Screening for cognitive sequelae of SARS-CoV-2 infection: a comparison between the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA).

Background: Due to SARS-CoV-2-related encephalopathic features, COVID-19 patients may show cognitive sequelae that negatively affect functional outcomes. However, although cognitive screening has been recommended in recovered individuals, little is known about which instruments are suitable to this scope by also accounting for clinical status. This study thus aimed at comparatively assessing the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) in detecting cognitive deficits in post-COVID-19 patients premorbidly/contextually being or not at risk for cognitive deficits (RCD + ; RCD-).

Methods: Data from N = 100 COVID-19-recovered individuals having been administered both the MMSE and the MoCA were retrospectively analyzed separately for each group. RCD ± classification was performed by taking into consideration both previous and disease-related conditions. Equivalent scores (ESs) were adopted to examine classification performances of the two screeners.

Results: The two groups were comparable as for most background and cognitive measures. MMSE or MoCA adjusted scores were mostly unrelated to disease-related features. The two screeners yielded similar estimates of below-cut-off performances-RCD + : MMSE: 20%, MoCA: 23.6%; RCD-: MMSE: 2.2%, MoCA: 4.4%. However, agreement rates dropped when also addressing borderline, "low-end" normal, and normal ability categories-with the MoCA attributing lower levels than the MMSE (RCD + : Cohen's k = .47; RCD-: Cohen's k = .17).

Discussion: Although both the MMSE and the MoCA proved to be equally able to detect severe cognitive sequelae of SARS-CoV-2 infection in both RCD + and RCD- patients, the MoCA appeared to be able to reveal sub-clinical defects and more sharply discriminate between different levels of ability.