Exploring the effects of dopamine on sensorimotor inhibition and mobility in older adults

Martini, Douglas N., Morris, Rosie, Harker, Graham, Kelly, Valerie E., Nutt, John G. and Horak, Fay B. (2023) Exploring the effects of dopamine on sensorimotor inhibition and mobility in older adults. Experimental Brain Research, 241 (1). pp. 127-133. ISSN 0014-4819

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Official URL: https://doi.org/10.1007/s00221-022-06509-1


Dopaminergic activity decreases in older adults (OAs) with normal aging and is further reduced in Parkinson’s disease (PD), affecting cortical motor and sensorimotor pathways. Levodopa is the prevailing therapy to counter dopamine loss in PD, though not all PD motor signs improve with levodopa. The purpose of this preliminary study was to explore the effects of levodopa on sensorimotor inhibition, gait and quiet standing in OAs and to investigate the relationships between sensorimotor inhibition and both gait and standing balance both OFF- and ON-levodopa. Fifteen OA males completed a gait, balance and sensorimotor assessments before and 1 h after they were given a 100 mg dose of levodopa. Short-latency afferent inhibition quantified sensorimotor inhibition. Wearable sensors characterized gait (two-minute walk) and standing balance (1-min stance). No sensorimotor inhibition, gait, or standing balance measures changed from OFF- to ON-levodopa. When OFF-levodopa, worse inhibition significantly related to increased double stance (r = 0.62; p = 0.01), increased jerkiness of sway (r = 0.57; p = 0.03) and sway area (r = 0.58; p = 0.02). While ON-levodopa, worse inhibition related to increased arm swing range of motion (r = 0.63; p = 0.01) and jerkiness of sway (r = 0.53; p = 0.04). The relationship between SAI and arm swing excursion significantly changed from OFF- to ON-levodopa (z = − 3.05; p = 0.002; 95% confidence interval = − 0.95, − 0.21). Sensorimotor inhibition relationships to both gait and balance may be affected by dopamine in OAs. Cortical restructuring due to the loss of dopamine may be responsible for the heterogeneity of levodopa effect in people with PD and OAs.

Item Type: Article
Additional Information: Funding Information: This work was supported by the National Institutes of Neurological Disorders and Stroke (P50 NS062684), the US Department of Veterans Affairs (101 CX001702), and the Medical Research Foundation of Oregon (ANEUR0967).
Uncontrolled Keywords: Balance, Drug related, Gait, Short-latency afferent inhibition
Subjects: B900 Others in Subjects allied to Medicine
C900 Others in Biological Sciences
Depositing User: Rachel Branson
Date Deposited: 27 Jan 2023 10:19
Last Modified: 17 Nov 2023 03:30
URI: https://nrl.northumbria.ac.uk/id/eprint/51255

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