Pediatric cerebrovascular disease. Alterations of regional cerebral blood flow detected by TC 99m-HMPAO SPECT
E. Shahar, D. L. Gilday, P. A. Hwang, E. K. Cohen and R. Lambert
Department of Pediatrics, Hospital for Sick Children, University of Toronto Faculty of Medicine, Ontario, Canada.
Regional cerebral blood flow (rCBF) alterations, as determined by single
photon emission computed tomography (SPECT) using technetium Tc 99m
hexamethyl propylenamine oxime (Tc 99m-HM-PAO), were studied in 15 infants
and children presenting with cerebrovascular disorders between the ages of
2 weeks and 16 years. The rCBF patterns were correlated with clinical
presentation, electroencephalographic patterns, radiologic studies,
including computed tomography and magnetic resonance imaging of the head,
and cerebral angiography. All patients presented with motor weakness that
was accompanied in some with dysphasia, defects in visual fields,
obtundation, seizures, and high temperature. Perturbations of rCBF with Tc
99m-HMPAO SPECT brain scanning were detected in all patients investigated,
with no adverse effects related to the radiotracer. All patients had a
focal area of decreased rCBF, with adjacent hyperemia in 3 patients. In 7
patients, there was an rCBF decrease in a vascular distribution, mainly
that of the middle cerebral artery, that correlated with the clinical
findings and a focal electroencephalogram, as well as computed tomography
and magnetic resonance imaging of the head. Impairment of rCBF was more
extensive in 3 children, while early abnormal SPECT findings preceded
abnormal computed tomographic findings in another 2 children. In 2
patients, Tc 99m-HMPAO SPECT was the only positive radiologic test to
correlate with focal clinical and electroencephalographic abnormalities, in
view of repeated normal computed tomographic scans. We conclude that Tc
99m-HMPAO SPECT brain scanning is a sensitive, complementary diagnostic
measure in the early detection, localization, and estimation of rCBF
alterations in pediatric cerebrovascular disease.
