Medicine and Health Sciences Commons^™

Biomarkers Of Parkinson's Disease: Striatal Sub-Regional Structural Morphometry And Diffusion Mri, Ali R. Khan, Nole M. Hiebert, Andrew Vo, Brian T. Wang, Adrian M. Owen, Ken N. Seergobin, Penny A. Macdonald

Brain and Mind Institute Researchers' Publications

© 2018 The Authors Parkinson's disease (PD) is a progressive neurological disorder that has no reliable biomarkers. The aim of this study was to explore the potential of semi-automated sub-regional analysis of the striatum with magnetic resonance imaging (MRI) to distinguish PD patients from controls (i.e., as a diagnostic biomarker) and to compare PD patients at different stages of disease. With 3 Tesla MRI, diffusion- and T1-weighted scans were obtained on two occasions in 24 PD patients and 18 age-matched, healthy controls. PD patients completed one session on and the other session off dopaminergic medication. The striatum was parcellated into …

Linked Mri Signatures Of The Brain's Acute And Persistent Response To Concussion In Female Varsity Rugby Players, Kathryn Y. Manning, Alberto Llera, Gregory A. Dekaban, Robert Bartha, Christy Barreira, Arthur Brown, Lisa Fischer, Tatiana Jevremovic, Kevin Blackney, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Christian F. Beckmann, Ravi S. Menon

Brain and Mind Institute Researchers' Publications

Acute brain changes are expected after concussion, yet there is growing evidence of persistent abnormalities well beyond clinical recovery and clearance to return to play. Multiparametric MRI is a powerful approach to non-invasively study structure-function relationships in the brain, however it remains challenging to interpret the complex and heterogeneous cascade of brain changes that manifest after concussion. Emerging conjunctive, data-driven analysis approaches like linked independent component analysis can integrate structural and functional imaging data to produce linked components that describe the shared inter-subject variance across images. These linked components not only offer the potential of a more comprehensive understanding of …

Brain Activation Time-Locked To Sleep Spindles Associated With Human Cognitive Abilities, Zhuo Fang, Laura B. Ray, Adrian M. Owen, Stuart M. Fogel

Brain and Mind Institute Researchers' Publications

Simultaneous electroencephalography and functional magnetic resonance imaging (EEG-fMRI) studies have revealed brain activations time-locked to spindles. Yet, the functional significance of these spindle-related brain activations is not understood. EEG studies have shown that inter-individual differences in the electrophysiological characteristics of spindles (e.g., density, amplitude, duration) are highly correlated with "Reasoning" abilities (i.e., "fluid intelligence"; problem solving skills, the ability to employ logic, identify complex patterns), but not short-term memory (STM) or verbal abilities. Spindle-dependent reactivation of brain areas recruited during new learning suggests night-to-night variations reflect offline memory processing. However, the functional significance of stable, trait-like inter-individual differences in brain …

Alive Inside, Andrew Peterson, Adrian M. Owen, Jason Karlawish

Brain and Mind Institute Researchers' Publications

This article provides an ethical analysis of the U.S. practice guideline update on disorders of consciousness. Our analysis focuses on the guideline’s recommendations regarding the use of investigational neuroimaging methods to assess brain-injured patients. Complex and multifaceted ethical issues have emerged because these methods alter the clinical understanding of consciousness. We address issues of false hope, patient suffering, and cost. We argue that, in spite of these concerns, there is significant benefit to using neuroimaging to assess brain-injured patients in most cases.

The Neural Basis Of External Responsiveness In Prolonged Disorders Of Consciousness, Clara A. Stafford, Adrian M. Owen, Davinia Fernández-Espejo

Brain and Mind Institute Researchers' Publications

Objective: To investigate the structural integrity of fibre tracts underlying overt motor behaviour in PDOC. Methods: This cross-sectional study examined 15 PDOC patients and 22 healthy participants. Eight PDOC patients met the criteria for the vegetative state, 5 met the criteria for the minimally conscious state and 2 met the criteria for emerging from the minimally conscious state. We used fibre tractography to reconstruct the white matter fibres known to be involved in voluntary motor execution (i.e., those connecting thalamus with M1, M1 with cerebellum, and cerebellum with thalamus) and used fractional anisotropy (FA) as a measure of their integrity. …

Developing And Validating Tools To Assess Higher Level Cognition In Children And Adolescents, Brainscan, Western University, Bobby Stojanoski, Marc Joanisse, Ryan Stevenson, Cambridge Brain Sciences Inc.

Project Summaries

Collaborating with CBS, we will create a unique platform for understanding, detecting and predicting delays in cognition during the formative period from childhood to adolescence. The aim of this project is to develop and validate a battery of tests specifically for children and adolescents between the ages of 7 and 15 to measure various aspects of higher-level cognitive abilities. These include short-term and episodic memory, planning, reasoning, verbal abilities and executive functioning (those processes necessary to control behaviour, such as controlling attention and inhibition, working memory, reasoning and problem solving).

Multi-Area Organization Of Saccade-Evoked Traveling Waves, Brainscan, Western University, Julio Martinez-Trujillo, Lyle Muller, Adam Williamson

Project Summaries

In this project, we will employ new, large-scale electrophysiological recording techniques to sample widely across the visual system. It will allow us to test our hypothesis that neural traveling waves coordinated across multiple areas contribute to perceptual stability during eye movements. Using our newly developed signal processing technique to track traveling waves moment-by-moment in noisy multichannel data, we will detect and quantify them across multiple visual areas.

Detecting Fine-Grained Population Codes In Human Prefrontal Cortex, Brainscan, Western University, Marieke Mur, Julio Martinez-Trujillo, Ravi Menon, Joe Gati

Project Summaries

In this project, we will develop techniques for improving our measurement resolution so that we can gain access to prefrontal population codes. We will combine high-field fMRI with pattern analysis techniques to unlock population coding in the prefrontal cortex. This is essential for understanding how the brain supports higher-order cognition, and ultimately, for treating dysfunctions of cognitive flexibility in the clinic.

Can Self-Efficacy Training Improve Memory And Functional Activation In Older Adults With Mild Cognitive Impairment? A Proof-Of-Concept Intervention Study, Brainscan, Western University, Lindsay Nagamatsu, Derek Mitchell, Paul Minda, Amer Burhan, Becky Horst

Project Summaries

The goal of this study is to examine the changes in brain activity after a memory self-efficacy training program to better understand the mechanisms of memory self-efficacy. We will conduct a proof-of-concept six-week memory self-efficacy intervention in older adults with MCI, in order to demonstrate that self-efficacy impacts brain function. This will allow us to determine whether self-efficacy interventions may be a potential strategy for combating AD in the future.

Developing A Mechanistic Understanding Of Crossmodal Reorganization Following Sensory Loss, Brainscan, Western University, Blake E. Butler, Brian Allman, Ravi Menon

Project Summaries

Our long-term goal is to understand how plasticity reshapes circuits in the brain in response to atypical early experiences. This will allow us to better understand how the Deaf brain processes the world around us, and will make clear the challenges that must be overcome to optimize the function of cochlear implants and prostheses designed to restore sensory functions more broadly.

Assessment Of A Novel 32-Channel Phased Array For Cardiovascular Hybrid Pet/Mri Imaging: Mri Performance., Adam Farag, R Terry Thompson, Jonathan D Thiessen, John Butler, Frank S Prato, Jean Theberge

Department of Medicine Publications

BACKGROUND: Cardiovascular imaging using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) requires a radio frequency phased array resonator capable of high acceleration factors in order to achieve the shortest breath-holds while maintaining optimal MRI signal-to-noise ratio (SNR) and minimum PET photon attenuation. To our knowledge, the only two arrays used today for hybrid PET/MRI cardiovascular imaging are either incapable of achieving high acceleration or affect the PET photon count greatly.

PURPOSE: This study is focused on the evaluation of the MRI performance of a novel third-party prototype 32-channel phased array designed for simultaneous PET/MRI cardiovascular imaging. The …

The Threatful Self: Midbrain Functional Connectivity To Cortical Midline And Parietal Regions During Subliminal Trauma-Related Processing In Ptsd., Braeden A Terpou, Maria Densmore, Jean Theberge, Janine Thome, Paul Frewen, Margaret C Mckinnon, Ruth A Lanius

Department of Medicine Publications

BACKGROUND: The innate alarm system consists of a subcortical network of interconnected midbrain, lower brainstem, and thalamic nuclei, which together mediate the detection of evolutionarily-relevant stimuli. The periaqueductal gray is a midbrain structure innervated by the innate alarm system that coordinates the expression of defensive states following threat detection. In participants with post-traumatic stress disorder, the periaqueductal gray displays overactivation during the subliminal presentation of trauma-related stimuli as well as altered resting-state functional connectivity. Aberrant functional connectivity is also reported in post-traumatic stress disorder for the default-mode network, a large-scale brain network recruited during self-referential processing and autobiographical memory. Here, …

Back To The Basics: Resting State Functional Connectivity Of The Reticular Activation System In Ptsd And Its Dissociative Subtype., Janine Thome, Maria Densmore, Georgia Koppe, Braeden Terpou, Jean Theberge, Margaret C Mckinnon, Ruth A Lanius

Department of Medicine Publications

BACKGROUND: Brainstem and midbrain neuronal circuits that control innate, reflexive responses and arousal are increasingly recognized as central to the neurobiological framework of post-traumatic stress disorder (PTSD). The reticular activation system represents a fundamental neuronal circuit that plays a critical role not only in generating arousal but also in coordinating innate, reflexive responding. Accordingly, the present investigation aims to characterize the resting state functional connectivity of the reticular activation system in PTSD and its dissociative subtype.

METHODS: We investigated patterns of resting state functional connectivity of a central node of the reticular activation system, namely, the pedunculopontine nuclei, among individuals …

Overlapping Frontoparietal Networks In Response To Oculomotion And Traumatic Autobiographical Memory Retrieval: Implications For Eye Movement Desensitization And Reprocessing., Sherain Harricharan, Margaret C Mckinnon, Mischa Tursich, Maria Densmore, Paul Frewen, Jean Theberge, Bessel Van Der Kolk, Ruth A Lanius

Department of Medicine Publications

Background: Oculomotor movements have been shown to aid in the retrieval of episodic memories, serving as sensory cues that engage frontoparietal brain regions to reconstruct visuospatial details of a memory. Frontoparietal brain regions not only are involved in oculomotion, but also mediate, in part, the retrieval of autobiographical episodic memories and assist in emotion regulation. Objective: We sought to investigate how oculomotion influences retrieval of traumatic memories by examining patterns of frontoparietal brain activation during autobiographical memory retrieval in post-traumatic stress disorder (PTSD) and in healthy controls. Method: Thirty-nine participants (controls, n = 19; PTSD, n = 20) recollected both …

The Risk Of New-Onset Epilepsy And Refractory Epilepsy In Older Adult Stroke Survivors, Jorge G. Burneo, Tresah C. Antaya, Britney N. Allen, Andrea Belisle, Salimah Z. Shariff, Gustavo Saposnik

Neuroepidemiology Research Unit Project Summaries

Research Summary: Key Findings

• Stroke is a common cause of epilepsy in older adults, but little is known about stroke-related epilepsy or its outcomes in this population.
• 1.1% of older adult stroke survivors developed epilepsy in this study, of whom 12.9% developed refractory epilepsy, indicating that this population is particularly responsive to treatment.
• Over 85% of deaths in this population are not due to stroke or epilepsy.

Sound Quality Effects Of An Adaptive Nonlinear Frequency Compression Processor With Normal-Hearing And Hearing-Impaired Listeners, Danielle Glista, Marianne Hawkins, Jonathan M. Vaisberg, Nazanin Pourmand, Vijay Parsa, Susan Scollie

Communication Sciences and Disorders Publications

© 2019 American Academy of Audiology. All rights reserved. Background: Frequency lowering (FL) technology offers a means of improving audibility of high-frequency sounds. For some listeners, the benefit of such technology can be accompanied by a perceived degradation in sound quality, depending on the strength of the FL setting. Purpose: The studies presented in this article investigate the effect of a new type of FL signal processing for hearing aids, adaptive nonlinear frequency compression (ANFC), on subjective speech quality. Research Design: Listener ratings of sound quality were collected for speech stimuli processed with systematically varied fitting parameters. Study Sample: Study …

Auditory Brainstem Responses In Children With Auditory Processing Disorder, Sangamanatha Ankmnal-Veeranna, Chris Allan, Prudence Allen

Communication Sciences and Disorders Publications

Background: The ASHA recommends including electrophysiological measures in an auditory processing disorder (APD) assessment battery, but few audiologists do so, potentially because of limited published evidence for its utility. Purpose: This study compared the auditory brainstem responses (ABRs) of children with APD with age-matched children and adults. Study Sample: This study retrospectively examined the records of 108 children suspected of APD (sAPD) who had click-evoked ABRs recorded as part of their clinical assessment. Twenty adults and 22 typically developing (TD) children were recruited as controls. Data collection and Analysis: Click-evoked ABRs were recorded at slow (13.3 clicks/sec) and faster (57.7 …

The Medial Olivocochlear Reflex Is Unlikely To Play A Role In Listening Difficulties In Children, Sriram Boothalingam, Chris Allan, Prudence Allen, David W. Purcell

Communication Sciences and Disorders Publications

The medial olivocochlear reflex (MOCR) has been implicated in several auditory processes. The putative role of the MOCR in improving speech perception in noise is particularly relevant for children who complain of listening difficulties (LiD). The hypothesis that the MOCR may be impaired in individuals with LiD or auditory processing disorder has led to several investigations but without consensus. In two related studies, we compared the MOCR functioning of children with LiD and typically developing (TD) children in the same age range (7–17 years). In Study 1, we investigated ipsilateral, contralateral, and bilateral MOCR using forward-masked click-evoked otoacoustic emissions (CEOAEs; …

Maternal Protein Restriction During Perinatal Life Affects Lung Mechanics And The Surfactant System During Early Postnatal Life In Female Rats., Reza Khazaee, Lynda A Mccaig, Cory Yamashita, Daniel B Hardy, Ruud A W Veldhuizen

Physiology and Pharmacology Publications

Limited information is available on how fetal growth retardation (FGR) affects the lung in the neonatal period in males and females. This led us to test the hypothesis that FGR alters lung mechanics and the surfactant system during the neonatal period. To test this hypothesis a model of FGR was utilized in which pregnant rat dams were fed a low protein diet during both the gestation and lactation period. We subsequently analyzed lung mechanics using a FlexiVent ventilator in male and female pups at postnatal day 7 and 21. Lung lavage material was obtained at postnatal day 1, 7 and …

Developmental Trajectories And Reference Percentiles For The 6-Minute Walk Test For Children With Cerebral Palsy., Alyssa Laforme Fiss, Lynn Jeffries, Kristie Bjornson, Lisa Avery, Steven Hanna, Sarah Westcott Mccoy

Physical Therapy Publications

PURPOSE: The purposes of this study were to document longitudinal developmental trajectories in 6-minute walk test (6MWT) distances and to develop age-specific reference percentiles for children across different Gross Motor Function Classification System (GMFCS) levels.

METHODS: A TOTAL OF: 456 children with cerebral palsy ages 3 to 12 years of, GMFCS levels I to III participated. Children's motor function was classified on the GMFCS, and children completed the 6MWT 2 to 5 times in 2 years.

RESULTS: Longitudinal developmental trajectories support that 6MWT distances increase with age followed by a tapering, as children approach their functional limit relative to their …

Cognition Predicts Mobility Change In Lower Extremity Amputees Between Discharge From Rehabilitation And 4-Month Follow-Up: A Prospective Cohort Study., Susan W. Hunter, Pavlos Bobos, Courtney Frengopoulos, Austin Macpherson, Ricardo Viana, Michael W Payne

Physical Therapy Publications

OBJECTIVES: To assess (1) the effect of task (single and dual task), time (discharge and 4mo), and their interaction for mobility; (2) task prioritization during dual-task testing; and (3) the association between cognition on change in mobility between discharge from rehabilitation and 4 months' follow-up.

DESIGN: Prospective cohort study.

SETTING: Rehabilitation hospital.

PARTICIPANTS: People with lower extremity amputations (N=22) were consecutively recruited at discharge from an inpatient prosthetic rehabilitation program.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Gait velocity and the L Test of Functional Mobility, single and dual task (serial subtractions by 3), were the primary outcomes. Montreal Cognitive Assessment …

Reliability, Validity, And Agreement Of The Short-Form Activities-Specific Balance Confidence Scale In People With Lower Extremity Amputations., Katherine Fuller, Humberto Adolfo Omaña Moreno, Courtney Frengopoulos, Michael W Payne, Ricardo Viana, Susan W. Hunter

Physical Therapy Publications

BACKGROUND: Clinicians use the Activities-specific Balance Confidence Scale to understand balance confidence. A short-form Activities-specific Balance Confidence scale, was developed using the six most difficult tasks from the original Activities-specific Balance Confidence scale; however, short-form the short-form scale psychometrics and agreement with the original scale have yet to be explored in people with lower extremity amputations.

OBJECTIVE: To determine the relative and absolute reliability, construct validity, and agreement of the short-form Activities-specific Balance Confidence scale.

STUDY DESIGN: Test-retest with a 2-week interval.

METHODS: Analysis for relative reliability and internal consistency was intraclass correlation coefficient and Cronbach's

RESULTS: The short-form Activities-specific …

Relationship Between Body Image And Physical Functioning Following Rehabilitation For Lower-Limb Amputation, Jessica Desrochers, Courtney Frengopoulos, Michael W.C. Payne, Ricardo Viana, Susan W. Hunter

Physical Therapy Publications

The aim of the present study was to evaluate change in body image and the association between body image at discharge and mobility 4 months after rehabilitation. A prospective cohort comprising adults older than or equal to 50 years of age undergoing rehabilitation for first major lower-limb amputation at an inpatient prosthetic rehabilitation program were assessed at discharge and 4 months after rehabilitation. Paired t-tests compared total Amputee Body Image Scale (ABIS), gait velocity, and L-test scores between discharge (T1) and 4 months (T2). Multivariable linear regression assessed relationship between ABIS scores and mobility. Nineteen participants completed assessments …

Effect Of Learning To Use A Mobility Aid On Gait And Cognitive Demands In People With Mild To Moderate Alzheimer's Disease: Part Ii - 4-Wheeled Walker., Susan W. Hunter, Alison Divine, Humberto Omana, Walter Wittich, Keith D Hill, Andrew M Johnson, Jeffrey D Holmes

Physical Therapy Publications

BACKGROUND: Cognitive deficits and gait problems are common and progressive in Alzheimer's disease (AD). Prescription of a 4-wheeled walker is a common intervention to improve stability and independence, yet can be associated with an increased falls risk.

OBJECTIVES: 1) To examine changes in spatial-temporal gait parameters while using a 4-wheeled walker under different walking conditions, and 2) to determine the cognitive and gait task costs of walking with the aid in adults with AD and healthy older adults.

METHODS: Twenty participants with AD (age 79.1±7.1 years) and 22 controls (age 68.5±10.7 years) walked using a 4-wheeled walker in a straight …

Physiotherapy Students’ Attitudes Toward Working With People With Dementia: A Cross-Sectional Survey, Susan W. Hunter, Jessica Armstrong, Mark Silva, Alison Devine

Physical Therapy Publications

Aims: To understand personal, educational and clinical experiences and the attitudes of physiotherapy students towards people with dementia.

Methods: Online survey questionnaire. Physiotherapy students in the last year of a two-year Masters of Physical Therapy (MPT) entry-to-practice degree program (n = 59) were surveyed. Descriptive statistics were used to analyze the data.

Results: Fifty-five students participated (93%). The majority of students (n = 52/55, 77%) had at least one clinical placement working with people with dementia. Overall, 53% (n = 29/55) felt their academic training was sufficient to effectively work with people with dementia. Moreover, …

Conceptualizing Youth Participation In Children’S Health Research: Insights From A Youth-Driven Process For Developing A Youth Advisory Council, Mohammad El-Bagdady, Krishna Arunkumar, Drew Bowman, Stephanie Coen, Christina Ergler, Jason Gilliland, Ahad Mahmood, Suraj Paul

Geography & Environment Publications

Given the power asymmetries between adults and young people, youth involvement in research is often at risk of tokenism. While many disciplines have seen a shift from conducting research on youth to conducting research with and for youth, engaging children and teens in research remains fraught with conceptual, methodological, and practical challenges. Arnstein’s foundational Ladder of Participation has been adapted in novel ways in youth research, but in this paper, we present a new rendering: a ‘rope ladder.’ This concept came out of our youth-driven planning process to develop a Youth Advisory Council for the Human Environments Analysis Laboratory, an …

Structured Diet And Exercise Guidance In Pregnancy To Improve Health In Women And Their Offspring: Study Protocol For The Be Healthy In Pregnancy (Bhip) Randomized Controlled Trial, Maude Perreault, Stephanie A. Atkinson, Michelle F. Mottola, Stuart M. Phillips, Keyna Bracken, Eileen K. Hutton, Feng Xie, David Meyre, Rita E. Morassut, Harry Prapavessis, Lehana Thabane

Anatomy and Cell Biology Publications

BackgroundEvidence from epidemiological and animal studies support the concept of programming fetal, neonatal, and adult health in response to in utero exposures such as maternal obesity and lifestyle variables. Excess gestational weight gain (GWG), maternal physical activity, and sub-optimal and excess nutrition during pregnancy may program the offspring's risk of obesity. Maternal intake of dairy foods rich in high-quality proteins, calcium, and vitamin D may influence later bone health status. Current clinical practice guidelines for managing GWG are not founded on randomized trials and lack specific active intervention ingredients. The Be Healthy in Pregnancy (BHIP) study is a randomized controlled …

Functional Outcomes In Early (T1/T2) Supraglottic Cancer: A Systematic Review, Benjamin Van Der Woerd, Krupal B. Patel, Anthony C. Nichols, Kevin Fung, John Yoo, Danielle S. Macneil

Anatomy and Cell Biology Publications

ObjectivesOrgan preserving surgery (OPS) and radiotherapy (RT) are both accepted treatment options for early stage supraglottic cancer (SGC). Radiation has supplanted surgery in most cases, because of the perception that surgery results in poorer functional outcomes. However, evidence suggests that OPS with a neck dissection may be associated with improved survival. Our objective was to conduct a systematic review of the literature to compare functional outcomes of OPS and RT for early SGC.MethodsWe searched Medline, EMBASE and Cochrane Central Register of Controlled Trials to identify studies. Studies were included if they reported functional outcomes on 10 or more patients with …

"C.H.A.M.P. Families": Description And Theoretical Foundations Of A Paediatric Overweight And Obesity Intervention Targeting Parents-A Single-Centre Non-Randomised Feasibility Study., Kristen Reilly, Trish Tucker, Jennifer D. Irwin Phd, Andrew Johnson, Erin S Pearson, Dirk E Bock, Shauna M. Burke

Paediatrics Publications

Childhood obesity represents a significant global health challenge, and treatment interventions are needed. The purpose of this paper is to describe the components and theoretical model that was used in the development and implementation of a unique parent-focussed paediatric overweight/obesity intervention. C.H.A.M.P. Families was a single-centre, prospective intervention offered to parents of children aged between 6⁻14 years with a body mass index (BMI) ≥85th percentile for age and sex. The intervention included: (1) eight group-based (parent-only) education sessions over 13-weeks; (2) eight home-based activities; and (3) two group-based (family) follow-up support sessions. The first section of the manuscript contains a …

Effect Of Ultrafiltration During Hemodialysis On Hepatic And Total-Body Water: An Observational Study., Claire J Grant, Trevor P Wade, Charles A Mckenzie, Guido Filler, Christopher W Mcintyre, Huang S. Shih-Han

Paediatrics Publications

Background

The hepatic circulation is involved in adaptive systemic responses to circulatory stress. However, it is vulnerable to both chronic hypervolemia and cardiac dysfunction. The influence of hemodialysis (HD) and ultrafiltration (UF) upon liver water content has been understudied. We conducted a detailed pilot study to characterize the effects of HD upon liver water content and stiffness, referenced to peripheral fluid mobilization and total body water.

Methods

We studied 14 established HD patients without liver disease. Magnetic resonance imaging (MRI) together with ultrasound-based elastography and bioimpedance assessment were employed to measure hepatic water content and stiffness, body composition, and water …