Deepak Lachhwani

Successful surgery for epilepsy due to early brain lesions despite generalized EEG findings

Objective: To understand the role of epilepsy surgery in children with generalized or bilateral findings on preoperative scalp EEG. Methods: From our pediatric epilepsy surgery series, we identified 50 patients in whom 30 to 100% of preoperative epileptiform discharges (ictal, interictal, or both) were generalized or contralateral to the side of surgery. Results: All patients had severe refractory epilepsy and an epileptogenic lesion on brain MRI. Ninety percent of the lesions were congenital, perinatal, or acquired during infancy, predominantly malformations of cortical development (44%) or cystic encephalomalacia (40%). Age at surgery was 0.2 to 24 (median 7.7) years. Surgeries were hemispherectomy (64%) or lobar or multilobar resection. At last follow-up (median 24.0 months), 72% of patients were seizure-free, 16% had marked improvement with only brief episodes of staring or tonic stiffening, and 12% were not improved. The rate of seizure-free outcome was not significantly associated with age at seizure onset or surgery, presence of hemiparesis or focal clinical features during seizures, type of lesion, or surgery type. Postoperative seizure-free rate did not differ from that in a comparison group of similar patients who matched the study group except for their high percentage (70 to 100%) of ipsilateral ictal and interictal epileptiform discharges on preoperative EEG. Conclusions: Epilepsy surgery may be successful for selected children and adolescents with a congenital or early-acquired brain lesion, despite abundant generalized or bilateral epileptiform discharges on EEG. The diffuse EEG expression may be due to an interaction between the early lesion and the developing brain.

Seizure outcome after epilepsy surgery in patients with normal preoperative MRI

Objective: To determine outcome after epilepsy surgery in patients with normal preoperative magnetic resonance imaging (MRI). Methods: 24 adult and paediatric patients with normal preoperative MRIs were studied. They underwent epilepsy surgery between 1994 and 2001 and had at least one year of follow up. Results: At the most recent follow up, nine patients (37%) were seizure-free and 18 (75%) had at least a 90% reduction in seizure frequency with weekly or monthly seizures. Seizure freedom was not significantly different after resections in frontal (5/9) or temporal regions (4/13) (p = 0.24, Fisher’s exact test), or among patients with or without localising features on EEG, PET, or ictal SPECT. Subdural grids, used in 15 of 24 patients, helped tailor resections but were not associated with differences in outcome. Histopathology showed cortical dysplasia in 10 patients (42%), non-specific findings in 13 (54%), and hippocampal sclerosis in one (4%). Cortical dysplasia was seen in seven patients with frontal resection (78%) and non-specific findings in nine (69%) with temporal resection. Seizure outcome did not differ on the basis of location of resection or histopathology. Conclusions: While these results were less favourable than expected for patients with focal epileptogenic lesions seen on MRI, they represented worthwhile improvement for this patient population with high preoperative seizure burden. In this highly selected group, no single test or combination of tests further predicted postoperative seizure outcome.

Hemispherectomy for catastrophic epilepsy in infants.

Summary:  Purpose: To report our experience with hemispherectomy in the treatment of catastrophic epilepsy in children younger than 2 years.

Longitudinal seizure outcome and prognostic predictors after hemispherectomy in 170 children

Objective: Data on longitudinal seizure outcome after hemispherectomy in children are limited. This study explores the posthemispherectomy longitudinal seizure outcome and its predictors. Methods: We reviewed 186 consecutive children who underwent hemispherectomy between 1997 and 2009 at our center. Clinical, EEG, imaging, and surgical data were collected. Seizure outcome data were collected via a structured questionnaire by contacting families (n = 125) or from the medical records at last follow-up (n = 58). Results: Of 186 patients, 3 were lost to follow-up; 13 seizure-free patients with new-onset nonepileptic spells were excluded. Perioperative complications were not collected. There was no mortality. At a mean follow-up of 5.3 years (±3.3 years), 112 of 170 children (66%) were seizure-free (Engel class 1a). In 58 patients with seizure recurrence, 8 had late remission and 16 had >90% reduction. Overall, at last follow-up, 136 patients (80%) were either seizure-free or had major improvement. Using survival analysis, the estimated probability of seizure freedom after hemispherectomy was 78% (95% confidence interval [CI] = 75%–81%) at 6 months, 76% (95% CI = 73%–79%) at 1 year, 71% (95% CI = 68%–74%) at 2 years, and 63% (95% CI = 59%–67%) at 5 years. On multivariate analysis, bilateral PET abnormalities (risk ratio = 2.53, 95% CI = 1.02–5.85) and acute postoperative seizures (risk ratio = 7.03, 95% CI = 3.07–15.9) independently predicted seizure recurrence. Conclusions: The long-term seizure-free rates after hemispherectomy remained stable at 63% at 5 years and beyond. This study will assist in better candidate selection for hemispherectomy, presurgical counseling, and early identification of surgical failures.

Resective surgery to treat refractory status epilepticus in children with focal epileptogenesis

Prolonged high-dose suppressive therapy (HDST) is a mainstay in the management of refractory status epilepticus (RSE), albeit with high morbidity and mortality. The authors studied 10 patients who were carefully selected for epilepsy surgery after failing prolonged (>2 weeks) HDST. Status epilepticus was stopped acutely in all of them with no mortality and no substantial morbidity. At follow-up (median 7 months), 7 (70%) of 10 patients were seizure free, and 3 (30%) of 10 had significant improvement in their epilepsy.

Epilepsy surgery in children with electrical status epilepticus in sleep.

OBJECTIVEPediatric epilepsy surgery candidates with unilateral congenital or early-acquired brain lesions may present with refractory seizures and generalized electroencephalographic features such as electrical status epilepticus in sleep (ESES). The purpose of our study was to review the clinical presentation, neuroimaging findings, and outcome in a series of children with unilateral brain lesions and ESES undergoing resective surgery for refractory epilepsy. METHODSA total of 415 consecutive patients younger than 18 years of age undergoing video electroencephalographic evaluation and epilepsy surgery at Cleveland Clinic were reviewed for ESES, an underlying pathological lesion, and outcome after surgery. RESULTSEight patients were included. All patients presented with medically refractory epilepsy, hemiparesis, and developmental delay. The pathogenesis was perinatal infarction in 7 patients and malformation of cortical development in 1 patient. Preoperative electroencephalography demonstrated generalized interictal spikes, electroencephalographic seizures, and ESES in all cases. Age at the time of surgery ranged from 3 to 14 years. Six patients underwent hemispherectomy, and 2 patients underwent focal resection. Six patients became seizure-free after resection. Two patients with functional hemispherectomy continued to have rare seizures, but were much improved. These patients also had perinatal infarctions in the hemisphere contralateral to the resection, possibly indicating a less beneficial outcome. Postoperative electroencephalography demonstrated resolution of generalized interictal discharges and ESES in all. Formal pre- and postoperative neuropsychological testing showed overall improvement of age-equivalent scores. CONCLUSIONChildren with unilateral brain lesions and seizures may become seizure-free after epilepsy surgery, even if the preoperative electroencephalogram shows generalized ESES. The lesion occurring early in life and the location of the lesion may play a role in the development of ESES. Cognitive impairment may be aggravated by the persistence of ESES. Preliminary developmental data in this small sample suggest that termination of seizures and possibly of ESES by epilepsy surgery may have developmental benefits.

Identification of candidates for epilepsy surgery in patients with tuberous sclerosis

The authors reviewed preoperative MRI and EEG findings in relation to postsurgical outcome in 17 patients with refractory epilepsy due to tuberous sclerosis complex (TSC). Resecting concordant MRI (main tuber) and EEG abnormalities offered seizure freedom (8/9, 89%; median follow-up 25 months) comparable to other focal etiologies. Patients with nonconcordant MRI and EEG findings did less well (3/8, 38%, seizure free; p = 0.027, OR = 13).

Long-term functional outcomes and their predictors after hemispherectomy in 115 children.

To examine the long‐term functional outcomes and their predictors using a patient/family centered approach in a cohort of children who had hemispherectomy. Functional outcome measures studied were the following: ambulation ability, visual symptoms, spoken language, reading skills, and behavioral problems.

Seizure Semiology in the Elderly: A Video Analysis

Summary:  Purpose: To describe the seizure semiology of patients older than 60 years and to compare it with that of a control group of younger adults matched according to the epilepsy diagnosis.

Contralateral MRI abnormalities in candidates for hemispherectomy for refractory epilepsy

Purpose:  To assess the impact of contralateral magnetic resonance imaging (MRI) findings on seizure outcome after hemispherectomy for refractory epilepsy.