A reduction of sleep spindles heralds seizures in focal epilepsy

ObjectivesSleep has profound effects on epilepsy. It may alter the occurrence of interictal discharges (IEDs) and seizures. Vice versa, an active epilepsy changes sleep. Sleep spindles are typically associated with an increase of IEDs. We examined whether seizures change the number and power of spindles preceding nightly seizures.MethodsWe retrospectively examined the nightly EEG recordings of presurgical epilepsy patients from our EEG-video-monitoring unit. We evaluated the 200 s before the EEG seizure onset for spindle density (spindles per minute) and spindle power and compared that to the interictal baseline sleep.ResultsThe spindle density and the spindle power decreased significantly before the first seizure. The reduction before secondarily generalized seizures (8.7 ± 2.5; p = 0.001) was more pronounced than before focal seizures (10.5 ± 2.5; p = 0.003) compared to baseline (12.2 ± 2.7). This finding was more pronounced in extratemporal lobe epilepsies than in temporal lobe epilepsies. The reduction of spindle power was also significant and was more pronounced in XTLE. These results were consistent for all other seizures during sleep, the mean spindle density decreased significantly in all focal (10.2 ± 1.9; p = 0.001) and generalized preictal period (8.8 ± 2.4; p = 0.001) compared to the mean interictal period (12.1 ± 2.1). These were also more significant in XTLE than TLE group.ConclusionsOur data demonstrate that the occurrence of seizures and propensity of seizure generalisation in focal epilepsy is modulated by specific characteristics of light sleep such as sleep spindles.SignificanceThis study supports the notion that changes in the epileptic network precede the seizure onset and have an influence on seizure generation and termination.     

Cessation of gamma activity in the dorsomedial nucleus associated with loss of consciousness during focal seizures

RationaleImpaired consciousness during seizures may be mediated by ictal propagation to the thalamus. Functions of individual thalamic nuclei with respect to consciousness, however, are largely unknown. The dorsomedial (DM) nucleus of the thalamus likely plays a role in arousal and cognition. We propose that alterations of firing patterns within the DM nucleus contribute to impaired arousal during focal seizures.MethodsElectroencephalograph data were collected from electrodes within the left DM thalamus and midcingulate cortex (MCC) in a patient undergoing seizure monitoring. Spectral power was computed across ictal states (preictal, ictal, and postictal) and level of consciousness (stupor/sleep vs. awake) in the DM nucleus and MCC.ResultsEighty-seven seizures of multifocal left frontal and temporal onsets were analyzed, characterized by loss of consciousness. At baseline, the left DM nucleus demonstrated rhythmic bursts of gamma activity, most frequently and with greatest amplitude during wakefulness. This activity ceased as ictal discharges spread to the MCC, and consciousness was impaired, and it recurred at the end of each seizure as awareness was regained.The analysis of gamma (30–40 Hz) power demonstrated that when seizures occurred during wakefulness, there was lower DM ictal power (p < 0.0001) and higher DM postictal power (p < 0.0001) relative to the preictal epoch. This spectral pattern was not evident within the MCC or when seizures occurred during sleep.ConclusionsData revealed a characteristic pattern of DM gamma bursts during wakefulness, which disappeared during partial seizures associated with impaired consciousness. The findings are consistent with studies suggesting that the DM nucleus participates in cognition and arousal.     

Cardiac electrographic and morphological changes following status epilepticus: Effect of clonidine

PurposeStatus epilepticus has been increasingly associated with cardiac injury in both clinical and animal studies. Our group has previously shown that excitotoxic seizure induction results in the formation of ischaemic myocardial infarcts and loss of cardiac haemodynamic function. We hypothesised that attenuation of cardiac sympathetic/parasympathetic balance with a central presynaptic α₂ agonist, clonidine, can reduce the development of interictal ECG and ventricular morphological changes resulting from kainic acid (KA; 10 mg/kg) induced status epilepticus in a conscious rat model.MethodsUsing simultaneous ECG and electrocorticogram (ECoG) radiotelemetry, animals were randomised into saline controls, saline-pretreated KA and clonidine (100 μg/kg, b.i.d.)-pretreated KA groups. Baseline ECG, ECoG and behavioural score recordings were acquired in conscious animals for 2 h post-KA administration.ResultsBradycardia and low level seizure activity occurred immediately following KA administration. As seizure activity (ECoG spiking and high level seizure behavioural scoring) progressively increased, tachycardia developed. Both QTc prolongation and T wave amplitude were transiently but significantly increased. Clonidine treatment attenuated seizure activity, increased the latency to onset of seizure behaviour and reduced seizure-induced changes in heart rate, QTc interval, and T wave amplitude. Histological examination of the ventricular myocardium revealed hypercontraction band necrosis, inflammatory cell infiltration, and oedema at 48 h post-KA. In contrast, clonidine-treatment in seizure animals preserved tissue integrity and structure.ConclusionThese results demonstrate that KA-induced seizures are associated with altered ECG activity and cardiac structural pathology. We suggest that pharmacological modulation of sympathetic/parasympathetic activity in status epilepticus provides a promising therapeutic approach to reduce seizure-induced cardiomyopathy.     

Benign infantile convulsions associated with mild gastroenteritis: An electroclinical study of 34 patients

PurposeTo analyze the electroclinical features and evolution of patients diagnosed with convulsions with mild gastroenteritis (CwG) from southwest China.MethodsWe reviewed and analyzed the medical records of 34 patients (13 males) diagnosed with CwG and followed-up for at least 12 months.ResultsThe age of onset was 6–29 months and the female/male ratio 1.62. Seizures were generalized in 32 cases. Single seizures in 15 cases were <5 min and multiple seizures 24–48 h after seizure onset were seen in 18 cases. Seizure duration was <1 min in 32.35%, between 1 and 5 min in 55.88%, and between 5 and 10 min in 8.82% of seizures. The average interval between the onset of gastroenteritis and seizures was 2.47 days. Rotavirus antigen was positive in stools in 26.47% of cases. During the acute phase, diazepam and phenobarbital as first-line treatment were effective in 25% and 83.33% of cases, respectively. Fourteen patients showed non-specific anomalies in the interictal electroencephalography. During 12–36 months follow-up, 33 cases showed normal psychomotor development and no seizures.ConclusionsCwG occurred mostly in toddlers. During the acute phase, phenobarbital is more effective in controlling seizures. For a good prognosis, it is unnecessary to administrate long-term anticonvulsants.     

Triggers and techniques in termination of partial seizures

ObjectiveGrowing interest in seizure prediction exists as a means to deliver newer antiepileptic therapies, though patient self-termination of seizures has received little attention.MethodsTwo hundred twenty-three patients able to recognize seizure onset were surveyed in an outpatient epilepsy clinic. A seven-question survey administered prospectively assessed self-reported seizure prediction and clinical techniques used for self-termination. Survey responses targeted percentage predictability of seizures, timing of clinical prediction, likelihood/timing of termination, frequency and effectiveness of methods used, and perspectives of patient and physician belief in self-termination.ResultsTwo hundred twenty-three patients (89 males) with a mean age of 42.7 years, average duration of epilepsy of 20.8 years and monthly mean seizure frequency of 4.1 comprised the study group. Thirty-eight percent completed >75% of the survey. Prior treatment included a mean of 6.0 AEDs (40/192 had surgery); 65% had ongoing seizures. Sixty percent of 223 patients reported a history of an aura, and 39% consistently noted auras for >75% of their current seizures. Of the patients with auras, seizure triggers were reported in 74%, with worry and stress (N = 69), sleep deprivation (N = 60), and missed medication (N = 56) most frequently cited. Seventeen percent were positive/somewhat sure they could predict onset, with approximately 20% noting rapid onset in <15 seconds. Twenty-two of 82 noted that they had some ability to self-terminate their seizures, and 9% were positive that they could do so. Methods to self-terminate were effective (>75% certainty) in 35% (26/75). The primary methods were lying down/resting and taking extra medication.ConclusionThe majority of patients with partial seizures recognize triggers of seizure onset. In addition, more than one-third believe they can effectively self-terminate their partial-onset seizures. Lying down, resting, and taking extra medication were the most common techniques instituted by patients. Correlating clinical symptoms at seizure onset with termination may help improve the sensitivity in seizure prediction.     

The role of altered tissue osmolality on the characteristics and propagation of seizure activity in the intact isolated mouse hippocampus

ObjectivesTo study the role of altered tissue osmolality on the characteristics and propagation dynamics of seizure activity and on interictal activity, in a low-Mg⁺² artificial cerebrospinal fluid (ACSF) model of recurrent seizures, using the immature (P8–P25) intact isolated mouse hippocampus.MethodsRecordings were obtained extracellularly from a single site in the CA1 region and from multiple sites along the septotemporal axis measuring spontaneous epileptiform field activity in ACSFs of different osmolalities.ResultsIn normal osmolar ACSF (310 mOsmol), the average duration of recorded seizures was 90 ± 10 s and the average peak amplitude was 0.9 ± 0.1 mV. In a hypoosmolar ACSF (270 mOsmol), the seizures were significantly prolonged at 165 ± 20 s (p < 0.05) with a peak amplitude of 1.2 ± 0.3 mV, whereas interictal activity was suppressed. Hyperosmolar ACSF (340 mOsmol) reduced the duration (65 ± 15 s) and peak amplitude (0.6 ± 0.1 mV, p < 0.05) from control, but interictal activity was not affected. No differences in seizure recurrence rate were noted in all three osmolar states.ConclusionThe present study, the first to assess of the role of altered tissue osmolality in an intact in vitro preparation, demonstrates that changes in perfusate osmolality play a significant role on the amplitude, duration, and propagation velocity of seizure-like events, and the characteristics of interictal activity, without affecting seizure recurrence rate.SignificanceIncreasing tissue osmolality should be considered as a valid target for anticonvulsant treatment.     

Peri-ictal broadband electrocorticographic activities between 1 and 700 Hz and seizure onset zones in 18 patients

ObjectiveWe investigated the relationship between locations of broadband peri-ictal electrocorticographic activities determined by a semi-automatic detection method and seizure onset zones in medically intractable epilepsy patients.MethodsWe included 18 patients. Peri-ictal periods (−15 to +5 s from the ictal onset) were divided into 4 periods of 5 s duration each in bandwidth from 1 to 700 Hz divided into 11 bins. Thereafter, we calculated the mean overlapping percentage of the maximum amplitude activity electrodes with the seizure onset zone in the total number of seizures in each patient. Significance was considered at an adjusted p-value of 0.05.ResultsBy the maximum amplitude method with the Bonferroni correction, only high-frequency activities (>60 Hz) during −5 to 0 s from the ictal onset were significantly related to seizure onset zones. In post hoc analyses, bands in 60–139 Hz and 4–7 Hz were significantly related to seizure onset zones in the Bonferroni correction. However, after the less conservative Benjamini–Yekutieli correction and with the epileptogenicity index, other bands and periods after −10 s from the ictal onset were also related with seizure onset zones.SignificanceDetailed bands, timings and analytic methods of peri-ictal activities with high relationships to seizure onset zones were identified.     

Semiology of hypermotor (hyperkinetic) seizures

BackgroundHypermotor seizures (HMSs) consist of complex movements involving proximal segments of the limbs and trunk that appear violent and inappropriate for the situation.MethodsWe analyzed hypermotor seizure videos in seizure-free patients (Engel class I) following resective epilepsy surgery. After completion of video analysis, we reviewed EEG and neuroimaging data.ResultsSearch of our epilepsy surgery database yielded 116 patients classified as having hypermotor seizures between 1996 and 2013. From this subset, 17/31 (55%) patients had been seizure-free for > 6 months (mean follow-up: 3.3 years). Mean seizure duration was 35 s (range: 6–91 s), of which the HM phase lasted a mean of 22 s (range: 3–53 s). In 16 patients (95%), hypermotor activity was seen at or within 10 s of clinical seizure onset.Type I semiology occurred in 6 patients, type II semiology in 10 patients, and 1 patient exhibited features of both. Type I and type II semiologies were noted in patients who had frontal lobe as well as extrafrontal resections. Nonversive head and body turning occurred in 10 patients (ranging from 90° to 270°) which was ipsilateral to the side of resection in all patients and seen both in frontal and extrafrontal resections. Six out of eleven patients with abnormal MRI and 4/6 patients with nonlesional MRI underwent invasive EEG evaluation. Eight patients (47%) had frontal lobe resection, 4/17 (23%) patients had temporal lobe resection, and one patient each had parietal lobe, insular, temporoparietooccipital, or motor sparing resection; 1 patient had functional hemispherectomy.ConclusionHypermotor semiology typically occurs at or within 10 s after seizure onset. Ipsilateral head/body turning appears to be of lateralizing value whereas asymmetry of limb movement was not lateralizing. Hypermotor semiology is most often seen in frontal lobe epilepsy but may occur in seizures arising from other locations.     

The value of video-EEG monitoring to diagnose juvenile myoclonic epilepsy

ObjectiveA diagnostic accuracy of conventional electroencephalography (EEG) is approximately 50% at best. We aimed to determine the accuracy of video-EEG monitoring (VEM) for a correct diagnosis and the feasibility of its clinical application. The data from all 55 patients (M:F = 31:24) with juvenile myoclonic epilepsy (JME) who underwent VEM were reviewed according to the clinical history, brain imaging and video-EEG findings.ResultsAge at seizure onset ranged from 10 to 25 (15.5 ± 2.7 years). The age at VEM ranged from 15 to 46 (21.8 ± 5.8 years) and 57% (29/51) showed seizures. Of those, 20 patients (69%) showed myoclonic jerks alone, whereas 3 (10%) showed generalized seizures alone. Both of these conditions were observed in 6 patients (21%). Interictal abnormalities alone without clinical seizures were detected in 16 patients (31%). Atypical semiologies such as asymmetric myoclonus or versive seizures were observed in 18 patients (35%) during video monitoring. Interestingly three patients complained of visual aura on history. The duration of VEM ranged from 1 to 6 days (1.8 ± 1.1). Overall, 88% of patients showed an EEG abnormality with/without seizure, concordant with JME. Among 10 patients with a normal conventional EEG before VEM, 9 showed interictal or ictal EEG abnormalities during approximately 1-day of VEM.ConclusionsVEM for 1 or 2 days is appropriate for making a correct diagnosis of JME, especially in patients having an atypical semiology and a normal result on the conventional EEG.     

Duration of focal complex,secondarily generalized tonic–clonic,and primarily generalized tonic–clonic seizures — A video-EEG analysis

IntroductionIdentifying seizures with prolonged duration during video-electroencephalographic (EEG) monitoring is of importance to inform clinicians when to start emergency treatment of seizures to prevent status epilepticus. The aims of this study were to assess the clinical and EEG seizure duration (SD) in consecutive patients with epilepsy who underwent prolonged video-EEG monitoring and to identify a seizure type-dependent time point to start emergency treatment based on the likelihood that seizures will not stop spontaneously. Furthermore, we sought to determine predictors of SD and explored the relationship between antiepileptic drug (AED) serum levels and SD.Material and methodsWe retrospectively analyzed 1796 seizures in 200 patients undergoing video-EEG monitoring between January 2006 and March 2008.ResultsFocal simple seizures lasted significantly shorter (clinical SD: 28 s, EEG SD: 42 s) compared with focal complex seizures (clinical SD: 64 s, EEG SD: 62 s), and both seizure types lasted significantly shorter compared with secondarily generalized tonic–clonic seizures (GTCSs; clinical SD: 90 s, EEG SD: 96 s). There was no difference between the duration of the convulsive phase of primary GTCSs (defined as nonfocal) and that of secondarily GTCSs (each 65 s). Cumulative clinical SD (99%) was 7 min in focal complex seizures and 11 min in focal simple seizures. Mixed linear regression model demonstrated that history of status epilepticus (P = 0.034), temporal lobe seizure onset (P = 0.040), and MRI lesions (P = 0.013) were significantly associated with logarithmic EEG SD in focal epilepsies recorded with scalp electrodes. We found significant negative correlations between the AED serum level and the EEG SD in patients treated with monotherapy: carbamazepine (P < 0.001), levetiracetam (P = 0.001), oxcarbazepine (P = 0.001), and valproic acid (P = 0.038) but not with lamotrigine monotherapy and EEG SD.DiscussionBased on the results of this study, we propose 2 min of convulsive seizure activity (irrespective of focal or generalized onset) as a prolonged seizure, which could serve as a time point to consider treatment to prevent status epilepticus. In focal complex seizures, we suggest an upper limit of 7 min, and in focal simple seizures 11 min, as definition of prolonged seizures. History of status epilepticus, temporal seizure onset, and lesional MRI findings are factors associated with significantly longer SD. Negative correlations of carbamazepine, levetiracetam, oxcarbazepine, and valproic acid serum levels and SD suggest a prolonging effect on seizures during withdrawal of these AEDs during video-EEG monitoring sessions.This article is part of a Special Issue entitled “Status Epilepticus”.     

Effect of cortical cooling on interictal epileptiform activities

ObjectiveTo determine if applying chilled solution to exposed cerebral cortex can reduce interictal epileptiform activities in patients during surgery.MethodsElectrocorticography was used to record the epileptiform activity of 12 patients (ages 18–53) undergoing cortical mapping and resection surgery. Interictal spikes were counted at baseline and compared with spikes after applying room temperature and chilled Lactated Ringer's or normal saline solution.ResultsCortical irrigation with 150-cm³, chilled (4 °C) normal saline solution reduced the mean number of interictal spikes from 11.46 to 4.87 spikes per minute (p = 0.04). There was no significant reduction in the epileptic spike frequency when room temperature normal saline was used.ConclusionThe application of chilled solution directly to the cortex can reduce interictal epileptiform activities, suggesting that seizure potential can be suppressed to avoid evoked seizures during intraoperative surgery.     

Comparison between febrile and afebrile seizures associated with mild rotavirus gastroenteritis

PurposeWe aimed on identifying the differences of febrile and afebrile seizures associated with mild rotavirus gastroenteritis (RVGE) in the pediatric population.MethodMedical charts of pediatric patients who had been admitted between July 1999 and June 2011 due to RVGE were retrospectively reviewed. Subjects were ultimately divided into three groups; ‘no seizure’ (NS: patients without seizure), ‘febrile seizure’ (FS: patients with fever during seizure), ‘afebrile seizure’ (AFS: patients without fever during seizure). Comparisons between groups were carried out on demographic and clinical characteristics, laboratory test results, electroencephalogram findings, brain magnetic resonance imaging findings, antiepileptic treatment, and prognosis.ResultsAmong the 755 subjects who had been admitted due to mild rotavirus enteritis, 696 (90.3%) did not have any seizures, 17 (2.2%) had febrile seizures, 42 (5.5%) had afebrile seizures. The duration of gastrointestinal symptoms before the onset of seizures were significantly shorter in the FS group compared to the AFS group (1.3 ± 0.8 vs. 2.8 ± 1.0 days; p < 0.0001). A single seizure attack was significantly higher in the AFS group (3.0 ± 1.6 vs. 1.7 ± 1.0 episodes; p = 0.0003), and the frequency of seizures that were of focal type with or without secondary generalization were significantly higher in the AFS group (33.3% vs. 6.0%; p = 0.0139). All patients among the FS and AFS group had not received further antiepileptic treatment after discharge, and none developed epilepsy during follow up period.ConclusionDespite some differences in seizure characteristics, both febrile and afebrile seizures associated with mild RVGE were mostly benign with a favorable prognosis.     

Seizure prediction in hippocampal and neocortical epilepsy using a model-based approach

ObjectivesThe aim of this study is to develop a model based seizure prediction method.MethodsA neural mass model was used to simulate the macro-scale dynamics of intracranial EEG data. The model was composed of pyramidal cells, excitatory and inhibitory interneurons described through state equations. Twelve model’s parameters were estimated by fitting the model to the power spectral density of intracranial EEG signals and then integrated based on information obtained by investigating changes in the parameters prior to seizures. Twenty-one patients with medically intractable hippocampal and neocortical focal epilepsy were studied.ResultsTuned to obtain maximum sensitivity, an average sensitivity of 87.07% and 92.6% with an average false prediction rate of 0.2 and 0.15/h were achieved using maximum seizure occurrence periods of 30 and 50 min and a minimum seizure prediction horizon of 10 s, respectively. Under maximum specificity conditions, the system sensitivity decreased to 82.9% and 90.05% and the false prediction rates were reduced to 0.16 and 0.12/h using maximum seizure occurrence periods of 30 and 50 min, respectively.ConclusionsThe spatio-temporal changes in the parameters demonstrated patient-specific preictal signatures that could be used for seizure prediction.SignificanceThe present findings suggest that the model-based approach may aid prediction of seizures.     

Seizure prediction in patients with mesial temporal lobe epilepsy using EEG measures of state similarity

ObjectivesIn patients with intractable epilepsy, predicting seizures above chance and with clinically acceptable performance has yet to be demonstrated. In this study, an intracranial EEG-based seizure prediction method using measures of similarity with a reference state is proposed.Methods1565 h of continuous intracranial EEG data from 17 patients with mesial temporal lobe epilepsy were investigated. The recordings included 175 seizures. In each patient the data was split into a training set and a testing set. EEG segments were analyzed using continuous wavelet transform. During training, a reference state was defined in the immediate preictal data and used to derive three features quantifying the discrimination between preictal and interictal states. A classifier was then trained in the feature space. Its performance was assessed using testing set and compared with a random predictor for statistical validation.ResultsBetter than random prediction performance was achieved in 7 patients. The sensitivity was higher than 85%, the warning rate was less than 0.35/h and the proportion of time under warning was less than 30%.ConclusionSeizures are predicted above chance in 41% of patients using measures of state similarity.SignificanceSensitivity and specificity levels are potentially interesting for closed-loop seizure control applications.     

Seizure suppression by EEG-guided repetitive transcranial magnetic stimulation in the rat

ObjectiveTo test the anticonvulsive potential of a range of repetitive transcranial magnetic stimulation (rTMS) frequencies by novel methods for simultaneous EEG and rTMS in a rat seizure model.MethodsSeizures were triggered by intraperitoneal kainic acid (KA; 10 mg/kg). Rats (n = 21) were divided into three groups in which individual seizures were treated with rTMS trains at one of three frequencies: 0.25, 0.5 or 0.75 Hz. EEG was continuously viewed by an operator who identified each seizure onset. Consecutive seizures in each animal were (1) treated with active rTMS, (2) treated with sham rTMS, or (3) were untreated. EEG was re-analyzed post hoc by visual inspection, and seizure durations were compared within and between treatment groups.ResultsKA-induced seizures were abbreviated by 0.75 Hz (P = 0.019) and 0.5 Hz (P = 0.033) active EEG-guided rTMS. In contrast, neither active 0.25 Hz rTMS nor the control conditions affected seizure duration (P > 0.2).ConclusionsWe demonstrate that EEG-guided rTMS can suppress seizures in the rat KA epilepsy model, and that the effect is frequency dependent, with 0.75 and 0.5 Hz rTMS being superior to 0.25 Hz rTMS.SignificanceThese data support the use of rat seizure models in translational research aimed at evaluation and development of effective rTMS anticonvulsive protocols. We also offer a proof of principle that real-time analysis of EEG can be used to guide rTMS to suppress individual seizures.     

Is ‘burned-out hippocampus’ syndrome a distinct electro‐clinical variant of MTLE-HS syndrome?

AimTo study the clinical, electrophysiological and imaging characteristics of patients with unilateral mesial temporal lobe epilepsy (MTLE) with contralateral ictal onset on scalp EEG, viz. ‘burned-out hippocampus’ syndrome (MTLE-BHS).MethodsMTLE-BHS was defined as TLE with unilateral hippocampal sclerosis (HS) without any dual pathology on MRI and contralateral ictal onset on scalp EEG, unlike in classical hippocampal sclerosis (HS). Consecutive “MTLE-BHS” patients evaluated at our Centre for Comprehensive Epilepsy Care from January 2005 to July 2014 were studied. Twenty-five cases of classic MTLE-HS operated during the same period were also analyzed for comparison.ResultsSeventeen patients were diagnosed to have MTLE-BHS. Mean age of seizure onset was 9.5 ± 7.7 years and the mean duration of epilepsy was18.2 ± 7.3 years. Epigastric aura was more common in MTLE-HS and fear, secondary generalized seizures and temporal polar changes on MRI were more prevalent in the MTLE-BHS subgroup. In the latter group, five (29%) exhibited seizure semiology and 2 (12%) had interictal discharges discordant to the side of MTS. Eight (47%) patients in the MTLE-BHS sub-group had normal medial temporal volume on Scheltens scale. Eight patients among MTLE-BHS underwent surgery (4 following intracranial monitoring that localized to the side of HS) with Engel class I outcome at 1 year follow-up in 6 and Engel class II outcome in 2.ConclusionAttenuation of ipsilateral fast ictal rhythms on scalp EEG as well as neocortical changes are likely to be deterministic factors for MTLE-BHS as opposed to the severity of hippocampal atrophy. Considering good post-operative outcomes, intracranial monitoring for surgical selection is not mandatory in MTLE-BHS despite discordant semiology and ictal onset, in the presence of inter-ictal, functional imaging and neuropsychology data concordant to the side of HS.     

Is elevated pre-ictal heart rate associated with secondary generalization in partial epilepsy?

BackgroundPeople with epilepsy are at risk for sudden unexpected death. Cardiac arrhythmia is one possible mechanism. We have studied seizure-related changes in cardiac rhythm.MethodsVideo-EEG and ECG from 38 patients with epileptic seizures during long-term monitoring for investigation of partial epilepsy with ictal impairment of consciousness were obtained. Seizures were classified as either complex partial or secondarily generalized. Inter-ictal, pre-ictal, ictal and post-ictal heart rate was calculated for the first recorded seizure.ResultsHeart rate during the pre-ictal period was higher (p = 0.016) in patients with secondarily generalized seizures (n = 11) compared to patients with complex partial seizures (n = 27). Heart rate was also elevated during and after generalized seizures (p < 0.015). Inter-ictal heart rate was not different in patients with secondary generalization compared to patients with partial seizures.ConclusionWe report elevated heart rate prior to partial seizure onset in those attacks which become secondarily generalized compared to seizures which remain localized. The finding may be relevant for the understanding of sudden death in epilepsy.     

Visual and semiautomated evaluation of epileptogenicity in focal cortical dysplasias — An intracranial EEG study

IntroductionThe aim of the study was the evaluation of the added value of depth to subdural electrodes in delineating epileptogenicity of focal cortical dysplasias (FCDs) and to test the Epileptogenicity Index (EI) in this setting.Material and methodsFifteen patients with FCD underwent iEEG with subdural and depth electrodes. Visual/EI analysis was performed in up to three habitual seizures per patient.ResultsVisual analysis: Grid onset seizures (n = 10) started in electrodes overlying the lesion in 7 and remote from it in 3 cases. Depth onset seizures (n = 7) affected only intralesional contacts in 4, intra- and extralesional in 2, and exclusively extralesional in 1 patient. Seizures started in depth and grid contacts simultaneously in 2 cases.EI analysis: The EI completely confirmed visual localization of seizure onset in 8 cases and depicted ictal onset-time accurately in 13. Beta/gamma ictal patterns were most reliably captured.Impact on surgical decision: Resection outline differed from MRI lesion in 7 patients based on grid and in three based on depth electrode information.DiscussionIn FCD, seizures can be generated within gyral/deep tissue appearing normal on imaging.ConclusionInvestigating FCD with subdural and depth electrodes is efficient to outline the seizure onset zone. The EI is a helpful additional tool to quantify epileptogenicity. Specific ictal patterns are prerequisite for reliable results.     

Electroclinical aspects and therapy of Han patients with juvenile myoclonic epilepsy in northern China

ObjectiveThe objective of this study was to assess the electroclinical aspects and treatment of Han patients with juvenile myoclonic epilepsy (JME) in northern China.MethodsOne hundred fifty-six outpatients with JME from six epilepsy centers, between January 2011 and June 2012, were followed up for at least two years. They underwent twenty-four-hour video-EEG recording. Brain imaging was performed using magnetic resonance imaging (MRI). Clinical aspects, electroencephalographic (EEG) features, and antiepileptic drugs (AEDs) received were reviewed.ResultsGeneralized tonic–clonic seizures (GTCS) were found in 150/156 patients. Delay of diagnosis was 4.60 ± 9.92 years. Photosensitivity was more common in eye closure condition during IPS in patients with JME; in addition, patients with JME with myoclonic seizures (MS) and GTCS as seizure types were likely to present photoparoxysmal responses (PPRs). The 82 nontreated patients showed a median latency to first interictal or ictal generalized spike–wave discharge (GSWD) of 50 min (IQR: 22–102 min). The first GSWDs were recorded in 63%, 76%, 90%, and 98% patients within one, two, three, and 4 h, respectively; only 2% of patients had first GSWDs after 4 h. One hundred eleven patients (111/156) chose extended-release valproate (VPA) at daily doses ≤ 1000 mg. The percentages of seizure-free patients among MS, GTCS, and absence seizure (AS) groups were 88.3%, 99.0%, and 94.9%, respectively.ConclusionPhotoparoxysmal responses were more common in patients with JME with MS and GTCS and rare in patients with JME with MS and AS in northern Chinese Han patients. Most patients with JME in northern China chose VPA as first therapeutic choice, and low dose (500 to 1000 mg daily) of extended-release VPA may be an optimal choice for them. Video-EEG monitoring for at least 4 h may be helpful in detecting the first interictal or ictal GSWD in patients with potential JME. Moreover, video-EEG monitoring performed at about 9 o'clock in the morning with patients in the awake state might be useful to find the first GSWD. For JME diagnosis, Class II criteria are more helpful than Class I counterparts, the latter yielding more missed diagnoses.     

Rufinamide for refractory focal seizures: An open-label,multicenter European study

PurposeThe present study aimed to assess the efficacy and tolerability of rufinamide as adjunctive drug for the treatment of a large series of children, adolescents and adults with refractory cryptogenic or symptomatic focal epilepsy.MethodsPatients were recruited in a prospective, add-on, open-label treatment study from six Italian and one German centers for pediatric and adolescent epilepsy care. Inclusion criteria were: (1) age 3 years or more; (2) diagnosis of cryptogenic or symptomatic focal epilepsy refractory to at least three previous antiepileptic drugs (AEDs), alone or in combination; (3) more than one seizure per month in the last 6 months; (4) use of at least one other AED, but no more than three, at baseline; (5) informed consent from parents and/or caregivers.ResultsSixty-eight patients (40 males, 28 females), aged between 3 and 63 years (mean 19.9 years, median 16.0) ± SD 12.58, with cryptogenic (28 pts, 41.2%) or symptomatic focal epilepsy (40 pts, 58.8%), were recruited in the study. After a mean follow-up period of 10.4 ± 10.29 months, twenty-two patients (32.3%) had a 50–99% seizure reduction, and none became seizure-free. Twelve patients (17.6%) had a 25–49% seizure decrease, while in 30 (44.1%) seizure frequency was unchanged. A seizure worsening was reported in 5 patients (7.3%). A better response to rufinamide occurred in frontal lobe seizures (51.6%) and secondary generalized tonic–clonic seizures (50%).ConclusionRufinamide was effective against focal-onset seizures, particularly in the treatment of secondary generalized frontal lobe seizures.