An Alzheimer's drug could also slow down Lewy body dementia

MONDAY, Aug. 24, 2024 (HealthDay News) — A drug used to treat Alzheimer's disease appears to slow the progression of Lewy body dementia, the brain disease that struck comedian Robin Williams before his suicide.

Cholinesterase inhibitors prevent the breakdown of acetylcholine, a chemical messenger important for memory and learning.

According to the Alzheimer's Association, the drugs are often prescribed to treat symptoms related to memory, thinking, language, judgment and other thought processes in Alzheimer's patients.

New research now suggests the drugs could also help people with Lewy body dementia, according to new data from nearly 1,100 people with this degenerative brain disease.

The drugs, known as ChEIs, significantly slowed cognitive decline in patients with Lewy body dementia compared to another Alzheimer's drug called memantine, researchers reported August 23 in the journal Alzheimer's and dementia.

“Our results underline the potential benefit of ChEIs for patients with [Lewy body dementia] and support the updating of treatment guidelines,” said lead researcher Maria Eriksdotter, professor of neurobiology at the Karolinska Institutet in Sweden.

Lewy body dementia is caused by abnormal deposits of a protein called alpha-synuclein in the nerve cells of the brain.

These deposits, called Lewy bodies, cause a rapid decline in brain function compared to Alzheimer's and other forms of dementia, researchers found. Patients have problems with thinking and memory, have visual hallucinations and suffer movement symptoms similar to those of Parkinson's disease.

Lewy body dementia accounts for 10 to 15 percent of all dementia cases, researchers explained in background information. By 2050, up to 14 million people worldwide are expected to suffer from this form of dementia.

An autopsy after his death in August 2014 revealed that Robin Williams' brain was riddled with Lewy bodies.

“He committed suicide in 2014, at the end of an intense, confusing and relatively brief chase due to the symptoms and pathology of this disease,” his widow Susan Schneider Williams wrote in the magazine neurology in 2016.

Williams suffered from tremors, paranoia, delusions, insomnia and memory problems in the months before his death, his widow wrote in a special editorial.

“All four doctors I met with afterward who reviewed his medical records said he had one of the worst illnesses they had ever seen,” Williams wrote. “He had a loss of about 40% of dopamine neurons and almost no neurons in the entire brain and brain stem were free of Lewy bodies.”

For the new study, researchers searched a Swedish registry of cognitive impairment in patients with Lewy body dementia. They found 814 patients who had been treated with ChEIs and compared them with 133 patients who had received memantine and another 148 who had not taken either drug.

“There are currently no approved treatments for [Lewy body dementia]therefore, doctors often use Alzheimer's drugs such as cholinesterase inhibitors and memantine to relieve symptoms,” said lead researcher Hong Xu, assistant professor of neurobiology at Karolinska Institutet.

Cognitive tests were performed on all patients, which showed that the brain function of those who received ChEIs declined more slowly than in the other two groups over a five-year observation period.

The researchers found that the ChEIs galantamine (Razadyne) and donepezil (Aricept) in particular could help stop the progression of symptoms of Lewy body dementia.

The researchers also found that ChEIs were associated with a 34 percent lower risk of death within the first year after diagnosis of Lewy body dementia.

These results should form the basis for new clinical trials to test cholinesterase inhibitors as a treatment for Lewy body dementia, the researchers concluded.

More information

The National Institute on Aging has more information on Lewy body dementia.

SOURCE: Karolinska Institutet, press release, 21 August 2024