Master of Science
Neurogenic orthostatic hypotension (NOH) is characterized by a drop in systolic blood pressure ≥20mmHg or diastolic blood pressure ≥10mmHg within three minutes of upright posture. A large drop in blood pressure can trigger cerebral hypoperfusion, which has been linked to deficits in cognitive function. The current thesis aimed to measure cerebral hemodynamics and cognitive function in 20 NOH patients and 20 controls in the supine and head-up tilt (HUT) positions. Information processing speed (IPS) was assessed using the Symbol-Digit Modalities Test and attention was measured using the Stroop Test. NOH patients had significantly slower IPS in both the supine(p
Summary for Lay Audience
Neurogenic orthostatic hypotension (NOH) is characterized by a drop in in systolic blood pressure ≥ 20mmHg or diastolic blood pressure ≥ 10mmHg within three minutes of upright posture. A severe drop in blood pressure can cause symptoms such as lightheadedness, dizziness, weakness, and fatigue. This thesis objected to determine if patients with NOH experienced alterations in cognitive function with a positional change from lying to standing. Cognitive function was assessed using the Symbol-Digit Modalities Test to measure information processing speed and the Stroop Test to measure attention. Recent research proposed that reductions in cerebral blood supply can accelerate the natural process of cognitive decline. Therefore, this thesis also aimed to measure cerebral blood flow using transcranial doppler and near infrared spectroscopy to determine if there were any differences between NOH patients and healthy control subjects. It was found that NOH patients had significantly slower information processing speed in both the lying and standing positions compared to controls, as well NOH patients had significantly reduced attention in the standing position compared to controls. Patients with NOH experienced a significant reduction in cerebral blood flow in the standing position compared to the lying position. Repeated exposure to reduced cerebral blood flow as a result of autonomic dysfunction is likely a contributing factor to our finding of impaired information processing speed and attention in NOH patients. This thesis sheds new light on cognitive function and cerebral blood flow in NOH patients.
Robinson, Lindsay, "Relationship Among Neurogenic Orthostatic Hypotension, Cerebral Hemodynamics, and Cognitive Functioning" (2019). Electronic Thesis and Dissertation Repository. 6288.