23 Apr 1999

At the American Academy of Neurology meeting in Toronto, Scott Small and colleagues presented data suggesting that fMRI can distinguish early AD-related memory decline from other sources of memory decline. Citing evidence that entorhinal cortex (EC) lesions occur early in Alzheimer's disease, while non-AD degenerative processes target other hippocampal areas, Small's group showed a correlation between EC dysfunction and cognitive impairment and memory loss.

The researchers studied non-demented, elderly participants who had experienced greater than normal memory loss over three years. Using fMRI (they describe their technique in the April issue of the Annals of Neurology), Small and colleagues stratified the patients into those with EC dysfunction (5 subjects) and those without (8 subjects). They found that—in addition to deficits on memory tests—the subjects with fMRI evidence of EC lesions also had greater then normal decline in the cognitive domain of abstract reasoning. This was not the case for subjects without evidence of EC lesions. No data are available yet on whether these patients went on to be diagnosed with Alzheimer's disease.—Hakon Heimer