2 episodic memory tests predict brain atrophy

Use of two episodic memory tests help in predicting brain atrophy and Alzheimer’s disease, as indicated by a study carried out by a team of the University of Helsinki and the University of California.

The research suggest comprehensive use of memory tests could improve the diagnosis of mild cognitive impairment due to Alzheimer’s disease, said a press release issued by University of Helsinki.

Mild cognitive impairment is a heterogeneous condition; it may be reversible or permanent, but it is also associated with a higher risk of dementia, Alzheimer’s disease in particular.

Mild cognitive impairment refers to impairment of memory or other cognitive domains in a situation where the individual remains capable of independently conducting daily activities and not fulfilling the criteria of dementia.

The study conducted at the University of Helsinki and the University of California, San Diego, found that the use of two memory tests assessing episodic memory made the diagnosing of mild cognitive impairment due to Alzheimer’s disease more precise.

Memory tests helped identify those individuals with an increased risk of receiving an Alzheimer’s diagnosis within the next three years.

“The use of two memory tests markedly improved the accuracy of the prognosis for an Alzheimer’s disease diagnosis and brain atrophy in the medial temporal lobes during a three-year follow-up period,” said Eero Vuoksimaa, an Academy of Finland research fellow at the University of Helsinki.

“The results highlight the importance of neuropsychological assessment as a cost-effective method of diagnosing mild cognitive impairment due to Alzheimer’s disease,” Vuoksimaa added.

The study utilised data collected in the United States under the Alzheimer’s Disease Neuroimaging Initiative (ADNI), comprising 230 cognitively normal individuals and 394 individuals with mild cognitive impairment on the basis of poor memory performance in one episodic memory measure, namely in story recall. Those with mild cognitive impairment were further divided into two groups based on whether their memory performance was impaired only in one (story recall) or two (story recall and word list recall) tests.

The researchers investigated baseline differences between the groups in terms of Alzheimer’s disease cerebrospinal fluid biomarkers, finding that those who performed poorly in both episodic memory tests more closely resembled Alzheimer’s patients than those who only did poorly in the story recall test.

“During the follow-up stage, brain atrophy in the medial temporal lobes of those who only performed poorly in the story recall test did not differ from the cognitively healthy participants, whereas in those who had poor performance in both the story and word list recall tests, brain atrophy was faster,” Vuoksimaa explained.

Alzheimer’s disease was diagnosed in approximately half of the participants who performed poorly in both episodic memory tests within the three-year study period, whereas only 16% of those with a poor performance in only one memory test received diagnosis of Alzheimer’s Disease.