Parkinson's disease (PD) is a neurodegenerative disease characterized by progressive loss of dopaminergic neurons of the substantia nigra pars compacta. Symptoms usually include akinesia, bradykinesia, muscle rigidity, postural imbalance and tremor. Despite numerous studies on the physiology and pathophysiology of tremor, its influence on voluntary motor behavior remains unclear. Accordingly, the main objectives of the present thesis were to (a) determine if a clinical relationship existed between tremor and performance of voluntary movements, and (b) characterize the impact of ventrolateral (VL) thalamotomy on tremor and voluntary motor behavior. Results indicate that age-related change of the supraspinal component of normal physiological tremor (NPT) has no influence on the performance of healthy elderly subjects making rapid alternating movements (RAM). Our results also show that subsets of patients presenting different tremor amplitudes and/or tremor power characteristics had similar RAM performance, hence negating any direct relationship between the supraspinal oscillator(s) generating tremor and RAM performance. Our results demonstrate that tremor can be detected during manual-tracking movements performed by patients with early PD, but this tremor has little consequence on the accuracy of these patients. / As for the impact of VL thalamotomy on tremor, our results show that the thalamic lesion eliminates selectively PD tremor oscillations, in addition to preventing a resurgence of the supraspinal component of physiological tremor. The surgical procedure did not however improve or worsen RAM performance, suggesting that tremor probably plays little role in bradykinesia. Accuracy during the manual-tracking task is nonetheless greatly improved post-surgery, hence confirming the anticipated clinical benefits of the surgical procedure. In conclusion, despite previous evidence that tremor and RAM may share common neural networks and that tremor may be pathophysiologically linked with bradykinesia, the aforementioned results suggest that there is little clinical relationship between tremor and bradykinesia observed in patients with PD making RAM.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82862 |
| Date | January 2002 |
| Creators | Duval, Christian, 1963- |
| Contributors | Sadikot, Abbas F. (advisor), Panisset, Michel (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Division of Neuroscience.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001973948, proquestno: AAINQ88457, Theses scanned by UMI/ProQuest. |
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