Scent test may help to sniff out Alzheimer's

WASHINGTON - A simple scratch and sniff test may help doctors to identify patients with Alzheimer's disease.

A study of patients with early signs of the disease found they may be unable to smell certain odours, including strawberry, smoke, soap and cloves.

"Early diagnosis of Alzheimer's disease is critical for patients and their families to receive the most beneficial treatment and medications," said Dr Davangere Devanand, a professor of psychiatry and neurology at New York's Columbia University, who led the study.

There are some drugs that may help slow the progression of the early disease, and researchers are working on vaccines and new drugs to treat Alzheimer's.

For the study Professor Devanand and colleagues studied 150 patients with minimal to mild cognitive impairment.

They compared them with 63 healthy elderly people and ran tests on them every six months.

The inability to identify 10 specific odours clearly predicted who would go on to develop Alzheimer's, they told a meeting of the American College of Neuropsychopharmacology.

These smells included strawberry, smoke, soap, menthol, clove, pineapple, natural gas, lilac, lemon and leather.

"Narrowing the list of odours can potentially expedite screening and help with early diagnosis," said Professor Devanand.

This made sense, he said, because examination of the brains of Alzheimer's patients showed that the nerve pathways involved in smell were affected at a very early stage.

- REUTERS