Motoric cognitive risk
Motoric cognitive risk syndrome (MCR) is a pre-dementia syndrome characterised by slow gait and subjective cognitive complaints in individuals without dementia or mobility disability.[1] The concept was introduced in 2013 as a clinical construct integrating motor and cognitive markers of dementia risk.[1]
MCR can be assessed without formal neuropsychological testing or neuroimaging and has been proposed as a simple clinical tool for identifying individuals at elevated risk of dementia in community and clinical settings.[2]
Diagnostic criteria
Motoric cognitive risk syndrome is typically defined by four criteria:[1]
- subjective cognitive complaint
- objectively measured slow gait speed
- absence of dementia
- absence of mobility disability.
Slow gait speed is generally operationalised as walking speed at least one standard deviation below age- and sex-specific population norms.[3]
The syndrome combines two clinical features independently associated with dementia risk: gait slowing and subjective cognitive decline.
Epidemiology
Motoric cognitive risk syndrome is relatively common among older adults. A pooled analysis of international cohort studies including more than 26,000 participants estimated a prevalence of approximately 9–10% among community-dwelling older adults.[3]
Population-based studies have investigated the prevalence and determinants of MCR in specific cohorts. Research in community-dwelling older adults in Scotland reported prevalence estimates and identified demographic and health-related predictors of the syndrome.[4]
Socioeconomic factors have also been examined as potential determinants of the syndrome, with longitudinal analyses suggesting associations between lower socioeconomic status and increased risk of MCR.[5]
Clinical significance
Longitudinal cohort studies indicate that individuals meeting criteria for motoric cognitive risk syndrome have an increased risk of developing dementia compared with individuals without the syndrome.[1]
Further longitudinal analyses have examined trajectories of MCR and their association with incident dementia over extended follow-up periods.[6]
MCR has also been associated with other adverse outcomes in ageing populations, including incident cognitive impairment, falls, functional decline and mortality.
Pathophysiology
The biological mechanisms underlying motoric cognitive risk syndrome are not fully understood. Proposed mechanisms include degeneration of frontal–subcortical neural networks involved in executive function and motor control, vascular pathology affecting cerebral white matter, neurodegenerative processes affecting gait and cognition simultaneously, and shared cardiometabolic risk factors.
Systematic review and meta-analysis of longitudinal cohort studies have explored potential mechanisms linking gait slowing and cognitive decline, including vascular disease, neurodegeneration and disruption of frontal–subcortical networks.[7]
Relationship to mild cognitive impairment
Motoric cognitive risk syndrome overlaps conceptually with mild cognitive impairment (MCI) but differs in several respects. MCR is defined using subjective cognitive complaints and gait speed, whereas MCI requires objective cognitive impairment on neuropsychological testing.
Because gait speed can be measured easily in clinical or community settings, MCR has been proposed as a pragmatic screening approach for identifying individuals at increased risk of dementia.
Research
Since its introduction in 2013, motoric cognitive risk syndrome has been studied in numerous ageing cohorts worldwide. Research has investigated epidemiology, risk factors, biological mechanisms, and the prognostic significance of the syndrome for dementia and other adverse outcomes.
Studies have also examined relationships between MCR and other geriatric syndromes including frailty and subjective cognitive decline.
See also
References
- ^ a b c d Verghese, J (2013). "Motoric cognitive risk syndrome and the risk of dementia". Neurology. 83 (8): 718–726. doi:10.1212/WNL.0000000000000717. PMC 4150127.
- ^ Sekhon, H (2019). "Motoric cognitive risk syndrome: a systematic review". Maturitas. 124: 36–44. doi:10.1016/j.maturitas.2019.02.008.
- ^ a b Verghese, J (2014). "Motoric cognitive risk syndrome: multicountry prevalence and dementia risk". Neurology. 83 (8): 718–726. doi:10.1212/WNL.0000000000000717. PMC 4150127.
- ^ Mullin, DS; Stirland, LE; Welstead, M; Russ, TC; Luciano, M; Muniz-Terrera, G (2022). "Prevalence and predictors of Motoric Cognitive Risk syndrome in a community-dwelling older Scottish population: A longitudinal observational study". International Journal of Geriatric Psychiatry. 37 (11). doi:10.1002/gps.5824. PMC 9828770. PMID 36200618.
{{cite journal}}: CS1 maint: PMC format (link) - ^ Mullin, DS; Stirland, LE; Russ, TC; Luciano, M; Muniz-Terrera, G (2023). "Socioeconomic status as a risk factor for motoric cognitive risk syndrome in a community-dwelling population: A longitudinal observational study". European Journal of Neurology. 30 (5): 1191–1199. doi:10.1111/ene.15731. hdl:20.500.11820/d6b4ef25-7d46-490e-858e-3f5556fba157. PMID 36755198.
- ^ Mullin, DS; Gadd, D; Russ, TC; Luciano, M; Muniz-Terrera, G (2023). "Motoric cognitive risk syndrome trajectories and incident dementia over 10 years". Cerebral Circulation – Cognition and Behavior. 5 100178. doi:10.1016/j.cccb.2023.100178. PMC 10757175. PMID 38162293.
{{cite journal}}: CS1 maint: PMC format (link) - ^ Mullin, DS; Cockburn, A; Welstead, M; Luciano, M; Russ, TC; Muniz-Terrera, G (2022). "Mechanisms of motoric cognitive risk: Hypotheses based on a systematic review and meta-analysis of longitudinal cohort studies of older adults". Alzheimer's & Dementia. 18 (12): 2413–2427. doi:10.1002/alz.12547. PMC 10078717. PMID 35142038.
{{cite journal}}: CS1 maint: PMC format (link)