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Montreal Cognitive Assessment (MoCA), specifically total score and delayed recall, proves effective in identifying mild cognitive impairment (MCI) and dementia with Lewy bodies (DLB) risk in isolated REM sleep behavior disorder (iRBD) patients, while the Clock Drawing Test (CDT) lacks similar capabilities.

The following is a summary of “Montreal Cognitive Assessment and Clock Drawing Test to Identify MCI and Predict Dementia in Isolated REM Sleep Behavior Disorder,” published in the January 2024 issue of Neurology by Cogné et al.

Researchers conducted a retrospective study to evaluate the psychometric properties of two screening tests in differentiating isolated/idiopathic REM sleep behavior disorder (iRBD) patients with mild cognitive impairment (MCI) from those at risk for dementia with Lewy bodies (DLB).

They examined 64 patients with polysomnography-confirmed iRBD at a sleep clinic (2006 to 2021), 32 had MCI (average age 68.44 years, 72% men), 32 did not have MCI (67.78 years, 66% men), and 32 were controls (69.84 years, 47% men). Participants underwent neurologic evaluation and neuropsychological assessment for MCI diagnosis. Montreal Cognitive Assessment (MoCA) and Clock Drawing Test (CDT) were completed. Fifty-three patients followed for 5.10 ± 2.64 years saw 6 develop DLB and 16 develop Parkinson’s. An additional cohort of 10 iRBD patients later developed DLB and was monitored. Receiver operating characteristic curves with AUC were employed to evaluate MoCA and CDT discriminant values.

The results showed MoCA total score (≤25/30) effectively differentiated DLB patients from controls, achieving 100% sensitivity (95% CI 61%–100%) and 78% specificity (61%–89%) with an AUC of 0.888. In the same context, MoCA delayed recall (≤3/5) displayed 83% sensitivity (44%–97%) and 78% specificity (61%–89%) with an AUC of 0.875. Both cutoff values maintained a 90% sensitivity (60%–98%) in identifying DLB risk in an independent cohort. For distinguishing MCI patients from controls, MoCA total score (≤25/30) showed 72% sensitivity (55%–84%), 78% specificity (61%–89%), and an AUC of 0.803.MoCA delayed recall (≤2/5) showed 63% sensitivity (45%–77%), 94% specificity (80%–98%), and an AUC of 0.843. No acceptable optimal values were found for CDT.

They concluded that for iRBD patients, MoCA proved effective in identifying both MCI and DLB risk, while the CDT lacked such capabilities.

Source: neurology.org/doi/10.1212/WNL.0000000000208020