Single photon emission computed tomography in seizure disorders.

Abstract

SUMMARY Fourteen children with various seizure disorders were studied using a cerebral blood flow tracer, 123I iodoamphetamine (0.05 mCi/kg), and single photon emission computed tomography (SPECT). In the five patients with radiological lesions, SPECT showed congruent or more extensive abnormalities. Five of the nine children with a normal scan on computed tomography had abnormal SPECT studies consisting of focal hypoperfusion, diffuse hemispheric hypoperfusion, multifocal and bilateral hypoperfusion, or focal hyperperfusion. A focal lesion seen on SPECT has been found in children with tonic-clonic seizures suggesting secondarily generalised seizures. Moreover the pattern seen on SPECT seemed to be related to the clinical status. An extensive impairment found on SPECT was associated with a poor evolution in terms of intellectual performance and seizure frequency. Conversely all children with a normal result on SPECT had less than two seizures per year and normal neurological and intellectual development.The usefulness of studies with positron emission tomography in adult epilepsy is now well established.1' Both cerebral metabolism and cerebral blood flow are significantly increased during focal or generalised seizures while both are depressed in the postictal and interictal state.2 3 The presence of the interictal abnormality is remarkable in view of the fact that neuroradiological techniques usually fail to show any structural lesions in patients who might benefit from surgical treatment.4Unfortunately, facilities for positron emission tomography are not widely available and remain very expensive. New cerebral blood flow tracers which are labelled with conventional y ray emitters have been developed and allow the use of the single photon emission computed tomographic (SPECT) devices present in most nuclear medicine departments. The major determinants of the brain distribution of these tracers are cerebral blood flow and neuronal mass.5 Although this technique is purely semiquantitative, its low cost and convenience make it highly attractive for a widespread clinical use.Studies performed in adults using 123I iodoamphetamine and SPECT have shown similar alterations as previously described in positron emission tomography.6 Childhood epilepsy is a complex disorder, as indicated by the clinical pleiomorphism, the variety of aetiologic factors, and the unpredictable evolutions. There are only a few available data on abnormalities of cerebral metabolism in seizure disorders.7 8 In this report we present our initial experience of cerebral blood flow imaging using 123i iodoamphetamine and SPECT in children with various seizure disorders. Patients and methodsFourteen children aged 2 months to 16 years were investigated after informed consent of the parents and according to a protocol accepted by our local committee for medical ethics. Nine were known and treated epileptics: three had tonic-clonic seizures, two had complex partial seizures, two suffered from Bravais-Jacksonian crisis, one from absences, and one from a Le...

Brain Single Photon Emission Computed Tomography (SPECT) in Neuropediatrics

“…Aseries of children with primarily generalised epilepsy is currently being investigated after injeetion of 99mTc-HM-PAO during photostimulation and hyperventilation. Promising results of SPECT in neonatal brain impairments have been published (7,12) and were achieved in the present study. Besides congruent findings with CT and ultrasound of structural lesions and periventricular leucomalacias, parasagittallesions, seen mainly in term infants (29), and other corticallesions were indicated.…”

“…The role of SPECT in the preoperative evaluation before epilepsy surgery has already been established (20,25). Promising reports have also recently emerged on the usefulness of SPECT for exploring neurological impairments other than epilepsy (19,28) ranging from ischemic brain lesions in the newbom (7) to dementia in the old (17).…”

Ictal 99mTc‐HMPAO Single Photon Emission Computed Tomography in Children with Temporal Lobe Epilepsy

“…Studies of SPECT in children with epilepsy have been mostly interictal and have investigated children with a variety of epilepsy syndromes (Denays et al, 1988; Chiron et al, 1989; Iivanainen et al, 1990; O'Tauma et al, 1990O'Tauma et al, , 1991; Vles et al, 1990; Uvebrant et al, 1991;Adams et al, 1992). Detailed study of ictal SPECT in children with partial epilepsy has not been reported.…”

Technetium-99m hexamethylpropylene amine oxime single photon emission tomography in febrile convulsions

“…1990) and children (Denays et al 1988;Gelfand and Stowens 1989;Ivanainen et al 1990) with seizure disorders. The EEG may not be able to assess the extent and severity of the underlying cerebral involvement and may have difficulty in localizing the origin of the seizure due to its limited spatial resolution.…”