Motoric Cognitive Risk Syndrome: Symptoms, Pathology, Diagnosis, and Recovery.

Ke Xiang,Li Sun,Yin Liu

doi:10.3389/fnagi.2021.728799

Ke Xiang, Li Sun + Show 1 more

Open Access

https://doi.org/10.3389/fnagi.2021.728799

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Abstract

The motoric cognitive risk (MCR) syndrome is a pre-dementia condition, marked by the enhanced risk for Alzheimer's disease (AD) and vascular dementia, together with falls, disability, and abnormal movements. The research studies revealed the distinct neurological and non-neurological clinical gait irregularities during dementia and accelerated functional decline, such as postural and balance impairments, memory loss, cognitive failure, and metabolic dysfunctions. The disabling characteristics of MCR comprise altered afferent sensory and efferent motor responses, together with disrupted visual, vestibular, and proprioceptive components. The pathological basis of MCR relates with the frontal lacunar infarcts, white matter hyperintensity (WMH), gray matter atrophy in the pre-motor and pre-frontal cortex, abnormal cholinergic functioning, inflammatory responses, and genetic factors. Further, cerebrovascular lesions and cardiovascular disorders exacerbate the disease pathology. The diagnosis of MCR is carried out through neuropsychological tests, biomarker assays, imaging studies, questionnaire-based evaluation, and motor function tests, including walking speed, dual-task gait tests, and ambulation ability. Recovery from MCR may include cognitive, physical, and social activities, exercise, diet, nutritional supplements, symptomatic drug treatment, and lifestyle habits that restrict the disease progression. Psychotherapeutic counseling, anti-depressants, and vitamins may support motor and cognitive improvement, primarily through the restorative pathways. However, an in-depth understanding of the association of immobility, dementia, and cognitive stress with MCR requires additional clinical and pre-clinical studies. They may have a significant contribution in reducing MCR syndrome and the risk for dementia. Overall, the current review informs the vital connection between gait performance and cognition in MCR and highlights the usefulness of future research in the discernment and treatment of dementiating illness.

Highlights

The world geriatric population shows an unprecedented and rapid increase, with a >8.5% aged about 65 years and above
MRI revealed changes in signal intensity in the thalamocortical fibers and corticospinal pyramidal tracts. These findings indicated interference in the long loop reflexes, essential for steady stride and footing, and a reduction in step length variability, which correlated with a cerebral infraction, arterial vaso-reactivity, and white matter hyperintensity (WMH) (Rosano et al, 2007)
The assessment of motor performance has a significant advantage in the terms of predicting the causes of motoric cognitive risk (MCR), such as vascular lesions and disorders, cerebral small vessel diseases, leukoaraiosis and morphological, and the functional abnormalities of the brain that relate with the reduced gait and cognitive decline (Verghese et al, 2014b) (Table 1)

Summary

Introduction

The world geriatric population shows an unprecedented and rapid increase, with a >8.5% aged about 65 years and above. The Cardiovascular Health Study cohort predicted increased mortality in the cases with combined cognitive and gait impairments, showing structural, functional, or pathological alterations in common areas of the brain, along with the upregulated inflammatory markers, interleukin-6 (IL-6), even in the patients with or without signs of dementia (Rosano et al, 2008; Nagga et al, 2014).

Results

Conclusion