Michael E. Newmark

The cost of epilepsy in the United States: an estimate from population-based clinical and survey data.

Summary: Purpose: To provide 1995 estimates of the lifetime and annual cost of epilepsy in the United States using data from patients with epilepsy, and adjusting for the effects of comorbidities and socioeconomic conditions.

The incidence of epilepsy and unprovoked seizures in multiethnic, urban health maintenance organizations.

Summary: Purpose: Studies of the incidence of epilepsy are limited to a few populations in which new cases can be ascertained. Health maintenance organization (HmO) populations were studied to determine the incidence in a multiethnic, urban United States population.

Drug Spotlight Program: The Use of Antiepileptic Drugs

: The use of antiepileptic drugs has become increasingly effective through several factors: new techniques that allow better diagnosis of the seizure disorder and its underlying cause; the development of new medications and increased knowledge of old ones; and the widespread use of antiepileptic drug-level determinations. The choice of a drug depends heavily on an accurate diagnosis of seizure type, which may determine the response to the medication. Because of better diagnostic criteria and intensive monitoring procedures, the correct seizure disorder can be more easily diagnosed and, therefore, the proper medication selected. Minimal efficacious and toxic blood concentrations have now been identified for most antiepileptic drugs. Several, including primidone, carbamazepine, methsuximide, and mephenytoin, have pharmacologically active metabolites that affect both the toxicity and efficacy of the prescribed drug and can now be measured in the plasma. The most effective use of the antiepileptic drugs depends on a combination of reliable blood level measurements, clinical observation, and knowledge of their pharmacokinetics and biotransformation.

Effect of Phenytoin on Human Cerebral Glucose Metabolism

We used serial positron emission tomography scans with [18F]2-deoxyglucose to study the effect of phenytoin on human cerebral glucose metabolism in 10 patients with seizure disorders. Local CMRglu for each patient was measured in 10 regions of interest. EEGs were performed during each procedure to match scans for state of consciousness and exclude data from scans with ictal activity. Serial scans without a drug change were performed in six control patients. Metabolic rates were significantly lower in two cortical regions while patients were taking phenytoin. No significant changes on repeat scan were seen in the control population. Measured across all regions of interest, metabolic rates were 13% higher when patients were off phenytoin (p < 0.02).

Sociodemographic disparities in epilepsy care: Results from the Houston/New York City health care use and outcomes study

Purpose:  The purpose of this study was to identify sociodemographic disparities in health care use among epilepsy patients receiving care at different sites and the extent to which the disparities persisted after adjusting for patient characteristics and site of care.

Socioeconomic status, health care use, and outcomes: persistence of disparities over time.

Purpose:  To determine the persistence of disparities in health care use and outcomes in socioeconomically diverse populations of epilepsy patients.

Socioeconomic status and self-management in epilepsy: Comparison of diverse clinical populations in Houston, Texas

We compared the scores on self-management and associated psychosocial scales of patients with epilepsy at two clinics in Houston, TX, USA, to determine if there were systematic differences associated with socioeconomic status (SES). Patients of low SES reported higher scores on overall, information, and safety management (P<0.03) and no differences on medication, seizure, and lifestyle management. The two groups were similar with respect to the pattern of high and low scores. Reported levels of self-efficacy, depression, social support, stigma, desire for control, and outcome expectations were higher for those of high SES (P<0.01). Knowledge of epilepsy and satisfaction with care were lower (P<0.01). Again, the patterns of high and low scores were similar. Tests of association between psychosocial factors and self-management revealed that people with higher levels of self-efficacy and social support also reported higher self-management (P<0.01) regardless of demographics, seizure frequency, and SES (P<0.05). These findings provide little support for SES-related disparities in self-management and suggest that the focus of strategies to improve self-management may be similar across diverse populations.

Zonisamide monotherapy in a multi-group clinic

OBJECTIVE Reports on zonisamide monotherapy are limited despite favourable preliminary data, and typically restricted to tertiary referral centres. The goal of this study is to report clinical experience with zonisamide monotherapy in a large, multi-group clinic setting. METHODS We reviewed the charts of patients treated with zonisamide monotherapy in the Neurology Department of the Kelsey-Seybold Clinic (Houston, Texas) during an 18-month period. We analysed subgroups of patients who were naive to antiepileptic drug (AED) therapy (Group 1) and those who had previous exposure to AEDs (Group 2). RESULTS The study included 54 paediatric and adult patients with a variety of seizure types: 15 patients in Group 1 and 39 patients in Group 2. Mean maintenance zonisamide dosages in the two groups were similar (193 mg/day in Group 1 vs. 218 mg/day in Group 2). Thirty-eight patients (70.4%) continued zonisamide monotherapy, with 7 patients (13.0%) adding a second AED and 9 patients (16.7%) switching to a different drug. Of the 24 patients who became seizure free on zonisamide monotherapy, 11 were on the 100-mg initial dosage. Zonisamide monotherapy was well tolerated. CONCLUSIONS Zonisamide monotherapy is safe and effective for a variety of seizure types and may be appropriate as first-line therapy in some cases.

Plasma concentrations of phensludmide, methsuximide, and their metabolites in relation to clinical efficacy

The clinical efficacy of phensuximide and methsuximide was studied in relation to plasma concentrations of these compounds and their desmethyl metabolites. Single- and chronic-dose studies of each drug were carried out in five patients with intractable seizures. Patients were evaluated before and during treatment by 6-hour simultaneous video and telemetered electroencephalographic recordings to characterize the seizure type and by daily determinatiions of plasma antiepileptic drug concentrations. Phensuximide had a mean half-life of 7.8 hours and accumulated to an average fasting level ofonly 5.7 pg per milliliter. Desmethylphensuximide averaged only 1.7 pg per milliliter with a similar half-life. Methsuximide had an even shorter half-life, averaging 1.4 hours, but its desmethyl metabolite had a mean half-life of 38 hours and therefore accumulated to levels in excess of 40 pg per milliliter. The addition of phensuximide to their regimens benefited none of the patients, but two had an excellent response to methsuximide. The failure of phensuximide and its desmethyl metabolite to accumulate to reasonable levels is the likely explanation for the relatively weak antiepileptic effect of phensuximide as compared with methsuximide.

Unilateral opercular lesion and eating-induced seizures

Eating-induced seizures are an uncommon presentation of reflex epilepsy, a condition characterized by seizures provoked by specific stimuli. Most reports have identified aetiology associated with malformations of cortical developmental, hypoxic brain injury, previous meningoencephalitis or static encephalopathy. We present a patient with eating-induced reflex seizures, which began several years after treatment for an opercular primitive neuroectodermal tumour (PNET), and who subsequently underwent in-depth clinical and video-EEG analysis for her seizures. This patient noted rapid improvement with decreased frequency of seizure activity after treatment with valproic acid. We discuss the aetiology of reflex epilepsy, the anatomical basis of eating-induced epilepsy, and review the current literature.