An existing drug used to treat epilepsy could reverse a condition in elderly patients who are at high risk for dementia due to Alzheimer's disease, according to researchers from Johns Hopkins University.

The epilepsy drug calms hyperactivity in the brain of patients with amnestic mild cognitive impairment (aMCI), a clinically recognized condition in which memory impairment is greater than expected for a person's age and which greatly increases risk for Alzheimer's dementia.

"What we've shown is that very low doses of the atypical antiepileptic levetiracetam reduces this over-activity," Michela Gallagher, lead investigator of the study, said in a statement. "At the same time, it improves memory performance on a task that depends on the hippocampus."

For the study, published in NeuroImage: Clinical, the team studied 84 subjects; 17 of them were normal healthy participants and the rest had the symptoms of pre-dementia memory loss defined as aMCI. Everyone was over 55 years old, with an average age of about 70.

The subjects were given varying doses of the drug and also a placebo in a double-blind randomized trial. Researchers found low doses both improved memory performance and normalized the over-activity detected by functional magnetic resonance imaging that measures brain activity during a memory task. The ideal dosing found in this clinical study matched earlier preclinical studies in animal models.

"What we want to discover now, is whether treatment over a longer time will prevent further cognitive decline and delay or stop progression to Alzheimer's dementia," Gallagher said.

The findings validate the Johns Hopkins team's initial conclusions, published three years ago in the journal Neuron. They also closely match the results in animal studies performed by the team and scientists elsewhere.

Next, researchers hope the therapy will be tested in a large-scale, longer-term clinical trial.