Differences Between Patients with Temporal Lobe Seizures and Those with Other Forms of Epileptic Attacks

Seventy-eight patients with temporal lobe type seizures were precisely matched for age, sex, and Wechsler I.Q. levels with patients suffering from other seizure types. Statistically significant differences were established between the groups in regard to treatment response, etiologies, and behavioral variables. Further analysis of the data showed that the behavioral problems of the temporal lobe patients were present only in that group that suffered from more than one seizure type. The temporal lobe epilepsy group having only one seizure type differed from the controls with one seizure type in regard to etiological factors; they actually showed better performance on certain subscales of the WAIS, as well as better employment records. The clinical impression of the temporal lobe epilepsy patient usually presenting more difficulties than other patients with epilepsy results from the fact that the temporal lobe patients have, in the overwhelming majority of instances, more than one seizure type.     

Memory and intelligence outcome following surgery for intractable temporal lobe epilepsy: relationship to seizure outcome and evaluation using a customized neuropsychological battery

The main objectives of this prospective study were to (1) assess memory and intelligence outcome following surgery for intractable temporal lobe epilepsy, (2) correlate this with seizure outcome and side of surgery, and (3) perform (1) and (2) using an indigenously developed battery customized to the Indian population. Prior to use in our epilepsy surgery program, the test-retest and interexaminer variance reliability of this battery had been established in both normal and cognitively compromised populations. The memory scores were overall rather than material-specific. The battery was administered to right-handed adults undergoing surgery for intractable temporal lobe epilepsy without any evidence of opposite temporal lobe abnormality, both presurgery and postsurgery at a mean follow-up of 8 months. Twenty-five consecutive patients were included; 13 underwent right and 12 underwent left temporal surgery. Seizure outcome was assessed using Engel's classification. Among 13 patients who underwent right temporal surgery, although 4 patients with poor seizure outcome had insignificant changes in scores, 7 of 9 patients with good seizure outcome exhibited considerable (> 20% over preoperative) improvement in their memory and intelligence scores. Statistical analysis using Student's t test and the Mann-Whitney test revealed that the patients who underwent right temporal surgery with good seizure outcome had significant improvement in both memory (P = 0.007) and intelligence (P = 0.043) scores compared with those with poor seizure outcome. In contrast, patients who underwent left temporal surgery had no significant change in cognitive scores irrespective of seizure outcome. Cognitive improvement seems to occur in patients with good seizure outcome following nondominant temporal lobe surgery for intractable epilepsy with no evidence of pathology in the opposite temporal lobe. The same finding was not observed in patients undergoing left temporal surgery.     

Neuropsychological tests with lateralizing value in patients with temporal lobe epilepsy: Reconsidering material-specific theory

PURPOSE: To assess the ability of neuropsychological tests to determine the side of seizure onset for preoperative assessment in patients with drug-resistant temporal lobe epilepsy. METHODS: Twenty-nine consecutive patients diagnosed with temporal lobe epilepsy (TLE), in whom the epileptogenic focus was clearly identified and localized to either the right or left hemisphere. Patients underwent a full neuropsychological assessment as part of their pre-surgical investigation, including the Boston Naming Test (BNT) and a variety of Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and Wechsler Memory Scale-Third Edition (WMS-III) subtests. Two multivariate analyses of variance were carried out to assess differences on memory and language measures between groups according to side of epileptogenic focus. Binary logistic regression analysis was performed to find the sets of tests that best predicted the side of seizure onset (determined by EEG and MRI). RESULTS: Memory multivariate analysis of variance failed to show significant differences between the right- and left-sided groups. Among language measures, only the BNT revealed significant differences between the groups. The neuropsychological measures that best predicted the side of seizure onset were the BNT and Visual Reproduction II. CONCLUSIONS: Language measures predict the side of seizure focus better than memory measures. The results of this study in a sample of drug-resistant temporal lobe epilepsy patients challenge the memory material-specific theory for the side of seizure focus.     

The effects of duration of intractable epilepsy on memory function

We assessed whether duration (time since diagnosis) of intractable epilepsy is associated with progressive memory loss in 250 individuals with left or right temporal lobe epilepsy and those diagnosed with psychogenic nonepileptic seizures. Verbal and nonverbal memory function was assessed using several memory assessment measures administered to all individuals as part of a larger neuropsychological assessment. Multivariate multiple regression analyses demonstrated that duration of temporal lobe epilepsy and age of seizure onset are significantly related to verbal memory deficits in patients with epilepsy. The interaction between duration of epilepsy and diagnostic group was nonsignificant, as was the interaction between age at spell onset and diagnostic group. As measured by several neuropsychological memory tests, duration of disease adversely affects verbal memory performance in patients diagnosed with temporal lobe epilepsy. Our study also supports the notion that age at seizure onset significantly affects verbal memory performance in this population. These results have implications for the strategy of treatment and counseling of patients with intractable temporal lobe epilepsy.     

Peri-ictal water drinking lateralizes seizure onset to the nondominant temporal lobe

The authors describe seven patients with medically refractory temporal lobe epilepsy whose seizures were associated with peri-ictal water drinking behavior. Presurgical evaluation, including video-EEG monitoring, MRI, SPECT, and neuropsychological testing, revealed a seizure onset in the nondominant temporal lobe. All patients had an excellent outcome after epilepsy surgery. Peri-ictal water drinking may represent a lateralizing sign indicating seizure onset in the nondominant temporal lobe.     

Quantitative MRI biomarkers of cognitive morbidity in temporal lobe epilepsy

PURPOSE: To determine the relation between neuropsychological morbidity, quantitative magnetic resonance imaging (MRI) measures of whole brain structure, and clinical seizure factors reflecting epilepsy cause, course, and treatment. METHODS: Quantitative MRI measurements of total (whole brain) cerebrospinal fluid (CSF) and gray- and white-matter volumes and clinical seizure features were examined in relation to summary indices of cognitive morbidity in 96 patients with temporal lobe epilepsy. MRI volumes were adjusted for intracranial volume (ICV), and cognitive scores were adjusted for age, education, and gender, based on a sample of 82 healthy controls. RESULTS: Whole-brain volumes (gray, white, and CSF) were abnormal in chronic temporal lobe epilepsy patients compared with controls and were related significantly to neuropsychological morbidity, especially total CSF. Statistical modeling demonstrated that markers of total atrophy (CSF) was the primary mediator of the relation between clinical seizure variables and neuropsychological morbidity. CONCLUSIONS: Quantitative measurements of overall brain abnormality (atrophy) in temporal lobe epilepsy are clinically meaningful markers that are associated with increased cognitive morbidity. These biomarkers appear to mediate the adverse effects of some clinical seizure variables on cognition.     

Impact of depressed mood on neuropsychological status in temporal lobe epilepsy

OBJECTIVES: Depression is a common psychiatric complication of temporal lobe epilepsy. This study examined the effect of depressed mood on neuropsychological performance among patients with chronic temporal lobe epilepsy. METHODS: Seventy consecutive surgery candidates for medication resistant complex partial seizures of unilateral temporal lobe origin were assessed for psychiatric symptoms and underwent comprehensive neuropsychological assessment. RESULTS: Standardised psychiatric interview disclosed that 34% of the patient sample exhibited significant depression. Controlling for seizure frequency, patients with comorbid depression at the time of neuropsychological assessment exhibited significantly poorer performance on measures of intelligence, language, visuoperceptual ability, memory, and executive function. Within lateralised temporal lobe epilepsy groups, the adverse effects of depression on cognitive function were greater in patients with left temporal lobe compared with those with right temporal lobe epilepsy. In addition, depression seemed to be underrecognised and undertreated as none of the patients with epilepsy and comorbid depression were treated for their psychiatric condition at the time of admission for monitoring. CONCLUSIONS: Depression, a common psychiatric comorbidity among patients with chronic temporal lobe epilepsy, seems to be undertreated and to have adverse effects on cognitive functioning.     

Aggression and Epilepsy: Seizure-Type Comparisons and High-Risk Variables

Summary: One hundred fifty-three patients with temporal lobe epilepsy and 79 patients with generalized epilepsy were compared on a measure of aggression (derived from the Minnesota Multiphasic Personality Inventory). Analysis of covariance indicated that seizure type was not related to aggression. Multiple-regression analyses for each seizure group indicated that in temporal lobe epilepsy the chronologic age was inversely correlated with aggression scores. In the group with generalized epilepsy, chronologic age and myoclonic seizures were inversely correlated with aggression, while akinetic seizures were directly associated with increased aggression.     

Clinical features of neocoritcal temporal lobe epilepsy

Few Studies have examined the clinical features of neocortical temporal lobe epilepsy (NTLE) in carefully selected patients. We reviewed records from 21 patients wtih NTLE, defined by intracranial electroencephal9ogram (EEG), who have been seizure free for 1 year or more following temporal lobectomy. The mean age of onset at the time of first seizure was 14 years (range, 1–41 years). Febrile seizures were reported in only 2 patients (9.5%). In contrast to prior mesial temporal lobe epilepsy (MTLE) studies, seizure-free intervals between the initial cerebral insult or first seizure and habitual seizures were uncommon. Possible or known risk factors for epilepsy were reported in 13 of 21 patients (62%). Fifteen (71%) patients reproted auras, with experiential phenomena being the most common type. Magnetic resonance imaging was normal or nospecific in 15 patients, revealed mild hippocampal atrophy in 2, tumors in 2, and resonance imaging was normal or nospecifc in 15 patients, revealed mild hippocampal atrophy in 2, tumors in 2, and heterotopic gray matter and hippocampal atrophy in 1, and cortical dysgensis in 1. Neuropsychological testing showed deficits consistent with the seizure focus in 13 patients (62%), and Wada test showed ipsilateral memory deficits in 10 (48%). The most common behavioral manifestatin was a motionless stare at ictal onset (48%). In contrast to prior studies of MTLE, only 1 NTLE patient had frequent independent, contralateral temporal lobe epileptiform spikes on scalp EEG.