Significance of interictal bilateral temporal hypometabolism in temporal lobe epilepsy

OBJECTIVE: To assess the clinical implications and the pathophysiologic determinants of interictal bitemporal hypometabolism (BTH) in temporal lobe epilepsy (TLE) not associated with bilateral MRI abnormalities or intracranial space-occupying lesions. METHODS: The authors compared the clinical, interictal, and ictal EEG, Wada test, and neuropsychology data of 15 patients with intractable complex partial seizures of temporal lobe origin and BTH with those of 13 consecutive patients with unilateral TLE associated with unilateral temporal hypometabolism (UTH) who remained seizure free for more than 3 years after anterior temporal lobectomy. 18F-fluorodeoxyglucose PET scans were analyzed visually and semiquantitatively, and ratios of counts in individual temporal areas to the rest of the cerebrum were compared with the corresponding values from 11 normal control subjects and with the nonepileptogenic hemisphere of the 13 patients with UTH. BTH was defined as more than 2.5 SDs below control values for two or more temporal areas on each side irrespective of any asymmetry. RESULTS: BTH reflected bilateral independent seizure onset in eight patients (53%). The topography of the metabolic depression was not a reliable predictor of epileptogenicity, but involvement of the inferior temporal gyrus was related specifically to ipsilateral seizure onset (70% sensitivity, 100% specificity). In patients with unilateral TLE, contralateral hypometabolism was associated with longer disease duration and worst memory performance during the Wada test, which amounted to global amnesia after ipsilateral injection in three patients, precluding surgical treatment. Contralateral seizure spread in the ictal EEG was significantly faster in patients with BTH. CONCLUSIONS: In TLE, symmetric or asymmetric BTH may signal bilateral independent seizure onset in approximately half the patients, especially when involving the inferior temporal gyrus. Alternatively, it may reflect an advanced stage of the disease process, characterized by a breakdown of the inhibitory mechanisms in the contralateral hemisphere, and secondary memory deficit associated with higher risk of postoperative memory decline. Patients with TLE and BTH but without bilateral MRI changes may still be operated on successfully, but surgical suitability should be proved by comprehensive intracranial EEG studies and Wada test.     

Lateralizing value of postictal automatisms in temporal lobe epilepsy

PURPOSE: To describe clinical characteristics and lateralizing value of postictal automatisms in patients with temporal lobe epilepsy (TLE). METHODS: One hundred and ninety-three videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed. Ictal as well as postictal (manual, oral and speech) automatisms were monitored. RESULTS: Thirty-four (62%) of the 55 patients showed PA at least once during their seizures. Postictal automatism was observed in 70 (36%) attacks as manual (21%), oral (13%) or speech (9%) automatisms. Fifteen seizures contained a combination of two different postictal automatisms. The presence of postictal oral automatisms did not lateralize the seizure onset zone (p=0.834). Speech automatisms (repetitive verbal behavior) occurred more frequently after left-sided seizures (p=0.002). Postictal unilateral manual automatism showed no lateralizing value occurring by the ipsilateral hand in 10 and the contralateral upper limb in 6 seizures (p=0.454). CONCLUSION: : Postictal automatism is a relatively frequent phenomenon in TLE. Postictal speech automatism lateralizes the seizure onset zone to the left hemisphere. Our observation can help the presurgical evaluation of TLE because verbal perseveration frequently occurs spontaneously, even in seizures without appropriate postictal language testing.     

The relevance of somatosensory auras in refractory temporal lobe epilepsies

The purpose of this study is to look at the prevalence, characteristics, and prognostic value of somatosensory auras (SSAs) in patients who have undergone temporal lobe epilepsy (TLE) surgery to treat drug‐resistant focal epilepsy. We retrospectively reviewed all patients with drug‐resistant epilepsy who underwent TLE surgery at Cleveland Clinic between 2005 and 2010 (n = 333) to study the prevalence, characteristics, and prognostic implications of SSA in the context of TLE surgery. Analyses were performed using two seizure outcome definitions: complete seizure freedom and Engel classification. Of the 333 patients, 26 (7.8%) had SSA. Almost half (12 patients) had unilateral sensory symptoms, whereas the rest had bilateral symptoms. Tingling and numbness were the most frequently reported sensations. Compared to their non‐SSA counterparts, patients with SSA had the same clinical and imaging characteristics, but had a higher rate of breakthrough seizures (p = 0.03), although most (54%) were still able to achieve Engel class of I (p = 0.02). Based on our results we would encourage detailed presurgical testing, which may include an invasive evaluation to analyze the extent of the epileptogenic zone in patients with SSA and suspected TLE.     

Bilateral reductions of hippocampal volume, glucose metabolism, and Wada hemispheric memory performance are related to the duration of mesial temporal lobe epilepsy

In refractory temporal lobe epilepsy (TLE) temporal lobe structures and functions are continuously or intermittently affected by abnormal brain electrical events, noxious neurochemical agents, and metabolic disturbances. There is conflicting evidence regarding the relationship between the duration of refractory mesial TLE and quantitative measures of temporal lobe functions and volumes of the hippocampi. Twenty patients (aged 28 ± 7 years, 14 males) with an initial precipitating injury before the age of 5 years were subjected to high-resolution magnetic resonance imaging, fluoro-2-deoxy-d-glucose positron-emission tomography (PET), and the Wada test. We investigated whether the duration of unilateral refractory TLE (12 left, 8 right) affects hippocampal volume, glucose metabolism, or Wada hemispheric memory performance. Ipsilateral to the epileptogenic zone the hippocampal volume, metabolism, and Wada hemispheric memory performance were reduced compared to the corresponding contralateral measures. The duration of epilepsy controlled for age at investigation, side of seizure origin, underlying cause, and sex were negatively correlated with ipsi- and contralateral hippocampal volume, hippocampal metabolism, and Wada hemispheric memory performance. Moreover, ipsilateral Wada hemispheric memory performance and contralateral hippocampal glucose metabolism were correlated with the frequency of habitual seizures. Refractory TLE seems to be associated with a slow but ongoing bilateral temporal lobe damage. These cross-sectional results require verification by longitudinal studies carried out over a period of more than two decades. Received: 30 July 1998 Received in revised form: 16 March 1999 Accepted: 24 April 1999     

Somatosensory auras in focal epilepsy: a clinical, video EEG and MRI study.

PURPOSE: To determine the clinical characteristics of somatosensory auras (SSA) and analyse features of seizure semiology predictive for localization in focal neocortical and limbic epilepsy. METHODS: This study analyses the clinical, video-EEG and MRI imaging features of 75 consecutive patients with focal epilepsy who described somatosensory auras at seizure onset to determine the frequency and localising value of SSAs in different types of focal epilepsy. Sensory characteristics, somatotopic distribution, evolution of the auras and subsequent ictal features in relation to MRI and EEG findings were analysed. RESULTS: The incidence of SSAs in 600 patients with focal epilepsy was 12%. Seventy-five patients were studied further: 77% reported tingling. Pain, thermal changes and a sense of movement or pulling were also reported. Distal unilateral auras in the hand and arm (46%) were most frequent and associated with a contralateral centroparietal focus. Contralateral auras were reported in 62% of lesional cases, focal cortical dysplasia was the commonest pathology in operated cases. Bilateral auras were associated with more diffuse pathologies or parasagittal foci. Evolution was centrifugal, somatotopic and usually unilaterally confined. Subsequent motor semiology was postural tonic, unilateral clonic, psychomotor or secondary generalized. CONCLUSION: SSA are highly correlated with centroparietal epilepsy but may occur in temporal lobe, mesial frontal and multifocal epilepsy. A lesional etiology including discrete dysplasias, tumours, ischemic and postencephalitic gliosis is likely.     

Semiology of Temporal Lobe Seizures: Value in Lateralizing the Seizure Focus

Summary: Purpose: To determine the lateralizing value of the clinical manifestations of seizures in patients with temporal lobe epilepsy (TLE), we made a retrospective videotape analysis of complex partial seizures (CPS) in 55 patients who underwent temporal lobectomy and were seizure-free postopera-tively for >2 years. Methods: Blinded to clinical details, we reviewed videotapes from video-EEG telemetry monitoring with attention paid to seizure semiology. Results: Useful lateralizing features included unilateral clonic activity (with the seizure focus contralateral in all patients), unilateral dystonic or tonic posturing (with the seizure focus contralateral in 90 and 86%, respectively), unilateral automatisms (with the seizure focus ipsilateral in 80%), and ictal speech preservation (with the seizure focus contralateral to the language-dominant hemisphere in 80%). Versive head rotation occurring ≤10 s before seizures secondarily generalized consistently predicted a contralateral focus. Seizure manifestations less predictive but suggestive of lateralization included ictal speech arrest and postictal speech status, with predictive values of 67%. Seizure manifestations not providing reliable lateralizing information included eye deviation, type of aura, and versive head movements occurring at times other than immediately before seizures secondarily generalized. Conclusions: In TLE, several clinical seizure manifestations are useful in lateralizing the seizure focus, although some provide no reliable information. Therefore, ictal semiology can assist in the evaluation of patients for seizure surgery, providing additional information in the lateralization of TLE.     

Ictal apnea linked to contralateral spread of temporal lobe seizures: Intracranial EEG recordings in refractory temporal lobe epilepsy

Purpose: Respiratory mechanisms are implicated in sudden unexpected death in epilepsy (SUDEP). We previously demonstrated a high incidence of ictal hypoxemia in temporal lobe seizures. We now report on the temporal relationship between ictal apnea and seizure onset and spread in patients undergoing video‐EEG (electroencephalography) telemetry (VET) with intracranial electrodes. Methods: Ten patients with medically refractory temporal lobe epilepsy (TLE) undergoing VET were studied. Data from synchronously recorded digital pulse oximetry (SaO₂), end‐tidal CO₂ (ETCO₂), nasal airflow, abdominal excursions, and electrocardiography were obtained. Results: Sixty‐one seizures were captured. SaO₂ in the ictal/postictal period was available for 52 seizures, apnea onset times for 27 seizures, and ETCO₂ for 16 seizures. Apneas occurred only when seizures spread to the contralateral temporal lobe. The mean delay to apnea onset was significantly shorter after contralateral seizure spread (2.87 s) than after seizure onset (58.4 s); p < 0.001. The mean SaO₂ nadir with partial seizures or partial seizures prior to secondary generalization was 89.4 ± 8.6% (91.5, 69–100). Following generalized convulsions the mean oxygen saturation nadir was 75.8 ± 10.6% (78.5, 58–90). ETCO₂ elevations occurred with each ictal desaturation below 85%. Conclusions: There is a close temporal relationship between spread of seizures to the contralateral hemisphere and the onset of seizure‐associated apnea. Apnea onsets are more tightly linked to time of contralateral spread than to time of seizure onset. Patients with TLE in whom there is evidence of contralateral seizure spread may be at higher risk for ictal‐related respiratory dysfunction than those in whom seizures remain unilateral.     

Electrode manipulation automatism during temporal lobe seizures.

OBJECTIVE: To describe clinical characteristics and lateralizing value of peri-ictal electrode manipulation automatism (EMA) in patients with temporal lobe epilepsy (TLE) and compare our data with ictal manual automatisms described in the literature. METHODS: Two-hundred and five videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed and EMA (tugging, scratching or adjusting the electrodes and cables) were monitored. RESULTS: Twenty-eight (51%) patients showed EMA during 47 (23%) seizures. Ictal start was noted in 22 seizures and in 19/22 cases EMA finished before the end of seizure. Ictal EMAs were always associated with automotor seizure components. During 25 seizures, exclusively postictal EMAs were observed. Electrode manipulation was presented during 24/112 left-sided and 23/93 right-sided seizures (p = 0.742). Peri-ictal EMA was unilateral (completed by one hand) in 24/47 seizures (10 ictal, 14 postictal); it was done by the hand ipsilateral to the seizure onset zone in 17/24 and by contralateral hand in 7/24 cases (p = 0.064). We observed concomitant contralateral dystonic posturing during 3/10 seizures with unilateral ictal EMA. Unilateral hand automatism, temporally independent from the EMA appeared in 30 (64%) of the 47 seizures. CONCLUSION: Peri-ictal EMA is a frequent phenomenon but shows no lateralizing value in TLE. The mechanism of EMA is in many ways dissimilar from that of earlier described manual automatisms.     

Nonmanipulative proximal upper extremity automatisms lateralize contralaterally in temporal lobe epilepsy

Purpose : Upper extremity automatisms are considered to be an ipsilateral seizure lateralizing sign in temporal lobe epilepsy (TLE). Herein we describe different types of contralateral upper extremity automatisms (CUEAs). Methods : One hundred ninety‐three video–(electroencephalography) EEG recordings of 59 patients were reviewed. Other than two patients who refused surgery, all patients underwent standardized temporal lobectomy with favorable postoperative outcome. Fifty‐seven seizures of 21 patients were selected with CUEAs. We evaluated their electroclinical characteristics and their relation to other lateralizing motor symptoms. Results : Two types of CUEAs were observed. Nonmanipulative, proximal upper extremity automatisms were seen unilaterally and contralaterally to the operated side. These automatisms were rhythmic; repetitive; and often occurred with a circulatory component resembling waving, flaunting, circling, or stirring movements. They occurred in 29 seizures (15%) of 11 patients (19%), in most seizures in the first half of the seizure, and never postictally, in various time sequences and combined with dystonic/tonic posturing or limb immobility. Manipulative/distal type of CUEAs occurred in 11 seizures (6%) of 7 patients (12%) on the unexpected contralateral side. These CUEAs were seen in all phases of the seizures, including in the postictal state. Discussion : Nonmanipulative unilateral proximal upper extremity automatism is a reliable lateralizing sign to the contralateral hemisphere in TLE. This sign may be pathophysiologically related to dystonic/tonic posturing. Manipulative distal automatisms have less lateralizing value.     

Lateralizing Value and Semiology of Ictal Limb Posturing and Version in Temporal Lobe and Extratemporal Epilepsy

Summary: Purpose : Unilateral dystonic limb posturing in partial seizures has been shown to be an accurate lateralizing sign indicating seizure onset in the contralateral hemisphere. However, its clinical utility may be reduced by confusion with other lateralized ictal motor phenomena. In this study, the ictal phenomena of dystonic limb posturing, tonic limb posturing, unilateral immobile limb, and version were distinguished and examined in patients with temporal and extratemporal seizures.
Methods : Partial seizures in 54 patients, successfully treated by surgery (34 temporal, 20 extratemporal; 14 frontal, 3 parietal, and 3 occipital), were analyzed blindly by 3 reviewers. Interobserver agreement was tested with kappa indexes and positive predictive value (PPV) was determined for each sign.
Results : In patients with temporal lobe epilepsy (TLE), dystonic posturing occurred in 35.3% (kappa 0.78, positive predictive value (PPV) for the sign being contralateral to seizure onset 92%); tonic limb posturing occurred in 17.7% (kappa 0.36, PPV 40%); unilateral immobile limb occurred in 11.8% (kappa 0.23, PPV 100%); and version occurred in 35.3% (kappa 0.77, PPV 100%). In patients with extratemporal epilepsy, dystonic posturing occurred in 20.0% (kappa 0.31, PPV 100%); tonic limb posturing occurred in 15.0% (kappa 0.08, PPV 67%); and version occurred in 40.0% (kappa 0.54, PPV 100%). The higher kappa indexes were significant for dystonic posturing (p < 0.001) and tonic limb posturing (p = 0.032) in TLE. Dystonic posturing (p = 0.034), tonic posturing (p = 0.07), and version (p = 0.0038) occurred earlier in extratemporal seizures than in temporal seizures.
Conclusions : Of the limb ictal motor phenomena, only dystonic posturing was accurate and had good interobserver agreement.     

Foramen ovale electrodes in the preoperative evaluation of temporal lobe epilepsy in children

Purpose:  Foramen ovale electrodes (FOEs) can localize the epileptogenic zone in adults with mesial temporal lobe epilepsy (TLE). Our aim was to investigate the feasibility and safety of using FOEs to investigate refractory TLE in children.
Methods:  Thirty-eight children with seizure semiology and video-EEG (electroencephalography) consistent with medically refractory TLE, and/or the presence of a lesion in the temporal lobe, had FOEs inserted. Complications occurring during the monitoring and up to 3 months after surgery and the long-term seizure outcome were registered.
Results:  Forty electrodes were placed in 38 patients. The mean age of the patients was 9.8 years (range 2.3–15.4 years). FOEs confirmed a unilateral mesial temporal lobe seizure onset in 14 patients, onset in both FOEs and lateral electrodes in two patients, and onset in the anterior temporal electrodes in only one patient. Six patients had seizures recorded but were not considered surgical candidates; four patients had no seizures recorded, and 11 patients were further investigated with depth electrodes. One patient (2.6%) developed a hematoma in the cheek, and in two patients the electrodes were extracranial but could still be used for recording. Twenty-eight children had a temporal resection; 25 were Engel class I at follow-up.
Discussion:  FOEs are safe to use in children and provide valuable information on the mesial temporal lobe structures in the preoperative investigation of pediatric TLE. Patient selection for FOE investigation is, however, essential for a conclusive result.     

Ipsilateral and contralateral MRI volumetric abnormalities in chronic unilateral temporal lobe epilepsy and their clinical correlates

PURPOSE: To assess the presence, extent, and clinical correlates of quantitative MR volumetric abnormalities in ipsilateral and contralateral hippocampus, and temporal and extratemporal lobe regions in unilateral temporal lobe epilepsy (TLE). METHODS: In total, 34 subjects with unilateral left (n = 15) or right (n = 19) TLE were compared with 65 healthy controls. Regions of interest included the ipsilateral and contralateral hippocampus as well as temporal, frontal, parietal, and occipital lobe gray and white matter. Clinical markers of neurodevelopmental insult (initial precipitating insult, early age of recurrent seizures) and chronicity of epilepsy (epilepsy duration, estimated number of lifetime generalized seizures) were related to magnetic resonance (MR) volume abnormalities. RESULTS: Quantitative MR abnormalities extend beyond the ipsilateral hippocampus and temporal lobe with extratemporal (frontal and parietal lobe) reductions in cerebral white matter, especially ipsilateral but also contralateral to the side of seizure onset. Volumetric abnormalities in ipsilateral hippocampus and bilateral cerebral white matter are associated with factors related to both the onset and the chronicity of the patients' epilepsy. CONCLUSIONS: These cross-sectional findings support the view that volumetric abnormalities in chronic TLE are associated with a combination of neurodevelopmental and progressive effects, characterized by a prominent disruption in ipsilateral hippocampus and neural connectivity (i.e., white matter volume loss) that extends beyond the temporal lobe, affecting both ipsilateral and contralateral hemispheres.     

Ictal head turning in frontal and temporal lobe epilepsy

Purpose: To quantitatively evaluate the difference of ictal head turning movements between patients with temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE). Methods: We investigated 38 seizures of 31 patients with unilateral TLE and 22 seizures of 14 patients with unilateral FLE where head turning occurred in the seizure evolution. The head movements were defined as ipsilateral or contralateral in reference to the lateralization of the patient’s focal epilepsy syndrome. Head movements were quantified by either referencing the head position with manually placed markers or by automatic detection of infrared marked reference points. The time of onset, duration, and angular speed of the head movements were computed, and interindividual and intraindividual analyses were performed. Key Findings: All of the TLE seizures had both contralateral and ipsilateral head turning, whereas all FLE had contralateral head turning; only 6 of 22 seizures were associated with ipsilateral head turning. Ipsilateral head turning always preceded contralateral head turning in both TLE and FLE. The head turning occurred significantly sooner after clinical seizure onset in FLE than in TLE patients (ipsilateral 0.5 vs. 16.0 s, contralateral: 4.5 vs. 21.3 s; p < 0.001). Furthermore, the duration of head turning was shorter in FLE for contralateral head turning (4.1 s) than in TLE (contralateral 6.0 s, p < 0.01); the ipsilateral head turning in the two groups did not differ (3.0 vs. 2.9 s) in duration. The angular speed of head turning did not differ for ipsilateral and for contralateral head turning in FLE and TLE. Significance: Quantitative analysis of head turning demonstrates significant differences between patients with FLE and TLE. These differences likely represent differences in spread of epileptic activity. This information may be useful in the seizure evaluation of patients considered for resective epilepsy surgery.     

The amygdala and temporal lobe simple partial seizures: a prospective and quantitative MRI study

PURPOSE: To determine whether specific temporal lobe simple partial seizures (SPSs) are associated with an abnormal amygdala T2 (AT2) ipsilateral to the seizure focus in patients with intractable unilateral temporal lobe epilepsy (TLE). AT2 relaxation time mapping is a sensitive method for the detection of abnormal tissue in the amygdala in patients with refractory TLE. The relation between an abnormal AT2 in the epileptic temporal lobe and amygdala seizure onset has not been established. METHODS: Fifty patients with intractable unilateral TLE and concordant data during presurgical evaluation were included. Patients with a foreign-tissue lesion on standard magnetic resonance imaging (MRI) were excluded. All had AT2 mapping. Fifteen types of SPSs were ascertained prospectively, systematically, and blinded to the results of AT2 mapping. The SPSs of patients with a normal AT2 (n = 25) were compared with those of patients with an abnormal AT2 ipsilateral to the seizure focus (n = 25). RESULTS: The group of patients with an abnormal AT2 reported a median of six types of SPSs (range 1-11), in comparison with a median of three types of SPSs (range, 0-7) for the group with a normal AT2 (p<0.01). Déjà vu, a warm sensation, an indescribable strange sensation, a cephalic sensation, and fear were associated with an abnormal AT2. The combination of déjà vu, a cephalic sensation, a warm sensation, a gustatory hallucination, and an indescribable strange sensation discriminated best between the 25 patients with a normal and the 25 patients with an abnormal AT2. CONCLUSIONS: A high number and the types of different SPSs provide clinical evidence for early involvement of the amygdala during seizures in patients with refractory unilateral TLE and an abnormal AT2 in the epileptic temporal lobe     

Seizure outcome after anterior temporal lobectomy and its predictors in patients with apparent temporal lobe epilepsy and normal MRI

PURPOSE: Very little reliable information is available regarding the role of anterior temporal lobectomy (ATL), optimal presurgical evaluation strategy, post-ATL seizure outcome, and the factors that predict the outcome in patients with medically refractory temporal lobe epilepsy (TLE) and normal high-resolution magnetic resonance imaging (MRI). To be cost-effective, epilepsy surgery centers in developing countries will have to select candidates for epilepsy surgery by using the locally available technology and expertise. METHODS: We reviewed the electroclinical and pathological characteristics and seizure outcome of 17 patients who underwent ATL for medically refractory TLE after being selected for ATL based on a noninvasive selection protocol without the aid of positron emission tomography (PET) or single-photon emission computed tomography (SPECT), despite a normal preoperative high-resolution MRI. RESULTS: Seven (41%) patients achieved an excellent seizure outcome; five of them were totally seizure free. An additional five (29%) patients had >75% reduction in seizure frequency. The following pre-ATL factors predicted an excellent outcome: antecedent history of febrile seizures, strictly unilateral anterior temporal interictal epileptiform discharges (IEDs), and concordant type 1 ictal EEG pattern. All the five patients with pathologically verified hippocampal formation neuronal loss were seizure free. The presence of posterior temporal, bilateral temporal, and generalized IEDs portended unfavorable post-ATL seizure outcome. CONCLUSIONS: A subgroup of patients destined to have an excellent post-ATL outcome can be selected from MRI-negative TLE patients by using history and scalp-recorded interictal and ictal EEG data. The attributes of these patients are antecedent history of febrile seizures, strictly unilateral anterior IEDs, and concordant type 1 ictal EEG pattern.     

Persistent seizures following left temporal lobe surgery are associated with posterior and bilateral structural and functional brain abnormalities

PURPOSE: To perform a quantitative MRI and retrospective electrophysiological study to investigate whether persistent post-surgical seizures may be due to brain structural and functional abnormalities in temporal lobe cortex beyond the margins of resection and/or bilateral abnormalities in patients with temporal lobe epilepsy (TLE). METHODS: In 22 patients with left TLE and histopathological evidence of hippocampal sclerosis, we compared pre-surgical brain morphology between patients surgically remedied (Engel's I) and patients with persistent post-surgical seizures (PPS, Engel's II-IV) using voxel-based morphometry (VBM). Routine pre-surgical EEG and invasive and non-invasive telemetry investigations were additionally compared between patient groups. RESULTS: Results indicated widespread structural and functional abnormalities in patients with PPS relative to surgically remedied patients. In particular, patients with PPS had significantly reduced volume of the ipsilateral posterior medial temporal lobe and contralateral medial temporal lobe relative to surgically remedied patients. Furthermore, successful surgery was associated with clear anterior (89%) and unilateral (100%) temporal lobe EEG abnormalities, whilst PPS were associated with widespread ipsilateral (91%) and bilateral (82%) temporal lobe abnormalities. DISCUSSION: We suggest that these preliminary data support the hypothesis that PPS after temporal lobe surgery are due to functionally connected epileptogenic cortex remaining in the ipsilateral posterior temporal lobe and/or in temporal lobe contralateral to resection.     

Postoperative interictal spikes during sleep contralateral to the operated side is associated with unfavourable surgical outcome in patients with preoperative bitemporal spikes.

PURPOSE: To correlate the persistence of contralateral spikes during sleep after unilateral surgery with seizure outcome in a temporal lobe epilepsy (TLE) population and to test the existing hypotheses about the origin of the contralateral spikes in temporal lobe epilepsy. METHODS: In the 19 patients selected for this study unilateral temporal lobe surgery was performed. To investigate the course of bilateral interictal epileptiform discharges observed before surgery in awake or sleep over the temporal lobe contralateral to surgery, 24 h mobile 12 channel EEG recording was performed at minimum two, in average 4.6 (2-10) years after the surgery. RESULTS: The association of postoperative contralateral spikes and non-seizure free outcome was highly significant. The existence of unilateral pathology before surgery was highly predictive for good outcome and disappearance of contralateral spikes. The association between good seizure outcome, disappearance of contralateral spikes and the existence of unilateral pathology before surgery was also significant. Our data partially satisfies the expectations of both the "seizure induced" and mirror type secondary epileptogenesis hypotheses concerning origin of contralateral spikes, but were not completely congruent with either of them. CONCLUSIONS: Unfavourable surgical outcome in a temporal lobe epilepsy group with preoperative independent bilateral interictal spikes was associated with the persistence of postoperative contralateral spikes and lack of unilateral pathology. Compared with seizure outcome the presence/absence and distribution of postoperative interictal spikes in NREM sleep not entirely fit to the predictions of existing secondary epileptogenesis hypotheses.     

Temporal lobe epilepsy with bilateral seizure origin studied by [18F]FDG-positron emission tomography

Nine patients who underwent presurgical evaluation because of medically refractory temporal lobe epilepsy (TLE) showed either unilateral, although alternating in side, or bilateral simultaneous seizure onsets in both temporal lobes (TL). EEG recordings with semi-invasive foramen ovale electrodes revealed in seven patients a predominance of seizure onset in one TL of between 50% and 88%. In two patients the majority of seizures originated simultaneously in both TL. In four patients a unilateral selective amygdalohippocampectomy resulted in a good to excellent seizure outcome without noteworthy memory deficits and confirmed the preoperative lateralization of the primary epileptogenic focus by interictal ¹⁸F-fluorodeoxyglucose positron emission tomography (PET). Five patients were rejected from surgery due to strong bilaterality of their epilepsy and/or divergent presurgical findings. PET contributed to the decision of whether surgery should be performed: all patients who underwent surgery had a unilateral TL hypometabolism which was concordant with the findings of other tests. Patients in whom surgery was denied had either bilateral temporal hypometabolism or the PET findings were discordant with other results obtained during the presurgical evaluation.     

Hyperkinetic seizures in patients with temporal lobe epilepsy: clinical features and outcome after temporal lobe resection

Purpose: Temporal lobe epilepsy (TLE) is usually associated with automatisms. Hyperkinetic seizures are supposed to be unusual. Because we witnessed several patients with TLE and ictal hyperkinetic symptoms, we retrospectively assessed the number, clinical findings, and seizure outcome in such patients who had undergone temporal lobe resection. Methods: We reviewed medical history, video–electroencephalography (EEG) recording and neuroimaging of adult patients who underwent epilepsy surgery for TLE at the Kork Epilepsy Center over the last 20 years with a minimum postoperative follow‐up of 12 months. Key Findings: Among 294 patients who were resected exclusively in the temporal region, we identified 17 (6%) who presented with hyperkinetic semiology such as violent vocalization, complex movements of the proximal segments of the limbs, rotation of the trunk, pelvic thrusting, or early tonic or dystonic posturing. Most of the patients had a preceding aura. Ictal EEG activity was located in the corresponding temporal region, usually with a wide distribution over temporal electrodes with fast spread to unilateral frontal electrodes and to the contralateral side. Neuroimaging revealed extended lesions in the temporal lobe involving mesial and neocortical structures. Most of the patients underwent classical anterior temporal lobe resection including amygdalo‐hippocampectomy. Fourteen patients (82%) became completely seizure‐free (Engel class Ia). Histopathology showed mainly focal cortical dysplasia plus hippocampal sclerosis. Significance: Hyperkinetic seizure semiology may occasionally occur in patients with TLE and is, therefore, no contradiction to the hypothesis of TLE if scalp EEG patterns and neuroimaging findings correspond. The postoperative seizure outcome is favorable in such patients and not different from outcome data in classical TLE.     

Significance of lateralization of upper limb automatisms in temporal lobe epilepsy: A quantitative movement analysis

Purpose: To evaluate the significance of lateralization of ictal upper limb automatisms in patients with temporal lobe epilepsy (TLE). Methods: Ictal upper limb automatisms of 28 patients with temporal lobe epilepsy were quantified. Duration of automatisms in relation to total seizure duration, movement speed, extent, length, and predominant frequencies of the movements were analyzed for both upper extremities separately and compared to the lateralization of the epileptogenic temporal lobe. Results: Predominantly ipsilateral upper limb automatisms were more common (n = 19) than predominantly contralateral automatisms (n = 9). The duration of ictal ipsilateral upper limb automatisms was significantly longer than the duration of contralateral automatisms (ipsilateral automatisms: 29 of 86 s total seizure duration; contralateral automatisms: 19 of 110 s total seizure duration; p = 0.048). Patients with ipsilateral upper limb automatisms had more often exclusively unitemporal interictal epileptiform discharges (IEDs) (84.2%) than patients with contralateral automatisms (11.1%; p < 0.001). The positive predictive value (PPV) of the combination of these parameters is 84.2%. Excellent surgical seizure outcome was better in patients with ipsilateral upper limb automatisms (77.8%) compared to those with contralateral automatisms (20%) (p = 0.09). The quantitative analysis of movement extent, average speed, maximum speed, and repetition rate of ipsilateral and contralateral upper limb automatisms did not show any statistically significant difference in this patient sample. Conclusion: The lateralization of upper limb automatisms in TLE has a good lateralizing value if the lateralization of IEDs were also taken into consideration.