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.     

视频脑电图与发作期SPECT对痫灶定位的对比研究

Objective To investigate the value of ictal single photon emission computed tomography and VEEG in localization of epileptogenic foci for intractable epilepsy. Method The data of ictal SPECT and VEEG were reviewed from 48 patients with intractable epilepsy, all the results were analyzed and compared with each other. Surgical treatment were performed on 48 cases. Results The positive rate of ictal SPECT and VEEG localization was 94% and 96% respectively. The rate of complete coincidence of the two methods was 46% (22/48), partial coincidence was 29% (14/48). Comparing ictal SPECT with video EEG in the ratio of lateral and focal epileptic foci localization, twenty - seven of 48 patients had an Engel Class Ⅰ outcome after surgery and an additional ten patients had rare seizure (Engel Class Ⅱ), and eight patient had a decrease in seizure frequency (Engel Class Ⅲ) , no marked chang (Engel Class Ⅳ) in three patients. In Engel Class Ⅰ and Class Ⅱ outcome cases, there were 33 (out of 37) cases came from its coincidence of ictal SPECT and VEEG localization. Conclusions VEEG combined with ictal SPECT can increase the accuracy on localization of epileptogenic foci for intractable epilepsy.     

视频脑电图与发作期SPECT对痫灶定位的对比研究

目的 探讨视频脑电图(VEEG)、发作期SPECT在术前痫灶定位中的作用.方法 回顾性对比分析48例难治性癫痫患者术前所行长程VEEG与发作期SPECT定位的情况,比较两者定位的一致性.结果 发作期SPECT定位阳性率为94%,VEEG为96%.两者完全一致占46%,部分一致占29%,完全不一致占25%.阳性率及定侧率差异无统计学意义(P＞0.05),局灶定位差异有统计学意义(P＜0.01).随访结果显示48例患者中Engel Ⅰ级27例,Ⅱ级10例,Ⅲ级8例,Ⅳ级3例;其中EngelⅠ～Ⅱ级的37例中33例来自两者定位一致的患者.结论 发作期SPECT与VEEG检查有较高的一致性,两者联合应用优势互补,可提高定位准确性,获得良好的手术疗效.     

视频脑电图与发作期SPECT对痫灶定位的对比研究

Objective To investigate the value of ictal single photon emission computed tomography and VEEG in localization of epileptogenic foci for intractable epilepsy. Method The data of ictal SPECT and VEEG were reviewed from 48 patients with intractable epilepsy, all the results were analyzed and compared with each other. Surgical treatment were performed on 48 cases. Results The positive rate of ictal SPECT and VEEG localization was 94% and 96% respectively. The rate of complete coincidence of the two methods was 46% (22/48), partial coincidence was 29% (14/48). Comparing ictal SPECT with video EEG in the ratio of lateral and focal epileptic foci localization, twenty - seven of 48 patients had an Engel Class Ⅰ outcome after surgery and an additional ten patients had rare seizure (Engel Class Ⅱ), and eight patient had a decrease in seizure frequency (Engel Class Ⅲ) , no marked chang (Engel Class Ⅳ) in three patients. In Engel Class Ⅰ and Class Ⅱ outcome cases, there were 33 (out of 37) cases came from its coincidence of ictal SPECT and VEEG localization. Conclusions VEEG combined with ictal SPECT can increase the accuracy on localization of epileptogenic foci for intractable epilepsy.     

Correlation between provoked ictal SPECT and depth recordings in adult drug-resistant epilepsy patients

PURPOSE: To correlate ictal hyperperfusion single-photon emission computed tomography (SPECT) area during provoked seizures to the epileptogenic zone (EZ), as defined by depth recordings in adult drug-resistant patients. METHODS: We included in the study eight drug-resistant epilepsy patients, subjected to both noninvasive and invasive (stereo-electroencephalography, SEEG) presurgical evaluation in the Epilepsy Surgery Center of the Catholic University in Rome, from 2001 to 2003. All patients were subjected to interictal and provoked ictal SPECT scans during scalp video-EEG monitoring. The ictal hyperperfusion area assessed by visual image analysis and, when possible, by statistical parametric mapping (SPM), was compared with the EZ, as assessed by SEEG, to define whether they colocalized. RESULTS: For each provoked seizure, we obtained a SPECT hyperperfusion area. In five patients, the SPECT hyperperfusion area was included in the EZ as assessed by SEEG. The effectiveness of provoked SPECT was confirmed by comparison with SEEG data, SPM analysis (four patients), and spontaneous ictal SPECT (two patients). Our data were obtained in adult drug-resistant epilepsy patients whose EZ was either located in or extended to extratemporal regions in all but two patients. CONCLUSIONS: Provoked ictal SPECT confirmed its efficacy and accuracy in the presurgical evaluation because of the colocalization to the EZ. Although the low number of patients precluded any statistical correlation with the surgical outcome, it is worth pointing out that the five patients in whom the hyperperfusion area was included in the EZ showed very satisfactory results.     

Magnetoencephalography and ictal SPECT in patients with failed epilepsy surgery

Objective

Selected patients with intractable focal epilepsy who have failed a previous epilepsy surgery can become seizure-free with reoperation. Preoperative evaluation is exceedingly challenging in this cohort. We aim to investigate the diagnostic value of two noninvasive approaches, magnetoencephalography (MEG) and ictal single-photon emission computed tomography (SPECT), in patients with failed epilepsy surgery.

Correlation between temporal pole MRI abnormalities and surface ictal EEG patterns in patients with unilateral mesial temporal lobe epilepsy.

OBJECTIVE: The objective of this retrospective study is to analyze ictal patterns observed during continuous Video-EEG monitoring in patients with temporal lobe epilepsy (TLE) due to unilateral hippocampal sclerosis (HS), and to correlate these EEG patterns to temporal pole abnormalities observed on magnetic resonance imaging exams. METHODS: We analyzed 147 seizures from 35 patients with TLE and unilateral HS. Ictal patterns were classified and correlated to signal abnormalities and volumetric measures of the temporal poles. Volume differences over 10% were considered abnormal. RESULTS: The most frequent type of ictal pattern was rhythmic theta activity (RTA), encountered in 65.5% of the seizures. Rhythmic beta activity (RBA) was observed in 11% of the seizures, localized attenuation in 8%, interruption of epileptiform discharges in 6%, repetitive discharges in 5.5%, and rhythmic delta activity (RDA) in 4%. Sixty-six percent of the patients presented signal abnormalities in the temporal pole that were always ipsilateral to the HS. Sixty percent presented significant asymmetry of the temporal poles consisting of reduced volume that was also always ipsilateral to HS. Although patients with RTA as the predominant ictal pattern tended to present asymmetry of temporal poles (p=0.305), the ictal EEG pattern did not correlate with temporal pole asymmetry or signal abnormalities. CONCLUSIONS: RTA is the most frequent initial ictal pattern in patients with TLE due to unilateral HS. Temporal pole signal changes and volumetric reduction were commonly found in this group of patients, both abnormalities appearing always ipsilateral to the HS. However, neither temporal pole volume reduction nor signal abnormalities correlated with the predominant ictal pattern, suggesting that the temporal poles are not crucially involved in the process of epileptogenesis.     

Blindness as an ictal phenomenon: investigations with EEG and SPECT in two patients suffering from epilepsy

Summary Blindness is a rare ictal phenomenon in epileptic seizures. It can occur as an aura, as the seizure itself, or postictally. We investigated two such patients, in one of whom blindness manifested as an aura prior to tonic clonic seizures; the interictal EEG exhibited a spike-wave focus bioccipitally. In the second patient blindness occurred postictally. An ictal SPECT, carried out at the onset of the seizure demonstrated marked hyperperfusion in both occipital regions.     

发作期SPECT在儿童难治性癫痫外科治疗中的应用

目的评估发作期SPECT在儿童难治性癫痫外科治疗术前评估中的价值.方法对11例曾经癫痫外科治疗前行发作期SPECT检查的患儿进行了回顾性分析.11例患者中有6例患者是局限性灰质异构（FCD）,2例是缺血后的继发性损伤,1例是脑炎后损伤,还有2例病理诊断不明.11例患者术前均行发作间期SPECT或PET检查及发作期SPECT检查,通过对比观察两次检查的差异与手术切除区域进行对比.11例患者中9例患者是在癫痫发作过程中注射的SPECT示踪剂,另2例患者是在发作结束后立刻注射SPECT示踪剂.结果发作期SPECT显示：10例患者发作期有局部血流灌注增强,有1例患者未发现局部血流灌注增强.11例患者中有4例患者的颅内脑电记录提示与发作期SPECT有同样的异常部位,3例显示与核磁共振检查结果相一致;6例患者行局部切除术,另外5例患者由于不能局限病变的位置,最终进行多处软膜下横切手术.6例局部切除术患者术后发作完全消失,5例多处软膜下横切手术患者中,术后2例发作消失,2例发作显著减少,1例无效.结论发作期SPECT在儿童局限性癫痫术前评估中具有很大价值,对癫痫灶位置判断的准确性好.     

Interictal PET and ictal subtraction SPECT: Sensitivity in the detection of seizure foci in patients with medically intractable epilepsy

Purpose: Interictal positron emission tomography (PET) and ictal subtraction single photon emission computed tomography (SPECT) of the brain have been shown to be valuable tests in the presurgical evaluation of epilepsy. To determine the relative utility of these methods in the localization of seizure foci, we compared interictal PET and ictal subtraction SPECT to subdural and depth electrode recordings in patients with medically intractable epilepsy. Methods: Between 2003 and 2009, clinical information on all patients at our institution undergoing intracranial electroencephalography (EEG) monitoring was charted in a prospectively recorded database. Patients who underwent preoperative interictal PET and ictal subtraction SPECT were selected from this database. Patient characteristics and the findings on preoperative interictal PET and ictal subtraction SPECT were analyzed. Sensitivity of detection of seizure foci for each modality, as compared to intracranial EEG monitoring, was calculated. Key Findings: Fifty‐three patients underwent intracranial EEG monitoring with preoperative interictal PET and ictal subtraction SPECT scans. The average patient age was 32.7 years (median 32 years, range 1–60 years). Twenty‐seven patients had findings of reduced metabolism on interictal PET scan, whereas all 53 patients studied demonstrated a region of relative hyperperfusion on ictal subtraction SPECT suggestive of an epileptogenic zone. Intracranial EEG monitoring identified a single seizure focus in 45 patients, with 39 eventually undergoing resective surgery. Of the 45 patients in whom a seizure focus was localized, PET scan identified the same region in 25 cases (56% sensitivity) and SPECT in 39 cases (87% sensitivity). Intracranial EEG was concordant with at least one study in 41 cases (91%) and both studies in 23 cases (51%). In 16 (80%) of 20 cases where PET did not correlate with intracranial EEG, the SPECT study was concordant. Conversely, PET and intracranial EEG were concordant in two (33%) of the six cases where the SPECT did not demonstrate the seizure focus outlined by intracranial EEG. Thirty‐three patients had surgical resection and >2 years of follow‐up, and 21 of these (64%) had Engel class 1 outcome. No significant effect of imaging concordance on seizure outcome was seen. Significance: Interictal PET and ictal subtraction SPECT studies can provide important information in the preoperative evaluation of medically intractable epilepsy. Of the two studies, ictal subtraction SPECT appears to be the more sensitive. When both studies are used together, however, they can provide complementary information.     

MRI正常的难治性癫痫的手术疗效及相关因素分析

目的 探讨颅脑MRI检查正常的难治性癫痫患者的手术疗效及提示手术预后的相关因素.方法 1997年8月至2010年10月间,对解放军第四○一医院手术治疗的难治性癫痫病例(出院≥1年),且经颅脑MRI检查未见异常的患者跟踪随访1-6年,并对获完整资料的62例患者进行分析.Engel分级Ⅰ、Ⅱ级视为预后良好,Ⅲ、Ⅳ级为预后不良,分析相关因素与手术疗效的关系.结果 Engel分级Ⅰ、Ⅱ级共47例,占76％.颞叶切除较额叶及顶枕叶皮质致痫灶切除的预后良好率高(P＜0.01);而额叶及顶枕叶皮质致痫灶切除术后疗效差异无统计学意义;术前轻度发作的较重度发作组术后预后良好(P＜0.05);手术后晚期出现发作的较早期出现发作预后不良(P＜0.05);病理检查异常较病理正常的术后预后良好(P＜0.05);手术时患者的年龄与预后无关.结论 颅脑MRI正常的难治性癫痫,颞叶切除较颞叶外致痫灶切除预后良好,术前发作轻的、术后病理检查异常的也提示预后良好,手术后晚期出现发作者则预后不良.     

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.     

难治性癫癎MRJ颞极信号特点与癫癎的相关性分析

目的探讨难治性癫癎MRI颞极信号特点与致癎区相关性。方法回顾性分析339例难治性癫癎病人MRI颞极信号特点。根据癫癎发作起始区将研究对象分为颞叶癫癎、额叶癫癎、顶叶癫癎、枕叶癫癎、岛叶癫癎、多脑叶癫癎等6类。结果颞极信号异常187例,颞极信号异常侧别与致癎区侧别一致率达98．93％,颞极信号异常与癫癎类型或致癎区有关（χ2=311．339,P〈0．001）。与颞叶外癫癎比较,颢极信号异常更常见于颞叶癫癎。结论在各类癫癎中均可出现MR／颞极信号异常,但更常见于颞叶癫癎。颞极信号异常侧常与致癎区侧别一致．特别是颞叶癫癎。     

Repeated ictal SPECT in partial epilepsy patients: SISCOM analysis

Purpose: Ictal single‐photon emission computerized tomography (SPECT) is often nonlocalized in patients with partial epilepsy. We repeated ictal SPECT in patients with partial epilepsy whose first ictal SPECT was nonlocalized. We also performed subtraction ictal SPECT coregistered to magnetic resonance imaging (MRI) (SISCOM) to test the localizability of ictal SPECT. Methods: We recruited 69 patients with partial epilepsy (33 male and 36 female, mean plus or minus standard deviation age 29.5 ± 12.2 years), who had a repeated ictal SPECT. Ictal‐interictal SPECT subtractions were performed, and the subtracted SPECTs were coregistered with their brain MRI studies. SISCOM results were considered to be localizing when the results were concordant with the final location of the epileptic focus, as determined by the presurgical evaluation. We compared seizure duration, tracer injection time, interictal and ictal scalp electroencephalography (EEG) patterns, presence and time of secondary generalization, and epilepsy classification between the localized and nonlocalized SISCOM groups. Key Findings: The SISCOM results of the second ictal SPECT were localized in 43 (62.3%) patients and nonlocalized in 26 (37.7%) patients. In the second ictal SPECT, the radiotracer injection time was significantly shorter in the localized group (25.1 ± 8.9 s), as compared to the nonlocalized group (49.2 ± 55.8 s) (p = 0.008). Furthermore, the radiotracer injection time of the second ictal SPECT was significantly shorter than the first ictal SPECT, only in the localized group (36.8 ± 23.8 s in the first and 25.1 ± 8.9 s in the second ictal SPECT in the localized group, p = 0.004). The percent injection time ([(tracer injection time−seizure onset time)/total seizure duration] × 100%) in the second SPECT was significantly shorter in the localized group, as compared to the nonlocalized group (37.9 ± 23.0% in the localized group and 72.3 ± 46.2% in the nonlocalized group, p < 0.001). The localized ictal EEG patterns at the time of injection were more frequent in the localized SISCOM group. The secondary generalization of seizures at the time of injection was more frequent in nonlocalized groups. Significance: Repeated ictal SPECT with SISCOM analysis is helpful for localizing an epileptic focus in patients with partial epilepsy who have a nonlocalized first ictal SPECT. The most important factor for increasing the localizability of repeated ictal SPECT is early injection time and a localizing ictal EEG pattern at the time of radiotracer injection.     

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.     

Micturition induced seizures: ictal EEG and subtraction ictal SPECT findings

We report an 8-year-old girl with seizures induced by micturition. Her seizures were characterized by extension of upper extremities with preserved consciousness. Magnetic resonance imaging and interictal electroencephalograms were normal. Ictal electroencephalogram showed low voltage fast waves without clear focal features followed by frontal dominant rhythmic multiple spikes. Subtraction ictal single photon emission computed tomography revealed a significant increase in blood flow in the mesial frontal area.     

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.     

Brain perfusion SPECT and EEG findings in children with autism spectrum disorders and medically intractable epilepsy

Objective: We performed brain perfusion single-photon emission computed tomography (SPECT) to detect the abnormal brain region in children with both autism spectrum disorders (ASD) and medically intractable epilepsy. Methods: Fifteen children aged 4–16 years underwent multimodal examinations (MRI, interictal and/or ictal ECD-SPECT, EEG and MEG) to investigate their indications for surgical treatment. All children were diagnosed with ASD according to DSM-IV criteria and intractable epilepsy. Despite medical treatment for more than a year, all experienced at least one seizure per month. All had no underlying basic disorders. Each SPECT result was statistically analyzed by comparing with standard SPECT images obtained from our institute (easy Z-score imaging system; eZIS). The relationship between the eZIS pattern and EEG abnormalities or clinical symptoms was investigated. Results: All children showed focal abnormal patterns on eZIS and focal spikes on EEG. In all children, eZIS revealed a mixed hypoperfusion pattern, especially in the prefrontal cortex, medial frontal cortex, anterior cingulate cortex, medial parietal cortex, and/or anterior temporal cortex. In seven of 12 children who underwent interictal SPECT studies, areas of hypoperfusion were related to the focus observed on EEG; in six children, the focal EEG spikes represented areas of hyperperfusion. The children were divided into two groups according to the main type of hypoperfusion patterns seen on eZIS; medial-cingulate type and temporal type. No significant relationship was observed between the areas of hypoperfusion and clinical symptoms. eZIS showed the epileptic focus clearly on ictal SPECT. Conclusions: SPECT was useful to detect the abnormal brain region not only in searching for the epileptic focus but also in assessing the low or high functioning region of the brain.