Influence of levetiracetame on ictal and postictal EEG in patients with partial seizures

To investigate the influence of levetiracetame (LEV) treatment on the interhemispheric seizure pattern propagation and postictal recovery of electroencephalography (EEG) background activity. Twenty-three adult patients (age > 16 years) with pharmacoresistant focal epilepsies presenting at the Epilepsy Center Erlangen for pre-surgical evaluation were enrolled in the study. Those eligible patients receiving only one antiepileptic drugs were recruited to the 48-h baseline phase and, after at least two seizures, were randomized to the 7-day treatment phase with either LEV ( n  = 11) or placebo ( n  = 12). All participants were submitted to continuous day-and-night video-EEG monitoring. The daily dose of LEV was 1000 mg (500 mg bid.) on the first treatment day and was increased to 2000 mg (1000 mg bid.) from the second day onward. The EEG changes relating to the time delay of the interhemispheric seizure pattern propagation and to the postictal recovery of the background activity were analysed by computerized video-EEG recording and compared using the non-parameter Mann–Whitney U -exact test ( α  = 0.05). A prolonged latency of the contralateral seizure pattern propagation was observed in the LEV group, whereas a more rapid propagation was observed in the placebo group ( P  = 0.009). Postictal generalized slowing of the background activity was recorded in 21 patients during the baseline phase. More rapid postictal recovery of the EEG background activity was observed in the LEV, but not in the placebo group ( P  = 0.03). This study demonstrated that LEV not only prevented the seizure pattern propagation but also helped the speedy recovery of the postictal background activity in the EEG.     

Prognostic value of the consistency of lateralizing ictal features and ictal EEG in patients undergoing temporal lobectomy for refractory complex partial seizures.

PURPOSE: Ictal and postictal clinical manifestations have lateralizing value in the presurgical evaluation of intractable seizures. The consistency and frequency of these signs during seizures and the associated implications for postoperative seizure outcome are unknown. METHODS: The videotaped complex partial seizures of 49 patients with known postoperative outcomes greater than 2 years after temporal lobectomy were blindly reviewed for: (1) unilateral hand posturing (UHP), (2) unilateral hand automatism (UHA), (3) forced and nonforced head turning (HT), and (4) postictal dysphasia (PID). The presence and laterality of each assessable sign were recorded. Data were analyzed as follows: (1) the prevalence of each sign in patients with Engel class 1 and Engel class 2-4, and (2) the postsurgical outcome when the sign was present in more than or less than 50% of the seizures for each patient. We reviewed patients' presurgical work-up, specifically ictal EEG and MRI. RESULTS: The prevalence of UHP, UHA, HT, and PID was similar for Engel class 1 and Engel class 2-4 patients. Engel class 1 outcome when UHP, UHA, HT, and PID were present for greater than 50% of seizures was no different compared to when these signs were present for less than 50% of seizures. Patients who had concordant ictal EEG and MRI abnormalities had the best postsurgical outcome. CONCLUSIONS: The consistency and frequency of ictal manifestations in the presurgical evaluation of complex partial seizures does not predict seizure outcome. The presence of any specific lateralizing sign need not be present in every complex partial seizure for the sign to hold predictive value. Concordant ictal EEG and MRI abnormalities are still the best predictors of outcome.     

Ictal clinical patterns and ictal EEG in a case of partial seizures of frontotemporal origin associated with complex symptomatology

The patient was a 35-year-old, unmarried male whose epileptic psychomotor fits persisted since the age of 13. The author has observed the case for about 12 years, so that incomplete information concerning epileptic symptoms was considered to be compensated considerably by longitudinal observation, including ictal seizure and ictal EEG's. In this patient seizure with impaired consciousness which correspond rhythmic slow waves of EEG tracing might be a nuclear sign; several kinds of automatism then might be considered as postictal phenomenon. The most important of all was tonic seizure of psychomotor epilepsy particularly in the face which was not seen in the petit mal epilepsy. With observation of ictal period as well as ictal EEG, differential identification of centrencephalic epilepsy and psychomotor epilepsy may not be totally impossible. The case also showed a typical productive psychotic episodes of Landolt, which could be treated favorably by 10 mg of intravenous Haloperidol. This method, named as "pathologization" of Helmchen, was found by the present author as a useful treatmental means of choice.     

Sphenoidal EEG recording in complex partial seizures

A prospective study was performed to evaluate the usefulness of sphenoidal EEG recording during wakefulness, as compared to routine tracings awake and asleep, for recognizing epileptic electroencephalographic foci in patients with complex partial seizures. Fifty patients were investigated. Following sleep deprivation a routine waking EEG, a sleep tracing and an awake recording with sphenoidal needles were obtained. In nine patients temporal epileptiform activity was apparent in all three conditions (wakefulness, sleep and with sphenoidal electrodes). In 21 patients temporal epileptiform activity was seen during sleep only, while the sphenoidal leads were non-contributory. In 20 patients epileptiform activity was not recorded under any of the above conditions. This study indicates that sphenoidal recording during wakefulness does not contribute to the detection of epileptic discharges in patients with complex partial seizures.     

Febrile seizures in patients with complex partial seizures

Febrile seizures occurred in 14 of 155 (9%) out-patients with complex partial seizures. Twelve patients had prolonged or recurrent febrile seizures, convulsive status epilepticus or a transient postictal neurological deficit. Febrile seizures were associated with perinatal abnormalities, an earlier onset of epilepsy and with a poor seizure control. Recurrent febrile seizures or those with complicating features are associated with an unfavourable therapeutic outcome in adult patients with complex partial seizures.     

Presurgical evaluation for partial epilepsy: relative contributions of chronic depth-electrode recordings versus FDG-PET and scalp-sphenoidal ictal EEG

One hundred fifty-three patients with medically refractory partial epilepsy underwent chronic stereotactic depth-electrode EEG (SEEG) evaluations after being studied by positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) and scalp-sphenoidal EEG telemetry. We carried out retrospective standardized reviews of local cerebral metabolism and scalp-sphenoidal ictal onsets to determine when SEEG recordings revealed additional useful information. FDG-PET localization was misleading in only 3 patients with temporal lobe SEEG ictal onsets for whom extratemporal or contralateral hypometabolism could be attributed to obvious nonepileptic structural defects. Two patients with predominantly temporal hypometabolism may have had frontal epileptogenic regions, but ultimate localization remains uncertain. Scalp-sphenoidal ictal onsets were misleading in 5 patients. For 37 patients with congruent focal scalp-sphenoidal ictal onsets and temporal hypometabolic zones, SEEG recordings never demonstrated extratemporal or contralateral epileptogenic regions; however, 3 of these patients had nondiagnostic SEEG evaluations. The results of subsequent subdural grid recordings indicated that at least 1 of these patients may have been denied beneficial surgery as a result of an equivocal SEEG evaluation. Weighing risks and benefits, it is concluded that anterior temporal lobectomy is justified without chronic intracranial recording when specific criteria for focal scalp-sphenoidal ictal EEG onsets are met, localized hypometabolism predominantly involves the same temporal lobe, and no other conflicting information has been obtained from additional tests of focal functional deficit, structural imaging, or seizure semiology.     

The start-stop-start phenomenon in scalp-sphenoidal ictal recordings

The start-stop-start (SSS) phenomenon is an apparent abortive ictal onset separated from the main seizure discharge. It was previously described in seizures recorded with subdural electrodes. We have observed this phenomenon in scalp-sphenoidal ictal recordings as well. We retrospectively reviewed 435 seizures recorded with scalp-sphenoidal electrodes from 61 patients with temporal lobe epilepsy. We found SSS onset in 15 seizures of 8 patients, representing 26% of these patients' seizures. The first “start” usually had a narrow field, typically in the sphenoidal electrode. The mean duration of the first “start” was 11 sec and that of the stop 8 sec. The restart had a different morphology and frequency in 87% and had'a wider field in 67% of seizures. The clinical onset followed the first start and preceded the restart in most of the seizures. In 1 patient, 1 seizure with SSS was correctly localized and lateralized, whereas 5 of 7 without SSS were falsely lateralized.The recognition of the SSS phenomenon may improve the accuracy of seizure localization in scalp-sphenoidal recordings.     

Comparative study of interictal PET and ictal SPECT in complex partial seizures

Objective – To compare the sensitivity of ictal ^99mTc-HMPAO single photon emission computed tomography (SPECT) with interictal ¹⁸F-fluorodeoxyglucose positron emission tomography (PET) in localization of the epileptogenic focus in patients with medically intractable complex partial seizures (MI-CPS). Material and methods – Retrospective analysis was performed on patients with MI-CPS who underwent anterior temporal lobectomy from January 1993 onwards when PET became available to us for clinical studies at the Indiana University Medical Center. There were 38 female and 29 male patients (total=67) with MI-CPS, 10 to 55.5 years of age (mean 31) and duration of their epilepsy from 1-46 years (mean 21). Interictal PET was evaluated for evidence of focal hypometabolism and ictal SPECT for focal perfusion abnormality (hyperperfusion or hypoperfusion) by visual analysis. Results – Both Ictal SPECT and interictal FDG-PET studies were obtained in 36 patients with MI-CPS. PET showed definite hypometabolism in 30 and questionable hypometabolism in an additional two patients. Ictal SPECT correctly localized the seizure focus in 27 patients by demonstrating ictal hyperperfusion whereas in one the hyperperfusion was falsely localized. In an additional seven patients the ictal SPECT provided probable localization by demonstrating ictal hypoperfusion in the appropriate temporal lobe. The sensitivity of ictal SPECT and interictal PET was 34/36 and 32/36, respectively, the difference was not statistically significant (χ²_y=0.18, DF=1, P=0.67). In six of the 36 patients the two tests were complementary to each other in providing localizing information. Conclusion – Ictal SPECT and interictal PET are equally sensitive and reliable techniques in localizing the epileptogenic focus in patients with MI-CPS. They play a critical role in providing localization in MRI negative patients allowing surgical resection to be undertaken in many without additional invasive electrographic monitoring.     

Self-injection ictal SPECT during partial seizures

The authors compared ictal SPECT injection performed by medical personnel with self-injection ictal SPECT in six patients with refractory temporal lobe epilepsy. Self-injection was safe and started faster. Self-injection subtraction ictal SPECT coregistered to MRI (SISCOM) was localizing in three patients who had a complex partial seizure, but only one of three patients who had a simple partial seizure, which may limit its usefulness in clinical practice. The localizing information of self-injection was better in three patients, and obviated the need for depth-EEG studies in one patient.     

Postictal language dysfunction in complex partial seizures: effect of contralateral ictal spread

The authors report postictal language evaluation in patients monitored with bitemporal depth electrodes. Patients whose seizures began in the nondominant temporal lobe and propagated to the contralateral temporal lobe had a prolonged postictal language delay (PILD) with paraphasic errors compared with seizures that did not spread. Shorter propagation time was also associated with a longer PILD. Our study suggests that ictal involvement of the dominant temporal lobe is important in postictal language behavior.     

Regional brain glucose metabolism in patients with complex partial seizures investigated by intracranial EEG.

We performed interictal 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) studies in 57 patients with complex partial epilepsy (CPE), not controlled by medical treatment and considered for surgical resection of their epileptic focus. A precise localization of the epileptic focus was obtained in 37 of these patients with a combination of subdural and depth electrodes. We visually inspected the metabolic images; we also measured glucose consumption in a number of brain regions and compared the values with those obtained in 17 normal controls. Eighty-two percent of the 57 patients had an area of glucose hypometabolism on the 18FDG-PET images. Six patients had a frontal epileptic focus, 3 of them had a frontal lobe hypometabolism. Twenty-six patients had a unilateral temporal lobe focus and all of them displayed a temporal lobe hypometabolism. The asymmetry was more pronounced in the lateral temporal cortex (-20%) than in the mesial part of the temporal lobe (-9.6%). In each cortical brain region on the side of the epileptic focus (except the sensorimotor cortex), glucose consumption rate was lower than in the contralateral region or than in controls. No differences could be found between patients with a seizure onset restricted to the hippocampus and patients with a seizure onset involving the hippocampus and the adjacent neocortex. Divergent metabolic patterns were obtained in 5 patients with bilateral temporal seizure foci. Combined with other non invasive techniques (EEG, neuroradiology), PET contributes increasingly to the selection of patients with CPE who could benefit from surgical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Micturition induced seizures: ictal EEG and subtraction ictal SPECT findings

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

额叶癫痫发作录像脑电图特点分析

目的通过录像脑电图观察额叶癫痫的临床特征、发作期及发作间歇期的脑电图特点。方法使用录像脑电图（ｖｉｄｅｏＥＥＧ,ＶＥＥＧ）对５０例确诊为额叶癫痫的患者进行常规及长时间记录,对其中１７例（２０次）癫痫发作的临床表现及脑电图所见进行分析。结果额叶癫痫常见的发作形式有：姿势性发作,具有额叶癫痫特点的自动症;复杂部分性发作时伴发声、偏转或表情的变化,有时出现发作性情绪改变或强迫思维等少见症状。其发作特点为：持续时间短,发作相对较频繁,无明显发作后意识障碍。发作间歇期脑电图有时可无阳性所见,典型的临床发作及发作时ＶＥＥＧ记录到的额部爆发性节律有助于诊断。本组９例儿童期起病的额叶癫痫患者,以夜间频繁的躯体自动症发作为主,检查均未发现相应的脑器质性病变。脑电图睡眠描记可见频繁的额部导联癫痫样放电。临床治疗观察预后良好,提示可能为一组儿童原发性部分发作型癫痫综合征。结论额叶癫痫是一组较为特征性的癫痫综合征,临床并不少见,及时而正确的诊断有助于治疗。     

Scalp EEG differs in temporal and extratemporal complex partial seizures

We compared scalp ictal EEG in complex partial seizures originating in extratemporal regions with seizures originating in the temporal lobe. All patients were seizure-free for 2 or more years after appropriate cortical resection confirming focus of seizure onset. The electroencephalographer reviewing seizures was blind to patient identity. Extratemporal seizures were shorter, more difficult to lateralize, and had postictal slowing less often. Confident lateralization of seizure onset could not be made in 19% of the seizures, usually because onset was diffuse or artifact obscured the seizure. When lateralization judgments were thought possible, lateralization errors occurred in only 3% of the seizures. Five percent of the seizures had no detectable scalp ictal changes.     

Duration of complex partial seizures: an intracranial EEG study

PURPOSE: The dynamics of partial seizures originating from neocortical and mesial temporal regions are thought to differ, yet there are no quantitative comparative studies. The studies reported here investigate the duration of complex partial seizures in these populations using analyses of seizures recorded from intracranial arrays. METHODS: Data were collected from patients undergoing presurgical evaluation with intracranial electrodes. Seizure duration was defined as the time of earliest sustained ictal activity until the termination either in all electrodes (global duration, GD), or at the onset area (focal duration, FD). Patients were divided into three groups: mesial temporal lobe epilepsy (MTLE), neocortical temporal lobe epilepsy (NCTLE), and neocortical extratemporal lobe epilepsy (NCXTLE). RESULTS: Complex partial seizure durations were significantly longer in the MTLE group compared to the NCXTLE group. Median GD for MTLE was 106 s, and for NCXTLE was 78 s. There were no significant differences between seizure durations when comparing MTLE group to NCTLE group, or comparing NCTLE group to NCXTLE group. In the MTLE group, patients with bilateral recording arrays had significantly longer median seizure durations (GD and FD) than those sampled with unilateral arrays. CONCLUSIONS: In this select group of patients there is a significant difference between the duration of complex partial seizures of mesial temporal and neocortical extratemporal origin with mesial temporal complex partial seizures being longer. This may result from a number of possibilities including the bilateral propagation of some mesial temporal seizures and differences in ictal generators of the underlying networks.     

Electrophysiologic pathologic correlations in patients with complex partial seizures

We studied interictal activity and site of ictal onset in 26 patients with complex partial seizures of temporal lobe origin. All patients had prolonged electrocorticographic recordings from subdural electrode arrays placed both over the convexity and beneath the temporal lobe. We found a significant correlation between the epileptogenic focus and the type of pathologic lesion found at time of surgery. Macroscopic lesions strongly tended to have an epileptogenic focus on the lateral surface of the temporal lobe; patients with only microscopic abnormalities tended to have an epileptogenic focus in the mesial/basal region of the temporal lobe.     

Microwave oven injuries in patients with complex partial seizures

Microwave ovens are often recommended as a safe cooking alternative for persons with epilepsy. We report four patients who suffered serious burns to their hands while handling microwave-heated liquids during a complex partial seizure (CPS). Injuries were due to the contact of the skin with a very hot container. The fact that all patients held on to the hot containers despite being burned and that they did not remember experiencing any pain at the time of the accident indicates that neither high temperatures nor pain will prevent patients who are having a CPS from suffering this type of injury. Unfortunately, there is no foolproof way to prevent the individual from opening the oven and removing its contents during a CPS. The only solution for this problem is "prevention"-individuals with poorly controlled CPS should be cautioned about these risks. The use of microwave settings that permit the heating but not boiling of liquids and the use of gloves while heating food and liquids to scalding temperatures may minimize the risk of this type of injury.     

Frequency domain EEG source localization of ictal epileptiform activity in patients with partial complex epilepsy of temporal lobe origin.

The aim of this study was to investigate whether EEG source localization in the frequency domain, using the FFT dipole approximation (Lehmann, D. and Michel, C.M. Electroenceph. clin. Neurophysiol., 1990, 76: 271-276), would be useful for quantifying the frequency content of epileptic seizure activity. Between one and 7 extracranially recorded seizures were analyzed in each of 7 patients with mesolimbic epilepsy, who were seizure-free after temporal lobe resection. The full scalp frequency spectrum for the first 4 s after seizure onset, as well as for subsequent periods, was determined. Power peaks in the spectra were identified, and an instant dipole fit was performed for the frequencies corresponding to these peaks. Ictal frequencies, ranging between 3.5 and 8.5 Hz, showed a variable degree of stability over time in the different patients. For a particular frequency, dipole results were similar during the different phases of seizure development. In patients with more than one prominent frequency, dipole results for the different frequencies were similar. Dipole results were also similar between patients. We conclude that dipole localization of dominant frequencies, as obtained from full scalp FFT analysis, gives quite reproducible results for seizures originating in the mesial temporal area. The method may become a useful tool for the pre-surgical identification of patients with mesolimbic epilepsy.