Examining Relationships Between Musculoskeletal Function Measurements of Movement Efficiency and Nervous System Function After Chronic Stroke

Overview

Stroke remains the leading cause of severe disability, and survivors frequently have incomplete recovery. More than half of older survivors have impaired mobility which contributes to poorer quality-of-life (QoL) and suffering. The annual rate of disability compared to myocardial infarction triples, and stroke accelerates natural age-related functional decline. Somatic dysfunction (SD) is impaired function of the body framework identified by physical examination. Few studies have rigorously studied SD among stroke survivors. We recently demonstrated the reliability of a novel, more construct valid osteopathic examination methodology \[called the Functional Pathology of the Musculoskeletal System (FPMSS) model\] to quantify SD among asymptomatic participants and patients with acute cerebral ischemia. The preliminary findings suggest that dysfunction may develop within the first week after acute ischemic stroke (IS) and be more severe among those with paralysis compared to healthy volunteers. The precise pathophysiologic mechanism underlying SD remains unknown. The objective of this proposal is to establish the relationship between SD severity during chronic stroke recovery and physiologic biomarkers. The central hypothesis is that SD is quantifiable, correlates with biomarkers that reflect functional status, and is associated with QoL among chronic stroke survivors. There are currently no biomarkers that correlate with SD severity after IS. Establishing valid biomarkers associated with physiologic processes that are otherwise inferred by physical examination would allow for quantification of changes in response to treatment (e.g., osteopathic manipulative treatment; OMT) aimed at restoring economical biomechanical function. Testing this hypothesis will address several fundamental gaps in knowledge about osteopathic palpatory diagnosis, physiologic processes associated with SD, and its association with survivor outcomes. Until these knowledge gaps are filled, optimal strategies to complement stroke recovery in patients with neurological disability cannot fully be determined. The project specific aims are to quantify the association between SD among chronic (\>3 months) IS survivors and measured (1) energy expenditure, (2) heart rate variability (HRV), and (3) patient-reported outcome (PRO) health domains. The proposed research is significant because it will establish a novel osteopathic approach that determines the impact of whole musculoskeletal system (MSS) health on QoL among stroke survivors living with chronic disability and correlate physiologic properties related to SD. This approach will allow us to quantify SD and show meaningful associations with autonomic function, biomechanical economy, and QoL after chronic stroke. These new metrics would then be derived in stroke patients to determine SD and physiologic thresholds for those that would benefit most from OMT in a future trial. This proposal is innovative in that it seeks to shift current research and practice paradigms by re-appraising the impact of whole musculoskeletal functional economy on patient-centered outcomes among stroke survivors. Methodologically, use of the FPMSS model represents a novel, more construct valid, diagnostic paradigm to reliably identify SD and establish an osteopathic, cross-disciplinary approach to the field of stroke research. The model examines the MSS as integrated, highlighting proportionate, not merely symmetrical, posture and motion among survivors with chronic disability. Similarly, PROs have been used to quantify health status after stroke, but have not been used to study the relationship between chronic neurologic impairment and SD. Integrating contemporary patient-centered stroke outcomes, rigorous osteopathic assessment, and analysis of physiologic processes will advance our understanding of how musculoskeletal dysfunction impacts QoL after stroke.