Medicine and Health Sciences Commons^™

The Combined Effects Of Physical Exercise And Cognitive Training On Gait Speed And Primary Motor Cortex Metabolism In Individuals With Mild Cognitive Impairment: A 1h-Mrs Analysis, Jack Thomas Emsey Elkas

Electronic Thesis and Dissertation Repository

Mild cognitive impairment (MCI) is a transitional stage before dementia. Altered gait in MCI has been associated with progression to dementia. Using magnetic resonance spectroscopy, a relationship between primary motor cortex (M1) neurochemistry and dual task gait speed has been reported in MCI. Interventional research suggests exercise, cognitive training, and vitamin D supplementation may benefit MCI, yet the combined effect of these treatments on gait speed and M1 metabolism is unknown. Participants with MCI (N=75) were assigned to one of five intervention arms and dual task cost on gait speed and M1 metabolism was assessed before and five months after …

Data-Driven Neuroanatomical Subtypes In Various Stages Of Schizophrenia: Linking Cortical Thickness, Glutamate, And Language Functioning, Liangbing Liang

Electronic Thesis and Dissertation Repository

The considerable variation in the spatial distribution of cortical thickness changes has been used to parse heterogeneity in schizophrenia. We aimed to recover a ‘cortical impoverishment’ subgroup with widespread cortical thinning. We applied hierarchical cluster analysis to cortical thickness data of three datasets in different stages of psychosis and studied the cognitive, functional, neurochemical, language and symptom profiles of the observed subgroups. Our consensus-based clustering procedure consistently produced a subgroup characterized by significantly lower cortical thickness. This ‘cortical impoverishment’ subgroup was associated with a higher symptom burden in a clinically stable sample and higher glutamate levels with language impairments in …

Occipital Lobe Abscess Causing Homonymous Hemianopsia After A Dental Procedure, Kristin Mcdougall Od, Julie Staats Od, Ashley Fritz Od

Optometric Clinical Practice

Background: A homonymous hemianopsia visual field defect is defined as vision loss on the same side of the vertical midline in both eyes. Although the vast majority are caused by an ischemic stroke, other neurologic etiologies must be considered and ruled out. This case highlights the importance of a rapid and thorough investigation of a patient’s symptoms using both clinical examination and imaging to reduce the risk of permanent complications and potential fatality.

Case Report: A 67-year-old Caucasian male presented to the eye clinic with sudden onset reduced peripheral vision to his right side in both eyes. Entering visual acuities …

An In-Vivo 1h-Mrs Short-Echo Time Technique At 7t: Quantification Of Metabolites In Chronic Multiple Sclerosis And Neuromyelitis Optica Brain Lesions And Normal Appearing Brain Tissue, George Tackley, Yazhuo Kong, Rachel Minne, Silvia Messina, Anderson M. Winkler, Ana Cavey, Rosie Everett, Gabriele C. Deluca, Andrew Weir, Matthew Craner

School of Medicine Publications and Presentations

Highlights

• NAAG likely contributes to the total NAA differences between multiple sclerosis lesion and normal appearing brain tissue.

• myo-Inositol was not shown to be different between chronic AQP4Ab-NMOSD brain lesions and normal appearing brain tissue.

• An optimised MRS methodology is described, using 7T field strength and correcting for tissue T2 water relaxion differences.

• 7-tesla MRS profiles of chronic brain lesions and normal appearing white matter are presented for MS and AQP4Ab-NMOSD.

Abstract

Magnetic Resonance Spectroscopy (MRS) allows for the non-invasive quantification of neurochemicals and has the potential to differentiate between the pathologically distinct diseases, multiple sclerosis (MS) and …

Progressive Changes In Glutamate Concentration In Early Stages Of Schizophrenia: A Longitudinal 7-Tesla Mrs Study, Peter Jeon, Roberto Limongi, Sabrina D. Ford, Michael Mackinley, Kara Dempster, Jean Théberge, Lena Palaniyappan

Department of Medicine Publications

Progressive reduction in glutamatergic transmission has been proposed as an important component of the illness trajectory of schizophrenia. Despite its popularity, to date, this notion has not been convincingly tested in patients in early stages of schizophrenia. In a longitudinal 7T magnetic resonance spectroscopy (1H-MRS), we quantified glutamate at the dorsal anterior cingulate cortex in 21 participants with a median lifetime antipsychotic exposure of less than 3 days and followed them up after 6 months of treatment. Ten healthy controls were also scanned at 2 time points. While patients had significantly lower overall glutamate levels than healthy controls (F(1,27) = …

Brain Metabolite Levels In Sedentary Women And Non-Contact Athletes Differ From Contact Athletes, Amy L. Schranz, Gregory A. Dekaban, Lisa Fischer, Kevin Blackney, Christy Barreira, Timothy J. Doherty, Douglas D. Fraser, Arthur Brown, Jeff Holmes, Ravi S. Menon, Robert Bartha

Medical Biophysics Publications

White matter tracts are known to be susceptible to injury following concussion. The objective of this study was to determine whether contact play in sport could alter white matter metabolite levels in female varsity athletes independent of changes induced by long-term exercise. Metabolite levels were measured by single voxel proton magnetic resonance spectroscopy (MRS) in the prefrontal white matter at the beginning (In-Season) and end (Off-Season) of season in contact (N = 54, rugby players) and non-contact (N = 23, swimmers and rowers) varsity athletes. Sedentary women (N = 23) were scanned once, at a time equivalent to the Off-Season …

Brain Metabolite Levels In Sedentary Women And Non-Contact Athletes Differ From Contact Athletes, Amy L. Schranz, Gregory A. Dekaban, Lisa Fischer, Kevin Blackney, Christy Barreira, Timothy J. Doherty, Douglas D. Fraser, Arthur Brown, Jeff Holmes, Ravi S. Menon, Robert Bartha

Brain and Mind Institute Researchers' Publications

White matter tracts are known to be susceptible to injury following concussion. The objective of this study was to determine whether contact play in sport could alter white matter metabolite levels in female varsity athletes independent of changes induced by long-term exercise. Metabolite levels were measured by single voxel proton magnetic resonance spectroscopy (MRS) in the prefrontal white matter at the beginning (In-Season) and end (Off-Season) of season in contact (N = 54, rugby players) and non-contact (N = 23, swimmers and rowers) varsity athletes. Sedentary women (N = 23) were scanned once, at a time equivalent to the Off-Season …

Mri Investigations Of Metabolic And Structural Brain Changes In Alzheimer’S Disease And Vitamin D Deprivation, Dickson Wong

Electronic Thesis and Dissertation Repository

Alzheimer's disease (AD) is a neurodegenerative disorder of the brain that presents as progressive impairment across several cognitive domains. The biological mechanisms underlying the development of AD remain unclear, with amyloid-beta plaques, neurofibrillary tangles, calcium dysregulation, and oxidative stress all contributing to neurodegeneration in AD. Vitamin D (VitD) deficiency, a common condition in the elderly, may modulate these mechanisms and complicate the AD process. Due to this complicated pathogenesis, the diagnosis of AD requires subjective clinical judgement, staging of AD is challenging, and it remains difficult to predict when and who will progress to AD. The purpose of this thesis …

Investigating In Vivo Brain Metabolite Levels In Concussed Female Athletes And A Murine Model Of Repetitive Closed Head Injury, Amy L. Schranz

Electronic Thesis and Dissertation Repository

After a concussion there is a complex cascade of events, termed the neurometabolic cascade, that includes changes in ion flux, neurotransmission, and cellular energetics. How this pathophysiological process translates into cognitive deficits remains poorly understood. Magnetic resonance spectroscopy (MRS) provides a non-invasive technique that allows for the quantification of brain metabolites that are involved in these processes, including glutamate and glutamine, which are involved in neurotransmission. Moreover, female athletes are underrepresented in studies on concussion, limiting our knowledge and understanding of sex differences. The overall goal of this thesis was to examine metabolite changes using MRS in female athletes before …

Conformational Flexibility In The Enterovirus Rna Replication Platform, Meghan S. Warden, Kai Cai, Gabriel Cornilescu, Jordan E. Burke, Komala Ponniah, Samuel E. Butcher, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

A presumed RNA cloverleaf (5′CL), located at the 5′-most end of the noncoding region of the enterovirus genome, is the primary established site for initiation of genomic replication. Stem–loop B (SLB) and stem–loop D (SLD), the two largest stem–loops within the 5′CL, serve as recognition sites for protein interactions that are essential for replication. Here we present the solution structure of rhinovirus serotype 14 5′CL using a combination of nuclear magnetic resonance spectroscopy and small-angle X-ray scattering. In the absence of magnesium, the structure adopts an open, somewhat extended conformation. In the presence of magnesium, the structure compacts, bringing SLB …

The Role Of Proton Magnetic Resonance Spectroscopy In Grading Of Brain Gliomas, Basma Abd Elmoneim, Hala Hafez, Suzan F. Omar, Tarek Fawzy

Menoufia Medical Journal

Objective This study aimed to evaluate the role of proton magnetic resonance spectroscopy ( ¹ H-MRS) in grading of brain gliomas. Background Noninvasive and accurate grading of brain gliomas is important for determining the correct treatment plane and in some cases to avoid unnecessary aggressive surgical treatment. ¹ H-MRS has a potential for providing metabolic information about tumor tissues without surgical tissue sampling. Patients and methods This prospective study included 70 patients with brain gliomas. Single voxel spectroscopy was obtained using PRESS sequence with TE 136 ms. Results The number of male and female patients was 38 and 32, respectively; …

Effect Of 1-H Moderate-Intensity Aerobic Exercise On Intramyocellular Lipids In Obese Men Before And After A Lifestyle Intervention, Stephanie Ipavec-Levasseur, Ilaria Croci, Stephane Choquette, Nuala Byrne, Gary Cowin, Trisha O'Moore-Sullivan, Johannes Prins, Ingrid Hickman

Nuala Byrne

Intramyocellular lipids (IMCL) are depleted in response to an acute bout of exercise in lean endurance-trained individuals; however, it is unclear whether changes in IMCL content are also seen in response to acute and chronic exercise in obese individuals. We used magnetic resonance spectroscopy in 18 obese men and 5 normal-weight controls to assess IMCL content before and after an hour of cycling at the intensity corresponding with each participant’s maximal whole-body rate of fat oxidation (Fatmax). Fatmax was determined via indirect calorimetry during a graded exercise test on a cycle ergometer. The same outcome measures were reassessed in the …

1h-Magnetic Resonance Spectroscopy In First Episode And Chronic Schizophrenia Patients, Duygu Kirtaş, Ruki̇ye Fi̇li̇z Karadağ, Meli̇ke Ceyhan Balci Şengül, Yilmaz Kiroğlu

Turkish Journal of Medical Sciences

Background/aim: The aim of this study was to compare metabolite levels of the dorsolateral prefrontal cortex (DLPFC), anterior cingulate gyrus (ACG), thalamus, and hippocampus in patients with chronic schizophrenia (CSPs) and first psychotic episode patients (FEPs) by the use of magnetic resonance spectroscopy (MRS). Materials and methods: Thirty CSPs, 20 FEPs, and 30 healthy subjects participated in this study. N-Acetylaspartate (NAA), creatine, choline (Cho), and myoinositol levels of the DLPFC, ACG, thalamus, and hippocampus were measured by 1H-MRS. Results: It was determined that the NAA/Cho ratio was lower in both the FEPs and CSPs than the healthy controls in the …

A Review Of Transcranial Magnetic Stimulation And Multimodal Neuroimaging To Characterize Post-Stroke Neuroplasticity, Angela M. Auriat, Jason L. Neva, Sue Peters, Lara A. Boyd

Physical Therapy Publications

Following stroke, the brain undergoes various stages of recovery where the central nervous system can reorganize neural circuitry (neuroplasticity) both spontaneously and with the aid of behavioral rehabilitation and non-invasive brain stimulation. Multiple neuroimaging techniques can characterize common structural and functional stroke-related deficits, and importantly, help predict recovery of function. Diffusion tensor imaging (DTI) typically reveals increased overall diffusivity throughout the brain following stroke, and is capable of indexing the extent of white matter damage. Magnetic resonance spectroscopy (MRS) provides an index of metabolic changes in surviving neural tissue after stroke, serving as a marker of brain function. The neural …

Metabolic Correlates In Spinal Cord Compression Measured By Magnetic Resonance Spectroscopy In The Motor And Sensory Cortices, Sandy Goncalves

Electronic Thesis and Dissertation Repository

Surgical outcome for patients suffering from cervical myelopathy (CM) is unpredictable with varying motor and sensory symptom recovery. Previous in-vivo magnetic resonance spectroscopy (MRS) studies of patients surgically treated for CM have demonstrated decreased N-acetylaspartate (NAA)/creatine levels in the motor cortex indicating reduced neuronal function. The goal of this thesis was to determine whether absolute NAA changes in the motor and sensory cortices mirror the pattern of motor and sensory functional change observed in patients post surgical treatment.

MRS data were acquired on a 3.0 Tesla Siemens MRI along with clinical outcome measures at baseline, 6-weeks and 6-months post-surgery. …

Investigating Cortical Changes In Cervical Spondylotic Myelopathy Using Functional Magnetic Resonance Imaging, Proton Magnetic Resonance Spectroscopy And Diffusion Tensor Imaging, Izabela Kowalczyk

Electronic Thesis and Dissertation Repository

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in older adults. CSM can present abruptly with severe symptoms of neurological impairment or insidiously with a slow stepwise deterioration. There is no current imaging modality or biomarker that can help predict which patient will successfully respond to conservative versus surgical treatment. The goal of this thesis was to follow CSM patients longitudinally to assess how brain function, metabolism, and structure correlate to clinical outcomes in the context of recovering neurological function following surgery.

Chapter 1 of this thesis will provide a detailed literature review of the …

Structure Of Vibrio Cholerae Toxt Reveals A Mechanism For Fatty Acid Regulation Of Virulence Genes, Michael J. Lowden, Karen Skorupski, Maria Pellegrini, Michael G. Chiorazzo, Ronald K. Taylor, F. Jon Kull

Dartmouth Scholarship

Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 A resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that …

Methodology Development For Three-Dimensional Mr-Guided Near Infrared Spectroscopy Of Breast Tumors, Colin M. Carpenter, Subhadra Srinivasan, Brian W. Pogue, Keith D. Paulsen

Dartmouth Scholarship

Combined Magnetic Resonance (MR) and Near Infrared Spectroscopy (NIRS) has been proposed as a unique method to quantify hemodynamics, water content, and cellular size and packing density of breast tumors, as these tissue constituents can be quantified with increased resolution and overlaid on the structural features identified by the MR. However, the choices in how to reconstruct and visualize this information can have a dramatic impact on the feasibility of implementing this modality in the clinic. This is especially true in 3 dimensions, as there is often limited optical sampling of the breast tissue, and methods need to accurately reflect …

Identification Of Two Gene Clusters And A Transcriptional Regulator Required For Pseudomonas Aeruginosa Glycine Betaine Catabolism, Matthew J. Wargo, Benjamin S. Szwergold, Deborah A. Hogan

Dartmouth Scholarship

Glycine betaine (GB), which occurs freely in the environment and is an intermediate in the catabolism of choline and carnitine, can serve as a sole source of carbon or nitrogen in Pseudomonas aeruginosa. Twelve mutants defective in growth on GB as the sole carbon source were identified through a genetic screen of a nonredundant PA14 transposon mutant library. Further growth experiments showed that strains with mutations in two genes, gbcA (PA5410) and gbcB (PA5411), were capable of growth on dimethylglycine (DMG), a catabolic product of GB, but not on GB itself. Subsequent nuclear magnetic resonance (NMR) experiments with 1,2-(13)C-labeled choline …