Abstracts

Sturge-Weber Syndrome: Quantitative MRI and FDG PET Correlations.

Abstract number : 2.207
Submission category :
Year : 2001
Submission ID : 1709
Source : www.aesnet.org
Presentation date : 12/1/2001 12:00:00 AM
Published date : Dec 1, 2001, 06:00 AM

Authors :
Z. Pfund, MD, Department of Pediatrics, Children[ssquote]s Hospital of Michigan, WSU, Detroit, MI; C. Juhasz, MD, Department of Pediatrics, Children[ssquote]s Hospital of Michigan, WSU, Detroit, MI; D.C. Chugani, PhD, Department of Pediatrics, Radiology,

RATIONALE: The underlying mechanisms associated with neurological progression in Sturge-Weber syndrome (SWS) are poorly understood. Accelerated myelination and increased glucose metabolism in the area of the leptomeningeal angioma during the early stages remain unexplained. We studied the relation between regional brain volumes of gray and white matter, and glucose metabolism in children with SWS and epilepsy.
METHODS: Three girls (6-month, 9-month and 14-year old), all with left parieto-occipital angiomatosis, underwent MRI and interictal FDG PET scans. Probabilistic ([dsquote]fuzzy[dsquote]) segmentation of spoiled gradient echo MRI images was performed to determine the regional (parieto-occipital, temporal, frontal) gray and white matter volumes. Regional values of glucose metabolism were calculated after partial volume correction of PET images.
RESULTS: As compared to the intact hemisphere, the parieto-occipital gray matter underneath the angioma showed a severe volume decrease (Asymmetry Index [AI] range -26 to -36%) and glucose hypometabolism (AI range -7 to -13%) in all 3 patients. White matter volume loss was found in the older child (AI -18%) at the same location but, in contrast, white matter volumes in the 2 infants were increased (AI +49 and +10%). The frontal and temporal gray matter showed less atrophy (AI range -0.3 to -17%), but white matter volume deficit was more pronounced (AI range -6 to -72%) in all patients. Cortical glucose metabolism of the older child was mildly decreased (AI [lt] -3% in both frontal and temporal cortex), while increased glucose metabolism was found in the 2 infants (AI range +4 to +15%). White matter hypometabolism was detected in all examined regions of the patients (AI range -2.5 to -19%); however, this was less pronounced in regions of increased white matter volume or increased cortical glucose metabolism.
CONCLUSIONS: These results demonstrate structural and functional abnormalities beyond the angiomatosis in SWS, indicating that the parieto-occipital leptomeningeal lesion may interfere with growth and development of the whole hemisphere. Furthermore, these findings suggest that, while accelerated myelination underlying the angioma may be seen, ipsilateral white matter regions outside the angioma show delayed myelination with relative cortical sparing. We propose that ischemic astroglial activation and/or increased density of glucose transporters might account for the transient glucose hypermetabolism seen in infants with SWS, but further studies are required.