An existing therapy frequently used to reduce symptoms of Alzheimer's disease might work on patients with a rare neurological disease that destroys language and currently has no treatment, suggest researchers.

Alzheimer's patients are presently treated with a class of drugs called cholinesterase inhibitors which reduce its symptoms by preventing the breakdown of acetylcholine -- a chemical messenger that contributes to learning and memory.

The study, led by Northwestern University researchers, found that individuals with Primary Progressive Aphasia (PPA) undergo the same loss of cholinergic neurons and axons in the forebrain as individuals with Alzheimer's. Therefore, they might also benefit from these cholinesterase inhibitors.

The team focused on the type of PPA that shows a typical Alzheimer's pathology -- the plaques and tangles -- in the brain. However, these patients tend to be excluded from Alzheimer's-related clinical trials and are less likely to be prescribed cholinesterase inhibitors.

"That's why our study is so important for patients," said Changiz Geula from the varsity. No one knew before that this cholinergic system is destroyed in patients with PPA associated with Alzheimer's but we've now demonstrated that and have justified the need for clinical trials with this therapy, the researchers said.

"The findings provide the basic scientific foundation to spur a clinical trial to test the treatment on patients with PPA," Geula said. The study, reported in the Neurology journal, noted that chemical brain scans called positron emission tomography (PET) can determine if there is Alzheimer's disease pathology in someone's brain while they are alive.

This makes it possible to see if someone has the type of PPA associated with Alzheimer's disease or not. In individuals with PPA, brain regions responsible for language, located in the left hemisphere in the majority of the population, are damaged first. Patients with PPA progressively continue to lose their ability to talk, read, write or understand what they hear. In Alzheimer's, brain regions controlling memory are attacked first.