To determine the accuracy of the NIH Toolbox-Cognition Battery for cognitive assessment of patients with Parkinson disease (PD).

The Montreal Cognitive Assessment (MoCA) is a popular cognitive screening tool in PD due to its relative brevity and high sensitivity. Another cognitive screening option is the NIH Toolbox-Cognition Battery, which is normed for demographic factors and provides domain-specific information. However, there are limited data about the performance of the NIH Toolbox-Cognition Battery in PD patients and its correlation with MoCA scores.

A cohort of 31 patients with PD with varying degrees of cognitive impairment were prospectively enrolled in two clinical studies. Patients were assessed using the MoCA and NIH Toolbox-Cognition Battery. MoCA scores and T-scores for NIH Toolbox-Cognition Battery tests were calculated and analyzed using ROC curve analyses. A MoCA score below 26 was used to indicate cognitive impairment.

MoCA score significantly correlated with NIH Toolbox-Cognition Battery cognition total composite T-score (r = 0.55) and most subscale T-scores: pattern comparison processing speed (r = 0.82), cognition crystallized composite (r = 0.55), cognition fluid composite (r = 0.50), picture vocabulary (r = 0.50), list word sorting working memory (r = 0.45), oral reading recognition (r = 0.40), and dimensional change card sort (r = 0.40). For cognitively impaired patients, cognition total composite T-score had an AUC of 79.1% with an optimal cutoff value of 39 (sensitivity: 57.14%, specificity: 100%). In a similar analysis, pattern comparison processing speed T-score demonstrated high discriminatory ability (cutoff value: 42, AUC: 88.7%, sensitivity: 92.31%, specificity: 80%).

The NIH Toolbox-Cognition Battery significantly correlates with MoCA and is a valid tool to assess cognition in PD patients. Pattern comparison processing speed was most highly correlated with MoCA. Performance on this speeded task may indicate global cognitive performance in PD and could be a valuable outcome measure for therapeutic trials.