Medicine and Health Sciences Commons^™

Investigating The Cortical, Metabolic And Behavioral Effects Of Transcranial Direct Current Stimulation In Preparation For Combined Rehabilitation, Kayla N. Ryan

Electronic Thesis and Dissertation Repository

The goal of this thesis was to determine the cortical reorganization that occurs in patients with cervical spondylotic myelopathy (CSM) after surgical decompression and to implement this knowledge into a new rehabilitation strategy. Transcranial direct current stimulation (tDCS) is a non-invasive technique to modulate human behavior. Due to the novel electrode montage used, it was first pertinent that we determine how tDCS would modulate cortical, metabolic and motor behavior in healthy individuals.

We observed the longitudinal functional adaptations that occur in patients with CSM using functional MRI. Enhanced excitation of supplementary motor area (SMA) was observed following surgical decompression and …

Optimization Of Design Procedures For Delta Relaxation Enhanced Magnetic Resonance, Daniel J. Martire

Electronic Thesis and Dissertation Repository

Delta relaxation enhanced magnetic resonance (dreMR) is a magnetic resonance imaging (MRI) method that produces contrast based on longitudinal relaxation dispersion. Through modulation of the magnetic field using an actively-shielded, field-cycling insert coil, this technique increases probe specificity and suppresses remaining signal. However, significant improvements are needed. This thesis addresses two advancements in dreMR with a focus on optimizing design procedures. A general procedure was developed to design split power solenoid magnets. The procedure was then applied to the design of a switched-field exposure system. A coil was constructed and the method was validated. This procedure can be used for …

Imaging Fetal Brain Connectivity In High Risk Pregnancy, Brainscan, Western University, Sandrine De Ribaupierre, Barbara De Vrijer, Charles Mckenzie, Roy Eagleson, Simon Levin, Jacqueline Olgivie

Project Summaries

Our hypothesis is that differences in the regional connectivity within the fetal brain (the structural and functional connections between regions of the brain) can be observed with fetal fMRI as early as in the second trimester of pregnancy.

If we can detect differences in an at-risk fetal brain and associate that with plancental and maternal data, we could recommend interventions, such as diet or medication changes, and then monitor the impact of treatment on the fetal brain.

Magneto-Vestibular Stimulation (Mvs): Effects On Behaviour And Resting State Networks, Brainscan , Western University, Brian Corneil, Stefan Everling, Joe Gati, Pieter Medendorp

Project Summaries

The MRI environment can stimulate the balance sensors within the inner ear. This is known as magnetovestibular stimulation (MVS), which occurs within the inner ear. It arises because of biophysical interactions between the fluids within our inner ear, the balance sensors and the magnetic field within an MRI machine.

This vestibular system usually deteriorates with aging and is commonly dysfunctional in disorders like Parkinson's and Alzheimer's and following concussions and strokes.

Diffusion Mri Modelling Of The Cortex Informed By Macro- And Myelo-Architecture, Brainscan , Western University, Ali Khan, Corey Baron

Project Summaries

The overall goal of this transformative program is to develop novel imaging and analysis techniques for evaluating cortical architecture, providing a means to characterize and quantify structural features that have been invisible to MRI until now.

Relating Functional And Structural Signatures Of Parkinson’S Disease To Changes In Dopamine Signalling: A Pet/Fmri Study, Brainscan . Western University, Penny Macdonald, Udunna Anazodo, Justin Hicks, Frank Prato, Alain Dagher

Project Summaries

Cognitive impairments in early Parkinson's disease are known to be linked to complex changes in the dopamine system within the brain. For example, dopamine-producing neurons in one key region of the brain are significantly degenerated, but those in another are spared. Dopamine-replacement therapy (DRT) has been pursued and it has produced significant improvements in certain cognitive functions - unfortunately it also produced significant impairments in others.

Pet And Mri Measurements Of Neuroinflammation And Brain Plasticity After A Stroke, Brainscan , Western University, Jonathan Thiessen, Shawn Whitehead, Justin Hicks, Matthew Fox

Project Summaries

We are going to assess brain structure and function using magnetic resonance imaging (MRI) and positron emission tomography (PET) to study white matter inflammation and the density of synapses over time, alongside a behavioural assessment of motor and executive function. This kind of comprehensive assessment, especially using PET to measure synaptic density, has not been done before.

Integrating Behavioural, Imaging And Transcriptional Profiling To Discover The Impact Of Midlife Stress In Alzheimer's Disease, Brainscan , Western University, Tim Bussey, Flavio Beraldo, Chakravarty Maller, Rosemary Bagot, Sylvain Williams, Claudia Kleinman

Project Summaries

We will be integrating this cognitive assessment with imaging of brain structure and function to understand the mechanisms by which a risk factor, in this case modifiable life stress, influences Alzheimer's disease-related decline. The resultant data will be integrated and disseminated using a new open-access neuroinformatics platform developed at Western (MouseBytes.ca), which will become a unique resource for open science investigations and set the standard for sharing of behavioural data across the world.

Ommaba: The Open Multimodal Music And Auditory Brain Archive, Brainscan , Western University, Jessica Grahn, Jorn Diedrichsen, Joe Gati, Molly Henry, Robert Zatorre, Jean-Baptiste Poline, Bratislav Misic, Estrid Jakobsen, Mor Regev, Marcel Farrés Franch, Virginia Penhune, Emily Coffey

Project Summaries

We will create a specific neuroimaging database focused on the auditory domain. It will allow researchers to ask questions about the neural circuitry underlying auditory behaviour in the healthy brain and to understand the sources of individual variability. We will include detailed information about experiential factors, such as musicianship and bilingualism that are not documented in any existing databases, so that it will be possible to investigate plasticity-related effects. It will also provide baseline data for clinical studies.

Persistent Post-Concussion Brain Changes In Adolescent Hockey Players, Brainscan, Western University, Kathryn Y. Manning, Amy Schranz, Robert Bartha, Gregory A. Dekaban, Christy Barreira, Arthur Brown, Lisa Fischer, Kevin Asem, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Ravi S. Menon

Research Summaries

Changes continue to occur in a concussed brain even after standard clinical tests have returned to normal. Damage in the very long fibre tracks in the brain of concussed players can be detected up to three months after the concussion and after the individuals have been approved for return to athletics. It is also possible to detect ‘hyper-connectivity’ in the brain, suggesting the brain is still trying to compensate for the concussion.