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T S Walczak

Publications and source records attributed to T S Walczak.

15 recordsLinked to original sources
PubMed1997

The predictive value of intraoperative electrocorticography in resections for limbic epilepsy associated with mesial temporal sclerosis.

OBJECTIVE: Prior studies on the predictive value of intraoperative electrocorticography (ECoG) have been performed on heterogeneous groups of patients with both temporal and extratemporal interictal spikes, lesional and nonlesional pathological findings, and variably extensive resections by different surgeons. METHODS: We performed both pre- and postresection intraoperative ECoG on 29 consecutive patients with medial temporal lobe epilepsy (17 left-sided) who underwent standard nontailored resections by one surgeon (RRG). All patients had only temporal interictal spikes (six bitemporal) and mesial temporal sclerosis diagnosed by preoperative magnetic resonance imaging and confirmed by pathological examination of resected tissue. RESULTS: After a mean follow-up of 24.8 months, there were 15 (52%) patients who were seizure-free, 6 (21%) who were seizure-free except for auras, and 8 (28%) who had any seizure after the 1st postoperative month. Fourteen patients (48%) had active interictal discharges outside the area of planned resection revealed by preresection ECoG. Neither the presence of these spikes nor their mean frequency correlated with seizure outcome. Eleven patients (38%) had residual spike discharges after resection, and 18 patients (62%) had new spikes revealed by the postresection ECoG. Neither of these findings nor the mean spike frequency of residual or new spikes related to seizure outcome. Persistent spikes increased in frequency after resection in all outcome groups. CONCLUSIONS: Electrocorticographic monitoring of interictal epileptiform activity intraoperatively is not useful in the surgical treatment of patients undergoing standard resection for medial temporal lobe epilepsy with magnetic resonance imaging evidence of mesial temporal sclerosis.

Adolescent↗
PubMed1997

Effects of sleep and sleep stage on epileptic and nonepileptic seizures.

PURPOSE: Previous studies of patients with epilepsy and animal models of epilepsy suggest that sleep increases the frequency, duration, and secondary generalization of seizures. This information is, however, incomplete. METHODS: We retrospectively examined video-EEG monitoring reports from our comprehensive epilepsy center. We recorded seizure type, site of onset (for partial seizures), sleep state at onset, and whether partial seizures secondarily generalized. Seizures arising from sleep were then reviewed to determine sleep state. RESULTS: We analyzed 1,116 seizures in 188 patients. Thirty-five percent of complex partial seizures (CPSs) starting during sleep underwent secondary generalization compared with 18% in wakefulness (p < 0.0001). Frontal lobe CPSs secondarily generalized at equal rates during sleep (22%) and wakefulness (20%), but temporal lobe CPSs generalized much more frequently during sleep (45%) than in wakefulness (19%; p < 0.0001). Frontal lobe seizures were more likely to occur during sleep (37%) than were temporal lobe seizures (26%; p = 0.0068). CPSs were more frequent in stages 1 and 2 and occurred rarely during REM. Seizures starting during slow-wave sleep were significantly longer than seizures starting during wakefulness or stage 2 sleep. Psychogenic nonepileptic seizures (PNESs) were rare between midnight and 6 a m. and never occurred during sleep. CONCLUSIONS: Sleep has a pronounced effect on secondary generalization of partial seizures, especially those of temporal lobe origin. Frontal lobe seizures occur more often during sleep than do temporal lobe seizures, and occurrence during sleep helps to distinguish PNESs from CPSs.

Brain↗
PubMed1996

Weeping during psychogenic nonepileptic seizures.

Ictal weeping may help distinguish psychogenic nonepileptic seizures (PNES) from epileptic seizures. However, the prevalence of weeping during PNES or epileptic seizures is unknown. We reviewed videotapes of recorded events in 84 consecutive patients with PNES or epilepsy. Weeping was observed during 14% of PNES in 31% of patients with PNES. Ictal weeping was not observed in any epileptic seizures occurring in 48 patients. The differences were highly significant. One patient with epileptic seizures originating in the right temporal lobe wept soon after the end of a seizure. Depression was not more common in PNES patients with than without ictal weeping. Weeping during an apparent seizure strongly argues that the event is not epileptic.

Adult↗
PubMed1996

Sphenoidal electrode insertion using topical anesthesia.

Sphenoidal electrodes are frequently used in epilepsy centers, but ins ertion can be painful. We used a topical anesthetic cream on patients (2.5% lodocaine, 2.5% prilocaine) before inserting electrodes and had patients rate their discomfort on an analogue pain scale. As a comparison, the same patients rated the pain caused by inserting a heparin lock. There was no significant difference between the pain of sphenoidal electrode insertion with use of topical anesthesia and that of heparin lock insertion. We suggest that when a topical anesthetic is used, the discomfort of inserting sphenoidal electrodes is minimal and comparable to that of inserting a heparin lock.

Administration, Cutaneous↗
PubMed1996

Intracartotid amobarbital procedure memory performance and age at first risk for seizures distinguish between lateral neocortical and mesial temporal lobe epilepsy.

PURPOSE: To determine whether intracarotid amobarbital procedure (IAP) memory-performance asymmetries and early risk factors for epilepsy distinguish between lateral neocortical temporal lobe epilepsy (LNTLE) and mesiobasal temporal lobe epilepsy (MBTLE). METHODS: We studied 10 patients with LNTLE and 22 with MBTLE. All LNTLE patients showed (a) presence of temporal neocortical lesion or lateral seizure onset by intracranial recording, and (b) absence of mesial temporal sclerosis (MTS) by histopathologic analysis. All patients with MBTLE showed (a) video-scalp EEG seizures consistent with mesial TLE, and (b) presence of unilateral MTS by histopathologic analysis. All patients had good surgical outcomes (Engel I or II). Unilateral IAP memory performance was defined as percentage of memory items presented during hemispheric anesthesia that was recognized after recovery. IAP asymmetry scores were the differences in memory performance after right and left injections. RESULTS: Mean memory-asymmetry scores were significantly lower in the LNTLE than in the MBTLE group. An IAP memory asymmetry of < 25% correctly classified seven of 10 patients with LNTLE, and an asymmetry of > or = 25% correctly classified 18 of 22 patients with MBTLE. Age at first risk for epilepsy was significantly younger in those with MBTLE than in those with nonlesional LNTLE. Results suggest that both IAP memory performance and age at first risk can help distinguish between MBTLE and LNTLE.

Adult↗
PubMed1995

Propagation patterns of temporal spikes.

In standard EEG recordings, spikes appear as single events characterized mainly by the scalp location of the their peak voltage. The signal-to-noise ratio of raw EEG is usually too high to permit more detailed analysis. We used spike averaging to improve the resolution of interictal spikes in 40 patients with temporal lobe epilepsy. Spikes were identified visually in raw, digitally stored EEG. When multiple spike types were present in a patient, they were grouped separately. Spikes were synchronized for averaging by aligning their negative peaks in a designated channel. Sixteen patients demonstrated spike propagation from anterior temporal to posterior temporal electrode locations. Thirty-six patients demonstrated spread of spikes from anterior temporal to fronto-polar electrode sites. While anterior temporal and fronto-polar spikes were often synchronous, fronto-polar spikes followed anterior temporal discharges in 25% of cases and preceded them in 13%. Spike averaging revealed propagation patterns not apparent on visual inspection of raw EEG. We speculate that these patterns may reflect inherent physiological properties of temporal and frontal neuronal circuits, possibly utilized by the epileptogenic process.

Adolescent↗
PubMed1995

Outcome after diagnosis of psychogenic nonepileptic seizures.

Information regarding outcome in patients with psychogenic nonepileptic seizures (PNES) is limited. We attempted to contact 72 consecutive patients with PNES confirmed by video-EEG monitoring: 51 of 72 (71%) were reached a mean of 15 months (range 12-27 months) after diagnosis and agreed to answer a structured telephone questionnaire. The questionnaire assessed the number of PNES in the last 6 months, antiepileptic drug (AED) use, occupational status, global self-rating, and extent of psychotherapeutic treatments. PNES had ceased in 18 of 51 (35%), decreased > 80% in 21 of 51 (41%), and decreased < 80% in 12 of 51 (24%). Thirty-three of 51 (65%) were not taking AEDs. Occupational status improved in 20% and did not change in 75%. Overall, 29 of 51 (57%) rated themselves markedly improved and 15 of 51 (29%) rated themselves unchanged or worse. Persisting PNES were associated with longer duration of PNES before diagnosis (p < 0.02) and presence of additional psychiatric disease (p < 0.01). Persisting PNES were not associated with gender, presence of epileptic seizures, or extent of psychotherapeutic treatments after diagnosis. Placebo saline infusion had been administered in some patients to help precipitate PNES. This did not affect the number of psychotherapy visits or outcome. We conclude that PNES cease or significantly decrease in most patients, but occupational status does not improve as often. Earlier diagnosis may improve outcome.

Anticonvulsants↗
PubMed1994

Plantar responses after epileptic seizures.

We evaluated plantar responses after 75 epileptic seizures and 21 psychogenic seizures in 53 patients undergoing video-EEG monitoring. Extensor plantar responses (EPRs) were found after 27% of epileptic seizures in 42% of patients with epilepsy. EPRs were not found after psychogenic seizures but were seen after 52% of tonic-clonic seizures. Unilateral EPRs were usually contralateral to the side of seizure onset.

Adult↗
PubMed1994

Utility and reliability of placebo infusion in the evaluation of patients with seizures.

Placebo infusions are occasionally used to elicit psychogenic seizures. How frequently placebo infusions elicit patients' typical events, atypical and potentially confusing events, or even epileptic seizures is not known. We report the results of placebo infusions during video EEG in 68 patients who also had events recorded without placebo. A single investigator administered a saline placebo that was represented to the patient as an activating substance. We compared the events recorded without placebo with events recorded with placebo. Twenty patients had only epileptic seizures without placebo; with placebo, two of 20 (10%) had their typical epileptic seizures and three of 20 (15%) had atypical nonepileptic events. Forty patients had only psychogenic seizures without placebo; with placebo, 33 of 40 (82%) had their typical psychogenic seizures and three of 40 (8%) had atypical events. Eight patients had both psychogenic and epileptic seizures without placebo; with placebo, four of eight had their typical psychogenic seizures. Thus, placebo infusion elicits typical psychogenic events in most patients with psychogenic seizures, but atypical events or epileptic seizures may occur in a minority and lead to incorrect diagnosis.

Adult↗
PubMed1993

Temporal lobe hypometabolism on PET: predictor of seizure control after temporal lobectomy.

To investigate the relationship of temporal lobe hypometabolism demonstrated on PET to surgical outcome and underlying pathology, we reviewed 30 consecutive epilepsy patients who underwent interictal PET studies with 18F fluorodeoxyglucose before temporal lobectomy. Two interpreters blindly reviewed the PET studies and graded them for degree, extent, and location of temporal lobe hypometabolism. Pathologic analysis of en bloc resected tissue showed mesial temporal sclerosis (n = 22), astrocytoma (n = 2), and no pathologic diagnosis (n = 6). Outcome (24 to 40 months' follow-up) was rated as seizure-free (21 patients), significantly improved (five patients), and not significantly improved (four patients). Both the degree and extent of the temporal lobe hypometabolism demonstrated on PET were strongly associated with subsequent seizure control. Pathologic findings, however, did not correlate with degree of PET hypometabolism or subsequent outcome. These data demonstrate that in patients judged to have temporal lobe epilepsy, the presence of temporal lobe hypometabolism is associated with a positive outcome after ipsilateral temporal lobectomy.

Adolescent↗
PubMed1992

Accuracy and interobserver reliability of scalp ictal EEG.

We studied the accuracy and reliability of scalp ictal EEG in 137 complex partial seizures (119 temporal and 18 extratemporal) in 35 patients in whom we knew the correct site of seizure origin because all patients had been seizure-free for more than 2 years after seizure surgery. Three electroencephalographers independently determined side of seizure origin based on activity at onset of electrographic seizure (ASO), rhythmic theta and alpha (RTA), postictal findings (PIF), and the electrographic seizure as a whole. When all seizures were analyzed, including those with generalized features or obscured by artifact, we determined side of seizure onset correctly in 76% to 83% of temporal seizures and 47% to 65% of extratemporal seizures. In most of the remainder, a lateralization judgment was impossible. When analysis was confined to those seizures in which lateralization was possible, we correctly lateralized 93% to 99% of temporal seizures and 89% to 100% of extratemporal seizures. Interobserver reliability was excellent. RTA and PIF were more accurate than ASO. RTA was significantly more common in temporal seizures. Our data indicate that lateralization by scalp EEG is highly accurate and reliable.

Electroencephalography↗
PubMed1990

Anterior temporal lobectomy for complex partial seizures: evaluation, results, and long-term follow-up in 100 cases.

We report evaluation and results in 100 patients who had undergone anterior temporal lobectomy for intractable complex partial seizures. Average follow-up was 9.0 years (range, 2 to 21 years). In the 2nd postoperative year, 63% were seizure free, 16% were significantly improved, and 21% were considered not significantly improved. Mean number of seizures in the last group was 27% of preoperative levels. Surgical results did not change significantly in subsequent postoperative years; good outcomes tended to persist over the longer term. We also examined the utility of continuous depth electrode monitoring in the evaluation of patients with independent bitemporal interictal epileptiform activity. Despite limited numbers of subjects in this category, there was a trend toward improved surgical outcome when such subjects were evaluated with depth electrodes.

Adolescent↗
PubMedDate not supplied

Temporal lobectomy and independent bitemporal interictal activity: what degree of lateralization is sufficient?

We attempted to determine whether the degree of lateralization of independent bitemporal interictal spikes and sharp waves (ISSW) is correlated with good results after temporal lobectomy. Three observers independently counted ISSW in the scalp EEGs of 59 candidates for temporal lobectomy to determine the degree of lateralization of ISSW. Interobserver correlation in percentage of lateralization was excellent (r = 0.92). Thirty-one candidates were also evaluated with depth EEG (DEEG). Operative success was graded by the number of seizures reported in the second postoperative year. There was a significant progressive decrease in the number of good operative results as the degree of lateralization of ISSW lessened (p = 0.0142). Ninety-two percent of patients with greater than 90% lateralization had a good surgical outcome, whereas only 50% with less than 90% lateralization had a good outcome. Even when all DEEG-recorded seizures emerged from the side of the lobectomy, patients with greater than 90% lateralization appeared to have better outcomes than patients with less than 90% lateralization. We conclude that greater than 90% lateralization of temporal ISSW is associated with good surgical outcome, and DEEG may not be necessary in these patients. Less than 90% lateralization is associated with poor surgical outcome and the additional information provided by DEEG may be especially useful in such patients.

Adolescent↗