Search

Purpose: Children with drug-resistant focal epilepsy have a compromised quality of life. Epilepsy surgery can control or significantly reduce the seizures. We assessed and compared the usefulness of PISCOM, a new nuclear imaging processing technique, with SISCOM and 18F-FDG PET (FDG-PET) in pre-surgical evaluation of paediatric drug-resistant focal epilepsy.Methods: Twenty-two children with pharmcorefractory epilepsy, mainly extratemporal, who had undergone pre-surgical assessment including SISCOM and FDG-PET and with postsurgical favorable outcome (Engel class I or II) for at least two years, were included in this proof-of-concept study. All abnormalities observed in SISCOM, FDG-PET and PISCOM were compared with each other and with the known epileptogenic zone (EZ) based on surgical treatment, histopathologic and surgical outcome results. Global interobserver agreement, Cohen's Kappa coeficient and PABAK statistic were calculated for each technique.Results: PISCOM concordance with the known EZ was significantly higher than SISCOM (p<0.05), and no statistically differences were found with FDG-PET. PISCOM showed successful identification in 19 of 22 cases (86%), successful concordant with FDG-PET in 17 (77%), and SISCOM in 11 (50%). If we consider PISCOM and FDG-PET results together, both techniques successfully localized the known EZ in all cases. The measures of agreement between two experts in nuclear medicine were higher in PISCOM than in SISCOM and FDG-PET.Conclusion: PISCOM could provide complementary presurgical information in drug-resistant paediatric focal epilepsy, particularly in cases in which FDG-PET is doubtful or negative, replacing SISCOM and sparing the use of interictal SPECT. [ABSTRACT FROM AUTHOR]

Introduction: The diagnosis of psychogenic non-epileptic seizures (PNES) can often be challenging. When video-electroencephalography (EEG) is not conclusive, single-photon emission computed tomography (SPECT) can be useful by quantifying changes in regional cerebral blood flow (rCBF).Methods: We conducted a retrospective case-control study in adult patients with pharmacoresistant temporal lobe epilepsy (TLE). Those patients with an ictal SPECT obtained during an event finally diagnosed as PNES were included as cases (PNES+). The control group consisted of patients with TLE without PNES (PNES-). Clinical episodes were analysed and classified according to PNES subtypes. Subtraction ictal SPECT coregistered to MRI (SISCOM) analysis was performed for the detection of areas with significant changes in perfusion compared to individual interictal studies. Group comparisons in SPM12 included paired t-tests of ictal vs. interictal studies in each group of temporal lobe seizures and PNES events.Results: Ten patients with TLE and PNES were included. We found no patterns of regional hyperperfusion typical of TLE seizures during the PNES events. In two of these cases, an ictal SPECT during a confirmed epileptic seizure was also obtained, showing antero-mesial temporal lobe hyperperfusion. Group comparisons between ictal and interictal SPECTs showed increased rCBF in the temporal lobe with reduced perfusion in the default mode network areas and cerebellum during temporal lobe seizures in PNES- patients and decreased perfusion restricted to the posterior parietal cortex without significant rCBF increases in PNES events.Conclusions: Ictal SPECT can be a helpful tool to characterize rCBF changes in PNES and for differential diagnosis with seizures in TLE patients. [ABSTRACT FROM AUTHOR]

La neuroimagen funcional de la PET con 18F-FDG y la SPECT de perfusión son exploraciones cada vez más imprescindibles para la localización prequirúrgica del foco epileptógeno. Presentamos el caso de un paciente varón de 18 años con crisis epilépticas refractarias a tratamiento antiepiléptico. La RM mostró displasia en córtex insular posterior derecho. El SISCOM detectó un aumento focal de captación en cíngulo frontoparietal izquierdo y en la PET-FDG se visualizaba una distribución normal del radiotrazador. Se realizó resección insular posterior derecha, cuyo resultado anatomopatológico fue ganglioglioma grado I de la clasificación de la OMS. El paciente mostró una evolución posquirúrgica favorable, encontrándose libre de crisis desde hace 5 años (Engel I). Un análisis retrospectivo de este caso con 2 nuevos métodos de procesamiento de imágenes: PET-Analysis y PISCOM, permitió localizar correctamente el foco epileptógeno en córtex insular posterior derecho. Functional neuroimaging with positron emission tomography with 18F - fluorodeoxyglucose (PET-18F-FDG) and perfusion single photon emission computerized tomography (SPECT) are increasingly more essential for presurgically locating the epileptogenic focus. We present the case of an 18-year-old male with epileptic seizures refractory to antiepileptic treatment. Magnetic resonance (MR) showed dysplasia in the posterior right insular cortex. Subtraction of ictal SPECT co-registered to MR (SICOM) detected a focal increase of uptake in the left fronto-parietal cingulate and PET-FDG showed normal distribution of the radiotracer. The posterior right insula was resected with histopathological results of grade I ganglioglioma according to the World Health Organization classification. The patient made favourable post-surgical progress, and remains seizure-free after 5 years (Engel I). Retrospective analysis of this case with two new image processing methods (PET analysis and PET interictal subtracted ictal SPECT coregistered with MR [PISCOM]) correctly localized the epileptogenic focus in the posterior right insular cortex. [ABSTRACT FROM AUTHOR]

Purpose: The non-invasive localisation of insular lobe epilepsy is a challenge. We aimed to determine if ictal SPECT is a reliable adjunctive test in insular cases and to explore its role in the tailoring of intracranial strategies.Method: From a dataset of patients who underwent SEEG between December 2012 and December 2016, we collected patients with focal insular onset epilepsy. We examined semiology, EEG, PET and SPECT hyperperfusion pattern with SISCOM. We also reviewed relevant literature.Results: 5 patients were identified, 4 females, from a dataset of 51 patients. Median age of seizure onset was 8 years old (8 months to 10 years). All patients had an ictal SPECT during pre-surgical work-up: median injection time was 7 s (3-17 sec) from clinical onset, and median seizure duration was 42 s (11-85 sec). Insula cortex showed focal hyperaemia in four patients, all bilateral, with the greatest hyperperfusion contralateral to the ictal onset in two cases, using SISCOM threshold at 1.5 standard deviation. Other sites with hyperaemia included basal ganglia and middle temporal gyrus. The SEEG confirmed insular onset seizures in all the cases. All patients had epilepsy surgery and were seizure free at 21 to 50 months follow up. The results from the literature review showed frequent hyperperfusion in structures outside insula and frequently over the contralateral hemisphere.Conclusions: This study highlights the technical limitations of SPECT when attempting to assess seizures arising from the insula. Our findings and the literature show ictal SPECT can be localising but falsely lateralising in seizures arising from the insula. [ABSTRACT FROM AUTHOR]

Purpose: Demonstrating cerebral blood flow changes during seizures, ictal-interictal single photon emission computed tomography (SPECT) with co-registration to MRI (SISCOM) reflects brain activation and its pathways of spread. To investigate subcortical ictal hyperperfusion patterns during focal seizures, we retrospectively reviewed SISCOM analysis of patients who became seizure-free after cortical resection. Our aim was to evaluate the relationship between epileptogenic zones and subcortical hyperperfusion.Method: 67 patients were identified as having SISCOM evaluation and having remained seizure-free for at least one year after surgical resection. SISCOM analysis was blindly reviewed for localization of basal ganglia (BG), thalamic (TN) and cerebellar (CH) hyperperfusion based on three different thresholds. Subcortical activation and epilepsy characteristics were then compared between patients. For a given region of interest and threshold, the sensitivity, specificity and positive and negative predictive value for correct lateralization of the epilepsy side was calculated.Results: Depending on the threshold used, BG hyperperfusion was found in 37.3-73.9% of patients, TN hyperperfusion in 31.3-68.1% and CH hyperperfusion in 13.5-29%. For a threshold of 1.5, the best predictive positive value for correct lateralization of the epilepsy side was obtained with BG/CH coactivation (89%). For a threshold of 2.0 and 2.5, it was obtained with BG/TN coactivation (88%) and BG activation (82%), respectively.Conclusion: Subcortical SISCOM hyperperfusion could offer additional clues in terms of lateralization. [ABSTRACT FROM AUTHOR]

Objective We evaluated the impact of radiotracer injection latency and post-injection seizure duration on subtraction ictal SPECT co-registered to MRI (SISCOM) test performance in identifying the epileptogenic zone (EZ) in children with drug-resistant epilepsy who had undergone a resective epilepsy surgery. Methods SISCOM concordance with the EZ was retrospectively reviewed to evaluate its performance in 113 children. The impact of radiotracer injection latency and post-injection seizure duration was evaluated for their predictive value of SISCOM localization accuracy. Results The overall sensitivity and specificity of SISCOM in identifying an EZ was 64.8% (95%CI = 50.6–77.3) and 40.7% (95%CI = 28.1–54.3). The positive likelihood ratio and diagnostic odd ratio was 1.09 (95%CI = 0.80–1.48) and 1.26 (95%CI = 0.59–2.71), respectively. Logistic regression showed that injection latency and post-injection seizure duration did not significantly predict the probability of true positive SISCOM (p-value = 0.45 and 0.29, respectively). Conclusion Radiotracer injection latency and post-injection seizure duration were not shown to have a statistical significant impact on SISCOM performance in identifying the EZ. Significance This study demonstrates that further study of factors contributing to the performance of SISCOM in EZ identification in children is needed. [ABSTRACT FROM AUTHOR]

Purpose Localization of seizures in frontal lobe epilepsy using the 10–20 system scalp EEG is often challenging because neocortical seizure can spread rapidly, significant muscle artifact, and the suboptimal spatial resolution for seizure generators involving mesial frontal lobe cortex. Our aim in this study was to determine the value of visual interpretation of 76 channel high density EEG (hdEEG) monitoring (10-10 system) in patients with suspected frontal lobe epilepsy, and to evaluate concordance with MRI, subtraction ictal SPECT co-registered to MRI (SISCOM), conventional EEG, and intracranial EEG (iEEG). Methods We performed a retrospective cohort study of 14 consecutive patients who underwent hdEEG monitoring for suspected frontal lobe seizures. The gold standard for localization was considered to be iEEG. Concordance of hdEEG findings with MRI, subtraction ictal SPECT co-registered to MRI (SISCOM), conventional 10–20 EEG, and iEEG as well as correlation of hdEEG localization with surgical outcome were examined. Results hdEEG localization was concordant with iEEG in 12/14 and was superior to conventional EEG 3/14 (p < 0.01) and SISCOM 3/12 (p < 0.01). hdEEG correctly lateralized seizure onset in 14/14 cases, compared to 9/14 ( p = 0.04) cases with conventional EEG. Seven patients underwent surgical resection, of whom five were seizure free. Conclusions hdEEG monitoring should be considered in patients with suspected frontal epilepsy requiring localization of epileptogenic brain. hdEEG may assist in developing a hypothesis for iEEG monitoring and could potentially augment EEG source localization. [ABSTRACT FROM AUTHOR]

Purpose: To assess the specific value of subtraction ictal and inter-ictal SPECT co-registered to MRI (SISCOM) in identifying the epileptogenic zone (EZ) and predicting postoperative outcomes in epileptic surgical patients.Method: A meta-analysis of studies published from January 1995 to June 2015 was conducted through a comprehensive literature search, and 11 studies were included. R software was first used to calculate a pooled positive rate, concordant rate and positive predictive value (PPV) for good outcomes. Stata software was then used to explore the relationship between SISCOM localization and surgical outcomes, including a subgroup analysis for extra-temporal lobe epilepsy.Results: The unweighted positive and concordant rates of SISCOM were 85.9% and 65.3%, respectively. In 142 MRI-negative patients, the SISCOM positive rate was 83.8%. The pooled PPV of 178 surgical patients with concordant SISCOM was 56%. In the meta-analysis of 275 surgical patients, the seizure-free odds ratio was 3.28-times higher in concordant than in non-concordant SISCOM patients [95%CI (1.90, 5.67)]. For extra-temporal lobe epilepsy, the seizure-free odds ratio was 2.44-times higher in concordant than in non-concordant SISCOM patients [95%CI (1.34, 4.43)].Conclusion: Our data indicate that SISCOM has moderate sensitivity in localizing the epileptogenic zone and can provide complementary information when MRI is negative. Furthermore, SISCOM localization concordant with the gold standard demonstrates slightly higher predictive value for good surgical outcomes. Further research is required to explore the influence of SISCOM localization results in temporal lobe versus extra-temporal lobe epilepsy. [ABSTRACT FROM AUTHOR]

Resumen Objetivos La SPECT de perfusión ictal-interictal, subtraction ictal SPECT coregistered to MRI (SISCOM) y 18 F-FDG-PET (interictal), desempeñan un papel fundamental en la valoración prequirúrgica del paciente epiléptico fármaco-resistente. Los objetivos de este trabajo fueron establecer la reproducibilidad del análisis visual de la SPECT y SISCOM y la capacidad de la SPECT, SISCOM y PET en la identificación del foco epileptógeno. Material y métodos Se realizó una SPECT 99m Tc-HMPAO (ictal-interictal) y SISCOM (Analyze 7.0) en 47 pacientes epilépticos fármaco-resistentes (24 M, 19-60 años). En 13 pacientes se repitió el SISCOM utilizando el programa FocusDET. El análisis de las imágenes fue realizado por 2 observadores. Se valoró la reproducibilidad utilizando el índice Kappa. Los resultados conjuntos de la SPECT, SISCOM y PET, en 16 pacientes, fueron comparados con la localización del área resecada y el seguimiento clínico poscirugía (escala de Engel) o con la estereo-EEG. Resultados Grado de acuerdo interobservador de la SPECT 91% índice Kappa 0,86. Grado de acuerdo interobservador SISCOM Analyze 7.0 82%, índice Kappa 0,80. El Analyze 7.0 mostró un elevado número de resultados no concluyentes, superior al del análisis visual. El SISCOM FocusDET mostró un grado de acuerdo interobservador 92% con un índice Kappa 0,87 y menor número de resultados no concluyentes que el Analyze. La valoración conjunta SPECT, SISCOM y PET permitió identificar 87% focos epileptógenos: 79% temporales, 26% parieto-temporales y 7% frontales. Conclusión La SPECT ictal-interictal y el SISCOM mostraron una elevada reproducibilidad. La valoración conjunta de la SPECT ictal-interictal, SISCOM y PET permitió mejorar la rentabilidad diagnóstica de la valoración individualizada. Aims Brain perfusion SPECT (ictal-interictal), SPECT images and subtraction ictal SPECT coregistered to MRI (SISCOM) and 18 F-FDG-PET (interictal), play an important role in the pre-surgical diagnosis of patients with medically refractory epilepsy. This study aimed to establish: the reproducibility of visual ictal-interictal SPECT and SISCOM analysis altogether with the capacity of SPECT, SISCOM and PET to determine the epileptogenic zone. Material and methods 99m Tc-HMPAO SPECT ictal-interictal and SISCOM (Analyze 7.0) were performed on 47 refractory epilepsy patients (24 F, 19-60 yrs). In 13 patients, SISCOM was also performed using a new program (Focus DET). Ictal-interictal SPECT and SISCOM images were analysed independently by two nuclear medicine physicians (observer 1 and 2). Kappa concordance coefficient was used to evaluate the reproducibility. In sixteen patients, SPECT, SISCOM and PET findings were compared with the resected area during the surgery, and surgical outcome using Engel scale or with the stereo EEG-(SEEG). Results The ictal-interictal SPECT interobserver agreement was 91%, Kappa index 0.86, SISCOM (Analyze 7.0) interobserver agreement percentage was 82%, Kappa index 0.80, Analyze 7.0 showed a higher inconclusive results than visual SPECT analysis. SISCOM FocusDET interobserver agreement was 92%, Kappa index 0.87, with lower inconclusive results than Analyze 7.0. SPECT, SISCOM and PET combined findings identified 87% seizure onset zone: 79% temporal, 26% parieto-temporal and 7% frontal. Conclusions Ictal-interictal SPECT and SISCOM showed a high reproducibility in this sample of patients with drug-refractory epilepsy. SPECT,SISCOM and PET combined findings improved detection of epileptogenic zone in comparison with the individual assessment. [ABSTRACT FROM AUTHOR]

Summary We aimed to investigate the usefulness of coregistration of positron emission tomography (PET) and magnetic resonance imaging (MRI) findings (PET/MRI) and of coregistration of PET/MRI with subtraction ictal single-photon emission computed tomography (SPECT) coregistered to MRI (SISCOM) (PET/MRI/SISCOM) in localizing the potential epileptogenic zone in patients with drug-resistant epilepsy. We prospectively included 35 consecutive patients with refractory focal epilepsy whose presurgical evaluation included a PET study. Separately acquired PET and structural MRI images were coregistered for each patient. When possible, ictal SPECT and SISCOM were obtained and coregistered with PET/MRI. The potential location of the epileptogenic zone determined by neuroimaging was compared with the seizure onset zone determined by long-term video-EEG monitoring and with invasive EEG studies in patients who were implanted. Structural MRI showed no lesions in 15 patients. In these patients, PET/MRI coregistration showed a hypometabolic area in 12 (80%) patients that was concordant with seizure onset zone on EEG in 9. In 7 patients without MRI lesions, PET/MRI detected a hypometabolism that was undetected on PET alone. SISCOM, obtained in 25 patients, showed an area of hyperperfusion concordant with the seizure onset zone on EEG in 7 (58%) of the 12 of these patients who had normal MRI findings. SISCOM hyperperfusion was less extensive than PET hypometabolism. A total of 19 patients underwent surgery; 11 of these underwent invasive-EEG monitoring and the seizure onset zone was concordant with PET/MRI in all cases. PET/MRI/SISCOM coregistration, performed in 4 of these patients, was concordant in 3 (75%). After epilepsy surgery, 13 (68%) patients are seizure-free after a mean follow-up of 4.5 years. PET/MRI and PET/MRI/SISCOM coregistration are useful for determining the potential epileptogenic zone and thus for planning invasive EEG studies and surgery more precisely, especially in patients without lesions on MRI. [ABSTRACT FROM AUTHOR]

Abstract: Single photon emission computed tomography (SPECT) is an accurate imaging method for the diagnosis of refractory partial epilepsy. Two scans are carried out: interictal and ictal. The interest of this method is to provide an image in the ictal period, which allows hyperperfused areas linked to the seizure to be localized. The epileptic foci localization is improved by subtracting the two acquisitions (subtracted ictal SPECT: SIS). In some cases, the SIS method is not effective and does not isolate the seizure foci. In this article, we investigate a new method based on texture analysis using fractal geometry features. Fractal geometry features were extracted from each scan in order to quantify the heterogeneity change resulting from the hyperperfusion. A support vector machine (SVM) classification algorithm was used to classify the voxels into two classes: focal and healthy. Quantitative evaluation was performed on simulated images and clinical images from 22 patients with temporal lobe epilepsy. Results on both experiments showed that the proposed method is more specific and more sensitive than the SIS method. [Copyright &y& Elsevier]

Abstract: Purpose: We employed the results of imaging modalities from pediatric patients who received successful epilepsy surgery to determine the accuracy of each imaging tool in identifying epileptic zones in youngsters. Methods: All Engel class I pediatric patients who received epilepsy surgery between October 2003 and April 2008 were selected. Their pathology, EEG, MRI, PET, and subtraction ictal SPECT coregistered to MRI (SISCOM) results were compared for accuracy in locating the epileptic foci, defined as “area that resulted in seizure ablation after resection”. Results: Forty-two patients were enrolled (23 temporal lobectomy, 19 extratemporal resections). MRI showed concordance in 84.2% of extratemporal cases, all of which had precise localization of lesions. In temporal cases, lateralization was 91.3% and localization was 82.6%. PET showed a concordance rate of 95.5% and localization was 72.7% for temporal lesions. For extratemporal lesions, concordance was only 68.4%. SISCOM showed concordance in 100% of temporal and 92.3% of extratemporal cases, with localization in 66.7% of temporal and 84.6% of extratemporal cases. Most temporal lobe cases had hippocampal sclerosis, and cortical dysplasia was observed in extratemporal cases. Discussion: MRI was invariably reliable in all cases. PET results were as reliable in lateralizing the temporal epileptic area, while its efficacy was lower for extratemporal cases. SISCOM effectively localized lesions in extratemporal cases, but its efficacy was lower in temporal lesions. In cases of conflicting pre-surgical results, MRI, with supplementary data from PET, helped to establish correct decisions in temporal epilepsies, while utilization of SISCOM and MRI data is advised for extratemporal cases. [Copyright &y& Elsevier]

Summary: The impact of functional imaging tests on the decision-making and planning process for epilepsy surgery has never been prospectively assessed. We prospectively evaluated 50 consecutively eligible patients whose noninvasive evaluations showed nonlocalized findings and determined how their SISCOM (subtraction ictal SPECT [single photon emission computed tomography] co-registered to MRI [magnetic resonance imaging]) data altered consensus decisions for epilepsy surgery. At an epilepsy surgery conference where each patient was discussed, consensus decisions were documented after a standardized presentation of data from the noninvasive evaluation (SISCOM findings initially were excluded). Consensus decisions were again documented after presentation of SISCOM data. Consensus decisions changed for 10 of 32 patients (31%) with localizing SISCOM results, whereas the decision changed in only 1 of 18 patients (6%) with nonlocalizing SISCOM results (P <.05). Changes in consensus decisions were as follows: (1) intracranial electrode implantation (IEI) was obviated and resective surgery was recommended (n =2); (2) resective surgery or further evaluation for patients initially not considered surgical candidates (n =2); (3) IEI in patients for whom it was not recommended initially (n =3); (4) increased IEI coverage (n =3); and (5) antiepileptic drug trial or vagal nerve stimulation was recommended instead of IEI (n =1). For some patients whose noninvasive evaluations did not clearly localize a surgical focus, SISCOM data can have a major impact on decisions to recommend resective epilepsy surgery or IEI. [Copyright &y& Elsevier]

Summary: A 27-year-old man had complex partial seizures and a dysembryoplastic neuroepithelial tumor (DNT) in the left inferior-basal temporal region. The patient''s seizures consisted of incomprehensible speech, staring, unresponsiveness, fumbling and then looking around. For the brain SPECT study, radiotracer was injected during the preictal (11s prior to seizure onset), ictal (at 25s out of 47s seizure duration) and interictal periods. Interictal SPECT was subtracted from preictal or ictal-injection SPECTs and then the subtracted SPECTs were overlaid on the patient''s MRI (SISCOM). SISCOM with preictal-injection SPECT showed hyperperfusion at the brain lesion, whereas SISCOM with ictal-injection SPECT showed hyperperfusion at the ipsilateral amygdala-hippocampus and hypoperfusion around the tumor lesion. After the DNT and nearby temporal lobe tissues were resected with preservation of amygdala-hippocampus, the patient became seizure free without complaint of subjective postsurgical memory decline. In this patient, SISCOM with preictal injection of radiotracer localized an epileptogenic zone, whereas SISCOM with the ictal injection showed hyperperfusion at the symptomatogenic zone. [Copyright &y& Elsevier]

Summary: To localize the neural correlates of musicogenic epilepsy, subtraction ictal SPECT coregistered with MRI (SISCOM) and 18F-fluorodeoxy glucose positron emission tomography (FDG-PET) were performed in a woman who had suffered from frequent musicogenic seizures. She had complex partial seizures consisting of palpitation and an unpleasant feeling, which were followed by staring and oroalimentary automatisms. Ictal EEG showed rhythmic theta waves originated from the right temporal lobe, and SISCOM showed ictal hyperperfusion on right insula, amygdala, hippocampal head, and anterior temporal lobe, whereas interictal FDG-PET showed interictal hypometabolism in the same brain regions, suggesting dysfunction and abnormal activation of right temporo-limbic structures related to an emotional response to music. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

• The main limitations of ictal SPECT in epilepsy are the complex methodology of the tracer injection during a seizure. • First commercially available dedicated automated injector for ictal SPECT (epijet) has been evaluated. • Epijet showed a high rate of seizure focus localization allowing high ictal SPECT accuracy and maintaining the injection time compared with manual injection. • With the automated injection system ictal SPECT injection is much safer, simpler and effective, making ictal SPECT more accessible. Successful surgery depends on the accurate localization of epileptogenic zone before surgery. Ictal SPECT is the only imaging modality that allows identification of the ictal onset zone by measuring the regional cerebral blood flow at the time of injection. The main limitation of ictal SPECT in epilepsy is the complex methodology of the tracer injection during a seizure. To overcome this limitation, we present the main features of the first automated injector for ictal SPECT (epijet, LemerPax; La Chapelle -sur-Erdre; France). In this study we compared traditional manual injection with automated injection for ictal SPECT in 122 patients with drug-resistant epilepsy. The study included 55 consecutive prospective patients with drug-resistant epilepsy undergoing injection with the automated injector. The control group was our retrospective database of a historic pool of 67 patients, injected manually from 2014 to 2016. Calculated annual exposure/radioactive dose for operators was measured. Injection time, seizure focus localization with ictal SPECT, as well as repeated hospitalizations related to inconclusive findings of the SPECT were compared in these two groups of patients. There were no differences in the average injection time with epijet (13 s) compared with the traditional manual injection (14 s). The seizure focus was successfully localized with ictal SPECT with epijet in 44/55 (80 %) patients and with manual injection in 46/67 (68 %) patients (p = 0.097). Repeated studies were required in 9/67 (23 %) patients in the manual injection group compared to 3 patients (7%) in the epijet group (p = 0.141). Calculated annual exposure/dose for operators of 0.39 mSv/year and administered dose error inferior to 5% are other advantages of epijet. The first results using epijet are promising in adjustment of the injection dose, reducing the rate of radiation exposure for patients and nurses, maintaining the same injection time and allowing high SPECT accuracy. These preliminary results support the use of an automated injection system to inject radioactive ictal SPECT doses in epilepsy units. [ABSTRACT FROM AUTHOR]

• Proper utilization of SPECT may be limited depending on the resources available at each center. • SPECT may not add more localizing information to reinforce the decision for resective surgery in patients with single lesion and congruent clinical, EEG, and MRI findings. • In centers where IEM is not performed, SPECT is unlikely to be helpful in MRI-negative cases. • Careful selection of patients for SPECT imaging can improve its utility and prevent overutilization and potential harm to children. Single-photon emission computed tomography (SPECT) is an ancillary noninvasive test commonly used to identify the epileptogenic zone. However, its proper utilization may be limited depending on the resources available at each center. This study aimed to investigate the utility of SPECT in presurgical evaluation of children at our center. This was an observational retrospective study in 150 children who were admitted to the Epilepsy Monitoring Unit for presurgical evaluation between 2012 and 2019. The utility of interictal and ictal SPECT in different clinical cohorts was analyzed. Only interictal SPECT was performed on 87 patients (58 %), while ictal SPECT was performed on 62 (41.3 %), and interictal SPECT alone was considered of low diagnostic value. Ictal SPECT was unremarkable in 27 of 62 patients and abnormal in 35. Ictal SPECT was localized to the temporal lobe in 62.8 % and to the extratemporal lobe in 25.7 % of the patients and lateralized to one hemisphere in 11.4 % of the patients. In the abnormal SPECT group, ictal SPECT was considered unnecessary in 7/35 (20 %) patients with a single lesion and 3/35 (8.5 %) patients with a hemispheric lesion. In the remaining 25 patients, surgery was recommended more frequently than invasive EEG monitoring (IEM) for diffuse lesion cases (P = 0.03), while IEM was recommended more frequently than surgery for MRI-negative cases (P = 0.03), and in this group none of the MRI-negative patients underwent surgery. In our entire cohort, epilepsy surgery was performed on 24.4 % of the patients, 64 % with a single lesion, 7.6 % with a hemispheric lesion, 25.6 % with a diffuse lesion, and only one MRI-negative patient (2.5 %). Surgery was performed in 48.7 % of single lesion cases and 20.5 % of diffuse lesion cases with either unremarkable or no ictal SPECT. Engel class I outcome was achieved in 62 % and class II outcome in 33 % of the patients. In the single lesion etiology, 72 % (18/25) patients achieved excellent outcome and within this group, 22 % (4/18) patients had a positive ictal SPECT whereas 78 % (14/18) patients either did not get an ictal SPECT or it was unremarkable. Based on our findings, we suggest carefully selecting patients for SPECT imaging to improve its utility and prevent overutilization and potential harm to children. [ABSTRACT FROM AUTHOR]