Concussion/mild traumatic brain injury (mTBI) is a significant public health concern, particularly for young individuals and athletes. While the vast majority recover quickly and without lasting consequences, some will suffer from potentially long-term neuropsychiatric sequelae. These sequelae have been investigated in mTBI samples consisting largely of motor vehicle-related injuries, but very few have examined these following sport-related concussion (SRC). Further, new evidence indicates that participation in contact sports alone can result in similar problems with cognition and mood/anxiety. This thesis investigates neuropsychiatric sequelae in youth and young adults with concussion and who participate in contact sports.
The hippocampus is known to be vulnerable to head injury, and animal models indicate that mTBI impairs hippocampal neurogenesis — the process of the growth, maturation, and integration of adult-born neurons. Hippocampal neurogenesis is well-recognized for its importance to cognition, and has more recently been linked to mood and anxiety. Accumulating evidence indicates that a test involving a component of high memory interference, the mnemonic similarity test (MST), is sensitive to neurogenesis-dependent conditions in humans. To the best of our knowledge, this thesis is the first to investigate whether the MST is sensitive to concussion, contact sport participation, and athletic anxiety.
This thesis describes: (1) a critical review of the literature regarding the psychiatric sequelae of concussion, followed by (2) clinical profiles derived from retrospective data which document the new onset of immediate psychiatric problems in youth, and delayed psychiatric problems in youth with persistent concussion symptomology; that (3) anxiety is the most common and persistent psychiatric symptom in youth with concussion; that (4) concussion and contact sport participation negatively affect performance on the MST; that (5) a reprieve from contact sport participation is associated with an improvement in MST performance; that (6) these negative effects on the MST are not seen with other injuries; that (7) athletic anxiety impairs performance on the MST. Taken together, this thesis provides evidence that psychiatric problems can present immediately after concussion in persons without identifiable risk factors, and that concussion, contact sport participation, and athletic anxiety affect performance on a putatively neurogenesis-linked test. These results may implicate impaired hippocampal neurogenesis in postconcussion sequelae. / Thesis / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22079 |
| Date | 11 1900 |
| Creators | McCradden, Melissa D |
| Contributors | Mazurek, Michael, Neuroscience |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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