Braxton Wannamaker

Sudden Unexplained Death in Epilepsy: Observations from a Large Clinical Development Program

Summary: Purpose: The present study was conducted to determine the rate of sudden unexplained death in epilepsy (SUDEP) in a well‐defined cohort of patients included in the lamotrigine (LTG) clinical development database.

A population‐based study of risk of epilepsy after hospitalization for traumatic brain injury

Purpose:  This study was undertaken to determine the risk of developing posttraumatic epilepsy (PTE) within 3 years after discharge among a population‐based sample of older adolescents and adults hospitalized with traumatic brain injury (TBI) in South Carolina. It also identifies characteristics related to development of PTE within this population.

Autonomic Nervous System and Epilepsy

Summary: Seizures frequently manifest autonomic dysfunction clinically, and seizure discharges commonly spread into and involve autonomic pathways. These associations are direct and simple in some instances, and the result of multiple indirect and complex relationships in others. Effects of epileptic discharge on the autonomic nervous system are mediated through the cortical, limbic, and hypothalamic systems. Some significant consequences of altered autonomic function include convulsive apnea, abnormal sexual function, and potentially fatal effects on the cardiovascular system.

Complete heart block with ventricular asystole during left vagus nerve stimulation for epilepsy

Vagus nerve stimulation (VNS) is an important therapeutic option for individuals with refractory epilepsy who have failed multiple antiepileptic drugs (AEDs). The intricate relationship of the vagus nerve to cardiac function raises concern that vagal stimulation may affect cardiac rhythm and function. Previous pre- and postmarketing studies have not shown this to be a significant problem, with the incidence of bradyarrhythmias reported to be about 0.1%. We review three cases of ventricular asystole with complete heart block that occurred during intraoperative lead tests. The purpose of these case reports is to identify the specific type of cardiac abnormality associated with vagus nerve stimulation and to identify individuals at risk.

Psychosocial factors associated with stigma in adults with epilepsy.

Living Well with Epilepsy II called for further attention to stigma and its impact on people with epilepsy. In response, the South Carolina Health Outcomes Project on Epilepsy (SC HOPE) is examining the relationship between socioeconomic status, epilepsy severity, health care utilization, and quality of life in persons diagnosed with epilepsy. The current analysis quantifies perceived stigma reported by adults with epilepsy in relation to demographic, seizure-related, health, and psychosocial factors. It was found that reported levels of stigma were associated with interactions of seizure worry and employment status, self-efficacy and social support, and quality care and age at seizure onset. This information may be used to target and develop evidence-based interventions for adults with epilepsy at high risk for perceived stigma, as well as to inform epilepsy research in self-management.

Epilepsy beyond seizure: A population-based study of comorbidities

Comorbid conditions may affect the quality of life in persons with epilepsy (PWE) more than seizures. Using legally mandated healthcare encounter data, somatic, psychiatric, and neurodevelopmental comorbidities in a large population-based cohort of PWE, were compared to persons with migraine (PWM), a similar neurologic condition, and lower extremity fracture (PWLF), otherwise healthy controls. 64,188 PWE, 121,990 PWM, and 89,808 PWLF were identified from inpatient, outpatient, and emergency department from 2000 to 2011. Epilepsy was ascertained with ICD-9-CM code 345; migraine with 346; fracture of the tibia, fibula, and ankle with 823 and 824. Common comorbidities of epilepsy were identified from the literature. Differences in prevalence among PWE, PWM, and PWLF were assessed by comparison of 95% confidence intervals (CI) constructed under the assumption of independence and normal approximation. The association of the comorbid conditions with epilepsy and migraine, compared to lower extremity fracture, were evaluated with polytomous logistic regression controlling for demographic and mortality covariables. PWE had significantly elevated prevalence of comorbidities compared with PWM and PWLF. Compared with PWLF, the adjusted odds ratios (OR) of having both somatic and psychiatric/neurodevelopmental comorbidities were 5.44 (95% CI=5.25-5.63) and 2.49 (95% CI=2.42-2.55) in PWE and PWM, respectively. The association with epilepsy was the strongest for cognitive dysfunction (OR=28.1; 95% CI=23.3-33.8); autism spectrum disorders (OR=22.2; 95% CI=16.8-29.3); intellectual disability (OR=12.9; 95% CI=11.6-14.3); and stroke (OR=4.2; 95% CI=4.1-4.4). The absolute risk increase in PWE compared with PWM for any somatic or psychiatric/neurodevelopmental comorbidity was 58.8% and 94.3%, respectively. Identifying comorbidities that are strongly and consistently associated with seizures, particularly disorders with shared underlying pathophysiology, is critical in identifying specific research and practice goals that may ultimately improve the quality of life for PWE. This study contributes to that effort by providing population-based comorbidity data for PWE compared with PWM and PWLF.

Prevalence of self-reported epilepsy, health care access, and health behaviors among adults in South Carolina

Behavioral Risk Factor Surveillance System data from South Carolina for 2003-2005 were used to determine epilepsy prevalence and prevalence variation by demographic subgroups, and to compare health insurance coverage, health care visits, and health-related behaviors among persons with epilepsy and the general population. Two percent of respondents reported they had ever been told by a doctor that they had epilepsy, and 1% reported active epilepsy. Almost half of those with active epilepsy reported a seizure in the prior 3 months. More than one-third of respondents with active epilepsy reported that there was a time in the past 12 months when they needed to see a doctor but could not because of cost. Persons with epilepsy were more likely to smoke and have less physical activity. Persons with epilepsy need better access to health care, as well as interventions focused on smoking cessation and increased physical activity.

Improvement in Antiepileptic Drug Levels Following Reduction of Intervals Between Clinic Visits

Summary: Antiepileptic drug levels (AEDLs) may reflect how well patients adhere to prescribed medical regimens. Of 30 patients on stable drug regimens AEDLs were increased in 33% by decreasing clinic visit intervals from a mean of 3.4 months to 1.1 months. The testing situation was applied to patients who had AEDLs in the “therapeutic range”(n= 15) as well as those with one or more AEDLs below “therapeutic range” (n= 15). In the latter group 73% of patients showed improvement in AEDLs. Although a less reliable parameter, verbally reported seizure frequencies were also improved. Overall, the reduction in clinic visit interval could be expected to yield improvement in 46 to 80% (confidence interval = 95%). These patients responded equally well to physician and non‐physician practitioners. This technique may be useful as an intervening measure for those patients who are noncompliant.

Stroke after adult-onset epilepsy: A population-based retrospective cohort study

BACKGROUND Earlier studies indicate a higher risk of subsequent stroke in PWE aged ≥60. However, little is known of the incidence of subsequent stroke in people with epilepsy (PWE) aged 35 through 60. We determined the risk factors that increase the incidence of stroke following adult-onset epilepsy in a large statewide population over a 10-year period. METHODS South Carolina hospital discharge and emergency department (ED) data from 2000 to 2011 were used. The study was limited to persons aged ≥35years without prior stroke. Cases included patients diagnosed with epilepsy who were hospitalized or visited the ED. Controls were people with an isolated fracture of the lower extremity without any history of epilepsy or seizure disorders, presumed to approximate the health status of the general population. Epilepsy, fracture, stroke, and comorbid conditions were ascertained by diagnostic codes from health-care encounters. Only persons having stroke occurring ≥6months after the onset of epilepsy or after the first clinical encounter for controls were included. Cox proportional hazards modeling was performed to determine the risk of stroke. RESULTS There were 21,035 cases with epilepsy and 16,638 controls who met the inclusion criteria. Stroke incidence was 2.5 times higher following adult-onset epilepsy (6.3%) compared with controls (2.5%). After adjusting for comorbidities and other factors, cases with epilepsy showed a 60% higher risk of stroke (HR=1.6; 95% CI: 1.42-1.80) compared with controls. Nearly half of the strokes in cases with epilepsy occurred in those with first diagnosis between ages 35 and 55. Somatic comorbidities associated with increased risk of stroke were more prevalent in cases with epilepsy than controls yet similar in both groups with stroke. Risk of stroke increased with increasing age in both groups. However, the risk of stroke in cases with epilepsy increased faster and was similar to that in controls who were ≥10years older. CONCLUSION Adult-onset epilepsy at age 35 and older warrants consideration for occult cerebrovascular disease as an etiology of the epilepsy, which may also increase the risk of subsequent stroke. Somatic comorbidities frequently associated with epilepsy include comorbid conditions that share the same underlying pathology with stroke (i.e., hypertension, hyperlipidemia, myocardial infarction, diabetes, and arteriosclerosis). This increased risk of stroke in patients with adult-onset epilepsy should dictate the evaluation and management of stroke risk factors to prevent stroke.

Caregiver perceptions of seizure severity in pediatric epilepsy.

Purpose:  Seizure severity has been investigated using multiple tools over the years, and its defining features continue to be debated. Severity ratings are necessary for medical, psychological, and epidemiologic investigations. Adults with epilepsy have been evaluated more than youth with epilepsy.