technetium-tc-99m-exametazime and Epilepsy--Complex-Partial

Intracranial aneurysms in the pediatric age group are rare occurrences. They usually present with subarachnoid hemorrhage or mass effect. Their association with epilepsy has rarely been reported; such concurrence may not be a coincidence. We present a 16-year-old girl with a 5-year history of medically intractable complex partial seizures. Preoperative electrophysiological and neuroimaging studies demonstrated an epileptogenic focus and atrophy in the right mesial temporal lobe, and ipsilateral incidental aneurysm at the carotid artery bifurcation. The patient underwent a complete right anterior temporal lobectomy, followed by clipping of the aneurysm. We concluded that the epilepsy management in association with cerebral aneurysms is controversial, but when surgery is indicated, clipping of the aneurysm and resection of the epileptogenic focus may provide the optimal outcome. The relevant literature is reviewed and the possible mechanisms of production of epilepsy by intracranial aneurysms are discussed.

Topics: Adolescent; Atrophy; Cerebral Angiography; Electroencephalography; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Humans; Intracranial Aneurysm; Magnetic Resonance Imaging; Psychosurgery; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Cerebrovascular Circulation; Electroencephalography; Epilepsies, Partial; Epilepsy, Complex Partial; Female; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The respective contribution of interictal HMPAO-SPECT and FDG-PET to the imaging of the epileptogenic zone in intractable temporal lobe epilepsy is not known. Ten consecutive patients with drug resistant focal epilepsy of temporal lobe origin were studied with prolonged noninvasive video-EEG monitoring, magnetic resonance imaging, interictal FDG-PET and HMPAO-SPECT. Five patients demonstrated unitemporal and 5 patients bitemporal interictal and/or ictal EEG epileptiform abnormalities. We developed a 3-dimensional semiquantitative method for interpretation and comparison of FDG-PET and HMPAO-SPECT using a 15-compartment model of the temporal lobe. In all 5 patients with unilateral epileptogenicity, interictal hypometabolism and hypoperfusion were recorded on the side of the EEG abnormalities without discrepancy between PET and SPECT. The severity and the extent of focal abnormalities were consistently greater on PET than on SPECT, in agreement with previously well documented better 'sensitivity' of PET. Among the 5 patients with bitemporal epileptogenicity, results of SPECT and PET were convergent in only 2 cases. In this group, SPECT abnormalities appeared more profound but either SPECT or PET were not constantly correlated with the side of predominant EEG epileptogenicity. Abnormalities on PET and SPECT were more frequently limited to mesiobasal structures among cases with unilateral epileptogenicity and tended to involve neocortical structures in bitemporal cases. We conclude that interictal FDG-PET and HMPAO-SPECT provide the same type of information on the side of the epileptogenic zone in cases with clearly unilateral epileptogenicity, with abnormalities more intense and more extensive on PET.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Deoxyglucose; Electroencephalography; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Models, Biological; Organotechnetium Compounds; Oximes; Reproducibility of Results; Single-Blind Method; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Videotape Recording

Topics: Brain; Child; Cysteine; Epilepsy, Complex Partial; Hospitals, Pediatric; Humans; Injections; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Robotics; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Brain; Brain Diseases; Choristoma; Epilepsy, Complex Partial; Female; Humans; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Postictal psychosis is a well-known complication, occurring especially in patients with temporal lobe epilepsy. It usually runs a benign course. The literature on this topic is sparse, and the underlying pathogenic mechanisms are not known.. We report five patients with temporal lobe epilepsy in whom postictal psychosis developed during the course of video-EEG monitoring; they were studied with hexamethyl-propyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT) during and after the psychotic event.. In comparison to the interictal state, all SPECT scans obtained during postictal psychosis were remarkable for bifrontal and bitemporal hyperperfusion patterns. Some studies also demonstrated unilateral left lateral frontal hyperperfusion. These cortical blood-flow patterns appeared to be distinct from those obtained during complex partial seizures.. Our data suggest that postictal psychoses in patients with temporal lobe epilepsy are associated with hyperactivation of both temporal and frontal lobe structures. This hyperperfusion may reflect ongoing (subcortical) discharges, active inhibitory mechanisms that terminate the seizure, or simply a dysregulation of cerebral blood flow.

Topics: Adult; Dominance, Cerebral; Electroencephalography; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Frontal Lobe; Humans; Hyperemia; Male; Monitoring, Physiologic; Neurocognitive Disorders; Risk Factors; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Video Recording

We report a 4-year-old boy with ictal fear as his primary epileptic manifestation. Following an arrest of motion, the boy started to scream and struggle with an expression of horror on his face. Oral automatisms appeared around the end of the seizure. Complex visual and gustatory hallucinations and pain in the left leg were also observed. Ictal and interictal scalp EEGs revealed epileptic discharges in bilateral frontal regions. Ictal SPECT (99 mTc-HMPAO) showed hyperperfusion in right medial temporal area. These findings suggest that ictal fear associated with other ictal manifestations such as various hallucinations and oral automatisms resulted from rapid spread of epileptic discharges from frontal lobes to the right anterior temporal region.

Topics: Brain; Child, Preschool; Electroencephalography; Epilepsy, Complex Partial; Fear; Humans; Male; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

The goal of this report is to demonstrate the utility of ictal brain single photon emission tomography (SPECT) in a 39-year-old man with complex partial seizures arising from the anterior cingulate gyrus. Seizures originating from the anterior cingulate gyrus are difficult to localize because they have variable ictal semiology, are usually brief, and have rapid cortical propagation.. Clinical neurologic examination, electroencephalography, extended video-electroencephalography with scalp and sphenoidal electrodes, magnetic resonance imaging, computed tomography, and ictal brain SPECT with Tc-99m HMPAO were performed to identify the seizure focus. The patient's regional cerebral blood flow (rCBF) findings were compared with those of eight normal controls, and changes in rCBF were assessed by comparing the patient's ictal scan with those of normal controls at rest by using statistical parametric mapping (SPM).. Clinical and neurologic evaluations failed to demonstrate the epileptogenic focus. Ictal rCBF brain SPECT showed a focal region of hyperperfusion in the anterior cingulate gyrus. By using SPM, the ictal blood flow increase in the right anterior cingulate gyrus (x, y, z, -6, 42, 24 mm) was found to be statistically significant when compared with normal controls (z score, 4.88, p < 0.001). Subdural EEG recordings with intracranial electrodes positioned over this location confirmed that the cingulate gyrus was the origin of the seizures, and surgical resection resulted in >90% seizure reduction.. We concluded that ictal brain SPECT localization in conjunction with subdural electrode confirmation is a useful test in the presurgical evaluation of difficult to localize cingulate epilepsy.

Topics: Adult; Diagnosis, Computer-Assisted; Electrodes, Implanted; Electroencephalography; Epilepsy, Complex Partial; Gyrus Cinguli; Humans; Magnetic Resonance Imaging; Male; Monitoring, Physiologic; Neuropsychological Tests; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Videotape Recording

Although multiple cortical tubers are a hallmark of tuberous sclerosis complex (TSC), seizures often originate from a single tuber, making excisional surgery a therapeutic option for intractable patients. To assess the role of ictal single photon emission computed tomography (SPECT) in defining the epileptogenic tuber, we reviewed videoelectroencephalography (V/EEG) data, magnetic resonance imaging (MRI) and SPECT scans of 15 patients (aged 3 months to 15 years, mean 5.1) with medically resistant partial seizures and TSC. SPECT scans were performed using Tc-99m-hexamethylpropyleneamine oxime (HMPAO) injected within 30 seconds of electrographic seizure onset and were graded on a scale from 1 to 5 (1 weakly perfused, 5 strongly perfused). The scalp EEG revealed localized seizure origin in ten patients; five had concordant hyperperfused SPECT regions consisting of comma-shaped areas surrounding hypoperfused areas in the candidate tuber. Strongly hyperperfused regions (grade 3-5) were noted in two patients whose ictal EEG patterns were characterized by sustained, rhythmic fast activity or spiking. The other five patients had nonlocalizing or poorly sustained ictal EEG patterns; one patient in this group had focal hyperperfusion. Invasive EEG recordings in two patients revealed propagated EEG patterns that correlated with the ictal SPECT findings. These findings indicate a strong correlation between ictal SPECT and ictal scalp EEG, especially when there are sustained rhythmic fast ictal EEG patterns.

Topics: Adolescent; Brain Mapping; Cerebral Cortex; Child; Child, Preschool; Electroencephalography; Epilepsies, Partial; Epilepsy, Complex Partial; Female; Humans; Infant; Male; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tuberous Sclerosis; Video Recording

To assess the clinical utility of high-resolution inter-ictal single photon emission tomography (SPET) of regional cerebral perfusion and high-resolution magnetic resonance imaging (MRI) of the brain with a phased-array temporal lobe coil, 35 patients with presumed partial epilepsy were evaluated prospectively by these techniques in addition to prolonged video/electroencephalographic (EEG) monitoring. Twenty of these patients had surgical treatment of partial epilepsy with outcome determinations spanning from 12 months to 3 years at follow-up. There were four categories of imaging findings as compared to scalp/sphenoidal EEG localization. Category I included 12 patients (34% of total) in whom there was complete imaging and EEG concordance. Category II included 4 patients (11%) in whom MRI and EEG were concordant but SPET was divergent or normal. Category III included 13 patients (37%) in whom SPET and EEG were concordant but MRI was divergent or normal. Category IV included 4 patients (11%) in whom neither SPET nor MRI was concordant with EEG. In this study, the relative sensitivities of SPET and MRI for localization of partial epilepsy based on prolonged scalp/sphenoidal video/EEG recordings were 76% and 49%, respectively. We conclude that these neuroimaging techniques (phased-array MRI and inter-ictal cerebral perfusion SPET) are complementary and useful in the pre-operative evaluation of patients with partial epilepsy.

Topics: Adolescent; Adult; Aged; Cysteine; Electroencephalography; Epilepsies, Partial; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Time Factors; Tomography, Emission-Computed; Treatment Outcome; Videotape Recording

Topics: Amnesia; Brain; Cerebral Cortex; Cerebrovascular Circulation; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Follow-Up Studies; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Patients with epileptic and nonepileptic seizures are commonly encountered in clinical practice, and they can pose a difficult diagnostic problem. We present two cases that show the difficult task of differentiating between true epileptic and nonepileptic or psychogenic seizures in some patients. The clinical presentations were complex and the use of video-monitored EEG alone was insufficient to make definitive diagnoses. Ictal and interictal Tc-99m HMPAO brain perfusion SPECT imaging examinations were used to help establish the correct diagnoses. This report describes the advantage of using the brain perfusion SPECT imaging examination. The injection of stabilized Tc-99m HMPAO during an ictal event followed by appropriate medical therapy provides a method of obtaining a reasonable image of relative perfusion (activity) during the seizure. These images can then be compared with interictal examinations and an epileptic or nonepileptic focus may be localized. The Tc-99m HMPAO brain perfusion SPECT imaging study was helpful in establishing the correct diagnosis in both cases.

Topics: Adult; Anticonvulsants; Brain; Cerebrovascular Circulation; Delta Rhythm; Depression; Diagnosis, Differential; Diazepam; Electroencephalography; Epilepsy; Epilepsy, Complex Partial; Female; Frontal Lobe; Humans; Image Enhancement; Organotechnetium Compounds; Oximes; Psychophysiologic Disorders; Radiopharmaceuticals; Seizures; Subtraction Technique; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Video Recording

Previous studies of interictal regional cerebral blood flow (rCBF) in temporal lobe epilepsy have shown variable correlations with clinical measures. We used high spatial resolution hexamethyl propyleneamine oxime single photon emission computed tomography (HMPAO SPECT) in 80 consecutive patients with complex partial seizures (CPS), comparing results with those from a large series of normal subjects. Visual image analysis detected abnormalities of rCBF in 41 of 80 (51%; numeric analysis detected abnormalities in 38 of 80). Age at epilepsy onset was significantly younger in patients with temporal hypoperfusion (p = 0.002), and the frequency distribution of hypoperfusion versus age at epilepsy onset was reverse exponential. The results of numerical image analysis showed that degree of hypoperfusion did not vary with age at epilepsy onset. These data suggest a single insult operating early in life as a cause of temporal hypoperfusion, as has been shown for mesial temporal sclerosis (MTS). We could not demonstrate relationships with other clinical variables, including time since last seizure.

Topics: Adolescent; Adult; Age of Onset; Cerebrovascular Circulation; Child; Diagnosis, Differential; Electroencephalography; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Crossed cerebellar diaschisis (CCD) is a well-known brain SPECT finding in stroke patients. Two reports, however, have described supratentorial and contralateral cerebellar hyperperfusion (crossed cerebellar hyperperfusion) on ictal brain SPECT in epileptic patients. The purpose of this study was to assess the usefulness of crossed cerebellar hyperperfusion (CCH) for the detection of epileptic foci on ictal scan.. Twelve patients with complex partial seizures having characteristic clinical, electroencephalographic (EEG) and brain SPECT findings were included. Fifteen to 20 mCi 99mTc-HMPAO were injected intravenously during the seizure period or the aura for the ictal SPECT study. The SPECT findings were visually assessed to determine whether the finding of CCH was valuable in the localization of ictal foci.. Epileptic foci were found in the right temporal (n = 6), left temporal (n = 4), right occipital (n = 1) and left frontal (n = 1) areas. CCH was observed in 8 (75%) of the 12 patients. In two patients, contralateral cerebellar uptake was more obvious than that in the epileptic foci. In the interictal scans, cerebellar activity, which was increased in ictal period, was equalized in seven of eight patients, while perfusion was diminished in the remaining patient.. CCH is a frequent finding of ictal brain SPECT and may aid in the lateralization of epileptic foci.

Topics: Adolescent; Adult; Brain; Cerebellum; Cerebrovascular Circulation; Child; Child, Preschool; Electroencephalography; Epilepsy, Complex Partial; Female; Humans; Incidence; Male; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

For successful surgery for drug-resistant epilepsy the site of the seizure focus needs to be known exactly. The purpose of this study was to compare the evaluation of the regional cerebral blood flow (rCBF) (localization and degree of disturbances) by 99mTc-hexamethylpropyleneamineoxime (HMPAO) single photon emission computed tomography (SPECT) with computerized electroencephalographic topography (CET) and transmission computed X-ray tomography (CT) in partial epilepsy. The study included 20 patients with medically refractory complex partial seizures. Of the 20 patients included, 15 were studied interictally, four ictally and one in both states, interictally and ictally. 99mTc-HMPAO SPECT detected rCBF changes in 95% of the patients. Interictal studies demonstrated focal areas of hypoperfusion in 93% of the patients. Ictal studies demonstrated an area of hyperperfusion in all patients. Blood flow disturbances in deeper structures of the brain, such as basal ganglia, could be detected. The areas of abnormal 99mTc-HMPAO uptake were concordant, in localization, with CET in 85% of the patients. Abnormal data with CT scans were found in only 45% of the patients. Focal lesions were found in 20% of the patients by CT scans. 99mTc-HMPAO SPECT combined with CET may be a useful screening procedure prior to referral for invasive diagnostic procedures in future management with medically refractory complex partial seizures.

Topics: Adolescent; Adult; Brain Mapping; Cerebrovascular Circulation; Child; Computers; Electroencephalography; Epilepsy, Complex Partial; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

In selecting patients for epilepsy surgery, it is important to distinguish mesial temporal seizures from seizures originating in the posterolateral cortex. We studied ictal cerebral perfusion in five patients with complex partial seizures with clear posterior EEG ictal onsets and clinical seizures semiology suggesting seizure origin in the posterolateral cortex.. Ictal SPECT was performed during video EEG monitoring using 99mTc-HMPAO as a cerebral perfusion tracer and a rotating gamma camera to acquire images.. Three patterns of ictal hyperperfusion were seen: pattern A = temporoparieto-occipital junction extending into the lateral temporal cortex, involving the mesial temporal cortex and basal ganglia to a lesser degree and a small area of hyperperfusion in the contralateral parietal cortex (two patients); pattern B = pattern A but with no hyperperfusion of the mesial temporal cortex (one patient); and pattern C = localized hyperperfusion in the area of the temporoparieto-occipital junction (two patients).. Our results suggest distinct patterns of ictal perfusion in seizures with posterolateral ictal EEG onsets. Ictal SPECT may be useful in distinguishing such seizures.

Topics: Adolescent; Adult; Cerebral Cortex; Cerebrovascular Circulation; Electroencephalography; Epilepsy, Complex Partial; Female; Humans; Male; Organotechnetium Compounds; Oximes; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The gray-to-white matter ratio of technetium 99m-hexamethylpropyleneamine oxime (99mTc-HMPAO) in 14 anesthetized patients undergoing partial brain resection for treatment of complex partial seizures. The gray-to-white matter ratio of 99mTc-HMPAO was 1.8:1 (standard deviation 0.6) in the temporal lobe. Many of the biopsied specimens demonstrated histopathological abnormalities.

Topics: Adult; Cerebrovascular Circulation; Child; Cohort Studies; Epilepsy, Complex Partial; Female; Gliosis; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radiology, Interventional; Reoperation; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Most brain tumors show decreased uptake of blood flow tracers in brain SPECT imaging and in some cases meningiomas show increased uptake, mainly associated with high regional blood flow values. A reason for regionally increased tracer uptake is partial epilepsy when a tracer is injected during the ictal phase. We present a case of a histologically proven Grade II astrocytoma in the mesial part of the left temporal lobe that caused complex partial seizures. After tracer injection during a phase without signs of clinical seizure, markedly increased uptake of 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) occurred, although the tumor was partially calcified.

Topics: Adult; Astrocytoma; Brain Neoplasms; Epilepsy, Complex Partial; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The proper localization of regions of interest (ROIs) in Single Photon Emission Computed Tomography (SPECT) is an essential task. The limited spatial resolution makes it difficult to define regions by their structure. The particular problems are: 1) the difficulty to find the appropriate slice and its orientation in space; 2) the individual variation of the brain in dimension and shape. Referring to the basic work of Talairach and Szikla (1967), research is conducted to overcome these methodical problems in interpreting cranial computed tomography by using a proportional localization system. We analyzed four cases with focal motor seizures of different aetiology (tumour, hemorrhagic infarction, intracerebral hematoma, multifocal leukencephalopathy) by 99mTc HMPAO SPECT. The accumulation of the radiopharmacon was measured in ROIs which were delineated with the aid of the above mentioned system. The regions were selected in accordance to the autoradiographic study of penicillin induced epileptic seizures in animal experiments. Dependent on the severity of the clinical manifestation we were able to document the involvement of the supposed primary focus and of several related zones. We suggest that this approach should prove some usefulness in the examination of the interdependency of different brain areas.

Topics: Adult; Aged; Brain; Brain Mapping; Cerebral Cortex; Dominance, Cerebral; Epilepsies, Myoclonic; Epilepsy, Complex Partial; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Tc-99m HMPAO brain SPECT was performed in a patient who had partial complex seizures for 1 year after successful acyclovir treatment of biopsy-proven herpes simplex encephalitis 2 years earlier. In spite of antiepileptic medications, her seizures were intractable and occurred daily. Tc-99m HMPAO was administered intravenously while she was having subclinical seizures, and brain SPECT demonstrated an area of hyperperfusion in the right temporal lobe medially and in the contralateral cerebellum. This reverse of the crossed cerebellar diaschisis phenomenon in epileptic disorders has not previously been documented.

Topics: Adult; Brain; Cerebellar Diseases; Encephalitis; Epilepsy, Complex Partial; Female; Herpes Simplex; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Forty patients with epilepsy in the interictal period were studied with 99mTc (HM-PAO) SPECT brain imaging, EEG and CT scanning. Four cases of generalized epilepsy had normal findings on EEG, SPECT imaging and CT scanning. Two cases of childhood benign partial seizures had abnormal EEG, but the SPECT brain imagings were normal. Regional hypoperfusions of various extents were found in 20 of the 34 patients with complex partial seizures. Among the 34 patients, 17 had abnormal EEG and 8 had abnormal CT scans. A good topographic concordance between regional HM-PAO hypofixation and EEG foci was found (39.1%). Localization of the lesion by SPECT imaging and CT scan was coincident in 5 cases (27.8%). The correlation between these three examination methods is discussed.

Topics: Adolescent; Adult; Brain; Child; Child, Preschool; Electroencephalography; Epilepsy, Complex Partial; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Single photon emission computed tomography (SPECT) is increasingly being used as an adjunctive technique in the localisation of epileptogenic foci prior to surgery. As yet, few studies have been undertaken to establish the clinical associations of areas of reduced cerebral perfusion. Sixty-three consecutive patients (15 male, 48 female; median age 30 years, range 14-57 years) with medically intractable complex partial seizures (median/month 8, range 1-36) were investigated as outpatients. All had normal high resolution computerised X-ray tomography (CT) of brain. Twenty-seven (47%) exhibited significant perfusion defects on SPECT scanning with a rotating gamma camera system using Tc-99 HM-PAO. There were no significant differences between patients with normal and abnormal scans in terms of age at scanning or at onset of epilepsy or number of seizures. Patients with perfusion defects did, however, have longer median histories of epilepsy than those with normal scans (normal: 10 years, abnormal: 22 years; P = 0.01). Patients with abnormal scans were no more likely to have suffered febrile convulsions in early childhood. The correlation of abnormal SPECT scans with routine surface EEG recordings was poor with only 41% of cases showing clear agreement between the site of hypoperfusion and focal epileptic activity. It is not yet possible to predict clinically those patients who will exhibit perfusion defects on interictal TC-99 HM-PAO SPECT scanning.

Topics: Adolescent; Adult; Drug Resistance; Electroencephalography; Epilepsy, Complex Partial; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Brain perfusion was studied interictally with 99mTc-HM-PAO SPECT in 47 adult patients with partial epilepsy and normal brain CT. Epilepsy was classified as secondarily generalized in 24 patients, as complex partial in 17 patients and as simple partial in 6 patients. In 24 patients good seizure control was not achieved as these patients had a median number of 78 seizures during the preceding month, while in the rest of the patients seizure control was relatively good (less than 6 seizures during preceding month). Local brain hypoperfusion was observed in 41 or 87% of the patients. Hypoperfusion was located close to the EEG foci in 76% and equally often with temporal and frontal foci. Hypoperfusion and the EEG focus were located on the same side in 83%. Hypoperfusion was more frequent in secondarily generalized epilepsy and simple partial epilepsy than in complex partial epilepsy. Left-sided hypoperfusion was especially associated with complex partial epilepsy. It is likely that the significant epileptogenic brain area was revealed in patients with SPECT focus and EEG focus in the same brain area. In one of our patients MRI showed a small temporal lesion which on successful removal was identified as a low-grade oligodendroglioma. Abnormalities of regional brain uptake of HM-PAO demonstrated by SPECT in patients with partial epilepsy and normal brain CT give further information about pathophysiology in partial epilepsy; this may be of use both for selecting appropriate therapy and in presurgical localization of foci.

Topics: Adult; Brain; Brain Ischemia; Cerebral Cortex; Dominance, Cerebral; Electroencephalography; Epilepsies, Partial; Epilepsy, Complex Partial; Female; Humans; Male; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Adolescent; Epilepsy, Complex Partial; Humans; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Parietal Lobe; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We obtained single photon emission computed tomography (SPECT) scans with technetium-99M-hexamethyl-propylene-amine-oxime in 11 patients during 12 extratemporal partial seizures (9 simple partial, 3 complex partial). Ten ictal SPECT studies in 9 patients showed a focal region of hyperperfusion, which agreed with electrical seizure onset in 5 and with clinical seizure localization in 4 in whom ictal electroencephalography was not localized. Contralateral cerebellar and ipsilateral basal ganglia hyperperfusion was seen in 3 patients with a frontal lobe seizure focus. Ictal hyperperfusion was well circumscribed, unlike the diffuse hyperperfusion changes reported during temporal lobe seizures. This observation may indicate a different degree of seizure spread in temporal as opposed to extratemporal epilepsy. Because electroencephalographic localization is often elusive in extratemporal seizures, ictal SPECT may be very helpful for the localization of extratemporal foci.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Basal Ganglia; Cerebrovascular Circulation; Child; Child, Preschool; Electroencephalography; Epilepsies, Partial; Epilepsy, Complex Partial; Female; Frontal Lobe; Humans; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Parietal Lobe; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Technetium-HMPAO cerebral SPECT was performed interictally, immediately after an independent aura and ictally in a patient with complex partial seizures. Interictally there was a left inferior frontoparietal region of decreased perfusion. Ictally there were a number of foci of increased perfusion. The aura study showed focal hyperperfusion in the left frontal region and decreased perfusion in the adjacent cortex posteriorly, suggesting a zone of suppression. This may be the cause or effect of the nonprogression of the aura. The case raises the possibility that cerebral perfusion studies performed immediately after independent auras may localize seizure foci if ictal studies are nonfocal.

Topics: Adult; Cerebrovascular Circulation; Epilepsy, Complex Partial; Female; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A case of a 16 year old female patient with complex partial seizures has been presented. At the beginning of the illness the seizure focus had been located on the left temporal region according to the EEG finding and the clinical manifestation. Later on the epileptic focus changed sides to the right temporal region. The CT finding of this patient had been normal and the SPECT-HM-PAO method revealed a significant reduction of rCBF in the parietotemporal region of the left hemisphere, as well as the existence of a region of hyperperfusion in the right temporal lobe.

Topics: Adolescent; Brain; Cerebrovascular Circulation; Epilepsy, Complex Partial; Female; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon