Functional Near-Infrared Spectroscopy (fNIRS) imaging of Functional Connectivity and Task-Activity in the Cerebral Cortex of patients with mTBI

Duszynski, Christopher

Functional Near-Infrared Spectroscopy (fNIRS) imaging of Functional Connectivity and Task-Activity in the Cerebral Cortex of patients with mTBI

dc.contributor.advisor	Dunn, Jeff F.
dc.contributor.author	Duszynski, Christopher
dc.contributor.committeemember	Bray, Signe L.
dc.contributor.committeemember	Debert, Chantel Teresa
dc.date	2020-11
dc.date.accessioned	2020-09-15T18:40:13Z
dc.date.available	2020-09-15T18:40:13Z
dc.date.issued	2020-09-04
dc.description.abstract	Functional near-infrared spectroscopy (fNIRS) is a novel neuroimaging technology which has shown potential as a biomarker of mTBI. In this thesis, we developed novel easy-to-use software for analyzing measures of functional coherence and task-activity in the brain using fNIRS. We then applied this software to characterize fNIRS measures in healthy individuals, and to investigate whether fNIRS is sensitive to altered brain activity following mTBI. The software provides a full pipeline for preprocessing and utilizes wavelet analysis methods to estimate coherence, variability, phase, and power of fNIRS hemodynamic data. Using the software, we investigated the within-subject and between-subject variability of fNIRS coherence in healthy adults, finding poor-moderate between-subject reproducibility and high within-subject reliability, as well as task-effects of reduced interhemispheric coherence (IHC) and reduced power of low-frequency oscillations (LFOs) that were focused in the prefrontal brain regions during execution of a working memory task. In youth 30 days following mTBI, reduced IHC and IHC variability in the prefrontal cortex was observed during working memory, as well as a group effect of mTBI on power of LFO, compared to controls. In adults, fNIRS was used to study brain activity in pre, post, and two weeks following therapeutic repetitive transcranial magnetic stimulation (rTMS) as a treatment for persistent mTBI-related headache. In this case series, abnormal activation in the prefrontal cortex during working memory was observed on fNIRS in one subject prior to treatment which persisted at the post-treatment time point, but appeared to normalize by two weeks post-treatment, in comparison to controls, suggesting fNIRS as a potential method to study treatment effect in therapeutic rTMS trials in patients with mTBI. In this thesis, software was developed and published in the online repository GitHub, and utilized to characterize the variability and task effect in healthy individuals, informing future studies wanting to apply wavelet methodologies to investigate clinical populations. In subsequent observational studies, we observed alterations in fNIRS brain activity in pediatric patients with mTBI 1 month post-injury, as well as in an adult mTBI patient undergoing rTMS treatment, suggesting a potential role for fNIRS as an accessible technology to study mTBI-associated pathophysiology.	en_US
dc.identifier.citation	Duszynski, C. (2020). Functional Near-Infrared Spectroscopy (fNIRS) imaging of Functional Connectivity and Task-Activity in the Cerebral Cortex of patients with mTBI (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/38198
dc.identifier.uri	http://hdl.handle.net/1880/112533
dc.language.iso	eng	en_US
dc.publisher.faculty	Cumming School of Medicine	en_US
dc.publisher.institution	University of Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.	en_US
dc.subject	mTBI	en_US
dc.subject	Concussion	en_US
dc.subject	fNIRS	en_US
dc.subject	Functional Connectivity	en_US
dc.subject.classification	Neuroscience	en_US
dc.subject.classification	Biophysics--Medical	en_US
dc.subject.classification	Engineering--Biomedical	en_US
dc.title	Functional Near-Infrared Spectroscopy (fNIRS) imaging of Functional Connectivity and Task-Activity in the Cerebral Cortex of patients with mTBI	en_US
dc.type	doctoral thesis	en_US
thesis.degree.discipline	Medicine – Neuroscience	en_US
thesis.degree.grantor	University of Calgary	en_US
thesis.degree.name	Doctor of Philosophy (PhD)	en_US
ucalgary.item.requestcopy	true	en_US