PET Scan may Help to Detect Alzheimer's Non-invasively

by VR Sreeraman on Aug 13 2008 12:15 PM

A method of medical imaging known as PET scans may allow doctors to develop a non-invasive test for Alzheimer's by spotting abnormal brain "plaques" associated with the disease, Finnish researchers report in a new study.

Positron Emission Tomography, or PET scans, may help detect the presence of the brain plaques, including those made of the compound beta-amyloid which are considered hallmarks for developing Alzheimer's, according to a small study released on the Internet Monday and that will appear in the October issue of Archives of Neurology.

Alzheimer's causes dementia by destroying neurons. Currently the only reliable way to test for such brain plaque compounds is by analyzing brain tissue in a biopsy.

Ville Leinonen of Finland's University of Kuopio and his colleagues studied 10 patients without severe dementia who had undergone a biopsy of their frontal cortex because they were suspected of having hydrocephalus, an abnormal increase of cerebrospinal fluid in the brain.

The procedure allows cerebrospinal fluid pressure to be measured.

Both those with cerebrospinal fluid abnormalities and those with Alzheimer's may suffer from dementia, and between 22 and 42 percent of patients with hydrocephalus also have cerebral lesions characteristic of Alzheimer's.

The 10 patients in the study received injections of a marker called carbon 11 before undergoing a 90-minute PET scan. The results showed that patients with beta-amyloid plaques in their brain biopsies had a higher concentration of carbon 11 in certain areas of their brain than those who did not have these plaques.

The study's authors said more research is necessary to confirm their results.