Do the Cambridge Neuropsychological Test Automated Battery episodic memory measures discriminate amnestic mild cognitive impairment?

Objective: Although visual recognition memory and visuospatial paired associates learning has been shown to be impaired in amnestic mild cognitive impairment (aMCI), the sensitivity and specificity of the visual memory tests used to identify aMCI are not well defined. The current study attempted to analyze the sensitivity and specificity of three visual episodic memory tests (Pattern Recognition Memory [PRM], Delayed Matching to Sample [DMS], and Paired Associated Learning [PAL]) from the CANTAB, in differentiating aMCI patients from control healthy participants.

Methods: Seventy seven aMCI patients and 85 cognitive normal controls aged over 50 years performed the PRM, DMS, and PAL tests. Univariate and multivariate logistic regression and receiver operating characteristic curve analyses were used to study the relationships between aMCI and visual memory measures.

Results: The three Cambridge Neuropsychological Test Automated Battery measures significantly predicted aMCI. The optimal predictive model combined the total percent correct responses for PRM and DMS with the PAL total errors (six shapes adjusted), with a sensitivity of 72%, specificity of 83%, and achieved predictive accuracy of 80%.

Conclusion: Visual episodic memory tasks such as those involved in the PRM, DMS, and PAL tests (included in the Cambridge Neuropsychological Test Automated Battery) may sensitively discriminate aMCI patients from normal controls. These tests may be useful for correct diagnosis of aMCI.