Dynamic Cerebral Blood Flow Regulation in Adolescent Athletes with Sports-Related Concussion
General Material Designation
[Thesis]
First Statement of Responsibility
Haider, Mohammad Nadir
Subsequent Statement of Responsibility
Willer, Barry S.
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
State University of New York at Buffalo
Date of Publication, Distribution, etc.
2021
GENERAL NOTES
Text of Note
130 p.
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Ph.D.
Body granting the degree
State University of New York at Buffalo
Text preceding or following the note
2021
SUMMARY OR ABSTRACT
Text of Note
Sport-related concussion (SRC) are a form of mild traumatic brain injury that cause a variety of transient, non-specific symptoms and physical examination signs at rest and exertion. These are suggested to be due to abnormalities in the Autonomic Nervous System (ANS). Exercise-induced worsening of symptoms, such as headache and dizziness on physical exertion, is a clinical biomarker of physiological dysfunction after concussion; and is suspected to be due to abnormalities in cerebral blood flow (CBF) and CBF velocity (CBFv) regulation. This PhD project aims to understand this relationship at rest, and in response to a controlled physiological stimulus during a 6o head-down tilt (HdT) and during exercise on a cycle ergometer. Twenty acutely concussed adolescents and 18 age- and sex-matched healthy controls were assessed. For our first aim; this study found that CBF and CBFv did not follow a positive linear relationship and there were no significant differences in whole brain CBF at rest between acutely concussed and healthy adolescents. However, concussed adolescents were not able to maintain a near-constant CBF during the HdT and had a significantly greater relative decrease in CBF in the whole brain grey matter from their resting values than controls. For our second aim; no differences in estimated downstream vessel compliance in the Middle Cerebral Artery was found at rest between concussed and healthy adolescents, however, significant differences were found on morphological waveform analysis after 10 minutes of mild to moderate exercise; with healthy adolescents having a significantly lower estimated compliance in response to an increase in CBFv and mean arterial pressure. Results from this study suggests that there may be more blood going to the brain during physical exertion, and may be the underlying cause for exercise-induced headaches. This difference in vascular compliance was not observed after concussed adolescents had clinically recovered and were not experiencing exacerbation of symptoms on exercise, making this a possible diagnostic biomarker for concussion and its recovery.