To identify the prevalence of Mild Cognitive Impairment (MCI) and Dementia in Mexican patients with Parkinson’s Diseases with the Montreal Cognitive Assessment Spanish version 8.1 (MoCA-S) (PD).

Cognitive impairment in PD is one of the most common nonmotor symptoms, reported as high as 83%. MCI is a common feature of early PD and dementia of a late-stage PD. (1) The MoCA is a commonly used tool to assess the cognitive impairment in PD. In Mexican control patients, Aguilar-Navarro et al. (Mexico) proposed cut-offs of MCI ≤26, Dementia ≤24. (2) Recently Almeida et al. (Brazil) proposed a different cut-off for patients with PD (MCI ≤22.5, Dementia ≤17.5) (3)

Cross-sectional, observational study. We selected patients from the REMEPARK (Mexican’s Parkinson’s Diseases Registry) from 2018 to 2019. We analyzed the MoCA Spanish v. 8.1. We used two different cut-offs to assess the prevalence of MCI and Dementia. We compared groups using X² or t-student test, for categorical or numerical variables. A value of p<0.05 was used for statistical significance.

306 patients were included, 136(44.4%) were women, the mean of age was 63.04±13.1. (Table 1) The worst performance of the patients was in the Visuospatial/Executive, and Delayed Recall domains. (Table 2) (Fig 1) We found significance difference in the prevalence of MCI (13.4% vs 28.8%, p<0.001) and Dementia (71.6% vs 28.1%, p<0.001), using the tow different cut-offs (Table 3).

As shown, the prevalence of cognitive impairment by MoCA-S (MCI or Dementia), can change in function of the cut-offs used to assess the cognitive impairment. This short study suggest that MCI and Dementia can be over-diagnosed in patients with PD if physicians used the normal cut-offs used in non-PD patients. We must perform our own study, in Mexican PD patients, to assess new cut-offs for the diagnosis of MCI and Dementia.