Out of the top 10 causes of death in the United States, Alzheimer’s is the only one that cannot be prevented or cured.
But new research published in the journal Alzheimer's Research & Therapy suggests drugs meant to reduce seizures associated with epilepsy may be effective at reversing memory loss in Alzheimer’s patients.
Repurposing New and Existing Drugs for Alzheimer’s
Researchers at the University of British Columbia tested existing and experimental epilepsy drugs and concluded they could be effective in treating Alzheimer’s.
Their new findings build on previous studies, in both mice and humans, that suggested the widely used anticonvulsant drug levetiracetam may slow the progression of Alzheimer’s, namely the damaging effects of memory loss.
Levetiracetam, sold under the brand name Keppra, is an anticonvulsant drug that works against epilepsy by decreasing abnormal excitement in the brain.
The Canadian research team tested levetiracetam and brivaracetam, an experimental epilepsy drug that’s similar yet 10 times stronger than levetiracetam. In a Phase III randomized trial completed last year, 50 milligrams of brivaracetam resulted in significantly lower frequency of seizures compared with a group of participants taking a placebo.
In the new study, researchers tested the effects of brivaracetam on mice with Alzheimer’s disease and found it completely reversed memory loss.
The exact mechanism that causes this, however, remains a mystery to researchers.
But researchers say their findings reinforce the theory that brain hyperexcitability — or overreaction to stimuli — plays an important role not only in epilepsy but also Alzheimer's disease.
Dr. Haakon Nygaard, a researcher with the Djavad Mowafaghian Centre for Brain Health, Vancouver, anticipates levetiracetam and brivaracetam will be part of ongoing Alzheimer’s research over the next five to 10 years.
“Now we have many different research groups using antiepileptic drugs that engage the same target, and all point to a therapeutic effect in both Alzheimer's disease models, and patients with the disease,” he said. “Larger clinical studies in human subjects will be needed before we can determine whether anticonvulsant therapy will be part of our future therapeutic arsenal against Alzheimer's.”
There are currently five drugs approved by the U.S. Food and Drug Administration to treat Alzheimer’s disease, all of which work to combat disruptions in the neuron and synapses process caused during dementia.
Alzheimer’s and Epilepsy Connection
An estimated 10 to 22 percent of patients with Alzheimer’s develop epilepsy. Some research suggests those who do are more likely to suffer serious memory impairments.
One study in the Journal of Geriatric Psychiatry and Neurology found patients with early-onset Alzheimer’s disease are particularly susceptible to seizures. People with advanced dementia who experienced seizures typically experienced them at an average of nearly seven years into their Alzheimer’s disease.
A 2013 study published in the journal JAMA Neurology examined 54 men and women, all with epilepsy and some form of cognitive impairment. Patients with epilepsy had memory and other cognitive impairment five to seven years sooner than those without epilepsy, the study found.
“Epileptic activity associated with Alzheimer’s disease deserves increased attention because it has a harmful impact on these patients, can easily go unrecognized and untreated, and may reflect pathogenic processes that also contribute to other aspects of the illness,” researchers at the Memory and Aging Center at the University of California, San Francisco, concluded.
The study authors noted patients were able to control their seizures with the anticonvulsants lamotrigine and levetiracetam. The underlying reasons for these seizures, however, remains unclear.