technetium-tc-99m-exametazime and Spasms--Infantile

We report the ictal brain single photon emission computed tomographic (SPECT) findings in two neonates. One neonate had hypoxic-ischemic encephalopathy, a disorganized discontinuous electroencephalogram (EEG) background, lethargy, seizures, and brainstem release phenomena. A brain SPECT was performed during a brainstem release phenomenon characterized by a 34-second sustained tonic posture of the right arm and chewing. It did not reveal focal cerebral hemisphere hyperfusion. The second neonate had hemimegalencephaly, low-voltage irregular EEG background, and seizures. A brain SPECT was performed during a seizure characterized by a 32-second sustained tonic posture of the right arm. It revealed focal hyperperfusion in the posterior region of the left hemisphere. The brain SPECT findings in these patients indicate that despite clinically similar events, brainstem release phenomena and seizures have different perfusion characteristics, and refute the theory that brainstem release phenomena are due to epileptic foci in the cerebral hemispheres undetectable by EEG.

Topics: Brain; Brain Stem; Electroencephalography; Epilepsy, Benign Neonatal; Evoked Potentials; Humans; Hypoxia-Ischemia, Brain; Infant, Newborn; Monitoring, Physiologic; Radionuclide Imaging; Spasms, Infantile; Technetium Tc 99m Exametazime

Diffuse and focal changes in glucose utilization and abnormal cerebral cortical perfusion were found in West syndrome by PET and SPECT investigations. In this study 99mTc-HMPAO SPECT was performed on seven patients with symptomatic West syndrome several months after the onset of the spasms. Regions of interest of the cerebral cortex and cerebellum were delineated by an automated computer program and cortical/cerebellar ratios of the HMPAO uptake in the patients were compared to those of controls. The basal ganglia/cerebellar ratios were compared after manual placement of regions of interest. Significantly reduced perfusion was found in the bilateral anterior, mid frontal and perisylvian cortex, and in the left posterior frontal and temporal areas. Well localized, focal changes in the cortical perfusion were not found and the perfusion in the basal ganglia proved to be normal. These abnormalities in the cortical perfusion may reflect a pre-existing brain pathology together with an encephalopathy due to the hypsarrhythmia and infantile spasms.

Topics: Cerebellum; Cerebral Cortex; Child, Preschool; Female; Humans; Infant; Male; Organotechnetium Compounds; Oximes; Spasms, Infantile; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

This ongoing study examines abnormalities of cerebral perfusion in a consecutive series of children with infantile spasms and correlates cerebral blood flow (CBF) abnormalities with electroencephalographic (EEG), neuroimaging, and pathologic findings. A consecutive series of children with infantile spasms, diagnosed by standard clinical and EEG criteria, had cerebral perfusion studies using 99Tc-HmPAO single photon emission computed tomography (SPECT), together with neuroimaging studies using computed tomography (CT) and/or magnetic resonance imaging (MRI), interpreted independently and correlated with surgical pathologic findings. Twenty children aged 2-13 months (mean 9.3 months) were studied over a 4-year period; 60% had symptomatic infantile spasms due to cerebral dysgenesis (33%), other congenital lesions (25%), tuberous sclerosis (17%), or other causes (25%), and the remaining patients were cryptogenic (40%). CBF abnormalities were present in 85%: multifocal decrease (40%), focal increase (25%), diffuse decrease (15%), and focal increase (10%), while the remaining 15% had normal cerebral blood flow. Focal cortical lesions may lead to infantile spasms, even in cryptogenic patients diagnosed by functional neuroimaging such as 99Tc-HmPAO SPECT. In selected patients, surgical excision of the cortical lesions leads to improved seizure control and possibly outcome. The localization and surgical excision of focal cortical lesions in infantile spasms required further investigation with functional and structural neuroimaging, EEG, and intraoperative electrocorticography.

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

We experienced a 6-month-old girl with infantile spasms who had localized cerebral lesion detected by 99mTcHMPAO-SPECT. She was born vaginally after a full term uncomplicated delivery with a birth weight of 3,100 g. She developed emprosthotonic spasms with series formation and EEG showed asymmetric periodic hypsarrhythmia which was predominant in the right hemisphere. While MRI could not detected any focal lesion, 99mTcHMPAO-SPECT disclosed hypoperfusion at the right anterior temporal and frontal areas. Although vitamin B6, clonazepam and sodium valproate were administered with no remarkable benefit, the treatment with ACTH-Z or carbamazepine resulted in cessation of spasms and improvement of the EEG findings. Consequently, the study with 99mTcHMPAO-SPECT was useful to clarify the pathology of infantile spasms, and we concluded that a patient with localized cerebral lesions should be given carbamazepine.

Topics: Brain; Female; Humans; Infant; Organotechnetium Compounds; Oximes; Spasms, Infantile; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We report a case of infantile spasm induced by hemisphere pachygria in which ultrasound and MRI provided precise anatomic information of hemisphere pachygria and Tc-99m HMPAO SPECT scintigraphy supplied an accurate assessment regional cerebral blood flow of infantile spasm during a seizure.

Topics: Cerebral Cortex; Diagnostic Imaging; Humans; Infant; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Spasms, Infantile; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon