabolism within the affected area in SWS is known as a finding in recent seizures . Therefore, we accept the transient hypermetabolism on FDG‐PET study as a relative indication for epilepsy surgery.…”

Reliability and Clinical Correlation of Transcranial Doppler Ultrasound in Sturge-Weber Syndrome

“…One would also anticipate a greater MCA and PCA (compared to ACA) relative decrease in mean flow velocity in the affected hemisphere, compared to the unaffected hemisphere, since SWS brain involvement is more commonly in posterior occipital, parietal, and temporal regions of the brain [18], as was seen in our cohort of subjects. The frontal lobe, perfused in part by the ACA, is the least likely region to be affected by SWS brain involvement [19].…”