Abstracts

OBJECTIVE: At the end of this activity, participants should be able to discuss the effectiveness of vagus nerve stimulation (VNS) Therapy in reducing seizure frequency and improving quality of life among patients aged 65 years and older.
RATIONALE: As the world[ssquote]s population ages, the proportion of patients with a history of stroke, dementia, and tumor increases. Such underlying illnesses are highly associated with seizures in the elderly. Treating the older patient with seizures presents several challenges. Medications prescribed for co-morbid conditions and diseases increase the likelihood of drug interactions among patients who are also receiving antiepileptic drugs (AEDs) for seizures. The elderly may be more sensitive to the side effects of AEDs, which can exacerbate problems with cognition and activities of daily living (Sirven JI. Acute and chronic seizures in patients older than 60 years. Mayo Clin Proc 2001;76:175-183). VNS Therapy, delivered by a pulse generator implanted in the chest, neither interacts with drugs nor impairs cognitive function.
METHODS: The VNS Therapy Outcome Registry, which collects data on patients receiving VNS for seizures, was queried for changes in seizure frequency and quality of life (QOL) for a constant cohort of patients aged 65 years and older with data at baseline and 3- and 12-month follow-up.
RESULTS: Query of the registry identified 15 patients who met analysis criteria. After 3 months of VNS Therapy, seizure frequency was reduced from that at baseline by a median of 56% (range, 0% to [ndash]100%). Seizures were reduced 50% in 9 (60%) of the patients, 75% in 3 (20%), 90% in 2 (13%), and no seizures were reported in 1 (7%). After 12 months of VNS therapy, median seizure frequency was reduced by 59% (range, 25% to [ndash]100%). Seizures were reduced 50% in 8 (53%) of the patients, 75% in 5 (33%) of the patients, 90% in 3 (20%) of the patients, and no seizures were reported in 1 (7%).
After 3 months of VNS Therapy, QOL measures were reported as better or much better among 9 (60%) of patients for alertness, 7 (47%) for verbal, 3 (20%) for memory, 3 (20%) for achievement, 6 (40%) for mood, 9 (60%) for postictal period, and 3 (20%) for seizure clustering. After 12 months, QOL improvements were reported among 8 (53%) of patients for alertness, 5 (33%) for verbal, 3 (20%) for memory, 1 (7%) for achievement, 4 (27%) for mood, 7 (47%) for postictal period, and 2 (13%) for seizure clustering. No measure of QOL was reported as [dsquote]much worse[dsquote] for any patients at either time point.
CONCLUSIONS: Although the number of patients in this analysis is small, reductions in seizure frequency and improvements in quality of life are notable. Between 3 and 12 months of VNS Therapy, the median reduction in seizure frequency increased, and the number of patients with robust ([gte]75% reductions) increased from 3 to 5 patients. Alertness was reported as improved among more than half the patients at both time points. VNS Therapy has potential for treating seizures in patients aged 65 years and older.