Hot-water epilepsy in an adult: ictal EEG, MRI and SPECT features.

Reflex epilepsy constitutes a rare form of epileptic seizures. We observed a 20-year-old man who presented with seizures induced by immersion in hot water. The trigger stimulus was specific. Contrast CT scan and MRI were all normal, not revealing any structural lesion. Ictal EEG recorded during a hot bath showed focal epileptic discharges in the left temporo-occipital area. Interictal SPECT showed a hypometabolism in the same cerebral region. Neuroimaging studies were rarely performed in this uncommon type of epilepsy. Nevertheless, in our case the result of the SPECT suggests a localized functional disturbance in the emergence of the disorder.     

Correlation of SPECT, EEG and CT in patients with epilepsy. A preliminary report

Single photon emission computed tomography (SPECT) were performed in 14 patients with epilepsy. Among 6 patients with GTC, five had no focal abnormalities in EEG and CT scan, SPECT also showed no changes of regional cerebral perfusion. In another one patient EEG was normal, CT scan showed hypodensity in right frontal area, SPECT showed decreased regional cerebral perfusion in right frontotemporal area. AVM in frontal lobe was found at operation. In 3 patients with complex partial seizures and 5 patients with complex partial seizures and GTC, SPECT showed regional cerebral perfusion coincided with the area of focal epileptic form discharges in EEG. In one patient with complex partial seizures and GTC EEG showed right antero-temporal focal sharp wave discharges, discrete calcification in superior suprasella cisterna on CT, SPECT showed decreased regional perfusion in right temporal area, pathological examination revealed hematoma in right temporal lobe. SPECT is useful for localizing epileptogenic foci in epileptics.     

Brain SPECT, CT and EEG in 45 cases of epilepsy during the intermission

The regional cerebral blood flows (rCBF) in 45 cases of epilepsy during the interictal period were determined with brain SPECT. The results were compared those obtained with CT scans and EEG. 48.89% of the SPECT were found to be abnormal while 8.98% were suspected to be abnormal; the 35.71% of the CT scans were found to be abnormal; 16 cases (39.02%) were found to show focal abnormalities in the EEG while 9 cases (21.95%) had epileptic form discharge. SPECT seemed to show more significance in discovering the abnormalities in the epileptics during the interictal period than CT or EEG. However, the combined use of these three methods of examinations would be of greater help for identifying the focal abnormalities in epilepsy. Two of the 22 cases with abnormal SPECT had increased rCBF, whereas the other 20 cases had decreased rCBF. Among the 22 cases of abnormal SPECT and 4 cases of suspected abnormalities, the locations of the lesions as indicated with SPECT in 3 cases were not consistent with those as with CT. There were 5 cases in which the SPECT findings were not consistent with those in EEG.     

Neuronal migrational disorders in children with epilepsy: MRI,interictal SPECT and EEG comparisons

Single-photon emission computed tomography (SPECT) is being increasingly used in the investigation of children with epilepsy and may provide insights into congenital malformations. We analyzed the interictal⁹⁹Tc-HMPAOSPECT in a series of seven children with developmental disorders of the neocortex, each of them representing a prototype of cerebral dysgenesis, such as lissencephaly, pachygyria, opercular dysplasia, polymicrogyria, nodular heterotopia and band heterotopia. The patients studied were selected among 22 epileptic children with neuronal migrational disorders (NMDs). Interictal SPECT hypoperfusion was observed in the area homologous to MRI findings in all the examined children. In three patients low perfusion was also present in the opposite hemisphere, probably due to functional involvement or related to an underlying microdysgenesis, not revealed by structural imaging. EEG features were in agreement with low perfusion areas, both anatomically and functionally, in all children. In one patient hypoperfusion area differed from that revealed by MRI and EEG. Ictal SPECT has been considered a useful tool for accurately locating the epileptic focus. Nevertheless, interictal brain perfusion studies, together with proton magnetic resonance spectroscopy, may play an important role in detecting anatomic substrate in developmental disorders of the neocortex.     

Functional and morphological abnormalities in temporal lobe epilepsy: a comparison of interictal and ictal EEG,CT, MRI,SPECT and PET

Summary Ten patients suffering from drug-resistant complex partial seizures, with EEG abnormalities in the temporal region, were studied by means of non-invasive electrophysiological techniques (video-monitored, 16-channel, prolonged surface and sphenoidal EEG) as well as by imaging techniques (CT, MRI, SPECT and PET). Analysis of interictal and ictal EEG indicated the localization of epileptic activity in one side in eight cases. CT demonstrated focal abnormalities in three, SPECT in five unequivocally (in another four questionably, with the same lateralization as indicated by PET), MRI in eight, and PET in all cases. While only EEG provided specific diagnostic information, the focus definition was consistently good on PET images, poor on CT scans, and generally good but less consistent on MRI.     

EEG and neuroimaging localization in partial epilepsy.

We have studied cortical localization provided by surface and sphenoidal electroencephalograms (EEGs) and that of computed tomography (CT), magnetic resonance imaging (MR) and single photon emission tomography (SPECT) in 58 patients with partial epilepsy. Each patient had EEG, MR and SPECT during a hospitalization period of 1-2 weeks. CT scans were obtained either during the same period or had been performed in the preceding year. EEG evaluation consisted of 3-5 days of continuous monitoring including video-telemetry and ambulatory recording as well as conventional EEGs with special electrode placements. Additionally 33 of 58 patients (55%) who were potential surgical candidates had sphenoidal recordings. All patients had an abnormal EEG which showed evidence of epileptic hyperexcitability. EEG abnormality was localized in 43 patients (74%). Neuroimaging studies were focally abnormal in 38 patients (66%); 12 CT (21%), 29 MR (50%) and 24 SPECT (41%). Thirty four of 43 patients with localized EEG had at least 1 focally abnormal neuroimaging study (79%), whereas 4 of 15 (27%) patients with non-localized EEG did so. Twenty-eight of 29 patients with focal MR (97%), 11 of 12 patients with focal CT (92%) and 20 of 24 patients with focal SPECT (83%) had a concordant focal EEG. EEG and neuroimaging localization agreed in all 15 patients in whom both MR and SPECT disclosed a concordant focal abnormality. This study demonstrates a significant (P less than 0.005) correlation between surface/sphenoid EEG and neuroimaging localization in partial epilepsy.     

CT, MR and SPECT imaging in temporal lobe epilepsy.

Cranial computed tomography (CT) with modified temporal lobe technique, 0.15T magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) were carried out on 30 patients with intractable temporal lobe epilepsy. Lateralising abnormalities were detected in 21/30 patients overall. Specific lesions were detected by CT in one patient and by MRI in seven patients (in one case bilateral). In addition CT detected asymmetry of the sylvian fissures or temporal horns in 10 patients, and MRI in eight patients. SPECT detected lateralising abnormalities in 19 patients (in five cases bilateral). It is concluded that low field MRI is superior to modified CT in demonstrating subtle structural lesions of the temporal lobe. Functional scanning with SPECT supports the evidence of origin of an epileptic focus in a substantial proportion of cases and may improve the selection of patients for surgery.     

The usefulness of subtraction ictal SPECT coregistered to MRI in single- and dual-headed SPECT cameras in partial epilepsy

PURPOSE: To prove the clinical usefulness of SISCOM and compare SISCOM images derived from single- and dual-headed single-photon computed tomography (SPECT) cameras for localization of partial epileptic seizures. METHODS: We retrospectively studied 38 partial epilepsy patients, using subtraction SPECT coregistered to magnetic resonance imaging (MRI; SISCOM). SPECT imaging of the first 15 patients was performed by single-headed camera, and the next 23 patients by dual-headed camera. Side-by-side ictal-interictal SPECT evaluation and SISCOM images were blindly reviewed and classified as either localizing to one of 16 sites or nonlocalizing. A third reviewer evaluated cases of disagreement between primary reviewers. Results were compared with seizure localization by any of the following three traditional techniques: surgical outcome, invasive, and noninvasive video-EEG monitoring. The results from the single- and dual-headed SPECT cameras were compared. RESULTS: Reviewers localized areas of hyperperfusion with SISCOM images more often than with side-by-side SPECT evaluation (71.0 vs. 47.4%; p = 0.01). When we compared results of SPECT evaluation with traditional techniques, SISCOM showed greater concordance than side-by-side SPECT evaluation (60.53 vs. 36.84%; p = 0.006). There were no differences in localization between images derived from single- and dual-headed cameras. Concordance of seizure localization, compared with traditional techniques, also was not different between these groups [kappa = 0.38, 95% confidence interval (CI), 0.18-0.58] vs. kappa = 0.63, 95% CI (0.45-0.81)]. CONCLUSIONS: SISCOM is a worthwhile technique for preoperative evaluation in partial epilepsy patients and improves the sensitivity and specificity of seizure localization of SPECT images derived from both single- and dual-headed SPECT cameras.     

EEG mapping in partial epilepsy

Even if mathematic treatment of EEG signals by Fast Fourier Transformation (FFT) in cases of transient epileptic discharges is still controversial, this method has been applied to 21 cases of epileptic partial seizures. Examples are shown, and compared to CT-Scan data. In 17 cases, EEG mapping identified alterations of basic activities upon a definite area. In addition, a focal peak of maximal alterations displacing itself into the limits of the whole epileptogenic area is demonstrated; it is furthermore suggested that the power spectrum keeps, especially during seizures, a peculiar ("combing") morphology, possibly specific of epileptic diseases.     

Correlation of ictal EEG and SPECT studies in patients of intractable epilepsy with normal MRI

Identification of the epileptic focus is the most important requirement for a successful surgical outcome in intractable epilepsy. Patients with normal MRI on high-resolution imaging pose a significant challenge in this regard. We tried to identify the epileptic focus using interictal / ictal SPECT and ictal EEG patterns in 14 patients with normal MRI. Rhythmic ictal onset activity helped to identify a single focus in 10 patients (71.43%). Inter ictal SPECT detected a focus corresponding to ictal EEG in 6 out of 10 patients (60%) in whom the test was performed. Ictal SPECT done in 5 patients correctly identified the focus in all patients (100%). Our data indicate that it is possible to obtain localization in patients with normal MRI using a combination of ictal EEG patterns and an ictal SPECT study.     

CT,MRI and SPECT neuroimaging in status epilepticus with simple partial and complex partial seizures: case report

Summary A 35-year-old female patient suffering from epilepsy was examined during status epilepticus with simple partial and complex partial seizures by means of EEG, CT, MRI and ictal SPECT. All these examinations showed focal abnormalities with identical location due to oedema and hypervascularisation; these were, however, absent during examinations carried out before and after status epilepticus.     

CT、MRI和EEG对病毒性脑炎的诊断价值

目的探讨CT、MRI和EEG对病毒性脑炎的诊断价值。方法回顾性分析137例病毒性脑炎的临床资料，统计CT、MRI和EEG阳性率检查结果。结果137例全部检测分析。（1）CT的检出阳性率16、8％，MRI为76．4％，EEG为85．12％；（2）MRI与CT比较，两者检出阳性率有显著性差异（x^2=65．56，P〈0.005），EEG与CT比较栓出阳性率有显著性差异（x^2=81．55，P〈0.005）；EEG与MRI比较检出阳性率无差异（x^2=0．34，P〉0．05）。结论MRI和EEG检查对病毒性脑炎的诊断价值较大，病毒性脑炎做CT无多大意义。     

Jansky-Bielschowsky variant disease: CT, MRI, and SPECT findings.

Six patients with a variant type of Jansky-Bielschowsky (JBVD) disease were examined using 3 different imaging methods. Five of the patients underwent computed tomography, 4 magnetic resonance imaging, and 5 single photon emission computed tomography. All patients had brain atrophy that was most severe in the cerebellum. Magnetic resonance imaging demonstrated the parenchymal abnormalities well; all patients had hyperintense periventricular white matter, especially around the bodies and atria of the lateral ventricles, and a significant decrease in signal intensity in the thalami and/or putamina. Single photon emission computed tomography disclosed hypoperfusion of the cerebellum in all patients. Neuroimaging examinations are valuable in the diagnosis of JBVD. It may be difficult to divide patients with neuronal ceroid-lipofuscinosis disorders into clinical subtypes in the early stage of the disease. Magnetic resonance imaging, especially when combined with a typical clinical pattern, makes the diagnosis of JBVD highly likely. Radiologic examinations of the brain may also prove important in following the progression, as well as in investigating the pathophysiology, of the disease.     

Comparison of voxel-based 3-D MRI analysis and subtraction ictal SPECT coregistered to MRI in focal epilepsy

While voxel-based 3-D MRI analysis methods as well as assessment of subtracted ictal versus interictal perfusion studies (SISCOM) have proven their potential in the detection of lesions in focal epilepsy, a combined approach has not yet been reported. The present study investigates if individual automated voxel-based 3-D MRI analyses combined with SISCOM studies contribute to an enhanced detection of mesiotemporal epileptogenic foci. Seven consecutive patients with refractory complex partial epilepsy were prospectively evaluated by SISCOM and voxel-based 3-D MRI analysis. The functional perfusion maps and voxel-based statistical maps were coregistered in 3-D space. In five patients with temporal lobe epilepsy (TLE), the area of ictal hyperperfusion and corresponding structural abnormalities detected by 3-D MRI analysis were identified within the same temporal lobe. In two patients, additional structural and functional abnormalities were detected beyond the mesial temporal lobe. Five patients with TLE underwent epileptic surgery with favourable postoperative outcome (Engel class Ia and Ib) after 3-5 years of follow-up, while two patients remained on conservative treatment. In summary, multimodal assessment of structural abnormalities by voxel-based analysis and SISCOM may contribute to advanced observer-independent preoperative assessment of seizure origin.     

EEG and CT findings in poststroke epilepsy

The present study was undertaken to assess the diagnostic value of CT in patients with poststroke epilepsy, related to EEG in revealing the factors contributing to the development of epileptic fits. The EEG and CT results were evaluated in 50 patients with poststroke epilepsy and compared with those of 50 patients without epilepsy after stroke. Cortical and extensive lesions involving the cortex were more frequent among patients with poststroke epilepsy. Sparing of certain parts of cerebral cortex was observed within vasogenic lesion. This type of change was only found in the poststroke epilepsy group and may be responsible for development of epileptic fits. It seems that CT has a higher diagnostic value than EEG in evaluating the risk of development of poststroke epilepsy.     

Comparison of PET, MRI, and CT with pathology in a proven case of Alzheimer's disease

Positron emission tomography (PET) with fluorodeoxyglucose (FDG), magnetic resonance imaging (MRI), and CT were carried out in a patient with Alzheimer's disease 16 months before he died. At autopsy, the gross appearance of the brain correlated with MRI and CT, which showed some regional atrophy. These were much less revealing than PET, which correlated with microscopic findings of neuronal loss and proliferation of glia. In areas of moderately impaired local cerebral metabolic rate of glucose, as revealed by reduced FDG uptake, there was some gliosis, primarily around the numerous senile plaques. In areas of severe metabolic impairment, there was a profound loss of neurons, extensive gliosis, and a diminished appearance of plaques. PET-FDG is a better measure of the severity of Alzheimer's disease than MRI or CT, because it reflects the degree of neuronal pathology.