Mesial temporal lobe epilepsy with childhood febrile seizure.

OBJECTIVES: To evaluate the demographic and clinical manifestations of patients with mesial temporal sclerosis and temporal lobe epilepsy (MTS-TLE) with childhood febrile seizure (FS) and establishing the potential differences as compared to those without FS. We also investigated the surgery outcome in these two groups of patients. MATERIALS AND METHODS: In this retrospective study, all patients with a clinical diagnosis of drug-resistant TLE due to mesial temporal sclerosis, who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center, were recruited. Patients were prospectively registered in a database from 1986 through 2014. Postsurgical outcome was classified into two groups; seizure-free or relapsed. Clinical manifestations and outcome were compared between patients with MTS-TLE with FS and those without FS. RESULTS: Two hundred and sixty-two patients were eligible for this study. One hundred and seventy patients (64.9%) did not have FS in their childhood, while 92 patients (35.1%) reported experiencing FS in their childhood. Demographic and clinical characteristics of these two groups of patients were not different. Postoperative seizure outcome was not statistically different between these two groups of patients (P = 0.19). CONCLUSIONS: When MTS is the pathological substrate of TLE, clinical manifestations and response to surgical treatment of patients are very similar in patients with history of febrile seizure in their childhood compared to those without such an experience. In other words, when the subgroup of patients with MTS-TLE and drug-resistant seizures is examined history of childhood febrile seizure loses its value as a distinguishing factor in characteristics or predictive factor for surgery outcome.

Seasonality of birth in patients with temporal lobe epilepsy.

OBJECTIVES: We investigated the seasonal pattern in births of patients with temporal lobe epilepsy and mesial temporal sclerosis. We hypothesized that the seasonal pattern in births of these patients is different from that in the general population. MATERIALS AND METHODS: In this retrospective study, all patients who were evaluated for epilepsy surgery at Jefferson Comprehensive Epilepsy Center, Thomas Jefferson, Philadelphia, USA, between 1986 and 2014 and had a diagnosis of mesial temporal sclerosis (made by definite imaging findings of atrophy and/or sclerosis) were included. The seasonality in births of patients was compared with the seasonal pattern in the live births of the general population from Pennsylvania State. RESULTS: Two hundred and eighty-two patients (146 females and 136 males) were studied. The seasonality pattern in birth of patients was not statistically different from that in the general population. CONCLUSIONS: The observed contradictory findings among various studies indicate the need for further studies to elucidate whether season of birth brings the possibility of acquiring various epilepsy syndromes in the future. To investigate any possible association between season of birth and epilepsy, we suggest avoid pooling all patients with epilepsy together.

A comparison of occipital and temporal lobe epilepsies.

PURPOSE: Differentiating between occipital lobe epilepsy (OLE) and temporal lobe epilepsy (TLE) is often challenging. This retrospective case-control study compares OLE to TLE and explores markers that suggest the diagnosis of OLE. METHODS: We queried the Jefferson Epilepsy Center surgery database for patients who underwent a resection that involved the occipital lobe. For each patient with OLE, three sequential case-control patients with TLE were matched. Demographic characteristics, symptoms, electrophysiological findings, imaging findings, and surgical outcome were compared. RESULTS: Nineteen patients with OLE and 57 patients with TLE were included in the study. Visual symptoms were unique to patients with OLE (8/19) and were not reported by patients with TLE (P < 0.0001). Occipital interictal spikes (IIS) were found only in one-third of the patients with OLE (6/19) and in no patients with TLE (P < 0.0001). IIS in the posterior temporal lobe were found in five of 19 patients with OLE vs one of 57 patients with TLE (P = 0.003). IIS involved more than one lobe of the brain in most patients with OLE (11/19) but only in nine of 57 the TLE group. (P = 0.0003) Multilobar resection was needed in most patients with OLE (15/19), typically including the temporal lobe, but in only one of the patients with TLE (P < 0.0001). CONCLUSION: Occipital lobe epilepsy is difficult to identify and may masquerade as temporal lobe epilepsy. Visual symptoms and occipital findings in the EEG suggest the diagnosis of OLE, but absence of these features, does not exclude the diagnosis. When posterior temporal EEG findings or multilobar involvement occurs, the diagnosis of OLE should be considered.

Expectations prior to epilepsy surgery: an exploratory comparison of men and women.

Although the clinical goal of resective epilepsy surgery is seizure freedom, patients have a wide set of expectations for this invasive procedure. The goal of this study was to evaluate potential gender differences in expectations among patients undergoing resective epilepsy surgery. Ratings of the importance of 12 potential impacts ("expectations") of resective surgery were analyzed in a seven-center cohort study including 389 adults aged 16 and older who underwent resective epilepsy surgery. Men and women both ranked anticipated changes in driving and memory as the most important presurgical expectations. Women rated driving, physical activity limitations, and economic worries as less important, and fatigue and pregnancy concerns as more important than did men (p's< or =0.05). Exploratory factor analysis indicated a different pattern of associations among the 12 importance items for men and women. Whether gender differences in presurgical values are associated with outcomes needs exploration.

Medial temporal lobe functional connectivity predicts stimulation-induced theta power.

Focal electrical stimulation of the brain incites a cascade of neural activity that propagates from the stimulated region to both nearby and remote areas, offering the potential to control the activity of brain networks. Understanding how exogenous electrical signals perturb such networks in humans is key to its clinical translation. To investigate this, we applied electrical stimulation to subregions of the medial temporal lobe in 26 neurosurgical patients fitted with indwelling electrodes. Networks of low-frequency (5-13 Hz) spectral coherence predicted stimulation-evoked increases in theta (5-8 Hz) power, particularly when stimulation was applied in or adjacent to white matter. Stimulation tended to decrease power in the high-frequency broadband (HFB; 50-200 Hz) range, and these modulations were correlated with HFB-based networks in a subset of subjects. Our results demonstrate that functional connectivity is predictive of causal changes in the brain, capturing evoked activity across brain regions and frequency bands.

Widespread theta synchrony and high-frequency desynchronization underlies enhanced cognition.

The idea that synchronous neural activity underlies cognition has driven an extensive body of research in human and animal neuroscience. Yet, insufficient data on intracranial electrical connectivity has precluded a direct test of this hypothesis in a whole-brain setting. Through the lens of memory encoding and retrieval processes, we construct whole-brain connectivity maps of fast gamma (30-100 Hz) and slow theta (3-8 Hz) spectral neural activity, based on data from 294 neurosurgical patients fitted with indwelling electrodes. Here we report that gamma networks desynchronize and theta networks synchronize during encoding and retrieval. Furthermore, for nearly all brain regions we studied, gamma power rises as that region desynchronizes with gamma activity elsewhere in the brain, establishing gamma as a largely asynchronous phenomenon. The abundant phenomenon of theta synchrony is positively correlated with a brain region's gamma power, suggesting a predominant low-frequency mechanism for inter-regional communication.

Positron emission tomography in Dyke-Davidoff-Masson syndrome.

Dyke-Davidoff-Masson syndrome is clinically characterized by hemiparesis, hemiplegia, seizures, mental retardation, and facial asymmetry secondary to congenital or early childhood vascular insult. A 21-year-old man with Dyke-Davidoff-Masson syndrome presented with uncontrolled seizures. The authors present the magnetic resonance (MR) and positron emission tomography (PET) findings of this syndrome.

Syndrome of palatal myoclonus and progressive ataxia: two cases with magnetic resonance imaging.

Two patients are reported with palatal myoclonus, progressive ataxia, and dysarthria, unresponsive to treatment with trihexyphenidyl or L-5-hydroxytryptophan. MRI showed enlargement of the inferior olives in one patient, consistent with the pathology usually associated with palatal myoclonus. The syndrome of progressive ataxia and palatal myoclonus should be distinguished from other ataxias and degenerations that affect the brainstem and cerebellum. Pathology and specificity of site of the lesions are distinctive.

Comparison of depth and subdural electrodes in recording temporal lobe seizures.

Intracranial EEG recording is often required to identify an area of the brain for resective surgery for intractable epilepsy. We simultaneously compared bilaterally placed depth and limited subdural electrode EEG to determine the most effective method of recording seizures from the temporal lobes. Localized complex partial seizures usually appeared earlier in hippocampal depth electrodes and spread later to subdural recording sites. In 3 patients, hippocampal recordings showed localized seizure origin but subdural recording was nonlocalizing due to rapid bilateral seizure propagation. In 1 patient with nonlocalized seizures presumably of extratemporal origin, subdural electrodes incorrectly lateralized seizure origin to a temporal lobe. Auras and subclinical seizures detected by depth electrode recording were often not evident with subdural electrodes. We conclude that EEG recording with hippocampal depth electrodes correctly identifies and lateralizes temporal lobe seizures more often than with limited subdural electrodes.

Cardiac rhythm during temporal lobe seizures.

We studied the neuroanatomic correlates of ictal tachycardia in 27 seizures from five patients with unilateral temporal lobe epilepsy being evaluated with bilateral temporal lobe depth electrodes and orbitofrontal subdural electrodes. There were 11 complex partial seizures, three simple partial seizures, and 13 subclinical seizures. For all seizures, heart rate (HR) increased in a graded fashion as new cortical regions anywhere in the brain were recruited into the seizure. HR plateaued at the new level despite EEG frequency changes until the next region became involved. Increases in HR did not correlate with increased duration of seizures but rather with volume of brain involved. Restricted amygdaloid seizure activity was generally insufficient to alter HR. We conclude that the amygdala has a limited role in modulating HR during seizures, and ictal tachycardia depends principally on the volume of cerebral structures recruited into a seizure.

Epileptic palatal myoclonus.

Palatal myoclonus (PM) is usually caused by lesions of the brainstem. We report a case of PM of focal cortical origin in a patient with epilepsia partialis continua. The PM sometimes occurred in isolation, and at other times was accompanied by unilateral face, neck, and arm twitching. This was documented by both EEG and SPECT.

Sexual dysfunction in partial epilepsy: a deficit in physiologic sexual arousal.

Men and women with epilepsy frequently complain of sexual dysfunction. We studied the sexual response in men and women with partial epilepsy of temporal lobe origin (TLE) by measuring genital blood flow (GBF) during sexual arousal. Nine women and eight men with TLE and 12 women and seven men as controls completed inventories for symptoms of depression, sexual experience, and sexual attitude and underwent measurement of digital pulse and GBF during alternating segments of sexually neutral and erotic videotape. Subjective ratings of arousal to the videotape were obtained. We calculated digital pulse and GBF response as the percentage increase in pulse amplitude during the erotic compared with the preceding sexually neutral film. No subject group reported symptoms of significant depression on the inventory. However, men and women with epilepsy had fewer sexual experiences than subjects without epilepsy, and women with epilepsy imagined specific sexual activities to be more anxiety-producing and less arousing than did women without epilepsy. Men and women with TLE had a diminished GBF response. The mean increase in GBF in men with TLE was 184% versus 660% for controls (p = 0.01). Women with TLE had a mean increase of 117% versus 161% for controls (p < 0.01). Digital pulse did not vary across stimulus conditions. Subjective ratings for all groups indicated moderate sexual arousal. We conclude that there is a diminution in one aspect of physiologic sexual arousal in some men and women with TLE.

The syndrome of frontal lobe epilepsy: characteristics and surgical management.

We reviewed the historical features, preoperative diagnostic evaluation, operative procedure, and surgical outcome in 16 patients with refractory frontal lobe epilepsy. Clinical expression of the epilepsy varied widely, particularly with respect to seizure characteristics, although high monthly seizure frequency and absence of a risk factor for epilepsy before age 5 occurred more often than in reported in temporal lobe epilepsy patients. Seizures often caused early bilateral movements, were brief, and lacked oroalimentary automatisms and a prolonged postictal state. Both the interictal and ictal scalp EEGs had relatively poor sensitivity and specificity and often either contained no epileptiform abnormalities or were misleading. MRI usually identified structural lesions when these were present, although it was negative in two patients with tumors. In the absence of an MRI lesion, intracranial EEG usually identified the area to be resected, although it too provided misleading information in one case. Surgical procedures consisted of focal resections with or without anterior corpus callosotomy, or of corpus callosotomy alone. Nearly all patients improved after surgery, with a majority (67%) becoming seizure-free (average follow-up, 46 months). Preoperative seizure frequency correlated with seizure relief after surgery, as did age of seizure onset, whereas presence of tumor did not. We conclude that frontal lobe epilepsy warrants aggressive investigation and that surgical treatment often can be successful.

Occupational outcome after temporal lobectomy for refractory epilepsy.

We evaluated employment after temporal lobectomy for refractory epilepsy in 86 patients (3.5 to 8 years of follow-up). Seventy-three patients qualified for the work force before and after surgery. Unemployment rates declined after surgery (18 patients [25%] unemployed before surgery, eight patients [11%] unemployed after surgery), and underemployment also tended to diminish. Improvement in occupational status related strongly to the degree of postoperative seizure relief. Seizure-free patients fared better (no unemployment, little underemployment) than patients with some seizure-free years and some years with seizures after surgery, whose high underemployment level persisted. Patients with seizures in each year after surgery fared worst (despite reduced seizure frequency), with increased unemployment after surgery. Age at surgery also influenced vocational outcome in patients who were unemployed before surgery. Historical, educational, cognitive, and behavioral measures did not correlate with vocational outcome. Employment gains came slowly; unemployed patients took up to 6 years to obtain work after surgery. Of 13 students at the time of surgery, 11 have graduated and nine are now employed. We conclude that seizures play a large role in limiting employment, and that by alleviating seizures, temporal lobectomy improves employability in people with refractory epilepsy. Surgery thereby provides benefit to individuals with epilepsy by increasing financial independence and to society by reducing unemployment.

Seizures in temporal lobe epilepsy: I. Reliability of scalp/sphenoidal ictal recording.

We determined both (1) the reliability (reproducibility) of seizure onset location in patients with temporal lobe recorded with extracranial EEG and (2) if interictal spike (IIS) location influences that reliability. EEGs were recorded with the 10-20 system and sphenoidal electrodes. Between 1985 and 1993, 166 patients with suspected temporal lobe epilepsy were eligible for inclusion with a total of 734 seizures recorded. Each seizure onset was classified as either localized, lateralized, or nonlocalized. Individual patients were then grouped according to interictal spike location (i.e., unilateral, bilateral, or none) as well as by ictal onset reproducibility patterns (i.e., concordant, semiconcordant, conflicting, or nonlocalized) based on each patient's monitoring session. Seizure onset location was reproducible in 68% of the cases and variable patterns of seizure onset were seen in 32% of patients. Patients with unilateral IIS (68%) were more likely to have consistent ictal onset patterns than patients with bilateral IIS (27%). The first seizure more often predicted subsequent seizure onset patterns when it was localized than when it was nonlocalized. Of 18 patients with conflicting temporal lobe seizures, up to four seizures were necessary to detect independent bilateral temporal lobe seizures.

Temporal lobectomy outcome in older versus younger adults.

A total of 340 patients age 50 years and older were compared with 30 patients younger than 50 years, all of whom had anterior temporal lobectomy for refractory epilepsy. Seizure outcome, neuropsychological test scores, and change in driving status were analyzed. Age and duration of epilepsy were related independently to outcome, but laterality of interictal sharp waves (an early epilepsy risk factor) and presence of tumor were not. Sixteen patients (52%) in the older group and 257 patients (75.6%) in the younger group (p < 0.008) were seizure free. Postoperative neuropsychological outcome and driving status were similar in older and younger patients.

Memory during subclinical hippocampal seizures.

We performed neuropsychological testing in 2 patients during subclinical hippocampal seizures recorded with depth electrodes. Neither subject showed impairment of consciousness, orientation, motor skills, or verbal fluency. The rapidity of recall of a well-learned word list was impaired in 1 subject during ictal fast spiking in the left hippocampus. Subclinical seizure activity may be responsible for a portion of the memory deficits found in patients with epilepsy.

Predictors of outcome after anterior temporal lobectomy: the intracarotid amobarbital test.

The intracarotid amobarbital test (IAT) examines hemispheric memory and language. We set out to determine whether memory performance on the IAT correlated with seizure relief after anterior temporal lobectomy in 117 patients with refractory epilepsy. The IAT assessed recognition memory performance for nine items with correction for false-positive recognitions. We then compared performance of one hemisphere with that of the other, defining a correctly lateralized memory deficit as worse performance when using the hemisphere containing the operated temporal lobe than when using the other hemisphere. The analysis included concurrent factors that might also affect outcome, such as age at first risk for epilepsy, presence or absence of tumor, and Full Scale IQ. A discriminant function analysis demonstrated that patients with a correctly lateralized memory deficit on the IAT had an increased probability of being seizure-free following surgery after controlling for other predictors. The performance of the nonoperated temporal lobe related to outcome, although less strongly. The magnitude of the difference in performance between the two hemispheres and the performance of the operated hemisphere did not relate to outcome. Patients who became seizure-free had an earlier age at first risk than did those with persistent seizures, and tumor presence weakly correlated with postoperative outcome. IQ did not correlate with outcome. We conclude that the IAT predicts seizure relief after anterior temporal lobectomy independent of other known risk factors we examined.

Predictors of outcome after anterior temporal lobectomy: positron emission tomography.

We assessed the relationship between temporal lobe metabolism measured quantitatively and qualitatively with PET using [18F]-fluorodeoxyglucose (FDG) and postoperative seizure frequency after anterior temporal lobectomy. Forty-three patients with refractory partial epilepsy had anterior temporal lobectomy and preoperative assessment with PET-FDG. Qualitative PET analysis was performed visually by two blinded observers, and quantitative PET analysis was performed using an anatomic template for six control and six temporal lobe subregions, deriving an asymmetry index for each region. Seizure outcome was assessed 1 year after surgery; patients were classified as being seizure-free or as having persistent seizures. Qualitative data were analyzed using Fisher's exact test and the t test, and quantitative data were analyzed using a repeated-measures ANOVA. Thirty-two patients (74%) were seizure-free at follow-up, and 11 had persistent seizures, although most improved. Twenty-nine of 35 patients (83%) with restricted temporal lobe hypometabolism by visual analysis were seizure-free, compared with three of eight patients (37.5%) with normal scans or multilobar hypometabolism. Quantitative analysis revealed that an asymmetry of mesial temporal lobe glucose consumption (uncal region) correlated with improved surgical outcome (p < 0.02). We developed a logistic regression model to predict individual outcome based on the asymmetry in uncal metabolism. Lateral temporal metabolism did not correlate with outcome. We conclude that both visual PET analysis and quantitative PET analysis predict outcome after temporal lobectomy, although quantitative measures offer more precise information.

A noninvasive protocol for anterior temporal lobectomy.

We report the results of a protocol for choosing candidates for temporal lobectomy using a standard battery of objective tests without intracranial electrodes. We assigned each test a level of importance, and an algorithm was used to determine whether temporal lobectomy could be performed. Fifty-one patients (total pool, 103 patients) met protocol requirements and had an anterior temporal lobectomy with a mean follow-up of 39.4 months (range, 21 to 64 months), most remaining on anticonvulsant therapy. Eighty percent are seizure free, 12% have less than 3 seizures per year or only nocturnal seizures, and 8% have greater than 80% reduction in seizure frequency. One-third of patients who failed protocol criteria did not have temporal lobe seizures when studied with intracranial electrodes. We analyzed and modified the algorithm after comparing these patients with others who were poor candidates for temporal lobectomy. We conclude that this protocol is effective and recommend using such an objective algorithm.