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”.     

Predictors of seizure occurrence in children undergoing pre-surgical monitoring

PurposeLong-Term-Monitoring (LTM) is a valuable tool for seizure localization/lateralization among children with refractory-epilepsy undergoing pre-surgical-monitoring. The aim of this study was to examine the factors predicting occurrence of single/multiple seizures in children undergoing pre-surgical monitoring in the LTM unit.MethodsChart review was done on 95 consecutive admissions on 92 children (40 females) admitted to the LTM-unit for pre-surgical workup. Relationship between occurrence of multiple (≥3) seizures and factors such as home seizure-frequency, demographics, MRI-lesions/seizure-type and localization/AED usage/neurological-exam/epilepsy-duration was evaluated by logistic-regression and survival-analysis. Home seizure-frequency was further categorized into low (up-to 1/month), medium (up-to 1/week) and high (>1/week) and relationship of these categories to the occurrence of multiple seizures was evaluated. Mean length of stay was 5.24 days in all 3 groups.ResultsHome seizure frequency was the only factor predicting the occurrence of single/multiple seizures in children undergoing presurgical workup. Other factors (age/sex/MRI-lesions/seizure-type and localization/AED-usage/neurological-exam/epilepsy-duration) did not affect occurrence of single/multiple seizures or time-to-occurrence of first/second seizure.Analysis of the home-seizure frequency categories revealed that 98% admissions in high-frequency, 94% in the medium, and 77% in low-frequency group had at-least 1 seizure recorded during the monitoring. Odds of first-seizure increased in high vs. low-frequency group (p = 0.01). Eighty-nine percent admissions in high-frequency, 78% in medium frequency, versus 50% in low-frequency group had ≥3 seizures. The odds of having ≥3 seizures increased in high-frequency (p = 0.0005) and in medium-frequency (p = 0.007), compared to low-frequency group. Mean time-to-first-seizure was 2.7 days in low-frequency, 2.1 days in medium, and 2 days in high-frequency group. Time-to-first-seizure in high and medium-frequency was less than in low-frequency group (p < 0.0014 and p = 0.038).ConclusionMajority of the admissions (92%) admitted to the LTM-unit for pre-surgical workup had at-least one seizure during a mean length of stay of 5.24 days. Home seizure-frequency was the only predictor influencing occurrence of single/multiple seizures in the LTM unit. Patients with low seizure-frequency are at risk for completing the monitoring with less than the optimum number (<3) of seizures captured.     

Effects of low-frequency electrical stimulation of the anterior piriform cortex on kainate-induced seizures in rats

ObjectiveRecent evidence in animals and humans suggests that low-frequency stimulation (LFS) has significant antiepileptic properties. The anterior piriform cortex (APC) is a highly susceptible seizure-trigger zone and may be critical for the initiation and propagation of seizures originating from cortical and limbic foci.We used the kainic acid (KA) seizure model in rats to assess the therapeutic effect of LFS of the APC on seizures.MethodsAdult male Sprague–Dawley rats were implanted with electrodes in the left APC and recording electrodes bilaterally in the hippocampal CA3 regions. Rats were monitored continuously with video-EEG after the emergence of spontaneous recurrent seizures that followed induction of status epilepticus by intraperitoneal KA. After two weeks of baseline recordings to determine seizure frequency, LFS of the APC was applied 60-min On 15-min Off, for two weeks with 1 Hz biphasic square waves, 0.2 ms pulse width, at 200 μA. Another 2-week period of video-EEG monitoring was done after the cessation of LFS to study the carry-over effect. Changes in seizure frequency, severity, and duration between baseline, during LFS, and post-LFS were analyzed using the Poisson regression model.ResultsOverall seizure frequency decreased during the post-LFS period to 5% of that at baseline (p = 0.003). Severe seizures (stages 4 and 5 on the Racine scale) decreased to 0% of the baseline during the post-LFS period.ConclusionsTwo weeks of LFS of the APC reduced spontaneous seizure frequency and severity in the KA model with the effect outlasting the stimulation. Our findings suggest that the APC can be an important therapeutic target for stimulation in epilepsy.     

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.     

Acute and spontaneous seizure onset zones in the intraperitoneal kainic acid model

ObjectiveHippocampal monitoring is often used in the intraperitoneal kainic acid (KA) seizure model for detection and quantification of early ictal activity. Here, we investigated extra-hippocampal seizure onset zones (SOZs) in this model.MethodsEight male Sprague Dawley rats implanted with depth electrodes were continuously recorded during intraperitoneal KA injections until status epilepticus (SE) was induced. Another group of four rats was monitored chronically up to two weeks after emergence of spontaneous recurrent seizures. All rats had hippocampal electrodes. Other sampled brain regions included, among others, the claustrum, piriform cortex, and orbital cortex. Seizures recorded with video-EEG were visually analyzed.ResultsIn the 58 seizures recorded during KA injections, the SOZ was extrahippocampal in 7 (12%), diffuse in 29 (50%), and hippocampal in 22 (38%). Of the 14 spontaneous seizures recorded, none were solely extrahippocampal, 10 (71%) were diffuse, and 4 (29%) were of hippocampal onset. All extra-hippocampal seizures propagated to the hippocampus within 4 to 50 s (mean = 14, n = 7). No distinctive semiological manifestations correlated with the SOZs.SignificanceWe conclude that seizures can have multifocal SOZs in the KA model. This finding is important to consider when using this model, among other purposes, to screen for new therapies, study pharmacoresistance, or investigate comorbidities of epilepsy.     

Epilepsy of infancy with migrating focal seizures: Six patients treated with bromide

PurposeWe present six patients with epilepsy of infancy with migrating focal seizures (EIMFS) and provide a comprehensive evaluation of potassium bromide therapy.MethodBetween February 1, 2007 and July 31, 2012, six patients who met the diagnostic criteria of EIMFS were treated with potassium bromide. Potassium bromide was added to other antiepileptic drugs (AEDs) in doses ranging from 30 to 80 mg/kg/day. Plasma bromide concentration was monitored. A therapeutic bromide concentration between 75 and 125 mg/dL was considered to be ideal.ResultsFour of six children responded well to bromide. One of these patients became seizure free, but remained severely mentally impaired. Two boys, currently 4 and 6 years of age, respectively, have monthly seizures as well as axial hypotonia and severe language impairment. The fourth child responded well to bromide, having only weekly seizures and moderate psychomotor retardation. The patient who became seizure free improved visual contact and head control. In the other three patients with good control, the seizures became focal without secondary generalization and status epilepticus and hospital admission was not required. The remaining two patients did not respond well to bromide. Adverse effects were seen in three cases: vomiting in one, drowsiness in another, and acneiform eruption in the face in the remaining patient. Adverse effects resolved with dose reduction.ConclusionEarly treatment with bromides should be considered in EIMFS to control the seizures and status epilepticus and to avoid progressive cognitive impairment. Potassium bromide is an old AED. Plasma concentration monitoring should be considered.     

Circadian patterns of generalized tonic-clonic evolutions in pediatric epilepsy patients

ObjectiveTo investigate the sleep/wake, day/night, and 24-h periodicity of pediatric evolution to generalized tonic–clonic seizures (GTC).MethodsCharts of 407 consecutive patients aged 0–21 years undergoing continuous video-EEG monitoring for epilepsy were reviewed for the presence of GTC evolution. Seizures were characterized according to 2001 ILAE terminology. Charts were reviewed for EEG seizure localization, MRI lesion, and for seizure occurrence in 3-h time blocks, out of sleep or wakefulness, and during the day (6 AM–6 PM) or night. Analysis was done with binomial testing. Regression models were fitted using generalized estimating equations with patients as the cluster level variable.Results71 patients (32 girls, mean age 12.63 ± 5.3 years) had 223 seizures with GTC evolution. Sleep/wake seizure distribution predicted tonic–clonic evolution better than time of day, with more occurring during sleep (p < 0.001). Tonic–clonic evolution occurred most frequently between 12–3 AM and 6–9 AM (p < 0.05). Patients with generalized EEG onset had more tonic–clonic evolution between 9 AM and 12 PM (p < 0.05). Patients with extratemporal focal seizures were more likely to evolve during sleep (p < 0.001); this pattern was not found in patients with temporal or generalized seizure onset on EEG. Patients without MRI lesions were more likely to evolve between 12 AM and 3 AM (p < 0.05), in the sleeping state (p < 0.001), and at night (p < 0.05). Logistic regression revealed that sleep and older patient age were the most important predictors of GTC evolution.ConclusionGTC evolution occurs most frequently out of sleep and in older patients. Our results may assist in seizure prediction, individualized treatment patterns, and potentially complication and SUDEP prevention.     

Background intracranial EEG spectral changes with anti-epileptic drug taper

ObjectivePrevious studies have revealed a surprising decrease in spike counts and Teager energy between on- and off-AEDs states during intracranial EEG (icEEG) monitoring. Here, we expand the measures evaluated to icEEG power and frequency band power.MethodsTwo icEEG epochs, on- and off-AEDs, each 1 h in duration, were studied for each of 21 unselected adult patients. Spike counts, Teager energy and total power were evaluated for each electrode contact. Power was also evaluated for delta (0–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta (13–25 Hz), gamma (25–55 Hz) and high (65–128 Hz) frequency bands.ResultsA decrease in power accompanies AED taper and the previously reported decrease in spike counts and Teager energy. The decrease in power was underpinned by a spatially widespread and broadband decrease in power in delta through gamma frequency bands with maximum decrease in the lowest frequency bands. An increase in high-frequency power was observed in some patients.ConclusionsThere is a decrease in spike counts, Teager energy and power from on- to off-AEDs state during intracranial monitoring. The decrease in power is spatially widespread and broadband including power in the delta through gamma frequency bands.SignificanceThe decrease in cortical activity with AED taper suggests that seizure generation during intracranial monitoring may not be mediated solely by poorly regulated cortical excitation.     

Bimodal ultradian seizure periodicity in human mesial temporal lobe epilepsy

BackgroundMesial temporal lobe epilepsy (mTLE) has been suggested to follow a circadian rhythm. Previous research found an afternoon peak in mTLE seizure occurrence. We evaluated the pattern of seizure occurrence in patients with well-localized mTLE and hypothesized that peak seizure frequency would occur in the afternoon, and that this pattern would not be altered by age, gender, or seizure focus.MethodsWe retrospectively identified consecutive mTLE patients with a seizure-free outcome following anterior temporal lobectomy from 1993 to 2004 with video-EEG captured seizures. We recorded and plotted the 24-h clock time for each seizure and performed cosinor analysis. SAS Proc GLIMMIX was used to fit the linearized transform of the cosinor model. Negative binomial regression fitted by the generalized estimating equations (GEE) method was also performed to estimate and compare the mean seizure rates over a 24-h day.ResultsSixty mTLE patients monitored between 2 and 16 days were analyzed. Mean (standard deviation), median number of seizures per subject were 10.47(7.86), 9.00. Cosinor plots indicated that the function had two modes: 7–8 a.m. and 4–5 p.m. GEE analysis was consistent with peak seizure frequency occurrence at 6–8 a.m. (p < 0.0001) and 3–5 p.m. (p < 0.01).ConclusionsWe found a bimodal pattern of seizure occurrence in human mTLE, with peak seizure frequencies occurring between 6–8 a.m. and 3–5 p.m. confirming an afternoon peak, as well as a previously unsuspected morning peak in seizure occurrence that provides rationale for future investigations of antiepileptic drug chronopharmacology and informs patient counseling regarding patterns of seizure occurrence.     

Epidemiology of uncontrolled epilepsy in the Al-Kharga District,New Valley,Egypt

BackgroundDespite advances in treating epilepsy, uncontrolled epilepsy continues to be a major clinical problem. Therefore, this work aimed to study the epidemiology of uncontrolled epilepsy in Al-Kharga District, New Valley.MethodsThis study was carried out in 3 stages via door-to-door screening of the total population (62,583 persons). All suspected cases of epilepsy were subjected to case ascertainment, conventional ElectroEncephaloGraphy (EEG), and the Stanford-Binet Intelligence Scale. Patients who had been receiving suitable anti-epileptic drugs (AEDs) over the previous 6 months and were having active seizures were considered uncontrolled, according to Ohtsuka et al.²³ The patients underwent serum AED level estimation, video EEG monitoring, and brain MRIs. Fifty age- and gender-matched patients with controlled epilepsy were chosen for statistical analysis and compared with true intractable patients.ResultsA total of 437 patients with epilepsy were identified, 30.7% of whom (n = 134/437) were uncontrolled, with a prevalence of 2.1/1000. A total of 52.2% of uncontrolled patients (n = 70/134) were inappropriately treated, while 47.8% (n = 64/134) were compliant with appropriate treatments. Video monitoring EEG of compliant uncontrolled patients demonstrated that 78.1% patients (n = 50/64) had definite epilepsy, while 21.9% (n = 14/64) had psychogenic non-epileptic seizures (PNES). A logistic regression analysis revealed that status epilepticus, focal seizures, and mixed seizure types were risk factors for intractability.     

Seizure frequency in children with epilepsy: Factors influencing accuracy and parental awareness

RationaleThe objective of this study was to ascertain the accuracy of clinical reports to determine the seizure frequency in children diagnosed with epilepsy.MethodsWe reviewed the clinical record of 78 children (January–May of 2006) admitted to the EEG–video monitoring with epilepsy diagnosis. Clinical reports of parents and the files of EEG–video monitoring were reviewed to determine parents’ awareness for seizures.ResultsDuring video–EEG monitoring, 1244 were recorded on 78 children. Seizures were confirmed in 1095 of which 472 were correctly reported (38%) by parents whereas 623 remained under-reported (50%). Parents’ report thus had a sensitivity of 43%, positive predictive value of 76% to identify seizures. Based on the EEG–video monitoring, seizures were reported accurately in 22 (28%) and under-reported in 38 (49%) children. In the under-reported group, none of the seizures were recognized in 10 (13%), only a portion identified in 28 children. The parents’ report describing seizure frequency has limited value for young children (p = 0.01) and children with absence seizures (p = 0.03). However, clinical reports were accurate for the children with developmental delay (p < 0.06) or not being on any anticonvulsant drug (AED) therapy (p = 0.02).ConclusionOur results indicate that a significant number of seizures remain under-reported by parents of children with epilepsy. The current study underscores that the seizure frequency should be interpreted with caution for young children and children with absence seizures. Video–EEG recording has a complimentary role to the clinical observation for the accurate assessment of seizure frequency in children.     

Rectal carbamazepine as effective long-acting treatment after cluster seizures and status epilepticus

Carbamazepine (CBZ) is the gold standard antiepileptic drug (AED) for focal onset seizures. Despite CBZ being the benchmark AED, with readily available therapeutic drug monitoring, patients presenting with recurrent secondarily generalized tonic–clonic (or cluster) seizures or generalized tonic–clonic status epilepticus (SE) are primarily treated with other long-acting agents. The aim of the study was to examine the potential use of rectal (PR) CBZ as alternative long-acting treatment to parenteral AEDs following the termination of cluster seizures or SE with acute intravenous therapies. Oral CBZ syrup was given PR using 400-mg equivalent aliquots. Serum CBZ levels were requested after administration to confirm achievement of minimum therapeutic levels (total CBZ > 20 μmol·L^− 1). Where levels were subtherapeutic, the procedure was repeated using 400-mg CBZ bolus aliquots until therapeutic levels were achieved. Seven patients received PR CBZ to manage cluster seizures or SE following the initial termination of acute seizures with IV therapies including benzodiazepines. Six patients had no prior history of seizures, and 1 patient with a prior history was not taking AED therapy at the time of presentation. All patients subsequently remained seizure-free, and therapeutic CBZ levels were achieved in 6 of the 7 subjects within 5–10 h of initial CBZ dosing. In conclusion, the present study reports 7 patients who were safely and effectively treated with PR CBZ, which proved to be a viable and safe alternative to parenteral AEDs for maintenance of seizure freedom.     

A case–control study of wicket spikes using video-EEG monitoring

PurposeTo investigate clinical characteristics associated with wicket spikes in patients undergoing long-term video-EEG monitoring.MethodsA case–control study was performed in 479 patients undergoing video-EEG monitoring, with 3 age- (±3 years) and gender-matched controls per patient with wicket spikes. Logistic regression was utilized to investigate the association between wicket spikes and other factors, including conditions that have been previously associated with wicket spikes.ResultsWicket spikes were recorded in 48 patients. There was a significantly higher prevalence of dizziness/vertigo (p = 0.002), headaches (p = 0.005), migraine (p = 0.015), and seizures (p = 0.016) in patients with wickets. The majority of patients with wicket spikes did not exhibit epileptiform activity on EEG; however, patients with history of seizures were more likely to have wickets (p = 0.017). There was no significant difference in the prevalence of psychogenic non-epileptic seizures between the groups. Wickets were more common on the left, during sleep, and more likely to be first recorded on day 1–2 of monitoring.ConclusionsPatients with wicket spikes are more likely to have dizziness/vertigo, headaches, migraine, and seizures. Patients with history of seizures are more likely to have wickets. The prevalence of psychogenic non-epileptic seizures is not significantly higher in patients with wickets.     

Gender and age influence in daytime and nighttime seizure occurrence in epilepsy associated with mesial temporal sclerosis

ObjectivesThe aim of this study was to analyze the daytime and nighttime seizure distribution during video-EEG monitoring in patients with epilepsy associated with unilateral mesial temporal sclerosis (MTS) and the role of gender, age, and lesion side on 24-hour seizure distribution.MethodsWe studied 167 consecutive adult (age ≥ 16 years) patients with epilepsy associated with unilateral mesial temporal sclerosis that had three or more recorded seizures during continuous video-EEG monitoring with a minimum recording time period of 24 h. Seizure onset time was classified according to occurrence in six 4-hour periods.ResultsSeven hundred thirty-five seizures were evaluated. We observed two higher seizure occurrence periods: 08:01–12:00 (p = 0.001) and 16:01–20:00 (p = 0.03). Significantly fewer seizures were observed between 0:01 and 4:00 (p = 0.01). Nonuniform seizure distribution was noted in women (p < 0.0001), in young patients (less than 45 years of age) (p < 0.0001), and in both patients with left (p = 0.03) and patients with right mesial temporal sclerosis (p = 0.008). Men presented uniform seizure occurrence distribution (p = 0.15). Women had fewer seizures than expected and fewer seizures than men between 0:01–04:00 (p < 0.0001 and p = 0.0015, respectively) and 04:01–08:00 (p = 0.01 and p = 0.03, respectively). Young patients (age < 45 years) had two seizure occurrence peaks, 08:01–12:00 (p = 0.016) and 16:01–20:00 (p = 0.004). Middle-aged/old patients (≥ 45 years) had only one seizure occurrence peak, 08:01–12:00 (p = 0.012). Young patients had more seizures than middle-aged/old patients between 16:01–20:00 (p = 0.04). No differences were noted between left and right MTS.SignificanceWe observed two seizure occurrence peaks: morning and late afternoon/evening. We encountered variations in daytime and nighttime seizure distribution according to gender and age, but not according to side of MTS. Future studies are needed to confirm these findings and to unravel the neurobiological substrate underlying daytime and nighttime variations of seizure occurrence in different age groups and between genders.     

Frontal hemodynamic changes precede EEG onset of temporal lobe seizures

ObjectiveA preictal state exists minutes or hours prior to the clinical seizure. We investigated whether hemodynamic changes preceding temporal lobe seizures were detectable in frontal scalp recordings using near-infrared spectroscopy (NIRS). Patients undergoing video-EEG telemetry (VET) were studied.MethodsA NIRS sensor was placed over the frontal scalp ipsilateral to the patient’s first recorded seizure. Regional cerebral oxygenation (rSO2) was recorded synchronously with VET data and peripheral oxygen saturation (SaO2). Periictal changes in rSO2 were compared with baseline interictal rSO2.ResultsEleven seizures were recorded in six patients. A mean peak preictal increase in rSO2 of 7.1% from the interictal baseline (p < 0.001) occurred at a mean peak latency of 298.9 s before seizure onset. rSO2 then decreased around seizure onset. SaO2 nadir occurred at a mean latency of 62 s following rSO2 nadir. A postictal increase in rSO2 occurred with a mean duration of about 35 min. Periictal rSO2 changes occurred with both ipsi and contralateral temporal lobe seizures.ConclusionWe have shown that preictal changes in cerebral oxygenation occur with a mean peak latency of about 4.98 min before seizure onset.SignificanceNIRS has the potential for providing a noninvasively detected signal of an imminent seizure.     

Seizure prognosis of patients with low-grade tumors

PurposeSeizures frequently impact the quality of life of patients with low grade tumors. Management is often based on best clinical judgment. We examined factors that correlate with seizure outcome to optimize seizure management.MethodsPatients with supratentorial low-grade tumors evaluated at a single institution were retrospectively reviewed. Using multiple regression analysis the patient characteristics and treatments were correlated with seizure outcome using Engel's classification.ResultsOf the 73 patients with low grade tumors and median follow up of 3.8 years (range 1–20 years), 54 (74%) patients had a seizure ever and 46 (63%) had at least one seizure before tumor surgery. The only factor significantly associated with pre-surgical seizures was tumor histology. Of the 54 patients with seizures ever, 25 (46.3%) had a class I outcome at last follow up. There was no difference in seizure outcome between grade II gliomas (astrocytoma grade II, oligodendroglioma grade II, mixed oligo-astrocytoma grade II) and other pathologies (pilocytic astrocytoma, ependymomas, DNET, gangliocytoma and ganglioglioma). Once seizures were established seizure prognosis was similar between different pathologies. Chemotherapy (p = 0.03) and radiation therapy (p = 0.02) had a positive effect on seizure outcome. No other parameter including significant tumor growth during the follow up period predicted seizure outcome. Only three patients developed new-onset seizures after tumor surgery that were non-perioperative. Anticonvulsant medication was tapered in 14 patients with seizures and 10 had no further seizures. Five patients underwent additional epilepsy surgery with a class I outcome in four. Two patients received a vagal nerve stimulator with >50% seizure reduction.DiscussionSeizures at presentation are the most important factor associated with continued seizures after tumor surgery. Pathology does not influence seizure outcome. Use of long term prophylactic anticonvulsants is unwarranted. Chemotherapy and radiation therapy have a favorable impact on seizure outcome. Additional epilepsy surgery is effective.     

Surgical treatment of hypermotor seizures originating from the temporal lobe

PurposeTo describe the characteristics of electroclinical manifestations in patients with hypermotor seizures (HMSs) originating from the temporal lobe.MethodsWe retrospectively reviewed the data of patients who underwent surgical treatments for seizure to identify patients with HMSs of temporal origin. We systematically reviewed patient seizure histories, imaging reports, video-EEG monitoring data, operative records and pathological findings.ResultsEight of the 9 patients reported auras. The ictal behavior included marked agitation in 5 patients and mild agitation in 4 patients. All of the 9 patients exhibited stiffness or dystonia of the upper limb or contralateral limbs during ictus. Seven of the 9 patients completed intracranial recording and at least 3 seizures were recorded for each patient. The intracranial recordings showed ictal activity originating from mesial temporal lobe in 6 patients and the lateral temporal lobe in 1 patient. The time interval of ictal propagation from the temporal to frontal lobe was 15.0 ± 8.3 s. While the time interval from EEG origination to the beginning of hypermotor behavior was 21.0 ± 8.1 s. Brain MRIs revealed hippocampal sclerosis in 3, neoplastic lesion in 1, and normal images in the remaining 5 patients. Patients were followed for 1–5 years after the anterior temporal lobectomy; 7 patients remained seizure-free throughout follow-up.ConclusionSome HMSs can originate from the temporal lobe. In carefully selected patients, surgical resection may lead to good outcomes.     

Prospective study on the withdrawal and reinstitution of antiepileptic drugs among seizure-free patients in west China

This study explored the relapse rates and risk factors for seizure recurrence after discontinuing antiepileptic drug (AED) therapy among seizure-free patients in west China, and explored whether to reinstitute AED immediately after a single seizure after AED withdrawal. Patients with epilepsy who were seizure-free for at least 2 years and decided to gradually stop AED therapy were followed up every 3 months for seizure relapse. Patients who experienced their first seizure after drug withdrawal were divided into two groups according to their willingness to reinstitute AED therapy, and were followed up until their second seizure. In the mean 29.35 months of follow-up, 37 patients (37/162, 22.8%) suffered at least one seizure after withdrawal. The cumulative probability of seizure recurrence was 16% at 12 months and 20.2% at 24 months. AED response time >1 year and multiple types of seizure were identified as risk factors for seizure recurrence. Eight patients (8/32, 25%) suffered a second seizure within 1 year after the first whether or not they reinstituted AED immediately. There were no significant demographic or clinical differences between patients who reinstituted AED therapy and those who did not. The epilepsy recurrence rate after AED withdrawal is relatively low, with a relatively slow tapering process. Patients with long AED response times and/or multiple types of seizures have a higher risk of seizure recurrence. The first seizure after drug withdrawal is not an indication for immediate AED reinstitution, but may be recommended after a second seizure.     

Clinical and economic burden of breakthrough seizures

PurposeThe purpose of this study was to measure health-care resource utilization and costs in treatment-adherent, previously seizure-free patients with epilepsy who were treated in the inpatient/emergency room (ER) setting for new-onset seizures, compared with matched controls.MethodsThe study used a retrospective case/control study design using administrative claims from the IMS PharMetrics™ database. We identified adult patients with epilepsy with 1 + ER visit/hospitalization with primary diagnosis of epilepsy between 1/1/2006 and 3/31/2011, preceded by 6 months of seizure-free activity and antiepileptic drug (AED) treatment adherence (≥ 80% of days covered by any AED); the first observed seizure defined the “breakthrough” seizure/index event. Treatment-adherent patients with epilepsy without any ER/hospital admission for seizures served as controls: an outpatient epilepsy-related medical claim within the selection window was chosen at random as the index date. The following were continuous enrollment requirements for all patients: ≥ 12-month pre- and ≥ 6-month postindex. Each case matched 1:1 to a control using propensity score matching. All-cause and epilepsy-related (epilepsy/convulsion diagnosis, AED pharmacy) resource utilization and unadjusted and adjusted direct health-care costs (per person, 2012 US dollars (USD)) were assessed in a 6-month follow-up period.Principal resultsThere were 5729 cases and 14,437 controls eligible. The final sample comprised 5279 matched case/control pairs. In unadjusted analyses, matched cases had significantly higher rates of all-cause hospitalization and ER visits compared to controls and significantly higher total all-cause direct health-care costs (median $12,714 vs. $5095, p < 0.001) and total epilepsy-related costs among cases vs. controls (median $7293 vs. $1712, p < 0.001), driven by higher inpatient costs. Among cases, costs increased with each subsequent seizure (driven by inpatient costs). Cases had 2.3 times higher adjusted all-cause costs and 8.1 times higher adjusted epilepsy-related costs than controls (both p < 0.001).ConclusionInpatient/ER-treated breakthrough seizures occurred among 28.4% of our treatment-adherent study sample and were associated with significant incremental health-care utilization and costs, primarily driven by hospitalizations. Our findings suggest the need for better seizure control via optimal patient management and the use of effective AED therapy, which can potentially lower health-care costs.