Employment outcomes following resective epilepsy surgery

PURPOSE: Analyze determinates of employment changes from before to 2 years after surgery in refractory focal epilepsy patients. METHODS: Preoperative employment was prospectively assessed in 375 adults with refractory epilepsy. Two-year postsurgical employment status was obtained for 299; factors potentially associated with employment status change among subgroups unemployed and employed at baseline were analyzed. RESULTS: Presurgical employment status was full-time (n = 148, 39.5%), part-time (n = 26, 6.9%), disabled and unemployed (n = 100, 26.7%), unemployed (n = 44, 11.7%), and other (n = 57, 15.2%). Those with and without 2-year follow-up did not differ on baseline characteristics (all p > 0.10). Two years after surgery, 42.8% were employed full-time and 12.4%, part-time. Among those unemployed before surgery, better seizure outcome was associated with gaining employment at 2 years (p = 0.03). CONCLUSIONS: Net employment gains were modest 2 years after surgery and higher with better seizure outcomes, reinforcing the need for optimizing surgical candidate selection, long-term follow-up studies, and postsurgical vocational rehabilitation.     

Small sharp spikes as EEG markers of mesiotemporal lobe epilepsy

Objective

Mesial temporal lobe epilepsy (mTLE) is the most common type of focal epilepsy, but often lacks scalp EEG correlates. We ask if hippocampal epileptiform discharges that are characteristic of mTLE are associated with small sharp spikes (SSS) recorded on scalp EEG. SSS are considered benign waveforms, so are not currently used as markers of epilepsy.

Activation of interictal spiking in mesiotemporal lobe epilepsy by propofol-induced sleep.

The objective of this study was to test whether low-dose propofol increases the number of interictal spikes in patients with mesiotemporal lobe epilepsy, and to determine whether this is the result of intrinsic properties and is restricted to the primary epileptogenic focus. Controlled infusion of propofol in step-up/-down target concentrations of 0, 0.3, 0.6, and 0.8 mg/L was administered to 10 patients during a 3.5-hour daytime EEG registration. The number of spikes were counted and related to propofol concentration and sleep level. Results were compared with a spontaneous, nocturnal first sleep cycle in 9 of 10 patients. All patients entered nonrapid eye movement 1 sleep during propofol administration, and 8 reached nonrapid eye movement 2 sleep. In 7 patients who showed spikes, spikes were related to sleep (P < 0.05) and not to increasing (P = 0.1) or decreasing (P = 0.5) propofol concentration. Six of nine patients showed more spikes during spontaneous (nocturnal) sleep than during propofol-induced sleep. Contralateral spiking was not suppressed selectively. Low-dose propofol is a safe means of increasing spiking in these patients because it induces sleep. There were no signs of an intrinsic epileptogenicity of propofol or a selective effect on ipsilateral spikes. Controlled sleep induction will increase the yield of interictal spikes during short interictal recordings such as in magnetoencephalography.     

Different seizure-onset patterns in mesiotemporal lobe epilepsy have a distinct interictal signature

Objective

Experimental research demonstrated that distinct underlying mechanisms go along with different seizure-onset patterns on EEG. These different mechanisms may reflect different tissue abnormalities which, we hypothesize, could also be reflected in morphological differences in the interictal epileptic and background EEG activity.

Outcome following resective surgery for temporal lobe epilepsy: a prospective follow up study of 102 consecutive cases.

The long term outcome has been assessed in a consecutive series of 102 cases undergoing resective temporal lobe surgery because of medically intractable epilepsy. Patients were followed prospectively for a median of 61 months. Actuarial statistics were used to measure the temporal patterns of remission and stability of outcome over prolonged periods of observation. The probability of achieving one year remission was 57% by one year, 70% by two years, and 77% by seven years. Once a patient was in one year remission the probability of remaining seizure free was 90%. This rose to 94% after two consecutive years of being seizure free. The majority of patients who remit following surgery have done so by two years of follow up. Outcome at the end of the second post operative year is a good predictor of long term prognosis.     

The effects on cognitive performance of tailored resection in surgery for nonlesional mesiotemporal lobe epilepsy

PURPOSE: Mesiotemporal lobe epilepsy (MTLE) can be treated with different surgical approaches. In tailored resections, neocortex is removed beyond "standard" margins when spikes are present in the electrocorticogram. We hypothesized that these larger resections are justified because spiking neocortex is dysfunctional. This would imply that in patients with spikes (a) postoperative cognitive performance is not affected, and (b) preoperative performance is worse than without spikes. METHODS: We studied 80 operated-on MTLE patients with pathologically confirmed nonlesional hippocampal sclerosis. All patients were left-sided language dominant and underwent cognitive tests 6 months pre- and postoperatively. A repeated measures analysis of variance (ANOVA) was performed, looking for within- and between-subjects interactions with presence of intraoperative neocortical spikes. RESULTS: Intraoperatively, neocortical spikes were present in 61% of patients. Improved postoperative cognitive outcome was seen only in left-sided patients with spikes. Their performance IQ (PIQ) increased by 8.1 points (95% confidence interval, 3.8-12.3; p = 0.02), and visual naming latency by 12.8 s (95% CI, 2.1-23.5; p = 0.07). Conversely, in left-sided patients without spikes, naming latency declined by 7.5 s (95% CI, -2.3-17.2; p = 0.07). Preoperative scores were comparable except for a 15.3-point (95% CI, 0.1-30.5; p = 0.02) lower VIQ in left-sided patients without spikes. CONCLUSIONS: Tailoring does not harm cognitive performance and is, in left-sided MTLE, associated with postoperative improvement. Left-sided MTLE without neocortical spikes has lower verbal scores, which tend to decline after standard resection and may represent a special pathophysiologic entity.     

MR tractography predicts visual field defects following temporal lobe resection

A superior homonymous quadrantanopia is a well recognized complication of anterior temporal lobe resection and occurs because of disruption of the Meyer loop, the anterior part of the optic radiation. The authors used diffusion tensor imaging tractography to visualize the optic radiation before and after surgery, demonstrating the disruption of Meyer loop in a patient who developed a quadrantanopia. Preoperative imaging of the optic radiation will be useful in predicting visual field defects following temporal lobe resection.     

Insular cortex involvement in mesiotemporal lobe epilepsy: a positron emission tomography study

Somesthetic and emotional symptoms that are common in patients with mesial temporal lobe epilepsy are usually related to hippocampo-amygdalar complex involvement. Recent stereo-electroencephalographic studies have shown a relationship between such symptoms and epileptic insular discharges. To further investigate this problem, we carried out a positron emission tomography study using fluorodeoxyglucose (18F-FDG) and flumazenil (11C-FMZ) in mesial temporal lobe epilepsy patients. The aim of our study was to assess the existence of a cortical insular involvement in order to examine its clinical correlates and the relationship between the postoperative outcome and the insular involvement. Fluorodeoxyglucose and flumazenil-positron emission tomography studies were carried out in 18 patients with mesial temporal lobe epilepsy patients. A statistical parametric mapping (SPM96) was performed to analyze the data in comparison to 18 healthy volunteers. For each set of fluorodeoxyglucose and flumazenil images a group and an individual analysis were performed. In addition, a region of interest analysis was performed to validate the results. Focusing on the metabolic abnormalities, we also investigated the role of insular cortex in the symptoms experienced by the patients and the prognostic value of insular metabolic abnormalities. Highly significant hypometabolism and BZR binding decreases were detected in the insular cortex. Results were similar using the region of interest approach. Insular involvement (mainly ipsilateral to the seizure focus) was present in 60% of the patients. Emotional symptoms correlated with hypometabolism in the anterior part of the ipsilateral insular cortex, whereas somesthetic symptoms correlated with hypometabolism in the posterior part. No relationship between postoperative outcome and ipsilateral insular hypometabolism was found. Unilateral mesial temporal lobe epilepsy is associated with insular hypometabolism and benzodiazepine receptor loss. Our results also suggest that the anterior part of the insular cortex is involved in the emotional symptoms and the posterior insular cortex is involved in the somesthetic symptoms. Hypometabolism located in the insula did not influence postoperative outcome after anterior lobectomy.     

Visual perseveration in temporal lobe epilepsy.

Ictal visual perseveration is reported in two patients with temporal lobe epilepsy. A distinction is drawn between visual perseveration and palinopsia, or recurrence of a visual image.     

Visual field defects after temporal lobe resection: a prospective quantitative analysis.

OBJECTIVE: To evaluate and quantify prospectively visual field changes in patients undergoing temporal lobe resections for intractable epilepsy. BACKGROUND: Visual field abnormalities occur after temporal lobe resections for epilepsy; however, we have not encountered published reports using automated static visual field analysis. METHODS: Humphrey visual fields (program 30-2) were obtained before and after partial temporal lobe resection in 32 consecutive patients with intractable epilepsy. A quantitative point-by-point analysis was made in the affected superior quadrant, and the defects were averaged for the whole patient group. RESULTS: Thirty-one patients developed a visual field defect, but none was aware of the defect. The points nearest fixation were relatively spared. The defects were greatest in the sector closest to the vertical meridian in the eye ipsilateral to the resection. The ipsilateral and contralateral mean field defects also differed in both topography and depth. A significant correlation was found between the extent of lateral temporal lobe resection and the degree of the defect in the contralateral eye. CONCLUSIONS: There are differences in the shape and depth of the ipsilateral and the contralateral field defects not previously reported. These findings demonstrate that certain fibers from the ipsilateral eye travel more anteriorly and laterally in Meyer's loop, and support the hypothesis that visual field defects due to anterior retrogeniculate lesions are relatively incongruous because of anatomic differences in the afferent pathways. Automated perimetry is a sensitive method of evaluating and quantifying visual field defects.     

枕叶癫痫患者的视觉症状分析

目的 枕叶癫痫的特征表现视觉症状不易被察觉,进行视觉症状分析,提高对枕叶癫痫症状学的认识,减少误诊、漏诊.方法 选择2017年6月至2019年12月就诊于空军军医大学西京医院癫痫专科门诊确诊为枕叶癫痫的患者128例,选取其中有视觉症状表现的59例患者进行视觉症状、病因学、脑电图、治疗及预后分析.结果 59例枕叶癫痫患者...     

Visual field defects in hydrocephalus

Eight patients representing visual field defects associated with hydrocephalus are reviewed. Seven cases had aqueductal stenosis and one had congenital communicating hydrocephalus. We found five cases of defects in visual field typical of a chiasmal or optic nerve lesion: (1) inferior altitudinal hemianopia with inferior nasal quadrantanopia in the opposite eye; (2) inferior binasal quadrantanopia; (3) unilateral inferior nasal depression; (4) unilateral temporal defect; (5) bilateral central scotoma. In these cases CT demonstrated moderate or marked symmetrical dilatation of the third and lateral ventricles. Four out of five cases showed bulging of the third ventricle anteriorly into the sella turcica on CT or ventriculography. Other three patients had incongruous homonymous hemianopia. Characteristic asymmetrical dilatation of the lateral ventricles was noted in all three cases. The more enlarged lateral ventricles were ipsilateral with the affected visual pathways. The sites of lesion responsible for these field defects seemed to be optic tract in one case and optic radiation in two cases. Ventriculoperitoneal shunt was placed in five out of seven cases. Impaired visual field improved in three patients after shunt insertion. A 28-year-old female who had history of blurred vision fos 14 days showed improvement in visual acuity and field when the enlarged ventricles became slit-like by shunting. In the other two patients defects in visual fields improved in spite of consistent ventriculomegaly. These facts suggested that not only the mechanical forces with distended third ventricle but also increased intracranial pressure played an important role in producing visual field defects in hydrocephalic patients.     

High-resolution source imaging in mesiotemporal lobe epilepsy: a comparison between MEG and simultaneous EEG.

Magnetic source imaging is claimed to have a high accuracy in epileptic focus localization and may be a guide for epilepsy surgery. Non-lesional mesiotemporal lobe epilepsy (MTLE), the most common form of epilepsy operated on, has different etiologies, which may affect the choice of surgical approach. The authors compared whole-head magnetoencephalography (MEG) with high-resolution EEG for source identification in MTLE. Nineteen patients with unilateral, nonlesional MTLE underwent a simultaneous 151-channel CTF MEG (CTF Systems, Inc., Port Coquitlam, British Columbia, Canada) and 64-channel EEG recordings with sleep induction. Three independent observers selected spikes from the EEG and MEG recordings separately. Only when there was interobserver agreement (kappa>0.4) on the presence of spikes in recordings were consensus spikes averaged. EEG and MEG equivalent current dipoles (ECD) were then integrated in the head model of the patient reconstructed from MRI. The results were compared with intraoperative electrocorticography findings. Spikes were detected in 32% of MEGs and 42% of EEGs. No patient showed MEG spikes only. Equivalent current dipole modeling correctly localized the source to the temporal lobe in four out of five MEG and three out of eight EEG recordings. MEG localized sources were more superficial and EEG localized sources were deeper. Unfortunately, basal temporal lobe areas were only partially covered by the sensor helmet of the MEG setup. Best correlation between EEG or MEG findings and electrocorticography findings was between horizontal EEG dipole orientation and prominent neocortical spiking; these patients also had a less favorable prognosis. Magnetic source imaging is currently unlikely to alter the surgical management of MTLE. The yield of spikes is too low, and ECD modeling shows only partial correlation with electrocorticography findings. Moreover, the whole-head MEG helmet provides insufficient coverage of the temporal lobe.     

Symptomatic occipital lobe epilepsy following neonatal hypoglycemia

This study reports on the clinical, electrophysiologic, and neuroradiologic aspects of patients with epilepsy secondary to neonatal hypoglycemia. Fifteen patients with epilepsy and/or posterior cerebral lesions, and neonatal hypoglycemia were studied in the epilepsy clinic between February 1990 and March 2003. The mean age was 12 years. The different types of neonatal hypoglycemia were as follows: four patients had transitional-adaptive, seven classic transient, two secondary-associated, and two severe recurrent hypoglycemia. As to epilepsy, we recognized a larger group of 12 patients characterized by focal seizures and posterior abnormalities on the electroencephalogram, the majority of whom had a good outcome, and a second group of two patients presenting electroclinical features of encephalopathy with refractory seizures. All patients except two manifested parieto-occipital lesions on neuroradiologic images. Neurologic examination was normal in one patient. Six patients had microcephaly; eight manifested visual disturbances. Fourteen patients were mentally retarded. One had a pervasive developmental disorder. This study indicates neonatal hypoglycemia may cause posterior cerebral lesions, abnormal findings at neurologic examination, and symptomatic epilepsy, most frequently occipital lobe epilepsy, usually with a good prognosis, and occasionally epileptic encephalopathy with refractory seizures. MRI studies are essential to define the characteristics of cerebral lesions after neonatal hypoglycemia.