Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Doctor of Philosophy

Program

Health and Rehabilitation Sciences

Supervisor

Overend, Tom

Abstract

Orthostatic hypotension (OH) is a common manifestation of autonomic dysfunction in Parkinson’s Disease. It can adversely affect a patient’s functional capacity, exercise tolerance and quality of life, while increasing the risk of falls, cerebrovascular disease and overall mortality. Use of an abdominal binder (AB) can help counter OH; however, this has not been sufficiently studied in patients with Parkinson’s Disease (PwPD). Moreover, the hemodynamic effects of upper and lower extremity exercise are unclear in PwPD with OH. Although OH can impair the cerebral circulation, the consequences on the cerebral hemodynamics of wearing an AB or performing exercise are unknown in PwPD with OH.

This thesis aimed to generate practical evidence that is useable by the clinicians as well as the patients during the rehabilitation process of PwPD with OH. The three research studies that constitute this thesis investigated the effects of the interventions on systemic hemodynamics, cerebral hemodynamics and symptoms of orthostasis in PwPD with and without OH. The first study investigated the effects of wearing an abdominal binder (AB) and its subsequent removal in the standing position. The results showed that AB was effective in countering OH and its removal negatively affected the hemodynamics. The second study investigated the effects of performing upright self-regulated aerobic cycling exercise (SRACE). The responses to SRACE were found to be largely similar in all PwPD, regardless of OH. However, PwPD with relatively severe OH developed exercise-induced hypotension (EIH) without symptomatic deterioration. The third study investigated if performing resisted upper limb exercise (RULE) can be used to counter OH in PwPD. The results showed that RULE can be a useful adjunct for a brief quick resolution of OH.

The findings of this thesis suggest that AB and RULE can be used successfully for countering OH, that AB should not be removed while standing, and that BP should be monitored in PwPD with severe OH in order to detect EIH during exercise. These conclusions are expected to expand the knowledge base and provide greater options for the management of OH during the rehabilitation of PwPD, thereby helping in the control of OH and the prevention of potential complications of OH while providing a more tailored rehabilitation.

Summary for Lay Audience

Orthostatic hypotension (OH), which is an abnormal decrease in blood pressure (BP) upon assumption of upright posture (such as standing), can occur in patients with Parkinson’s Disease (PwPD) due to abnormality in the regulation of blood pressure. OH can decrease the blood supply to the brain, often producing dizziness and/or fainting. These factors can have serious negative consequences on the patient’s ability to lead an active lifestyle, while elevating the risk of brain disorders and early death.

Compression of the belly by wearing an abdominal binder (AB) may help counter OH, but this has not been sufficiently studied in PwPD. Moreover, the effects of performing different types of exercise on the blood pressure are largely unexplored in these patients. Furthermore, it is unclear how wearing an AB or performing exercise influence the blood flow to the brain when PwPD have OH. We undertook three research studies to fill these gaps in knowledge. The studies investigated (1) the effects of wearing and later removing an AB in the upright position, (2) performing self-regulated aerobic cycling exercise (SRACE) in which the intensity of exercise was controlled by the participant, and (3) performing resisted (using weight) upper limb exercise (RULE) in the upright position by PwPD with and without OH. It was found that both wearing an AB as well as performing RULE helped counter OH; the removal of the AB led to adverse effects on the circulation of blood in PwPD with OH; and most PwPD with and without OH responded similarly to SRACE. However, a few PwPD with relatively severe OH had an abnormal decrease in BP, called exercise-induced hypotension (EIH), during SRACE.

We have shown that wearing an AB or performing RULE are useful for countering OH in PwPD; the AB should not be removed in the standing position; and BP should be monitored while PwPD with severe OH perform aerobic exercise in order to detect the development of EIH. The findings of this thesis should be able to help make the rehabilitation programs for PwPD with OH safer and better.

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