Annals of Long Term Care

American Academy of Neurology 2010 Annual Meeting
Toronto, Canada; April 10-17, 2010

Poster

Nursing Home Residents with Epilepsy Present Challenges

Toronto, Canada—Two separate posters presented at the AAN meeting shed more light on epilepsy in the nursing home setting in the United States. The first poster showed that blood levels of epilepsy drugs can vary widely, but it is not clear what the causes are or if this is worrisome outside of obvious concerns such as toxicity and breakthrough seizures. The second poster showed that elderly nursing home residents have much higher rates of new-onset epilepsy than their counterparts living in the community. Ilo Leppik, MD, Professor of Neurology and Pharmacy at the University of Minnesota in Minneapolis, was lead author of both posters. “Blood levels of epilepsy drugs can fluctuate wildly in nursing home residents, with no apparent reason,” he commented.

A study of 44 nursing home residents from 15 nursing homes showed that serum concentrations of carbamazepine in one individual varied from one measurement to the next by as much as 260%, and valproate levels varied up to 460%. Dr. Leppik and coinvestigators had previously reported wide intraindividual fluctuations in phenytoin levels in nursing home residents. This observation prompted him to study levels of other antiepileptic drugs. He emphasized that this could be the case with other drugs in elderly nursing home residents, but this has not been studied.

Blood levels were measured repeatedly over a period of at least 6 months in patients on stable doses of carbamazepine and valproate. Most patients had blood levels of carbamazepine within the therapeutic range, but ten patients had at least one measurement outside this range. A greater variability was found in valproate levels, and most patients were not in the therapeutic range; five patients had levels below this range, and one patient had levels above and below the therapeutic range. Dr. Leppik said that he has not yet studied the clinical impact of these fluctuations and cautioned against adjusting doses in an attempt to stabilize blood levels. “That approach just increases the variability,” he commented. He is planning a five-year study to look at the causes and effects of the variability in blood levels of antiepileptic drugs in nursing home residents.

A second study using Medicare/Medicaid datasets for > 4.5 million nursing home residents ≥ 65 years of age during the years 2003-2005 showed that a significant number of these residents had new-onset epileptic seizures. The incidence was 164.2 new-onset epileptic seizure cases per 10,000 patient-years, which is > 12 times higher than that reported in community-dwelling elderly people. A study in 1993 reported this rate as 13 per 10,000 annually.

The incidence of new-onset epileptic seizures varied by baseline conditions that are potential precursors to seizures. Very high incidence rates were reported in patients with brain tumor, head injury, hemiplegia, and stroke. Lower incidence rates, which were still higher than in people without these conditions, were seen in those with baseline primary and secondary nonmalignant brain tumors, diabetes mellitus, Parkinson’s disease, hypertension, dementia, and multiple sclerosis. Among 407,801 nursing home residents without these conditions, the incidence was significantly lower—124.5 per 10,000 patient-years, but still nine times higher than that reported in community-dwelling elderly persons.