Postictal language assessment and lateralization of complex partial seizures

We performed a prospective study of ictal and postictal language function after 105 temporal lobe complex partial seizures in 26 patients. Seizure localization was verified by a greater than 90% reduction in seizure frequency after temporal lobectomy. At the time of the seizure, the patient was asked to read a test phrase aloud until it was read correctly and clearly. In all 62 seizures originating from the left temporal lobe, the patient took more than 68 seconds to read the test phrase correctly (mean, 321.9 seconds); in 42 of 43 seizures from the right temporal lobe, the patient read the test phrase in less than 54 seconds (mean, 19.7 seconds). Postictal paraphasias occurred in 46 of 62 seizures from the left temporal lobe (11 of 14 patients). In this study, quantifying the time delay in reading a test phrase lateralized seizure onset in all 26 patients tested, proving significantly more accurate than any other single noninvasive presurgical test.     

Computer enhancement of scalp-sphenoidal ictal EEG in patients with complex partial seizures

Color topographic maps of scalp/sphenoidal ictal EEG records were computer-generated in 5 patients with medically refractory complex partial seizures of suspected temporal lobe origin. Seven ictal EEG records were analyzed by parsing them into a series of 1.28 sec epochs. User-interactive, computer techniques were utilized to replace eye movement and other artifactual segments in the peri-ictal records with nearby uncontaminated EEG segments. Artifact replacement techniques were designed to minimize or eliminate EEG discontinuities in those epochs in which artifact was removed. Significance probability maps consisting of z scores were constructed by comparing theta band power for each 1.28 sec epoch composing the peri-ictal period with the mean and standard deviation of theta power computed from a pre-ictal baseline period consisting of 50-75 epochs. The resulting maps were compared with available independent clinical measures in order to validate their usefulness. The independent measures consisted of non-invasive data (visual impressions of raw scalp/sphenoidal ictal EEGs and positron emission tomography) and invasive data (depth ictal recordings, pathological findings in resected temporal lobes, and surgical outcome). Ictal topographic maps appeared to either confirm or provide new localizing information in all 5 patients. In 3 of 5 patients, several seconds of localized theta suppression preceded localized theta augmentation during the peri-ictal period. The transition between the 2 states was very rapid (approximately 2 sec). The spatial locus of suppression was always in agreement with the spatial locus of augmentation. In general, the maps were considerably easier to interpret than the raw scalp/sphenoidal ictal EEGs: (1) Localized theta suppression in the maps was not evident from visual inspection of the raw ictal scalp/sphenoidal EEG. (2) Clear localized theta augmentation in the maps occurred well before the appearance of unambiguous phase reversals in the raw scalp/sphenoidal ictal EEG. (3) Mapping data were correctly lateralizing in 1 patient in whom visual interpretation of the raw scalp/sphenoidal ictal EEGs was considered non-localizing but often suggestive of a seizure origin in the hemisphere contralateral to that implicated by depth recordings, PET, and pathological data. These results suggest that topographic mapping of scalp/sphenoidal ictal EEGs in patients with complex partial seizures may eventually prove to be a useful adjunct to the interpretation of raw ictal 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.     

Lateralising value of ictal features in partial seizures: effect on postsurgical outcome.

We reviewed the videotapes of 49 consecutive patients with a history of medically refractory temporal lobe epilepsy for the presence and laterality of unilateral hand posturing (UHP), unilateral hand automatism (UHA), non-forced head turning (HT), and post-ictal dysphasia (PID). All of these patients underwent temporal resections with follow-up for more than 2 years after the surgery. We examined the correlation of consistency, frequency, and laterality of each of these signs on the postsurgical outcomes. The distribution of these signs was not significantly different between patients with Engel class 1 versus Engel class 2-4. The consistency and laterality of these signs do not correlate with postsurgical outcomes.     

Interictal and postictal language testing accurately lateralizes language dominant temporal lobe complex partial seizures

PURPOSE: Noninvasive tests that accurately localize seizure onset provide great value in the presurgical evaluation of patients with intractable epilepsy. This study examined the diagnostic utility of three expressive language disturbances in lateralizing language-dominant (DOM) temporal lobe complex partial seizures: (1) the postictal language delay (PILD; time taken to correctly read a test phrase out loud immediately following seizures); (2) the production of postictal phonemic paraphasic errors (PostPE); and (3) interictal phonemic paraphasic errors (InterPE). METHODS: All 60 subjects underwent inpatient video/EEG monitoring and had surgically confirmed temporal lobe epilepsy (TLE). We determined the presence and number of PostPE and, PILD times (in s) for 212 seizures, and InterPE on the Boston Naming Test (BNT). Each technique's diagnostic usefulness was evaluated via logistic regression and ROC curve analysis. Sensitivity, specificity, positive predictive value and negative predictive values were computed. RESULTS: PILD, PostPE and InterPE production were equally effective and accurate in lateralizing DOM seizure onset. Patients with DOM TLE had a longer PILD and committed more PostPE and InterPE than those with nondominant (NDOM) TLE. Respective sensitivity and specificity values were as follows: PILD (84%, 86%), PostPE (94%, 64%), and InterPE (97%, 86%). No single predictor was significantly better but a combination model yielded enough incremental utility to collectively outperform each separate predictor model. CONCLUSIONS: Interictal language testing is as accurate as postictal language testing in predicting DOM lateralization of TLE. Clinicians should also attend to the quality of errors produced during interictal and postictal language testing.     

Frontal lobe partial seizures and psychogenic seizures: comparison of clinical and ictal characteristics.

Of all partial seizures, those of frontal lobe origin (FLPS) are most bizarre and are often mistaken for psychogenic seizures (PS). The reverse can also be true. To clarify the confusing clinical presentation of these different seizure types, we compared the clinical ictal characteristics of 63 FLPS in 11 patients with 29 PS in 12 patients. Patients with PS had significantly later age at onset and longer ictal duration. There was no statistically significant difference between the two groups with respect to history of psychiatric disorder, ictal pelvic thrusting, rocking of body, side-to-side head movements, or rapid postictal recovery, all of which previously have been reported as characteristic features of PS. Turning to a prone position during the seizure occurred only in FLPS. Nocturnal occurrence, short ictal duration, younger age at onset, stereotyped patterns of movements, and MRI and EEG abnormality suggested FLPS.     

Indications and outcome of ictal recording with intracerebral and subdural electrodes in refractory complex partial seizures.

Intracranial electrophysiologic recording has often been used to localize ictal onset zones in presurgical evaluation of refractory complex partial seizures. Specific indications for intracranial ictal monitoring have not been analyzed in detail, however. The authors designed this study to test the utility of intracranial monitoring in specific indications and considered six specific indications for intracranial monitoring. They compared prospectively determined indications and outcomes of chronic intracerebral and subdural electrophysiologic recording in 50 consecutive patients whose ictal onset zones had been inadequately localized with interictal and ictal EEG using extracranial electrodes, magnetic resonance imaging, interictal[18F]fluorodeoxyglucose positron emission tomography, and neuropsychological testing. In 47 patients ictal onset zones were localized with intracranial recordings, leading to resections in 38 patients. Each indication for intracranial monitoring selected a group in which the majority went on to have efficacious epilepsy surgery (5-year follow-up). Definitive diagnosis of bilateral independent ictal onset zones in temporal lobe epilepsy required intracranial ictal EEG. Intracranial EEG localization supported efficacious resection in most patients, despite contradictory or nonlocalizing extracranial ictal EEG and neuroimaging abnormalities. Critical analysis of these specific indications for intracranial monitoring may be useful in multicenter evaluation of these techniques.     

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.     

Pre- and postictal, not ictal, heart rate distinguishes complex partial and psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) remain poorly understood neurobiologically. Previously reported work suggests that adjunct ictal heart rates (HRs) may differentiate PNES from complex partial seizures (CPS). We retrospectively reviewed and compared preictal, ictal, and postictal HR differences in patients with PNES (n=42) and CPS controls (n=46) electively admitted for video/EEG monitoring to further characterize PNES autonomic patterns. Statistically significant preictal HR increases (P=0.006) and postictal (P=0.015) HR reductions normalized to baseline were identified in subjects with PNES compared with CPS controls. Ictal HRs were not found to differentiate between PNES and CPS events. This pattern of pre-event HR increases and postevent HR decreases in patients with PNES compared with those with CPS suggests frontolimbic neural circuit dysfunction and merits further exploration.     

Epileptic spasms and partial seizures as a single ictal event

PURPOSE: To investigate the phenomenon of epileptic spasms (ESs) associated with other seizure types in a single ictal event and to study the predictive value of this phenomenon regarding etiology and prognosis. METHODS: We selected retrospectively eight female and five male patients, who had ESs and other seizure types within a single seizure event and for whom a video-EEG recording of the phenomenon was performed in at least one situation. RESULTS: The seizure type associated with ESs was a partial seizure in all patients. We identified three groups with different seizure patterns regarding the temporal association of ES and partial seizures (PSs): (a) PS followed by ES; (b) PS appearing during a cluster of ESs without interrupting the cluster; and (c) complex seizure interaction with a succession of ESs and PSs in a close but variable temporal association. Underlying disorders included cortical dysplasia (three patients), complex cerebral malformations (two patients), and perinatal anoxic-ischemic injuries (two patients); four cases were classified as cryptogenic, and in two children, etiology was unknown, but prenatal origin was suspected. Outcome was poor in nine cases with intractable epilepsy; four cases had a favorable outcome, defined as complete cessation of epileptic seizures. CONCLUSIONS: The phenomenon of associated ESs and PSs as a single ictal event can be related to different etiologies and should not be considered distinctive for cortical malformations or severe brain damage. Different seizure patterns of associated ESs and PSs provide no hint for etiology or prognosis. Outcome is prevalently but not constantly unfavorable in patients with the phenomenon.     

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.     

Self-abatement of complex partial seizures

Seven of 71 patients with complex partial seizures claimed they were able to abate their seizures, while none of 18 with simple partial seizures were able to do so. Self-abatement exercises included highly stereotyped cognitive and physical components unique to the individual. Those who could abate their seizures had attained higher educational status, better social and vocational adjustment, and better psychological adjustment than did the control group of patients with epilepsy. The self-abatement group was also more likely to have right hemispheric electroencephalographic abnormalities. Characterization of the self-abatement group may be relevant to the selection of candidates for behavioral therapy for epilepsy.     

Genital automatisms in complex partial seizures

OBJECTIVE: To determine which brain region is responsible for the generation of sexual automatisms. METHODS: Ninety consecutive patients with medically refractory focal epilepsy (74 with temporal lobe and 16 with frontal lobe epilepsy) referred to an epilepsy monitoring unit were studied. The occurrence of the following sexual automatisms was assessed during prolonged video-EEG monitoring: 1) repeatedly grabbing or fondling the genitals and 2) pelvic or truncal thrusting or similar movements. RESULTS: Five patients repeatedly fondled or grabbed their genitals during or immediately after some of their seizures. All five had temporal lobe epilepsy, as evidenced from prolonged video-EEG monitoring, high-resolution MRI, and good to excellent outcome after epilepsy surgery. Sexual automatisms did not occur with frontal lobe epilepsy. CONCLUSION: Sexual automatisms cannot be related exclusively to frontal lobe seizures. As previously proposed, apparently sexual hypermotoric pelvic or truncal movements are common in frontal lobe seizures, but this study suggests that discrete genital automatisms, like fondling and grabbing the genitals, are more common in seizures evolving from the temporal lobe.     

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.     

Covert complex partial seizures in psychotherapy

Complex partial seizures, especially those with predominantly affective and sensory symptoms, can simulate numerous psychiatric disorders. Diagnostic clues include abrupt recurrences, rapid shifts of symptoms, and hallucinations in people with relatively untroubled personalities. Accurate diagnosis may result in effective treatment with anticonvulsants or discovery of tumors of the brain.