technetium-tc-99m-exametazime and Epilepsy--Absence

Radiopharmaceutical brain imaging is clinically applied in planning resective epilepsy surgery. Cerebral sites of seizure generation-propagation are highly associated with regions of hyperperfusion during seizures, and with glucose hypometabolism interictally. For surgical planning in epilepsy, the functional imaging modalities currently established are ictal single photon emission computed tomography (SPECT) with [(99m)Tc]technetium-hexamethylpropyleneamine oxime (HMPAO) or with [(99m)Tc]technetium-ethylene cysteine dimer (ECD), and interictal positron emission tomography (PET) with 2-[(18)F]fluoro-2-deoxyglucose (FDG). Ictal SPECT and interictal FDG PET can be used in presurgical epilepsy evaluations to reliably: (1) determine the side of anterior temporal lobectomy, and in children the area of multilobar resection, without intracranial electroencephalographic recording of seizures; (2) select high-probability sites of intracranial electrode placement for recording ictal onsets; and, (3) determine the prognosis for complete seizure control following anterior temporal lobe resection. Coregistration of a patient's structural (magnetic resonance) and functional images, and statistical comparison of a patient's data with a normal data set, can increase the sensitivity and specificity of these SPECT and PET applications to the presurgical evaluation.

Topics: Brain; Cysteine; Epilepsy; Epilepsy, Absence; Epilepsy, Generalized; Epilepsy, Temporal Lobe; Fluorodeoxyglucose F18; Humans; Organotechnetium Compounds; Predictive Value of Tests; Preoperative Care; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to investigate the informative value of single photon emission tomography (SPECT) in relation to the pathophysiological functioning of the brain during absence seizures and the origin of ictal discharges in idiopathic generalized epilepsies (IGEs). Six patients with childhood absence epilepsy (CAE) were selected for the study and two consecutive SPECT sessions were performed concomitant with EEG recordings revealing normal results and during hyperventilation (HV) studies where the ictal discharges were induced either alone or accompanied by clinical absence seizures. All six patients had ictal discharges in their EEGs during HV and two of them also had clinical absences. SPECT findings during HV revealed an overall increase in the cerebral blood flow (CBF) with significantly higher values as compared to the baseline data. There was no indication for any focal origin in either the interictal or the ictal SPECT findings. Results of the study were supportive for the concept of subcortical origin for the absence seizures and they were also promising for the diagnostic value of ictal SPECT in epileptic cases with undetermined origin as to whether they were localization-related or generalized.

Topics: Adolescent; Brain; Case-Control Studies; Cerebrovascular Circulation; Child; Electroencephalography; Epilepsy, Absence; Female; Humans; Hyperventilation; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The authors report the results of a retrospective controlled study on the incidence of migraine in centro-temporal epilepsy compared to absence epilepsy, partial epilepsy and a group of patients with cranial trauma without epilepsy. The following observations from this series of 129 patients were made. Migraine was present in 63% of the patients with centro-temporal epilepsy (rolandic epilepsy), in 33% with absence epilepsy, in 7% with partial epilepsy and in 9% of the cranial trauma group. These results suggest that the association of centro-temporal epilepsy and migraine is non-fortuitous and also to a lesser degree in absence epilepsy. The role of neurotransmitters in this association is discussed. No decrease in cerebral blood flow was observed in 12 patients with rolandic epilepsy on a Hm-PAO SPECT study.

Topics: Adolescent; Brain Injuries; Chi-Square Distribution; Child; Electroencephalography; Epilepsies, Partial; Epilepsy, Absence; Female; Follow-Up Studies; Humans; Male; Migraine Disorders; Organotechnetium Compounds; Oximes; Retrospective Studies; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon