Scalp video-EEG Monitoring Research Articles

Surgery in intractable epilepsy-physicians' recommendations and patients' decisions.

To identify demographic and clinical variables independently associated with patients' decisions against their physicians' recommendations for resective epilepsy surgery or further scalp video-EEG monitoring (sca-VEM), semi-invasive (sem-)VEM with foramen ovale and/or peg electrodes, and invasive (in-)VEM. Consecutive patients, who underwent presurgical assessment with at least one sca-VEM between 2010 and 2014, were included into this retrospective analysis. Multivariate analysis was used to identify independent variables associated with patients' decisions. Within the study period, 352 patients underwent 544 VEM sessions comprising 451 sca-, 36 sem-, and 57 in-VEMs. Eventually, 96 patients were recommended resective surgery, and 106 were ineligible candidates; 149 patients denied further necessary VEMs; thus, no decision could be made. After sca- or additional sem-VEM, nine out of 51 eligible patients (17.6%) rejected resection. One hundred and ten patients were recommended in-VEM, 52 of those (47.2%) declined. Variables independently associated with rejection of in-VEM comprised intellectual disability (OR 4.721, 95% CI 1.047-21.284), extratemporal focal aware non-motor seizures ("aura") vs. no "aura" (OR 0.338, 95% CI 0.124-0.923), and unilateral or bilateral vs. no MRI lesion (OR 0.248, 95% CI 0.100-0.614 and 0.149, 95% CI 0.027-0.829, respectively). During and after presurgical evaluation, patients with intractable focal epilepsy declined resections and intracranial EEGs, as recommended by their epileptologists, in almost 20% and 50% of cases. This calls for early and thorough counseling of patients on risks and benefits of epilepsy surgery. Future prospective studies should ask patients in depth for specific reasons why they decline their physicians' recommendations.

Outcomes of stereoelectroencephalography exploration at an epilepsy surgery center.

Epilepsy surgery is offered in resistant focal epilepsy. Non-invasive investigations like scalp video EEG monitoring (SVEM) help delineate epileptogenic zone. Complex cases may require intracranial video EEG monitoring (IVEM). Stereoelectroencephalography (SEEG)-based intracerebral electrode implantation has better spatial resolution, lower morbidity, better tolerance, and superiority in sampling deep structures. Our objectives were to assess IVEM using SEEG with regard to reasoning behind implantation, course, surgical interventions, and outcomes. Seventy-two admissions for SEEG from January 2014 to December 2018 were included in the study. Demographic and clinical data were retrospectively collected. The cohort comprised of 69 adults of which 34 (47%) had lesional MRI. Reasons for SEEG consideringall cases includednon-localizing ictal onset (76%), ictal-interictal discordance (21%), discordant semiology (17%), proximity to eloquent cortex (33%), nuclear imaging discordance (34%), and discordance with neuropsychology (19%). Among lesional cases, additional reasons included SVEM discordance (68%) and dual or multiple pathology (47%). Forty-eight patients (67%) were offered resective surgery, and 41 underwent it. Twenty-three (56%) had at least one year post-surgical follow-up of which 14 (61%) had Engels class I outcome. Of the remaining 23 who were continued on medical management, 4 (17%) became seizure-free and 12 (51%) had reduction in seizure frequency. SEEG monitoring is an important and safe tool for presurgical evaluation with good surgical and non-surgical outcomes. Whether seizure freedom following non-surgical management could be related to SEEG implantation, medication change, or natural course needs to be determined.

Autonomic dysregulation in children with epilepsy with postictal generalized EEG suppression following generalized convulsive seizures

ObjectivePostictal generalized electroencephalographic suppression (PGES) has been associated with sudden unexpected death in epilepsy (SUDEP) in adults. Decreased heart rate variability (HRV) is one clinical marker of SUDEP in adults with epilepsy. The objective of this study was to analyze the characteristics of HRV associated with generalized convulsive seizures (GCS) ± PGES in children. MethodsNine hundred and seventy-seven consecutive children who underwent prolonged scalp video-EEG (vEEG) and 1-lead electrocardiogram (ECG) monitoring at the Hospital for Sick Children, Toronto, Ontario, Canada were reviewed retrospectively from 2009 to 2011. Thirty-five children had GCS captured during their vEEG with or without PGES and met inclusion criteria. Children were subdivided into three age groups and compared with age-matched controls: 3–6 years; 7–12 years; and 13–18 years. Interictal HRV was measured at 5 min during N2 sleep. Preictal HRV was measured at 1 h prior to GCS onset, and postictal HRV was measured at 3 min post-GCS cessation. Low frequency (LF: ms2, 0.04–0.15 Hz) and high frequency (HF: ms2, 0.15–0.4 Hz) bands of heart rate oscillations were analyzed during the interictal and preictal periods. The root mean square of successive differences (RMSSDs) was analyzed during the following time points: interictal; preictal; and postictal. ResultsThirty-five children had GCS: 18 children with PGES [3–6 years (n = 2); 7–12 years (n = 6); 13–18 years (n = 10)] and 17 children without PGES [3–6 years (n = 6); 7–12 years (n = 5); 13–18 years (n = 6)]. Seventeen additional age-matched controls were identified [3–6 years (n = 3); 7–12 years (n = 5); 13–18 years (n = 9)]. Seventy-four GCS were captured consisting of 36 GCS + PGES and 38 GCS − PGES. There was no difference of interictal HRV among children with GCS ± PGES and controls. The preictal LF and HF in 36 GCS + PGES were significantly higher compared with 38 GCS − PGES (p < 0.01). The postictal RMSSD in 36 GCS + PGES was significantly higher compared with 38 GCS − PGES (p < 0.01). The pre- to postictal RMSSD change was significantly lower in children with GCS + PGES than in those with GCS − PGES (p = 0.035). ConclusionsIn summary, the preictal HRV in GCS + PGES was significantly higher than in children with GCS − PGES. The higher remaining postictal RMSSD in children with GCS + PGES is a potential indicator of autonomic dysregulation. In certain children with epilepsy, autonomic dysregulation may contribute to poor recovery from a GCS with subsequent PGES, thereby contributing to SUDEP. Heart rate variability and autonomic regulation in children with epilepsy should be further studied prospectively in order to better understand the mechanism by which PGES may lead to SUDEP.

Clinical FDG-PET Findings in Patients with Temporal Lobe Epilepsy: Concordance with EEG and MRI.

We aimed to study the yield of PET in temporal lobe epilepsy (TLE) by analyzing the correlation of PET findings with MRI, and interictal and ictal EEG findings, in a single-center cohort of patients with TLE. Predictors of PET thalamic changes and its role in predicting postsurgical outcome were also studied. This was a retrospective study of 39 patients with TLE who underwent MRI, PET, and scalp video EEG monitoring at the University at Buffalo, New York from 2001 to 2011 during presurgical evaluation. PET-defined metabolism of the temporal lobes was evaluated using a 4-point ordinal rating scale. PET hypometabolism was associated with a variation in ictal (P = .034) and interictal (P<.001) foci in both lesional (by MRI) and nonlesional patients. Nonlesional MRI scans were associated with none to mild temporal PET hypometabolism (71% of patients) while lesional MRI scans were associated with moderate to severe hypometabolism (82% of patients) (P = .006). The odds of thalamic hypometabolism were 5.36 times higher when there was moderate to severe temporal hypometabolism (P = .039). This study underscores the utility of PET in localizing ictal foci in TLE patients even in those with normal MRI. The degree of PET hypometabolism corresponds to presence of MRI pathology. Coexistent thalamic hypometabolism with temporal hypometabolism suggests a secondary effect of distant temporal network disruption. Extratemporal metabolism is a predictor of poor postsurgical seizure outcome in TLE patients.

Features of ictal and interictal electrical activity in assessment of the epileptogenic zone in children with focal cortical dysplasias

We studied scalp video-EEG monitoring data of 38 FCD patients who underwent surgical treatment for intractable epilepsy in the period between 2010 and 2016. We analyzed the data on interictal and ictal activity localization and compared them with the data on FCD types and lesion location. Two types of the ictal onset pattern on EEG, local and generalized, were identified. The local and generalized types included two and four variants of the ictal onset pattern, respectively. Therefore, 6 combinations of rhythmic activity were identified, which manifested within the first 10 s after the onset of electrographic changes on EEG simultaneously with initial clinical manifestations of seizure. Co-localization of the interictal and ictal activity zones occurred in 42% of cases; of these, 88% of patients had the ictal onset pattern. In the remaining cases (58%), no co-localization of the interictal and ictal activity zones was detected; of these, 76% of patients were assigned to the group with the generalized ictal onset pattern. The local ictal onset pattern was more common in patients with type II FCD, while the generalized ictal onset pattern was more common in patients with type I and type III FCD. No correlation between the ictal onset pattern type and the lesion localization was found. We describe two ictal onset pattern types, local and generalized, on EEG in children with FCD. The co-localization of ictal and interictal activity zones prevails in the local ictal onset pattern group. The local ictal onset pattern is often associated with type II FCD. In the case of type I and type III FCD, the generalized ictal onset pattern predominates. There is no clear relationship between the ictal onset pattern type and the lesion location.

Clinical value and predictors of subclinical seizures in patients with temporal lobe epilepsy undergoing scalp video-EEG monitoring

The aim of this study was to determine the clinical importance and predictors of SCSs in a large population of patients with temporal epilepsy (TLE) undergoing video electroencephalographic (VEEG) monitoring. We reviewed the VEEG data of 327 consecutive patients with TLE admitted to our epilepsy center between August 2012 and January 2017. Demographic, electro-clinical, and neuroimaging data were recorded and re-analyzed. To our knowledge, this is the first study assessing SCSs recorded by long-term VEEG monitoring in patients with TLE. Twenty-seven of 327 (8.3%) patients exhibited SCSs during VEEG monitoring. Of these patients, 24 had both SCSs and clinical seizures. The mean duration of the SCSs was 23.18s (range: 5–1307s). Of the 27 patients with SCSs, 24 (88.9%) showed localizing value during the diagnostic process. Seventeen patients exhibited colocalization with clinical seizures, 4 showed useless localization related to clinical seizures, and 3 did not have clinical seizures. Sixteen patients (59.3%) experienced their first SCSs within the first 24h of monitoring and one had the first SCSs within 20min. Multivariate logistic regression analysis showed that age <18years at VEEG monitoring (OR=3.272, 95% CI=1.283–8.343, p=0.013) and bilateral IEDs (OR=4.558, 95% CI=1.982–10.477, p<0.001) were independently associated with the presence of SCSs. Thus, SCSs are not uncommon in patients with TLE, particularly those with age <18years or bilateral IEDs, and should be considered of significant clinical relevance during the diagnostic process.

Absolute spike frequency as a predictor of surgical outcome in temporal lobe epilepsy

PurposeFrequent interictal epileptiform abnormalities may correlate with poor prognosis after temporal lobe resection for refractory epilepsy. To date, studies have focused on limited resections such as selective amygdalohippocampectomy and apical temporal lobectomy without hippocampectomy. However, it is unclear whether the frequency of spikes predicts outcome after standard anterior temporal lobectomy. MethodPreoperative scalp video-EEG monitoring data from patients who subsequently underwent anterior temporal lobectomy over a three year period and were followed for at least one year were reviewed for the frequency of interictal epileptiform abnormalities. Surgical outcome for those patients with frequent spikes (>60/h) was compared with those with less frequent spikes. Additionally, spike frequency was evaluated as a continuous variable and correlated with outcome to determine if increased spike frequency correlated with worse outcome, as assessed by modified Engel Class outcome. ResultsForty-seven patients (18 men, 29 women; mean age 40 years at surgery) were included. Forty-six patients had standard anterior temporal lobectomy (24 right, 22 left) and one had a modified left temporal lobectomy. There was no significant difference in seizure outcome between those with frequent (57% Class I) vs. those with less frequent (58% Class I) spikes. Increased spike frequency did not correlate with worse outcome. Greater than 20 complex partial seizures/month and generalized tonic-clonic seizures within one year of surgery correlated with worse outcome. ConclusionsThis study suggests that absolute spike frequency does not predict seizure outcome after anterior temporal lobectomy unlike in selective procedures, and should not be used as a prognostic factor in this population.

Prevalence and predictors of subclinical seizures during scalp video-EEG monitoring in patients with epilepsy

Objective: This study first aimed to establish the prevalence and predictors of subclinical seizures in patients with epilepsy undergoing video electroencephalographic monitoring, then to evaluate the relationship of sleep/wake and circadian pattern with subclinical seizures. Methods: We retrospectively reviewed the charts of 742 consecutive patients admitted to our epilepsy center between July 2012 and October 2014. Demographic, electro-clinical data and neuroimage were collected. Results: A total of 148 subclinical seizures were detected in 39 patients (5.3%) during video electroencephalographic monitoring. The mean duration of subclinical seizures was 47.18 s (range, 5–311). Pharmacoresistant epilepsy, abnormal MRI and the presence of interictal epileptiform discharges were independently associated with subclinical seizures in multivariate logistic regression analysis. Subclinical seizures helped localizing the presumed epileptogenic zone in 24 (61.5%) patients, and suggested multifocal epilepsy in five (12.8%). In addition, subclinical seizures occurred more frequently in sleep and night than wakefulness and daytime, respectively, and they were more likely seen between 21:00–03:00 h, and less likely seen between 09:00–12:00 h. Thirty patients (76.9%) had their first subclinical seizures within the first 24 h of monitoring while only 7.7% of patients had their first subclinical seizures detected within 20 min. Conclusion: Subclinical seizures are not uncommon in patients with epilepsy, particularly in those with pharmacoresistant epilepsy, abnormal MRI or interictal epileptiform discharges. Subclinical seizures occur in specific circadian patterns and in specific sleep/wake distributions. A 20-min VEEG monitoring might not be long enough to allow for their detection.

Long-term scalp video-electroencephalography monitoring in the presurgical evaluation of epilepsy surgery

Background Diagnosis of the epileptogenic zone is the main aim of the presurgical evaluation in patients with drug-resistant epilepsy. Different diagnostic tools are being used to identify it. Objective This study aimed at studying the value of long-term scalp video-electroencephalography (video-EEG) monitoring to diagnose laterality and locality of the epileptic focus by comparing its results with other noninvasive methods, including interictal magnetoencephalography (MEG), interictal iodine-123 iomazenil single-photon emission computed tomography ( 123 I-IMZ SPECT), and interictal fluorine-18 fluorodeoxyglucose ( 18 F-FDG) PET. Patients and methods A total of 24 patients with drug-resistant epilepsy were included in this study; 17 had mesial temporal lobe epilepsy, whereas the remaining seven had neocortical epilepsy. All patients were admitted to Jichi University Hospital in Japan for the presurgical evaluation and surgical intervention. All patients were subjected to clinical evaluation, brain MRI, and long-term scalp video-EEG monitoring; a total of 23 patients had interictal 123 I-IMZ SPECT, 19 had interictal MEG recording, and 10 had interictal 18 F-FDG PET. The laterality and locality of the epileptogenic area predicted by these methods were defined in relation to the resected area. Results Long-term scalp video-EEG monitoring was significantly superior to interictal 123 I-IMZ SPECT and interictal 18 F-FDG PET in diagnosing laterality and locality of the epileptogenic zone and superior to interictal MEG in patients with mesial temporal lobe epilepsy and patients with epileptogenic MRI findings. Conclusion Long-term scalp video-EEG monitoring is the cornerstone in the presurgical evaluation of epilepsy surgery.

Video electroencephalogram telemetry in temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) is the most commonly encountered medically refractory epilepsy. It is also the substrate of refractory epilepsy that gives the most gratifying results in any epilepsy surgery program, with a minimum use of resources. Correlation of clinical behavior and the ictal patterns during ictal behavior is mandatory for success at epilepsy surgery. Video electroencephalogram (EEG) telemetry achieves this goal and hence plays a pivotal role in pre-surgical assessment. The role of telemetry is continuously evolving with the advent of digital EEG technology, of high-resolution volumetric magnetic resonance imaging and other functional imaging techniques. Most of surgical selection in patients with TLE can be done with a scalp video EEG monitoring. However, the limitations of the scalp EEG technique demand invasive recordings in a selected group of TLE patients. This subset of the patients can be a challenge to the epileptologist.

The evaluation of FDG-PET imaging for epileptogenic focus localization in patients with MRI positive and MRI negative temporal lobe epilepsy

We studied the contribution of interictal FDG-PET ([18F] fluorodeoxyglucose-positron emission tomography) in epileptic focus identification in temporal lobe epilepsy patients with positive, equivocal and negative magnetic resonance imaging (MRI). Ninety-eight patients who underwent surgical treatment for drug resistant temporal lobe epilepsy after neuropsychological evaluation, scalp video EEG monitoring, FDG-PET, MRI and/or long-term intracranial EEG and with >12months clinical follow-up were included in this study. FDG-PET findings were compared to MRI, histopathology, scalp video EEG and long-term intracranial EEG monitoring. FDG-PET lateralized the seizure focus in 95% of MRI positive, 69% of MRI equivocal and 84% of MRI negative patients. There was no statistically significant difference between the surgical outcomes among the groups with Engel class I and II outcomes achieved in 86%, 86%, 84% of MRI positive, equivocal and negative temporal lobe epilepsy patients, respectively. The patients with positive unilateral FDG-PET demonstrated excellent postsurgical outcomes, with 96% Engel class I and II. Histopathology revealed focal lesions in 75% of MRI equivocal, 84% of MRI positive, and 23% of MRI negative temporal lobe epilepsy cases. FDG-PET is an accurate noninvasive method in lateralizing the epileptogenic focus in temporal lobe epilepsy, especially in patients with normal or equivocal MRIs, or non-lateralized EEG monitoring. Very subtle findings in MRI are often associated with histopathological lesions and should be described in MRI reports. The patients with negative or equivocal MRI temporal lobe epilepsy are good surgical candidates with comparable postsurgical outcomes to patients with MRI positive temporal lobe epilepsy.

Parietal lobe epilepsy: the great imitator among focal epilepsies

Comprising large areas of association cortex, the parietal lobe is part of an extensive synaptic network elaborately intertwined with other brain regions. We hypothesize that such widespread projections are responsible for producing inaccurate localisation readings on scalp EEG and clinical semiology in patients with parietal lobe epilepsies, as opposed to frontal or temporal lobe epilepsies. Our study included 50 patients with pharmacoresistant focal epilepsy, who were subsequently rendered seizure-free for ≥12 months (median: 23 months) following resections limited to the frontal (n=17), temporal (n=17), or parietal (n=16) lobes. Interictal and ictal EEG data with accompanying seizure video recordings were extracted from archived files of scalp video-EEG monitoring. Two blinded raters independently reviewed the EEG according to predetermined criteria. Videos of seizures were then observed, as raters formulated their final electroclinical impression (ECI), identifying patients' abnormal neuronal activities with parietal, temporal, and frontal lobe epilepsy, or unspecified localisation. Groups did not differ significantly in demographics, age at epilepsy onset, or presence of MRI abnormalities. Interictal discharges in parietal lobe epilepsy showed the greatest magnitude of scatter outside the lobe of origin; the majority of patients with parietal lobe epilepsy had more than one spike population (p<0.045). Localised ictal EEG recognition was most frequent in temporal, followed by frontal and parietal lobe epilepsy cases (p=0.024). Whenever raters confidently limited their ECI to one lobar subtype, overall accuracy was excellent. Lobar classifications by ECI were highly accurate for temporal lobe epilepsy, vacillating in frontal lobe epilepsy, and least accurate in parietal lobe epilepsy subjects. Scalp EEG readings of parietal lobe epilepsy patients showed a more variable scatter of interictal discharges and a lower localisation value of ictal recordings compared to temporal and frontal lobe epilepsy subjects, suggesting an increased likelihood of misidentification and mislocalisation of parietal lobe epilepsy. Combining seizure semiology with scalp interictal and ictal EEG readings facilitates a more accurate lobar classification in patients with temporal and frontal, but not parietal, lobe epilepsy.

Intracranial localisation of ictal urinary urge epileptogenic zone to the non‐dominant temporal lobe

Ictal urinary urge is a rare symptom of focal epilepsy usually localising to the non-dominant hemisphere, specifically, the temporal lobe. Lateralisation in previously described cases has been established using scalp video-EEG monitoring or functional imaging. We report the case of a 19-year-old girl with refractory epilepsy and ictal urinary urge arising from the non-dominant temporal lobe, confirmed by invasive, subdural EEG monitoring. Since undergoing a temporal lobectomy two and a half years ago, the patient has not experienced ictal urinary urge. To our knowledge, this is the first report demonstrating localisation of ictal urinary urge epileptogenic zone to the non-dominant temporal lobe by invasive intracranial monitoring.

Safety of long-term video-electroencephalographic monitoring for evaluation of epilepsy.

To determine the rate of medical complications from long-term video-electroencephalographic (EEG) monitoring for epilepsy. We reviewed the medical records of 428 consecutive adult patients with epilepsy who were admitted for diagnostic scalp video-EEG monitoring at Mayo Clinic's site in Arizona from January 1, 2005, to December 31, 2006; 149 met inclusion criteria for the study. Seizure number and type as well as timing and presence of seizure-related adverse outcomes were noted. Of the 149 adult patients included in the study, seizure clusters occurred in 35 (23%); 752 seizures were recorded. The mean time to first seizure was 2 days, with a mean length of stay of 5 days. Among these patients, there was 1 episode of status epilepticus, 3 potentially serious electrocardiographic abnormalities, 2 cases of postictal psychosis, and 4 vertebral compression fractures during a generalized convulsion, representing 11% of patients with a recorded generalized tonic-clonic seizure. No deaths, transfers to the intensive care unit, falls, dental injuries, or pulmonary complications were recorded. An adverse event requiring intervention or interfering with normal activity occurred in 21% of these patients. Length of stay was not affected by occurrence of adverse events. Prolonged video-EEG monitoring is an acceptably safe procedure. Adverse events occur but need not result in substantial morbidity or increase length of hospitalization. Appropriate precautions must be in place to prevent falls and promptly detect and treat seizure clusters, status epilepticus, serious electrocardiographic abnormalities, psychosis, and fractures.

Insular-opercular seizures manifesting with sleep-related paroxysmal motor behaviors: A stereo-EEG study

Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nevertheless, recent studies also suggest that sleep-related hypermotor seizures can originate in the insula. The present study describes the electroclinical features of eight drug-resistant epileptic patients with insular-opercular seizures manifesting with nocturnal complex motor seizures. Patients underwent a comprehensive presurgical evaluation, which included history, interictal electroencephalography (EEG), scalp video-EEG monitoring, high-resolution magnetic resonance imaging (MRI), and intracerebral recording by stereo-EEG. Almost all patients reported an initial sensation consisting of viscerosensitive or somatosensory symptoms. Ictal clinical signs were represented by tonic-dystonic asymmetric posturing and/or hyperkinetic automatisms, including bimanual/bipedal activity and ballistic movements. Some patients exhibited dysarthric speech, hypersalivation, and apnea. Interictal and ictal EEG provided lateralizing information in the majority of patients. In three patients, MRI showed a focal anatomical abnormality in the insular-opercular region. Stereo-EEG ictal recordings demonstrated that the epileptic discharge involved simultaneously the insular cortex and the opercular region. Complex motor manifestations appeared when the ictal discharge showed an extrainsular spreading to frontomesial regions (cingulum, superior frontal gyrus, and supplementary motor area) and/or to internal and neocortical temporal lobe structures. Six patients received an insular-opercular cortical resection; three of them are seizure free (minimum follow-up 24 months) and in one a marked reduction in seizure frequency was obtained. Two patients have been operated on recently. Histology revealed a focal cortical dysplasia in three patients. One patient excluded from surgery died for sudden unexpected death in epilepsy during sleep. Our data strengthen the concept that sleep-related complex motor attacks can originate in the insula, and provide useful electroclinical information to differentiate this localization from those with similar clinical characteristics. Furthermore, this study indicates that in these drug-resistant patients, surgical treatment represents a highly effective treatment option.

Epilepsy surgery program in Tunisia: An example of a Tunisian French collaboration

Objective To describe the first Tunisian epilepsy surgery program establishment and to emphasize on its originality that is an exchange and surgery decision taken by two Mediterranean neurophysiological teams, via the Internet. Methods Patients with mesial temporal lobe epilepsy (MTLE) and refractory to antiepileptic drugs were included. A noninvasive protocol evaluation including a detailed history, neurological evaluation, brain imaging, scalp video-EEG monitoring and neuropsychological evaluation were performed. The different findings were discussed between the Neurophysiological Department of Charles Nicolle Hospital of Tunis and Rouen through the EUMEDCONNECT Internet network project. If cases of concordance of clinical, neuropsychological, neuroimaging data and video-EEG recordings, surgery was indicated. Results 15 patients (7 women and 8 men) with mean age of 30 years were included. 10 patients had right hippocampal sclerosis (HS) and 5 had left HS. MRI findings were concordant with the ictal EEG in 12 patients. One patient had bitemporal ictal EEG abnormalities and right HS on MRI. One patient had contralateral ictal clinical and EEG patterns to the side of HS. One patient had temporal ‘plus’ epilepsy. Surgery was performed in 10 cases. After surgery, all patients are seizure free, with no operative mortality or major surgery complications. Conclusion Our model of twin affiliations between advanced epilepsy surgery programs in a developed country and starting programs in a developing country, using Internet technology, can be a model for collaboration in other countries.

First Do No Harm: Safety in the Epilepsy Monitoring Unit

Safety of Long-Term Video-Electroencephalographic Monitoring for Evaluation of Epilepsy. Noe KH, Drazkowski JF. Mayo Clin Proc 2009;84(6):495–500. OBJECTIVE: To determine the rate of medical complications from long-term video-electroencephalographic (EEG) monitoring for epilepsy. PATIENTS AND METHODS: We reviewed the medical records of 428 consecutive adult patients with epilepsy who were admitted for diagnostic scalp video-EEG monitoring at Mayo Clinic's site in Arizona from January 1, 2005 to December 31, 2006; 149 met inclusion criteria for the study. Seizure number and type as well as timing and the presence of seizure-related adverse outcomes were noted. RESULTS: Of the 149 adult patients included in the study, seizure clusters occurred in 35 (23%); 752 seizures were recorded. The mean time to first seizure was 2 days, with a mean length of stay of 5 days. Among these patients, there was one episode of status epilepticus, three potentially serious electrocardiographic abnormalities, two cases of postictal psychosis, and four vertebral compression fractures during a generalized convulsion, representing 11% of patients with a recorded generalized tonic–clonic seizure. No deaths, transfers to the intensive care unit, falls, dental injuries, or pulmonary complications were recorded. An adverse event requiring intervention or interfering with normal activity occurred in 21% of these patients. Length of stay was not affected by occurrence of adverse events. CONCLUSION: Prolonged video-EEG monitoring is an acceptably safe procedure. Adverse events occur but need not result in substantial morbidity or increase length of hospitalization. Appropriate precautions must be in place to prevent falls and promptly detect and treat seizure clusters, status epilepticus, serious electrocardiographic abnormalities, psychosis, and fractures.

Safety of Long-term Video-Electroencephalographic Monitoring for Evaluation of Epilepsy

To determine the rate of medical complications from long-term video-electroencephalographic (EEG) monitoring for epilepsy. We reviewed the medical records of 428 consecutive adult patients with epilepsy who were admitted for diagnostic scalp video-EEG monitoring at Mayo Clinic's site in Arizona from January 1, 2005, to December 31, 2006; 149 met inclusion criteria for the study. Seizure number and type as well as timing and presence of seizure-related adverse outcomes were noted. Of the 149 adult patients included in the study, seizure clusters occurred in 35 (23%); 752 seizures were recorded. The mean time to first seizure was 2 days, with a mean length of stay of 5 days. Among these patients, there was 1 episode of status epilepticus, 3 potentially serious electrocardiographic abnormalities, 2 cases of postictal psychosis, and 4 vertebral compression fractures during a generalized convulsion, representing 11% of patients with a recorded generalized tonic-clonic seizure. No deaths, transfers to the intensive care unit, falls, dental injuries, or pulmonary complications were recorded. An adverse event requiring intervention or interfering with normal activity occurred in 21% of these patients. Length of stay was not affected by occurrence of adverse events. Prolonged video-EEG monitoring is an acceptably safe procedure. Adverse events occur but need not result in substantial morbidity or increase length of hospitalization. Appropriate precautions must be in place to prevent falls and promptly detect and treat seizure clusters, status epilepticus, serious electrocardiographic abnormalities, psychosis, and fractures.

A Neurofunctional Evaluation Strategy for Presurgical Selection of Temporal Lobe Epilepsy Patients

Introduction Temporal lobe epilepsy (TLE) is the prototype of a surgically correctable syndrome. Successful surgical outcomes depend on a thorough presurgical evaluation aimed primarily at identifying the epileptogenic zone. Objective Describe the noninvasive presurgical selection and evaluation strategy for TLE patients introduced at the International Neurological Restoration Center (CIREN) in Havana, Cuba, and evaluated between 2001 and 2006 for its accuracy in identifying candidates for non-lesional resection surgery. Methods Ictal onset electrographic patterns of 1,679 seizures in 72 patients with drug-resistant partial epilepsy, obtained through longterm scalp Video EEG (V-EEG) monitoring, were evaluated. The correlation between the V-EEG-defined epileptogenic zone and the dysfunction shown by single photon emission computed tomography (ictal and interictal brain SPECT) and nuclear magnetic resonance spectroscopy (MRS) was established. Results V-EEG monitoring determined that 44.4% of evaluated patients had complex partial temporal lobe seizures. Identification of patients with medial temporal epilepsy (MTE) increased as a result of lateralization and localization of the dominant mean ictal pattern frequency (5.56 ± 1.31 Hz) during the period of maximum spectral power VARETA localization of an ictal epileptiform activity source coincided with the epileptogenic zone in all TLE patients who subsequently underwent a successful temporal lobectomy. Semiquantitative analysis of ictal and interictal brain SPECT images, as well as metabolic ratios measured by MRS, combined with V-EEG findings, enabled localization/lateralization of the epileptogenic zone in TLE patients whose MRIs were normal or showed bilateral structural abnormalities. Conclusions Confirmation of correct localization/lateralization of the epileptogenic zone following successful surgical outcomes in selected TLE patients led CIREN to develop a surgical treatment strategy for patients in Cuba with drug-resistant temporal lobe epilepsy. This strategy offers an appropriate, cost-effective treatment alternative for developing countries like Cuba, with the benefit of significantly improving TLE patients' quality of life.

Application of the 2001 diagnostic scheme and the 2006 ILAE report of seizure and epilepsy: a feedback from the clinical practice of adult epilepsy

To clarify the clinical validity and feasibility of the diagnostic scheme for seizures and epilepsy proposed by the International League Against Epilepsy (ILAE) in 2001 (the 2001 Scheme) and the report of the ILAE classification core group in 2006 (the 2006 Report). One hundred consecutive patients with epilepsy who visited the Neurology Clinic (Group 1) and 100 patients with intractable epilepsy who had undergone prolonged scalp video-EEG monitoring (Group 2) in Kyoto University Hospital were enrolled. The 2001 Scheme (Axis 1 to 4) and the 2006 Report (seizure types and epileptic syndromes) were applied to Group 1. Axis 1 was applied to Group 2 to evaluate the diversity of seizure semiology. Group 1 demonstrated 145 seizures of different types (generalized tonic-clonic seizures: 23%, complex partial seizures (CPS): 29%, simple partial seizures: 21% and secondarily generalized tonic-clonic seizures: 21% according to the 1981 classification. In Axis 1 (ictal phenomenology) of the 2001 scheme, 184 and 333 items were listed in Groups 1 and 2, respectively, and seizure semiology was described independent of EEG findings. However, there was duplications or discordance among the items. In Axis 2 (seizure types) of Group 1, 62% and 26% of CPS were further labeled as focal motor or sensory seizures, respectively; the remainder (24%) did not meet inclusion criteria for any category. In Axis 3 (epilepsy syndromes), 94% of patients were sorted, and familial temporal lobe epilepsy was added. Axis 4 described detailed etiology. Application of seizure types of the 2006 Report required consideration of ictal phenomenology to determine spread patterns. Epileptic syndromes of the 2006 Report were assignable to 70% of patients. It is important to achieve intra- and inter-axial accordance for the establishment of a more practical diagnostic scheme, which may provide a more useful tool for the diagnosis of less obvious aspects of epilepsy.