Anticholinergic Drug and White Matter Hyperintensity Effects on Balance and Gait in Older Adults

Falls are a major cause of injury in older adults, leading to decreased quality of life and high economic cost. While the cause of falls is multi-dimensional, they have been linked to several characteristics seen in older adults. Specifically, this research focused on relating the use of medications and cerebrovascular changes with normal aging to changes in balance and gait, thus possibly increasing fall risk. The medications of interest were those with anticholinergic properties whose drug mechanism was to block the neurotransmitter acetylcholine. Medication use was measured using blood serum anticholinergic activity levels (SAA) of active receptor inhibitors. The cerebrovascular changes included those associated with white matter hyperintensities (WMH) in five regions of interest in the deep cerebral white matter detected by magnetic resonance imaging. The exact mechanism of action to negatively impact balance and gait is not well-known. \ud \ud Balance was assessed using measures of sway or center of pressure (COP) while gait was assessed using spatiotemporal variability parameters. Forty-eight participants, aged 65 to 80, were recruited. Balance and gait protocols were performed under single and dual-task digit recall conditions. Overall, performing tasks while standing or walking caused increased sway and temporal variability, respectively. When standing with eyes closed and not performing a task, participants’ sway increased with increasing WMH. However, no relationship was found with SAA. During gait, a positive relationship was found between WMH and cadence, stance time, and step time variability, but only within two WMH regions. No relationships with SAA were identified. The lack of more correlations between the variables of interest could be attributed to the lack of variability in WMH and SAA along with the overall excellent health of the participants. These results indicate the potential for negative effects on balance and gait with healthy neural aging and anticholinergic drug use. Further investigations must be conducted to better understand the mechanism of action causing the negative impact on balance and gait. Once understood, better care can be taken to monitor medication use and provide therapeutic training to people at a higher risk for falls as related to medication burden and increased WMH with age. \u