technetium-tc-99m-exametazime and Sturge-Weber-Syndrome

The aim of this study was to examine the haemodynamic response to seizures in three infants with Sturge-Weber syndrome by measuring regional cerebral blood flow using transcranial Doppler sonography and 99mTc HMPAO SPECT. Time-locked video/digital EEG recording was carried out for ictal studies. MRI was performed in all subjects. SPECT showed hemispheric hypoperfusion interictally in all three patients and also ictally in one of the three; a small region of hyperperfusion was seen on the same ictal scan in the latter, ie. the patient with interictal and ictal hypoperfusion. In the two older children middle cerebral artery velocity (MCAV) was reduced by between 29 and 62% in the middle cerebral artery of the predominantly affected hemisphere compared with the contralateral side. During seizures, increases of 6 to 30% in MCAV were recorded for the clinically seizing hemisphere compared with 24 to 170% for the contralateral side in four of the seizures recorded. In one infant, MCAV fell bilaterally during a seizure that generalized (-18 and -43% in the predominantly affected and contralateral side respectively). Sequential recordings in one infant suggested that, with time, the haemodynamic response to seizures of the unaffected hemisphere may decrease. These findings suggest that the venous malformation in SWS is associated with an impairment of the cerebral haemodynamic response to seizure activity.

Topics: Cerebral Cortex; Cerebrovascular Circulation; Electroencephalography; Female; Humans; Infant; Infant, Newborn; Intracranial Arteriovenous Malformations; Male; Radionuclide Imaging; Radiopharmaceuticals; Seizures; Sturge-Weber Syndrome; Technetium Tc 99m Exametazime

Demonstration of the full extent of abnormality in patients with the Struge-Weber syndrome (SWS) is important for prognosis and in planning surgery to remove the seizure focus. We compared single-photon emission computed tomography (SPECT), MRI and CT in nine children under the age of 4 years with seizures as part of SWS, in an attempt to determine the optimal method of imaging in different clinical settings. Seven unilateral and two bilateral cases were studied by interictal 99mtechnetium hexamethylpropyleneamineoxime (HMPAO) SPECT, and contrast-enhanced CT and MRI, giving information on 11 abnormal hemispheres. All imaging modalities showed abnormalities in every child. Perfusion imaging showed focal regions of decreased uptake in 9 of 11 (82%) abnormal hemispheres and demonstrated a widespread decrease but no focal defect in 2; it also revealed crossed cerebellar diaschisis in 2 cases. CT demonstrated typical gyriform calcification in 9 of 11 (82%) affected hemispheres. Contrast-enhanced MRI showed more extensive involvement than contrast-enhanced CT in 5 of 11 (45%) cases. The area of hypoperfusion shown by SPECT was smaller than the area of contrast enhancement on MRI in 6 of 11 cases (55%), comparable in 3 (27%) and larger in 2 cases (18%). CT is sufficient to confirm the clinical diagnosis of SWS, but MRI frequently shows more extensive abnormal areas. 99mTc HMPAO imaging is a useful addition when it is important to know the full extent of the disease, for example prior to surgery. It is likely to detect areas of hypoperfusion, representing ischaemic regions, which may act as an epileptogenic focus and may not be shown by CT or MRI.

Topics: Adolescent; Cerebral Cortex; Child; Child, Preschool; Dominance, Cerebral; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Regional Blood Flow; Sensitivity and Specificity; Sturge-Weber Syndrome; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

Topics: Brain; Deoxyglucose; Female; Fluorodeoxyglucose F18; Glucose; Humans; Infant; Infant, Newborn; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Sturge-Weber Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Technetium-99m-HMPAO interictal SPECT was performed on three pediatric patients with Sturge-Weber syndrome (SWS).. Brain SPECT of all three patients demonstrated markedly diminished tracer localization in the affected hemisphere. In one patient, the SPECT abnormality was more extensive than the associated abnormalities on CT and MRI.. Technetium-99m-HMPAO brain SPECT can detect cerebral perfusion abnormalities associated with SWS and deserves consideration in the imaging evaluation of SWS patients.

Topics: Brain; Cerebrovascular Circulation; Humans; Infant; Infant, Newborn; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Sturge-Weber Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The Tc-99m HMPAO brain imaging confirmed marked hypoperfusion secondary to anomalous cerebral venous drainage of the Sturge-Weber syndrome. Until now, this had been a hypothesis suggested by results obtained from conventional brain scans and cerebral arteriography.

Topics: Angiomatosis; Female; Humans; Middle Aged; Organotechnetium Compounds; Oximes; Sturge-Weber Syndrome; Sugar Acids; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed