The MoCA Memory Index Score (MIS) as an indicator of episodic memory impairment and its implications for cognitive...

The Montreal Cognitive Assessment (MoCA) Memory Index Score (MIS) has shown promise as a brief indicator of episodic memory decline, but its correspondence with standardized neuropsychological memory measures in diagnostically heterogeneous clinical populations remains poorly understood.

Participants were 119 adults referred for outpatient neuropsychological evaluation at a Southern California academic medical center for a range of neurological conditions. Hierarchical regression analyses examined whether the MIS predicted delayed recall on the Rey Auditory Verbal Learning Test (RAVLT), WMS-IV Logical Memory II, and a composite memory score, beyond age, education, and a nonmemory MoCA score. Classification accuracy for identifying memory impairment was evaluated using receiver operating characteristic (ROC) analysis.

The MIS was a significant predictor of delayed memory performance across measures, with the strongest and most consistent contribution for list-learning (RAVLT) and comparatively weaker, less consistent incremental value for story-based recall. ROC analysis showed good classification accuracy (AUC = .874), with a preliminary cutoff of ≤8.5 yielding high sensitivity (.944) and moderate specificity (.687). MIS scores also differed significantly across diagnostic groups.

The MIS may offer clinically meaningful, format specific information about episodic memory and support for referral decisions, though it should not substitute for comprehensive neuropsychological assessment.