Verbal Tests May Frequently Miss the Mark for Alzheimer's Disease

New research in a study published in “Neurology“, a journal of the American Academy of Neurology, has stated that women’s mild cognitive impairment might often be missed, because of their higher scores when verbal memory skill testing is done. Women normally perform better on verbal memory skills throughout their lives, which gives them some protection against losing those skills in the early stages of Alzheimer’s and cognitive impairment.

Mild cognitive impairment means that a person has minor problems with mental abilities, such as thinking or memory. It causes a slight, but notable and measurable decrease in cognitive capability. It is the intermediate stage that exists between normal aging decline, which is expected, and the much more serious dementia. Over 16 million people in the United States are affected by mild cognitive impairment, which can increase the risk of Alzheimer's or other dementia. Those higher scores by women may lead to their not being diagnosed with having Alzheimer's until it is in the advanced stages. According to the “Alzheimer's Disease Facts and Figures” report of the Alzheimer's Association, of the 5.1 million individuals in the United States aged 65 or older with the disease, 1.9 million are men and 3.2 million are women.

The study’s author was Erin E. Sundermann, Ph.D., University of California-San Diego. She conducted this research when she was at the Albert Einstein College of Medicine. The data used was from 254 people already having Alzheimer's, 672 people having mild cognitive impairment who were exhibiting memory problems, and 390 people with no thinking or memory problems. In addition to verbal memory skill testing, the participants were given PET brain scans that visualized how well the brain metabolized glucose, which is the brain's primary source of energy. A sign of dysfunction in brain cells is reduced glucose metabolism. Participants were read 15 words and asked to repeat them back (immediate recall) and then repeat them again after 30 minutes passed (delayed recall). The maximum score on the immediate recall test is 75,  and memory is considered to be impaired if the score is less than 37. The maximum score on the delayed recall test is 15, and memory is considered to be impaired if the score is less than eight.

The results were that women with no mild or moderate brain metabolism problems scored better on the memory test than men, because of their 'cognitive reserve' being able to compensate for changes in the brain until a more advanced stage of the disease is reached. With more advanced metabolism problems, both sexes scored similarly. Accurate prediction through the use of scans, memory tests, and measurements of protein levels isn’t yet fully possible to assess whether mild cognitive impairment will develop into Alzheimer's disease. However, the diagnosing of mild cognitive impairment can help people who are at increased risk of Alzheimer's by offering them advice, support, and information.