Study: PET Scans Increase Ability to Predict Worsening Memory Problems

PET scans significantly increase the ability to predict whether early memory problems will significantly worsen, according to a study reported in the November issue of Molecular Genetics and Metabolism.

A PET (positron emission tomography) scan provides an image of the brain's metabolism. Scanning a patient's brain metabolism with PET can indicate progressive dementia.

University of California at Los Angeles researchers studied the results of PET scans performed between 1991 and 1999 on 167 patients being evaluated by their neurologists for mild cognitive complaints, such as memory loss or changes in behavior and language ability.

The researchers compared their predictions to the patients' original clinical diagnoses by their neurologists and then to the patients' cognitive conditions two to ten years after their initial evaluation.

Neurologists who diagnosed their patients with progressive dementia were correct 84 percent of the time. Adding a positive diagnosis from a PET scan boosted the accuracy of that prediction to 94 percent. A negative PET scan made it 12 times more likely that these patients would remain cognitively stable during the follow-up period.

"Adding PET substantially boosted how often physicians were correct in predicting patients' future cognitive decline or stability," said lead researcher Dr. Dan Silverman, associate director of imaging at the university's Alzheimer's Center.

"The predictive power of brain PET scans may prove most helpful to people with early cognitive problems who would not otherwise be suspected to have progressive dementia," observed Silverman.

Other sources: University of California at Los Angeles