Faculty Bibliography

BACKGROUND AND PURPOSE: Patients with nonlesional temporal lobe epilepsy have long been known to have abnormalities of memory. Recently, these patients have been shown to have increased diffusivity in the hippocampus. We hypothesized that in these patients, a negative correlation would exist between diffusivity measures of the mesial temporal lobe and performance on neuropsychological tests. METHODS: Twenty presurgical patients with temporal lobe epilepsy and 20 age- and sex-matched healthy controls underwent MR imaging of the brain. Apparent diffusion coefficient region of interest measures were taken in both hippocampi and parahippocampal gyri by 2 independent observers. Mean whole brain diffusivity was calculated. All patients completed neuropsychological testing. Electroencephalogram and pathology results were collected. Patients and controls were compared with respect to each apparent diffusion coefficient measure. In patients, apparent diffusion coefficients ipsilateral and contralateral to the seizure focus were compared. Associations were assessed between diffusivity measures and neuropsychological scores. RESULTS: Eleven patients had right-sided seizure foci and 9 had left-sided seizure foci. Patients demonstrated higher apparent diffusion coefficient values than controls over the whole brain, in the hippocampi, and in the parahippocampal gyri (P < .05). Patients demonstrated higher apparent diffusion coefficient within the ipsilateral hippocampus (1.19 +/- 0.22 x 10(-3) s/mm2) and parahippocampal gyrus (1.02 +/- 0.12 x 10(-3) s/mm2) compared with the contralateral side (1.02 +/- 0.16 x 10(-3) s/mm2 and 0.96 +/- 0.09 x 10(-3) s/mm2, respectively) (P < .05). Negative correlations were seen between hippocampal apparent diffusion coefficients and multiple memory tests (P < .05). CONCLUSION: Quantitative diffusion measurements in the hippocampus correlate with memory dysfunction in patients with temporal lobe epilepsy

Antiepileptic drugs are important psychotropic agents that are commonly used to treat psychiatric disorders. The behavioral effects of antiepileptic drugs may differ between epilepsy and psychiatric patient populations. Randomized, double-blind, controlled data on the psychotropic efficacy of antiepileptic drugs are limited mainly to bipolar disorder

Medical therapy is the mainstay for epilepsy, with most patients well controlled on a single antiepileptic drug (AED). In this non-refractory group, many patients have medication side effects and occasional seizures. Approximately 30% of patients with partial epilepsy and 25% of patients with generalized epilepsy are not well controlled on medications. These patients are often receiving multiple AEDs, with disabling seizures and side effects. Although second-generation AEDs are safer and better tolerated than the older AEDs, there are scant data to support significant advantages in efficacy. In VA studies with older AEDS, therapy with two AEDs improved seizure control in 40% of patients but seizure freedom was achieved in only 9%. A meta-analysis of the second-generation AEDs used as adjunctive therapies shows that 12% to 29% of patients had a 50% or greater reduction in seizure frequency. Surgery and the vagus nerve stimulator provide important therapeutic options in patients whose seizures are not controlled by AEDs. Special considerations about epilepsy care must be made in pediatric populations, those with developmental delays, women, and the elderly

A 44-year-old man with a left perinatal stroke and recurrent refractory epilepsy underwent functional MRI (fMRI) for motor and language mapping to determine if further epilepsy surgery could be performed without loss of language. Language was activated excessively in the right hemisphere, with only small areas of left hemisphere activation. This suggests bilateral language dominance acquired secondary to the perinatal stroke with the right hemisphere activation resulting from neonatal neuronal reorganization. Functional data were overlaid onto 3D diffusion tensor tractography, providing a unique image of the right hemisphere language recruitment

Focal cortical dysplasia of Taylor type (FCDT) usually presents with seizures at an early age, whereas adult onset of epilepsy is uncommon. We reviewed the medical records of 213 patients with FCDT. In 21 patients (10%), age at seizure onset ranged from 18 to 55 years (mean 25.3). The outcome of seizures in patients with FCDT and adult-onset epilepsy seems favorable vs childhood-onset seizures

OBJECTIVE: To evaluate the safety, efficacy, and utility of a novel surgical strategy consisting of multiple (more than two) operative stages performed during the same hospital admission with subdural grid and strip electrodes in selected pediatric extratemporal epilepsy. METHODS: Subdural grid and strip electrodes were used for multistage chronic electroencephalographic monitoring in 15 pediatric patients (age, <19 yr) with refractory localization-related epilepsy and poor surgical prognostic factors. Initial resective surgery and/or multiple subpial transections were performed, followed by further monitoring and additional resection and/or multiple subpial transections. RESULTS: Mean patient age was 9.7 years. Mean duration of total invasive monitoring was 10.5 days (range, 8-14 d). The first monitoring period averaged 6.5 days, and the second averaged 3.9 days. Additional surgery was performed in 13 of 15 patients. Two patients who did not undergo additional surgery had a Class I outcome. Rationales for reinvestigation included incomplete localization, multifocality, and proximity to eloquent cortex. Complications were minimal, including two transfusions. There were no cases of wound infection, cerebral edema, hemorrhage, or major permanent neurological deficit. Minimum duration of follow-up was 31 months. Outcomes were 60% Engel Class I (9 of 15 patients), 27% Class III (4 of 15 patients), and 13% Class IV (2 of 15 patients). CONCLUSION: In a very select group of pediatric patients with poor surgical prognostic factors, the multistage approach can be beneficial. After failed epilepsy surgery, subsequent reoperation with additional intracranial investigation traditionally is used when a single residual focus is suspected. Our results, however, support the contention that multistage epilepsy surgery is safe, effective, and useful in a challenging and select pediatric population with extratemporal medically refractory epilepsy

The risk of death in people with epilepsy is increased because of disorders that cause epilepsy, known consequences of seizures, and SUDEP (sudden unexplained death in epilepsy). The incidence of sudden death is many times higher in an epilepsy population than for the general public. SUDEP risk increases with the severity of epilepsy but paradoxically affects young adults preferentially. Important risk factors for SUDEP include age 15 to 45 years, refractory epilepsy, tonic-clonic seizures, nocturnal seizures, and periods during which the patient is not observed. Analyses of epidemiologic studies, observations from witnessed near-deaths or deaths, and pathology data have helped focus attention on respiratory and cardiovascular dysfunction as potential mechanisms of SUDEP. Ictal and postictal effects on autonomic functioning and accidental suffocation are commonly cited as potential factors. Monitoring of patients with a history of nocturnal tonic-clonic seizures might help prevent SUDEP