HALIFAX – New research in Halifax could bring doctors one step closer to definitively diagnosing Alzheimer’s disease, which could one day open the door to finding a cure.
Doctors can diagnose patients with Alzheimer’s disease but right now, the only method for a definitive diagnosis is through an autopsy after death; Dr. Sultan Darvesh is looking to change that.
The neurologist at Capital Health has been studying the disease for about 20 years.
Using donated brains at the Maritime Brain Bank, overseen by Dalhousie University and the Alzheimer Society of Nova Scotia, Darvesh has been working on a way to test patients for the disease while they are still living.
Currently, MRI or CAT scans provide doctors with information about whether there is shrinkage of the brain or whether there is evidence of a tumour, bleed or stroke.
“There may be abnormalities that these scans may show but they don’t tell us this is Alzheimer’s disease,” Darvesh said.
Alzheimer’s is typified by abnormal proteins in the brain.
Past researchers have used radioactive compounds to tag abnormal proteins such as amyloid. However, Darvesh said that amyloid proteins can be found in both patients with Alzheimer’s and patients with normal cognitive health.
“It may not be accurate. You cannot use this scan to make a diagnosis of Alzheimer’s disease,” he said.
The limitations caused Darvesh to look for another protein present in Alzheimer’s: an enzyme called butyrylcholinesterase.
“Why is this enzyme important? It has been shown, in contrast to amyloid, which is found in these brains, this particular enzyme can distinguish normal people who have amyloid and Alzheimer’s disease,” he said. “This enzyme is able, in our preliminary studies, to distinguish between these two, therefore it’s really exciting to us.”
Darvesh has now been focusing his efforts on developing a compound to target the enzyme, which would then allow it to show up on scans, thereby possibly giving doctors a definitive diagnosis of Alzheimer’s.
“We have now preliminary data that these kinds of compounds can be synthesized. We have preliminary data on the pre-clinical evaluation that we are doing,” he said.
Darvesh is still working on pre-clinical trials, but hopes to apply to Health Canada or the FDA to do human clinical trials within the next two to three years.
He is hopeful the research will one day allow researchers to make definitive diagnoses.
“If we are able to make a definitive diagnosis of Alzheimer’s disease during life, it is going to be a game-changer in the discovery of better ways to treat Alzheimer’s disease,” Darvesh said. “When there is a discovery of this magnitude in the lab, albeit preliminary, it is very, very exciting.”
Wenda MacDonald, research liaison for the Alzheimer Society of Nova Scotia, estimates there are about 17,000 people in Nova Scotia with dementia and approximately two-thirds of them have Alzheimer’s.
“This is a growing problem as our population ages,” she said, adding the number is likely to double within a generation.
MacDonald said a definitive diagnosis would be not only a relief for patients and their families but important when helping those patients move forward.
“Getting a diagnosis earlier gives you the benefit of the medication that we have available to us right now. They may be more beneficial if you’re diagnosed at an earlier age,” she said.
“Another benefit, it gives [the person] a chance to participate in their own care planning. A diagnosis prompts us to take a good look at what we want for our care.”
While no cure is on the horizon for the disease yet, researchers remain hopeful and determined.
“Failure to find a cure is not an option,” Darvesh said.