Background: There exist functional deficits in motor, sensory, and olfactory abilities in dementias. Measures of these deficits have been discussed as potential clinical markers. Objective: We measured the deficit of motor, sensory, and olfactory functions on both the left and right body side, to study potential body lateralizations. Methods: This IRB-approved study (N = 84) performed left/right clinical tests of gross motor (dynamometer test), sensory (Von Frey test), and olfactory (peppermint oil test) ability. The Mini-Mental Status Exam was administered to determine level of dementia; medical and laboratory data were collected. Results: Sensory and olfactory deficits lateralized to the left side of the body, while motor deficits lateralized to the right side. We found clinical correlates of motor lateralization: female, depression, MMSE <15, and diabetes. While clinical correlates of sensory lateralization: use of psychotherapeutic agent, age ≥85, MMSE <15, and male. Lastly, clinical correlates of olfactory lateralization: age <85, number of medications >10, and male. Conclusion: These lateralized deficits in body function can act as early clinical markers for improved diagnosis and treatment. Future research should identify correlates and corresponding therapies to strengthen at-risk areas.

Background There exist functional deficits in motor, sensory, and cognitive abilities in dementias (Kluger et al, The Journals of Gerontology: Series B, 1997; Albers et al, Alzheimer’s and Dementia, 2015). In 2010, the National Institute on Aging combined the study of these functions, focusing on clinical manifestations of neurodegeneration of olfactory, sensory, and motor domains as potential clinical markers. Building on these results, we seek to study possible lateralizations in deficit severity to further clinical markers and improve outcomes through functional therapies. Method This IRB approved study performed left/right functional assays of olfactory, sensory, and motor ability. A Peppermint Oil test measured discrete left/right olfactory function; the Von Frey test measured discrete left/right sensory tactile function; a dynamometer was used to measure discrete left/right motor grip strength. The Mini Mental Status Exam was administered; social, medical, and laboratory data were collected (N=84). Result While the non‐dementia, right‐handed, population has significantly greater right motor grip strength, the dementia population showed no significant correlation (p=0.127, n=57). Deficit in sensory tactile function worsened on left side (p=0.0387, n=63). Deficit in cranial nerve 1 (CN1) function worsened on left side (p=0.0515, n=37). Enhancers of motor deficit to right side: female (p=0.434, n=32), depression (p=0.455, n=29), MMSE<15 (p=0.382, n=24), and diabetes (p=0.451, n=13). Enhancers of sensory deficit to left side: use of psychotherapeutic agent (p=0.0514, n=47), age≥85 (p=0.070, n=30), MMSE<15 (p=0.0732, n=30), and male (p=0.0826, n=25). Enhancers of CN1 deficit to left side: age<85 (p=0.00262, n=24), medication number>10 (p=0.0725, n=24), and male (p=0.0742, n=15). Conclusion The results suggest that in dementia, olfactory and sensory functional deficits lateralize to the left, and motor deficits to the right. Future research should identify enhancers and suppressors of these lateralizations to develop therapies to strengthen at‐risk areas. Furthermore, these lateralized LOF can act as early clinical markers.