A Comparison of the Czech Version of the Montreal Cognitive Assessment Test with the Mini Mental State Examination in Identifying Cognitive Deficits in Parkinson's Disease

Objective: Comparison of two brief screening tests for the detection of cognitive deficits in Parkinson's disease. Introduction: The Montreal Cognitive Assessment (MoCA) was developed as a screening tool for the identification of cognitive deficits in Alzheimer's disease and its use has been proposed in Parkinson's disease (PD). Cognitive deficit is common in PD and its early detection improves the prospects for medical intervention. The Czech version of MoCA is freely available, but its validity has not yet been demonstrated. We therefore compared the sensitivity of MoCA with that of the mini mental state examination (MMSE), currently the representative screening test for the detection of cognitive deficit. Unlike MMSE, MoCA contains subtests of executive functions and sustained attention as well employing more extensive tasks in naming and word recall. Methods: MMS and MoCA were administered in alternating order to 81 randomly selected PD patients and to 34 age-matched normal controls (NC). Results: Total raw scores of MoCA and MMS differed significantly between NC and PD. The total score for MoCA significantly differed from MMSE (p<0.0005) in PD as well as in NC (p<0.0005). Using the same cut-off score of less than 26, in the PD patient subgroup MoCA detected cognitive deficit in 74.1% of patients as against 38.3% judging by MMSE. In comparison to NC, about twice as many PD patients failed in executive functions subtests, which are not covered by MMSE. PD patients also failed more frequently than NC in the "naming subscale" (20 vs 3%) and "attention subscale" (41 vs 6%) of MoCA. Test-retest reliability of MoCA was 0.82, internal consistency (split-half) was 0.69, Cronbach's alpha = 0.72. Convergent validity between MoCA and MMSE was 0.73. The administration time of MoCA was approximately two times longer than that for MMSE (ca. 10 vs 5 min, p < 0.005). Conclusion: Our results indicate that MoCA may be a more efficient indicator of cognitive deficit than MMSE in PD, especially in executive functions, naming and attention. The Czech version of MoCA has shown good psychometric properties, comparable to those reported in previous studies. It can henceforth be viewed as an appropriate screening test of cognitive deficit in PD.