Side of seizure focus predicts left medial temporal lobe activation during verbal encoding

OBJECTIVE: Functional MRI (FMRI) was used to investigate the effect of medial temporal lobe (MTL) pathology on activation of language encoding areas in patients with temporal lobe epilepsy (TLE). METHODS: Whole-brain FMRI was obtained. Twenty-eight patients with either left TLE (LTLE) or right TLE (RTLE) performed a semantic decision task alternating with an auditory perceptual task. RESULTS: Activation of language areas in the frontal and parietal lobes was similar in both groups, with no group differences in the total number of active voxels. However, the RTLE group showed much stronger activation of the left MTL, including the hippocampus, parahippocampal gyrus, and collateral sulcus, than did the LTLE group. CONCLUSIONS: Activation of the left MTL during semantic encoding discriminates patients with RTLE and LTLE. This FMRI technique may potentially be of use in determining memory lateralization and for predicting the side of seizure focus in TLE.     

Wada memory testing and hippocampal volume measurements in the evaluation for temporal lobectomy

We examined the relationship of Wada memory performance and MRI hippocampal volume measurements to laterality of ultimate seizure localization in 20 patients with complex partial seizures who later underwent temporal lobectomy. Discriminant function analysis employing both Wada memory test asymmetries and hippocampal volume asymmetries correctly classified 100% of the patients into left and right temporal lobe groups. Wada memory asymmetries alone correctly classified 90% of the sample (80% of the sample when the discriminant function included all patients except the one being classified), and hippocampal volume asymmetries alone correctly classified 90% of the patients. A significant correlation was present between Wada memory asymmetries and hippocampal volume asymmetries (r = 0.78), indicating that structural evidence of reduced hippocampal volume has a functional correlate reflected by Wada memory performance. These data suggest that the combination of functional and structural measures is of value in the preoperative evaluation for epilepsy surgery.     

Lateralization of human temporal lobe epilepsy by 31P NMR spectroscopic imaging at 4.1 T

OBJECTIVE: To compare the phosphorous metabolite ratios in the mesial temporal lobe of healthy volunteers (n = 20) with the corresponding ratios in patients with temporal lobe epilepsy (n = 30) using 31P NMR spectroscopic imaging and to lateralize the seizure focus in temporal lobe epilepsy patients using various phosphorous metabolite ratios-phosphocreatine to inorganic phosphate (PCr/Pi), PCr to adenosine triphosphate (PCr/gamma-ATP), and (gamma-ATP/Pi)--and to compare with clinical lateralization results. METHODS: All 31P NMR spectroscopic imaging studies were performed on a high-field, 4.1 T, whole-body NMR spectroscopic imaging system using a 31P/1H double-tuned volume coil. RESULTS: We found an average reduction of 15% in the PCr/Pi and gamma-ATP/Pi ratios compared with the corresponding ratios in healthy volunteers in the entire mesial temporal lobe, and more than a 30% reduction in these two ratios in the anterior region of the epileptogenic mesial temporal lobe. These ratios were also reduced significantly in the ipsilateral lobe when compared with their corresponding values in the contralateral lobe. In patients we lateralized the seizure focus, based on these 31P NMR data, and compared the results with the clinical lateralization. The lateralization based on either the PCr/Pi or the gamma-ATP/Pi ratio yielded a correspondence of 70 to 73% with the final clinical lateralization. In the subgroup of patients (n = 9) that needed intracranial EEG for the presurgical lateralization because of inconclusive results from the noninvasive methods, a 78% correspondence was found with the 31P NMR-based lateralization, whereas MRI provided a correspondence of only 33%, and scalp EEG provided a correspondence of only 56%. CONCLUSIONS: These results suggest the utility of adding the 31P NMR method to the group of noninvasive modalities used for presurgical decision making in temporal lobe epilepsy patients.     

Spectral EEG during short-term discontinuation of antiepileptic medication in partial epilepsy

The effect of short-term discontinuation of antiepileptic drugs (AEDs) on spectral analysis of EEG background activity (spectral EEG) was studied in patients undergoing preoperative evaluation for epilepsy surgery. We also wished to clarify whether AED discontinuation would provide lateralizing evidence in spectral EEGs of patients with temporal lobe epilepsy (TLE). Spectral EEGs were performed in 15 patients receiving their regular medication regimen and again after a 1-week period during AED withdrawal. A subgroup of 9 patients who had previously undergone temporal lobectomies (TLE group) was studied separately. In this group, we evaluated the effect of preceding seizures on spectral EEG derived from temporal neocortical areas. In all patients, spectral EEG changes were detected even after a short-term AED withdrawal. The total amount of absolute delta activity was reduced and occipital peak frequency and relative alpha activity were increased as compared with baseline values. In TLE patients with habitual seizures occurring < 20 h before the spectral EEG recording, lateralization was correctly identified by the greater amount of absolute delta activity ipsilateral to the epileptogenic focus. Epileptic seizures are accompanied by subtle focal slowing in spectral EEG for a much longer period than has been assumed. In addition, postictal spectral EEG over the temporal lobes may have lateralizing value. Further studies in larger numbers of patients are needed to evaluate the role of spectral EEG in the preoperative evaluation of patients for temporal lobe surgery.     

"Cavernous sinus EEG": a new method for the preoperative evaluation of temporal lobe epilepsy

PURPOSE: In presurgical evaluation of temporal lobe epilepsy (TLE), invasive methods are necessary if results of various noninvasive methods are not sufficiently convergent enough to identify the epileptogenic area accurately. To detect the epileptiform discharges originating specifically from the mesial temporal lobe, we applied the cavernous sinus catheterization technique. METHODS: We placed Seeker Lite-10 guide wire electrodes into bilateral cavernous sinus through the internal jugular veins to record EEG (cavernous sinus EEG) in 6 patients with intractable TLE. Scalp EEG was simultaneously recorded in all 6 and electrocorticogram (ECoG) was also recorded in 4. RESULTS: The cavernous sinus EEG demonstrated clear epileptiform discharges, sometimes even when they were absent on the simultaneously recorded scalp EEG. The epileptiform discharges recorded from the cavernous sinus electrodes were specifically associated with those in the mesial temporal region on ECoG. Ictal EEG pattern originating from mesial temporal lobe was also clearly documented on the cavernous sinus EEG. CONCLUSIONS: This new, semi-invasive method of identifying epileptogenic areas can detect the epileptiform discharges specifically arising from the mesial temporal lobe; it is as useful as or complements the invasive techniques such as foramen ovale or depth recording.     

Continuous source imaging of scalp ictal rhythms in temporal lobe epilepsy

PURPOSE: We wished to determine whether continuous EEG source imaging can predict the location of seizure onset with sublobar accuracy in temporal lobe epilepsy (TLE). METHODS: We retrospectively analyzed the earliest scalp ictal rhythms, recorded with 23- to 27-channel EEG, in 40 patients with intractable TLE. A continuous source analysis technique with multiple fixed dipoles (Focus 1.1) decomposed the EEG into source components representing the activity of major cortical sublobar surfaces. For the temporal lobe, these were basal, anterior tip, anterolateral, and posterolateral cortex. Ictal EEG onset was categorized according to its most prominent and leading source component. All patients underwent intracranial EEG studies before epilepsy surgery, and all had a successful surgical outcome (follow-up >1 year). RESULTS: Most patients with ictal rhythms having a predominant basal source component had hippocampal-onset seizures, whereas those with seizures with prominent lateral source activity had predominantly temporal neocortical seizure origins. Seizures with a prominent anterior temporal tip source component mostly had onset in entorhinal cortex. Seizures in some patients had several equally large and nearly synchronous source components. These seizures, which could be modeled equally well by a single oblique dipole, had onset predominantly in either entorhinal or lateral temporal cortex. CONCLUSIONS: Multiple fixed dipole analysis of scalp EEG can provide information about the origin of temporal lobe seizures that is useful in presurgical planning. In particular, it can reliably distinguish seizures of mesial temporal origin from those of lateral temporal origin.     

Preoperative predictors of anterior temporal language areas

OBJECT: Although it is known that 5 to 10% of patients have language areas anterior to the rolandic cortex, many surgeons still perform standard anterior temporal lobectomies for epilepsy of mesial onset and report minimal long-term dysphasia. The authors examined the importance of language mapping before anterior temporal lobectomy. METHODS: The authors mapped naming, reading, and speech arrest in a series of 67 patients via stimulation of long-term implanted subdural grids before resective epilepsy surgery and correlated the presence of language areas in the anterior temporal lobe with preoperative demographic and neuropsychometric data. Naming (p < 0.03) and reading (p < 0.05) errors were more common than speech arrest in patients undergoing surgery in the anterior temporal lobe. In the approximate region of a standard anterior temporal lobectomy, including 2.5 cm of the superior temporal gyrus and 4.5 cm of both the middle and inferior temporal gyrus, the authors identified language areas in 14.5% of patients tested. Between 1.5 and 3.5 cm from the temporal tip, patients who had seizure onset before 6 years of age had more naming (p < 0.02) and reading (p < 0.01) areas than those in whom seizure onset occurred after age 6 years. Patients with a verbal intelligence quotient (IQ) lower than 90 had more naming (p < 0.05) and reading (p < 0.02) areas than those with an IQ higher than 90. Finally, patients who were either left handed or right hemisphere memory dominant had more naming (p < 0.05) and reading (p < 0.02) areas than right-handed patients with bilateral or left hemisphere memory lateralization. Postoperative neuropsychometric testing showed a trend toward a greater decline in naming ability in patients who were least likely to have anterior language areas, that is, those with higher verbal IQ and later seizure onset. CONCLUSIONS: Preoperative identification of markers of left hemisphere damage, such as early seizure onset, poor verbal IQ, left handedness, and right hemisphere memory dominance should alert neurosurgeons to the possibility of encountering essential language areas in the anterior temporal lobe (1.5-3.5 cm from the temporal tip). Naming and reading tasks are required to identify these areas. Whether removal of these areas necessarily induces long-term impairment in verbal abilities is unknown; however, in patients with a low verbal IQ and early seizure onset, these areas appear to be less critical for language processing.     

In vivo cerebral metabolism and central benzodiazepine-receptor binding in temporal lobe epilepsy

Positron emission tomography measured interictal cerebral glucose metabolism with [18F]fluorodeoxyglucose and central benzodiazepine-receptor binding with [11C]flumazenil in 10 mesial temporal lobe epilepsy (TLE) patients and in normal subjects. Eight TLE patients had mesial temporal, lateral temporal, and thalamic hypometabolism ipsilateral to EEG ictal onsets, with additional extratemporal hypometabolism in four. One had unilateral anterior mesial temporal hypometabolism only, and one had normal metabolism. Each patient had decreased benzodiazepine-receptor binding in the ipsilateral anterior mesial temporal region, without neocortical changes. Thus, interictal metabolic dysfunction is variable and usually extensive in TLE, whereas decreased central benzodiazepine-receptor density is more restricted to mesial temporal areas. Metabolic patterns in TLE may reflect diaschisis, while benzodiazepine-receptor changes may reflect localized neuronal and synaptic loss that is specific to the epileptogenic zone. [11C]Flumazenil imaging may be useful in presurgical evaluation of refractory complex partial seizures.     

Effects of long-term aerosol pentamidine for Pneumocystis carinii prophylaxis on pulmonary function

OBJECTIVE: To compare the reliability of clinical seizure lateralization in temporal lobe epilepsy patients with unitemporal and bitemporal independent interictal spikes and unilateral hippocampal atrophy or sclerosis (HA/HS) on MRI scan. PATIENTS AND METHODS: We studied 11 patients with unitemporal and 10 patients with bitemporal interictal spikes. We calculated a spike ratio by dividing the number of spikes ipsilateral to the side of HA/HS by those occurring contralaterally. RESULTS: Clinical seizure lateralization was correct, i.e., ipsilateral to the side of HA/HS, significantly more often in the unitemporal group. Spike ratios were significantly higher in seizures that were lateralized correctly as compared with both incorrectly and nonlateralized seizures. Within the individual patients, a significant positive correlation between spike ratios and the proportion of correctly lateralized seizures was found. We identified three categories of symptoms according to lateralization accuracy. Category 1 symptoms (version, postictal paresis, and early ictal vomiting/retching) lateralized to the side of HA/HS in 100% of patients in the uni- and bitemporal groups. Category 2 symptoms (dystonic posturing, mouth deviation, postictal dysnomia/dysphasia, and ictal speech) provided a 100% correct lateralization in the unitemporal but not in the bitemporal patients. Category 3 symptoms (nonversive early head turning and unilateral upper extremity automatisms) yielded erroneous lateralization in both patient groups. CONCLUSIONS: We conclude that reliable clinical seizure lateralization in mesial temporal lobe epilepsy can only be achieved in patients with unitemporal interictal spikes, whereas clinical lateralization in patients with bitemporal spikes must be viewed cautiously.     

A genetic propensity to high factor VII is not associated with the risk of myocardial infarction in men

Interictal brain SPECT is useful for the localization of a seizure focus. Concomitant hypoperfusion of the ipsilateral thalamus on interictal SPECT has been noted for temporal lobe epilepsy. In this study, we aimed to evaluate the prevalence of thalamic hypoperfusion ipsilateral to temporal hypoperfusion (ipsilateral thalamic hypoperfusion) and to assess the usefulness of this finding for the lateralization of epileptic foci on interictal SPECT for temporal lobe epilepsy patients. METHODS: Forty-six patients with refractory temporal lobe epilepsy underwent interictal brain SPECT after intravenous injection of 555-740 MBq of 99mTc-ECD. Perfusion impairments in the brain, especially the temporal lobe and thalamus, were evaluated. The localization of seizure foci was determined in conjunction with scalp, ictal and cortical electroencephalography, MRI and clinical outcomes. Ictal SPECT was performed for 5 of the 12 patients. RESULTS: Concomitant decreased perfusion in both the temporal lobe and the ipsilateral thalamus was observed for 12 (26%) of 46 temporal lobe epilepsy patients on interictal brain SPECT. Seven patients showed hypoperfusion in the left temporal lobe and ipsilateral thalamus. Five patients showed hypoperfusion in the right temporal lobe and ipsilateral thalamus. In addition, hypoperfusion in the ipsilateral basal ganglia (ten patients) or contralateral cerebellum (four patients) was observed. CONCLUSION: Ipsilateral thalamic hypoperfusion is not uncommon in temporal lobe epilepsy. The exact mechanism causing ipsilateral thalamic hypoperfusion is uncertain; however, corticothalamic diaschisis may be an important factor. This finding may aid in the lateralization of seizure foci on interictal brain SPECT.     

Olfactory prodromal symptoms and unilateral olfactory dysfunction are associated in patients with right mesial temporal lobe epilepsy

PURPOSE: We report a patient with mesial temporal lobe epilepsy (MTLE) with olfactory prodromal symptoms manifested as an unpleasant smell of onions, who was found to have an ipsilateral deficit of olfactory naming (olfactory agnosia). METHODS AND RESULTS: Preoperative olfactory testing revealed a selective right-sided olfactory deficit for naming of odors. Olfactory threshold was within the normal range. The patient has been seizure free after selective amygdalohippocampectomy for 4 months. No olfactory prodromal events have occurred since surgery. Olfactory testing 3 months after resection showed that right-sided odor naming was still impaired. CONCLUSIONS: We conclude that olfactory prodromal symptoms may be associated with unilateral olfactory dysfunction, and lateralization of seizure origin may be possible by unilateral olfactory testing.     

Material-specific memory in temporal lobe epilepsy: Effects of seizure laterality and language dominance.

This study investigated the effects of seizure laterality and language dominance on material-specific memory in temporal lobe epilepsy (TLE). Left TLE (LTLE) patients with left-hemisphere language dominance (LHLD) showed significantly higher nonverbal than verbal memory capacity, whereas right TLE patients with LHLD showed significantly better verbal than nonverbal memory capacity. LTLE patients with non-left-hemisphere language dominance (NLHLD) showed significantly better verbal memory capacity compared with LTLE patients with LHLD. Thus, selective verbal or nonverbal memory deficits that are dependent on side of seizure onset were apparent in patients with LHLD but not in patients with NLHLD. Relative sparing of verbal memory capacity in LTLE patients with NLHLD may reflect interhemispheric reorganization of verbal memory function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anterior temporal abnormality in temporal lobe epilepsy: a quantitative MRI and histopathologic study

OBJECTIVE: To examine the nature and frequency of anterior temporal lobe (AT) abnormalities that occur in intractable temporal lobe epilepsy (TLE). METHODS: We reviewed the MR scans and clinical histories of 50 consecutive patients with intractable TLE. Histopathology was available in 42 surgically treated cases. RESULTS: MRI demonstrated loss of the gray-white matter differentiation and decreased T1- and increased T2-weighted signal in the ipsilateral AT in 58% of the 50 patients. This appearance was observed in 64% of the 36 patients with hippocampal sclerosis (HS) but was also seen in patients without HS. These changes were associated with temporal lobe atrophy, a higher hippocampal T2 relaxation time, and a history of febrile convulsions. Pathologic examination showed that the MRI appearances were not caused by dysplasia, degenerative abnormalities, or inflammatory change. Histologic quantitation showed increased glial cell nuclei counts in the intractable TLE cases compared with controls. There was no difference in glial cell numbers between cases with AT abnormality and those without this appearance. Presence or absence of changes was not predictive of preoperative neuropsychology, postoperative change in neuropsychology, or seizure outcome after surgery. CONCLUSIONS: These frequently seen ipsilateral changes are not caused by gliosis and may reflect a nonspecific increase in water content in the temporal lobe. This may be due to myelin abnormalities or some other as yet unidentified pathologic factor.     

Clinical correlations with hippocampal atrophy

There is now a consensus that magnetic resonance imaging (MRI) is a sensitive and specific indicator of mesial temporal sclerosis (MTS) in patients with partial epilepsy. MTS is the most common pathological finding underlying the epileptogenic zone in patients undergoing temporal lobe surgery for medically refractory partial seizures. MRI-based hippocampal volumetric studies (i.e., quantitative MRI), has been shown to provide objective evidence for hippocampal atrophy in patients with MTS. The hippocampal volume in the epileptic temporal lobe has correlated with the neuronal cell densities in selected hippocampal subfields. A history of febrile seizures in childhood and age of unprovoked seizure onset have been associated with MRI-based hippocampal volumetry. There is conflicting evidence regarding the relationship between the duration of the seizure disorder and volumetry. Quantitative MRI has compared favorably to other noninvasive techniques (e.g., scalp-recorded EEG), in indicating the diagnosis of medical temporal lobe epilepsy (MTLE). MRI-identified hippocampal atrophy has also been a favorable prognostic indicator of seizure outcome after temporal lobe surgery. The presence of hippocampal atrophy appears to serve an in vivo surrogate for the presence of MTS.     

Single photon emission computed tomography-EEG relations in temporal lobe epilepsy

The role of single photon emission computed tomography (SPECT) as an independent confirmation test in presurgical evaluation of medically intractable temporal lobe epilepsy has not been critically investigated. Because spreading ictal discharges may cause a concomitant increase of cerebral blood flow in remote cerebral regions, a careful analysis of peri-injection EEG patterns and their relation to ictal SPECT may be important in evaluating the reliability of ictal SPECT. Both interictal and ictal EEG and SPECT were reviewed in 19 patients with temporal lobe epilepsy who achieved a successful seizure outcome after surgery. Patients were divided into unitemporal and bitemporal groups according to the lateralization of interictal epileptiform discharges (IED). Ictal EEG features were classified into lateralized and nonlateralized groups. The concordance between SPECT and EEG lateralizations was examined in each patient and correlated to the documented epileptogenic temporal lobe. Interictal SPECT correctly lateralized in eight of nine patients with unitemporal IED and in five of 10 patients with bitemporal IED. Ictal SPECT was highly concordant with the peri-injection ictal EEG but correctly lateralized the epileptogenic region in only 11 of 19 patients. When both pre- and postinjection EEG epochs lateralized ipsilaterally, all ictal SPECT images showed concordant lateralization. If pre- and postinjection EEG epochs were either different in lateralization or nonlateralization, ictal SPECT images often showed complex patterns of cerebral perfusion with a high incidence of false lateralization. Interictal SPECT was more sensitive and reliable in patients with unitemporal IED than in patients with bitemporal IEDs. Ictal SPECT was closely related with peri-injection EEG epochs but with frequent false lateralization. The role of ictal SPECT as an independent confirmation test in presurgical evaluation should be reappraised.     

Limbic ERPs predict verbal memory after left-sided hippocampectomy

Surgical removal of the dominant medial temporal lobe regions runs a considerable risk of verbal memory deficits which may be compensated for postoperatively by corresponding regions in the non-dominant medial temporal lobe. We examined this possibility by recording event-related potentials (ERPs) to words from the medial temporal lobes of patients with left-sided temporal lobe epilepsy (TLE) undergoing presurgical evaluation. N400 amplitudes in the right anterior medial temporal lobe predicted the postoperative verbal recall performance of individual patients with surprising accuracy, indicating that intracranial recordings can be used to quantify the functional capacities of the right hemisphere that can compensate for the verbal memory deficits after loss of medial temporal lobe structures in the left hemisphere.     

Verbal working memory components can be selectively influenced by transcranial magnetic stimulation in patients with left temporal lobe epilepsy

The aim of this study was to investigate whether transcranial magnetic stimulation (TMS) can be used for a lateralization of verbal and non-verbal memory functions in candidates for epilepsy surgery by inducing focal, material-specific memory deficits. Twenty patients who underwent presurgical epilepsy evaluation with chronically implanted subdural strip electrodes were submitted to focal TMS over the temporal lobes and the vertex while sequences of items of the Digit Span and the Corsi Block test were presented on a computer screen. TMS was applied synchronously or 200 msec following presentation of each item. The effects of TMS on the memory span and the serial position curve were analysed in comparison to baseline levels. The following results were obtained: the quantitative effects on the verbal (Digit Span) and non-verbal (Corsi Block) memory span were not significant, but there were significant qualitative changes of serial position effects. In the group of six patients with left temporal epilepsy, TMS over the left temporal lobe induced a significant recency effect in the Digit Span test, while TMS over the vertex significantly increased the recency errors. The absolute number of errors remained unchanged. No such effects were observed in the group of nine patients with right temporal lobe epilepsy. These results suggest that in the presence of a left temporal lobe focus TMS can induce qualitative, material specific changes in verbal working memory (phonological loop) which become apparent in the serial position curve. The dissociation of TMS effects for temporal and vertex stimulation imply that TMS can selectively influence specific phonological loop components and that the phonological loop has a functionally and neuroanatomically multimodular structure.     

Language lateralization of Chinese-English bilingual patients with temporal lobe epilepsy: A functional MRI study.

Functional MRI was used to examine language lateralization of Chinese characters and English words associated with temporal lobe epilepsy (TLE) in Chinese-English bilinguals with left or right TLE. The results suggest that the neural basis of processing Chinese and English seems to be different, as normal controls demonstrated left hemispheric lateralization in reading English words but bi-hemispheric lateralization in reading Chinese characters. This difference in the neural bases of Chinese and English processing was found to affect the patterns in change-of-language processing associated with TLE. That is, whereas left-TLE patients were more likely than right-TLE patients to demonstrate a bi-hemispheric language involvement in reading English, both left- and right-TLE patients demonstrated primarily bilateral hemispheric involvement for reading Chinese characters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological outcome following anterior temporal lobectomy in patients with and without the syndrome of mesial temporal lobe epilepsy.

The nature, pattern, and degree of neuropsychological change following anterior temporal lobectomy (ATL) were examined as a function of the presence or absence of the syndrome of mesial temporal lobe epilepsy (MTLE). Fifty-four patients exhibited the syndrome of MTLE, while 34 patients were without the syndrome (non-MTLE). The test-retest performance of a group of 40 epilepsy patients who did not undergo surgery was used to derive regression based estimates of test-retest change. Overall, the MTLE group did not show significant cognitive decline following ATL. In contrast, the left non-MTLE group showed significant declines on verbal memory, confrontation naming, and verbal conceptual ability. Further, verbal memory was the most substantial area of decline, and was independent of seizure outcome. Clinical and theoretical implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Medial temporal lobe epilepsy: videotape analysis of objective clinical seizure characteristics

PURPOSE: The syndrome of temporal lobe epilepsy has been described in great detail. Here we focus specifically on the clinical manifestations of seizures originating in the hippocampus and surrounding mesial temporal structures. METHODS: Seizure origin was confirmed in 67 cases by depth EEG recording and surgical cure after mesial temporal resection. RESULTS: Among nonlateralized manifestations, we commonly found oral automatisms, pupillary dilatation, impaired consciousness, and generalized rigidity. Appendicular automatisms were often ipsilateral to the seizure focus, whereas dystonia and postictal hemiparesis were usually contralateral. Head deviation, when it occurred early in the seizure, was an ipsilateral finding, but was contralateral to the seizure focus when it occurred late. Clear ictal speech and quick recovery were found when seizures originated in the non-language-dominant hemisphere, but postictal aphasia and prolonged recovery time were characteristic of seizure origin in the language-dominant hemisphere. CONCLUSIONS: These signs help to define the mesial temporal lobe epilepsy (MTLE) syndrome and often provide information as to the side of seizure origin.