Although they scored fine on cognitive tests, older adults with memory complaints still might have early onset Alzheimer’s disease, according to a new study.

Researchers at Dartmouth Medical School in Hanover, NH, studied 120 adults aged 60 to 90. Using MRI scans, the researchers determined that certain brain regions of participants who complained that they repeatedly had trouble with forgetfulness — despite having normal cognitive test scores — looked similar to those with early dementia. Researchers noted that the other brain regions of the subjects with memory loss appeared to be no different from healthy subjects.

The results indicate that older adults who report significant problems with memory loss “warrant evaluation and close monitoring over time,” according to researchers. The study appeared in the September issue of Neurology.