Low-frequency stimulation of a fiber tract in bilateral temporal lobe epilepsy.

OBJECTIVE: Pharmacoresistant bilateral mesial temporal lobe epilepsy often implies poor resective surgical candidacy. Low-frequency stimulation of a fiber tract connected to bilateral hippocampi, the fornicodorsocommissural tract, has been shown to be safe and efficacious in reducing seizures in a previous short-term study. Here, we report a single-blinded, within-subject control, long-term deep-brain stimulation trial of low-frequency stimulation of the fornicodorsocommissural tract in bilateral mesial temporal lobe epilepsy. Outcomes of interest included safety with respect to verbal memory scores and reduction of seizure frequency. METHODS: Our enrollment goal was 16 adult subjects to be randomized to 2-Hz or 5-Hz low-frequency stimulation of the fornicodorsocommissural tract starting at 2 mA. The study design consisted of four two-month blocks of stimulation with a 50%-duty cycle, alternating with two-month blocks of no stimulation. RESULTS: We terminated the study after enrollment of five subjects due to slow accrual. Fornicodorsocommissural tract stimulation elicited bilateral hippocampal evoked responses in all subjects. Three subjects underwent implantation of pulse generators and long-term low-frequency stimulation with mean monthly seizures of 3.14 ±â€¯2.67 (median 3.0 [IQR 1-4.0]) during stimulation-off blocks, compared with 0.96 ±â€¯1.23 (median 1.0 [IQR 0-1.0]) during stimulation-on blocks (p = 0.0005) during the blinded phase. Generalized Estimating Equations showed that low-frequency stimulation reduced monthly seizure-frequency by 0.71 per mA (p < 0.001). Verbal memory scores were stable with no psychiatric complications or other adverse events. SIGNIFICANCE: The results demonstrate feasibility of stimulating both hippocampi using a single deep-brain stimulation electrode in the fornicodorsocommissural tract, efficacy of low-frequency stimulation in reducing seizures, and safety as regards verbal memory.

Regulating drivers with epilepsy in Maryland: Results of the application of a United States consensus guideline.

OBJECTIVE: Driving regulations for people with seizures vary widely throughout the United States and the world. Maryland updated their guidelines in 2003 to reflect those of a U.S. consensus guideline requiring a minimum 3-month seizure-free period as well as an individual risk assessment by a Medical Advisory Board (MAB). This retrospective study provides the first analysis of outcomes after the implementation of the consensus guidelines and an assessment of their predictive validity through longitudinal outcome data. METHODS: MAB reviews and licensing records for Maryland driver applicants with seizures between 2004 and 2005 were reviewed, during which 254 first-time applicants were processed. The initial licensing decisions were assessed and the subsequent seizure recurrence and crash rates over the following 7 years were evaluated. RESULTS: The MAB approved driving for 74.8% of initial applicants; most had been seizure-free for over 6 months. Approved drivers had a longer median seizure-free period (563 days) compared to those who were denied (104.5 days, p < 0.01), and 22.7% of approved drivers had seizures recur during monitoring over the next year, although none resulted in crashes or deaths. Of applicants initially denied (n = 50), 89.3% were eventually licensed. Treating physicians recommended driving for 84.4% of applicants rejected by the MAB. SIGNIFICANCE: Maryland's individualized system for assessing driving applicants with seizures resulted in a dynamic process of approvals and denials based on favorable and unfavorable risk factors and lengths of seizure freedom. Seizure recurrences were comparable to internationally accepted rates. Over the course of monitoring, most applicants were eventually licensed. Treating physicians recommended that nearly all their patient applicants be permitted to drive, which raises safety concerns for the 10 states that rely solely on physician recommendations. Further assessment is needed of the risk factors deemed favorable and unfavorable by the U.S. consensus guidelines.

Video-EEG monitoring in a geriatric veteran population.

Video-EEG monitoring is a standard tool to evaluate possible seizures. However, there are limited data available for the elderly population, and no data are available for the elderly veteran population. The records of 71 veterans ages 60 and older who underwent video-EEG monitoring at the Michael E. DeBakey Veterans Affairs Medical Center from 1999 to 2006 were reviewed. The average age was 68 years, and 94% were male. Typical events occurred in 34 of 71 patients (48%). Twelve patients (35%) had epileptic seizures; most were temporal lobe seizures (75%). The remaining 22 patients (65%) had a nonepileptic event. Of these, 10 (45%) had psychogenic nonepileptic seizures and 12 (55%) had other physiologic nonepileptic events. AEDs were previously prescribed in 14 of the 22 nonepileptic patients (64%). In our study, most events were nonepileptic, partly reflecting the unique nature of the VA population. There was a slightly higher number of physiologic nonepileptic events; however, psychogenic seizures are also frequently seen. Most of the patients with nonepileptic events were previously treated with AEDs. Most of the epileptic events captured were temporal lobe seizures. Video-EEG monitoring in the elderly is useful in the characterization of paroxysmal events.

Prescribing antiepileptics for the elderly: differences between guideline recommendations and clinical practice.

The incidence of epilepsy in patients aged >60 years is higher than in any other period of life. Yet, until recently, what was known about the treatment of older patients with epilepsy has been inferred from studies in younger patients. A growing body of clinical evidence focused exclusively on the elderly suggests that, while some issues are similar for older and younger adults, older patients with epilepsy may require even more attention regarding antiepileptic drug (AED) selection than younger patients. This article reviews published guidelines and recommendations to identify explicit recommendations for use of specific AEDs in the elderly, and assesses the extent to which those recommendations have been adopted in clinical practice. We found that while one systematically derived guideline stated that lamotrigine may be a good choice for older patients because of its favourable adverse effect profile, only clinical recommendations based on expert opinion explicitly identified AEDs that are more and less appropriate for use in the elderly. Examination of published studies describing recent AED-prescribing patterns suggests that clinical recommendations have been, at best, slowly adopted. This observation is exemplified by the fact that older patients newly diagnosed with epilepsy are still prescribed phenobarbital--a drug identified as suboptimal in 1985. In order to better understand the delay in adopting clinical recommendations, we examine these findings in light of diffusion of innovations theory, a theory that has been used to understand dissemination of other new medical technologies. According to this theory, while it is too early to suggest that use of second-generation AEDs in the elderly has been delayed, the continued use of phenobarbital in older patients newly diagnosed with epilepsy represents a serious delay in adoption of recent guidelines. Delays may be related to lack of knowledge by primary care clinicians and emergency room physicians (who frequently treat older patients with epilepsy), lack of 'opinion leaders' in primary care and perhaps general neurology, clinicians' focus on seizure control as the primary endpoint in treating patients with epilepsy, and difficulties in changing long-standing prescribing patterns. Research targeting barriers to more appropriate prescribing is needed to determine appropriate strategies for changing AED prescribing practices in the elderly.