Verbal cued recall as a predictor of conversion to Alzheimer’s disease in mild cognitive impairment

Objective
This study was set up to investigate whether neuropsychological tests are able to predict conversion to AD among Mild Cognitive Impairment (MCI) patients.
Methods
At baseline the cognitive part of the Cambridge Examination for Mental Disorders of the Elderly (CAMCOG), the Mini Mental Status Examination (MMSE), the Geriatric Depression Scale (GDS), a Dutch variation of Rey's Auditory Verbal Learning Test, the Memory Impairment Screen plus (MISplus) and the Visual Association Test (VAT) were administered to 40 patients diagnosed with MCI. After 18 months, MCI-patients were reassessed and a follow up diagnosis was established. Of those who were seen for follow up (n=31), 7 fulfilled (NINCDS-ADRDA) criteria of probable AD, while 24 did not convert.
Results
A binary logistic regression analysis showed that the MISplus contributed most to the prediction of conversion (O.R. = 0.28, CI95%:0.099-0.790). With a cut-off of 2 out of 6, a positive predictive value of 71.5%, a negative predictive value of 91.5% and an overall diagnostic accuracy of 87.0% were achieved.
Conclusions
This prospective, longitudinal study shows that a score of 0 or 1 out of 6 on the MISplus may be a good indicator of future (within 18 months) progression to AD among MCI-patients.