Medical Sciences Commons^™

Paired Associative Transspinal And Transcortical Stimulation Produces Bidirectional Plasticity Of Human Cortical And Spinal Motor Pathways, Luke Dixon, Mohamed Ibrahim, Danielle Santora

Dissertations, Theses, and Capstone Projects

Anatomical, physiological, and functional connectivity exists between primary motor cortex (M1) and spinal cord neurons. Paired associative stimulation (PAS) produces enduring changes in M1 based on the Hebbian principle of associative plasticity. The present study aims to discover immediate neurophysiological changes on human corticomotor pathways by pairing noninvasive transspinal and transcortical stimulation via transcranial magnetic stimulation (TMS). We delivered paired transspinal and transcortical stimulation for 40-min at precise interstimulus intervals with TMS being delivered after (transspinal-transcortical PAS) or before (transcortical-transspinal PAS) transspinal stimulation. Transspinal-transcortical PAS markedly decreased intracortical inhibition, increased intracortical facilitation and M1 excitability with concomitant decreases of motor …

Micellular Electrokinetic Chromatography For Studying Amyloid Beta Oligomer Membrane Affinity, Andrew Bryson

Biomedical Engineering Undergraduate Honors Theses

Amyloid Beta (Aβ) was the major focus of this study. It is a peptide that is present in the brain with a high tendency to self-aggregate. When this protein aggregates, it forms oligomers and protofibrils which in turn are deposited as senile plaques in the brain. The reason for the concern with these plaques is their association with the neurological disorder Alzheimer’s disease. It has been found that the most dangerous oligomers are formed in a portion of the plasma membrane known as lipid rafts. The purpose of this study was to understand how micelles affect the aggregation properties of …

Role Of Slit2 In Reducing Complications After Surgical Brain Injury, Prativa Sherchan

Loma Linda University Electronic Theses, Dissertations & Projects

Surgical brain injury (SBI) is the inadvertent injury to brain tissue at the perisurgical site which occurs due to neurosurgical maneuvers such as incision, retraction, and electrocoagulation that can result in post-operative complications. Blood brain barrier (BBB) disruption and neuroinflammation are major pathophysiological consequences after neurosurgical injury. Blood brain barrier dysfunction leads to increased influx of water and plasma proteins as well as peripheral immune cell infiltration into the brain parenchyma that further potentiates brain edema and worsens post-operative neurological function. Activated resident immune cells and infiltrated peripheral immune cells release inflammatory mediators and promote oxidative stress and cell death …

Vitamin D Clinical Relevance In The Recovery From Traumatic Brain Injury Among The Military Population, Yuisa M. Colón

Honors Undergraduate Theses

Background: Traumatic brain injury (TBI) still remains a difficult disorder to treat. TBI has been associated to chronic neuroinflammation and a high risk for neurodegenerative disorders. Since 2001 between ten to twenty percent of all deployed military members have suffered a combat-related TBI. Nearly twenty to thirty percent of those will experience chronic cognitive, behavioral and somatic symptoms after suffering a TBI.
Methods: The objective of this review is to evaluate current literature examining vitamin D as a neurosteroid with protective properties and its clinical relevance after traumatic brain injury. Vitamin D is known to participate in neurobiological …

Cerebrovascular Risk Factors, Arteriolar Sclerosis, And Cognitive Decline In The Kentucky Appalachian “Stroke-Belt”, Omar M. Al-Janabi

Theses and Dissertations--Medical Sciences

The relationship between cerebrovascular disease (CVD) risk factors and cognitive impairment or dementia has been widely studied with significant variability in findings between groups. We hypothesized that chronic small vessel injury in the form of arteriolar sclerosis, measured quantitatively using MRI to measure total white matter hyperintensity (WMH) volumes, would identify specific association of CVD risk factors and patterns of cognitive decline, associated with mild cognitive impairment of the cerebrovascular type, that represent the core features of vascular cognitive impairment in our cohort.

A Cross-sectional analysis of clinical and quantitative MRI data on 114 subjects with normal cognitive function (n=52) …

Looking To The Future Of Stroke Treatment: Combining Recanalization And Neuroprotection In Acute Ischemic Stroke, Michael E. Maniskas

Theses and Dissertations--Neuroscience

Stroke is the 5^th leading cause of death in the U.S. with 130,000 deaths and around 800,000 affected annually. Currently, there is a significant disconnect between basic stroke research and clinical stroke therapeutic needs. Few animal models of stroke target the large vessels that produce cortical deficits seen in the clinical setting. Also, current routes of drug administration, intraperitoneal and intravenous, do not mimic the clinical route of intra-arterial drug administration. To bridge this divide, we have retro-engineered a mouse model of stroke from the current standard of care for emergent large vessel occlusion (ELVO) stroke, endovascular thrombectomy, to …

The Neurochemistry Of Group Singing: Bonding And Oxytocin, Jason Keeler

Masters Theses

The purpose of this study was to examine the neurochemical correlates of group vocal improvisation and to determine the feasibility of the research methods. One group of four participants sang together in two conditions: pre-composed and improvised. Concentrations of plasma oxytocin and adrenocorticotropic hormone (ACTH) were measured before and after each singing condition to assess levels of hormones associated with social affiliation, engagement and arousal. Successful implementation of the methodology, including recruitment, data collection, and sample analysis, served as the primary outcome of this study. ACTH concentrations decreased in both conditions, and significantly so in the pre-composed singing condition. Mean …

Concussion Education And The Self-Reporting Rate Of Concussion Symptoms Among College Athletes, Brian J. Hyma

Ed.D. Dissertations

This study addressed the effectiveness of a structured concussion education tool in order to increase the knowledge of concussion symptoms among college athletes. Also, efforts were made to determine if the gained knowledge from the education tool would lead to an increase in the self-reporting of acquired concussion symptoms. For the study, pre and postseason surveys were administered to athletes among six universities. Athletes representing the experimental group received pre-season concussion education while the control group did not receive the education. Data concerning the athlete’s history of structured concussion education, retained knowledge of concussion symptoms, along with the rate of …

The Therapeutic Role Of Turmeric In Treatment And Prevention Of Alzheimer’S Disease, Rylan M. Mcquade

Selected Honors Theses

As a devastating neurological condition that expends millions of lives each year, Alzheimer’s disease (AD) is a subject of intense investigation.¹ Although AD has been known for over a century, the precise mechanisms that underlie AD pathogenesis and development are still poorly understood. The Alzheimer phenotype is typified by extracellular amyloid-beta (Aβ) plaques and intracellular neurofibrillary tangles (NFTs), causing researchers to notice several key enzymes implicated in this process.¹ Most notable are β and γ secretases (which drive Aβ plaque production) and phospholipase

A₂ (which stimulates major cascade activation through the specific cleavage of fatty acyl esters). …

Morphometric Analysis Of Left & Right Tonsils In Adult Symptomatic Type 1 Chiari Patients And Healthy Controls, Louis J. Konstan

Williams Honors College, Honors Research Projects

Historically, CMI has been radiographically defined by cerebellar tonsillar descent below the foramen magnum (FM) more than 5 mm (2). This measurement is typically made with a single sagittal plane T1-or T2-weighted MR image. Studies have obtained additional morphometric measurements to help diagnose CMI, and establish normal values (3,4). These studies were somewhat These studies were somewhat successful in differentiating CMI patients from healthy subjects. However, results from these studies have shown that the standard TD measurement does not necessarily correlate with neurological symptom severity as patients with CMI-like symptoms have been found with a TD of less than 5 …

Axon Initial Segment Stability In Multiple Sclerosis, Suneel K. Thummala

Theses and Dissertations

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system characterized by inflammation and demyelination. In addition to these hallmark features, MS also presents with axonal pathology, which is likely responsible for the signs and symptoms of the disease. Although prominent in MS, axonal pathology is frequently considered a consequence of demyelination and not a primary event. This conclusion is consistent with demyelination inducing the loss of specific axonal domains, known as the nodes of Ranvier that are responsible for the propagation of action potentials along the axon. In contrast, we propose that axonal pathology associated with MS …

Quantitative Mri Correlates Of Hippocampal And Neocortical Pathology In Intractable Temporal Lobe Epilepsy, Maged Goubran

Electronic Thesis and Dissertation Repository

Intractable or drug-resistant epilepsy occurs in over 30% of epilepsy patients, with many of these patients undergoing surgical excision of the affected brain region to achieve seizure control. Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to investigate histopathological correlates of quantitative relaxometry and DTI from hippocampal and neocortical specimens of intractable TLE patients. To achieve this goal I developed and evaluated a pipeline for histology to in-vivo MRI …

Early-Onset Familial Alzheimer Disease, Laura J. Murphy

Nursing Student Class Projects (Formerly MSN)

An Alzheimer’s diagnosis is an overwhelming and devastating diagnosis for both patients and families. Now imagine if this diagnosis was made at age 55. Instead of looking forward to retirement and grandchildren, these people are preparing for a debilitating disease that will rob them of their memory, cognitive and functional abilities. Early-onset familial Alzheimer’s disease (EOFAD) affects people before the age of 65. Although extremely rare, some exhibit symptoms as early as in their 30s. One of the things most frustrating about this disease is so little is known about its cause. That and the fact there is no cure. …

Tension Pneumocephalus, Nicole Liebner

Nursing Student Class Projects (Formerly MSN)

Pneumocephalus is defined as the presence of air within the cranial vault; tension pneumocephalus occurs when air within the cranial vault becomes trapped and causes a mass effect or increased pressure, damaging the brain (Patel, Idicula, Carrau, & Prevedello, 2013). Small amounts of air within the cranial vault can be reabsorbed or metabolized by the body over a few days without causing symptoms, however, in tension pneumocephalus the air cannot escape, causing extensive neurological symptoms (Webber-Jones ,2005). Thus, asymptomatic pneumocephalus can be a common finding following a cranial surgery, where as tension pneumocephalus is extremely rare (Webber-Jones, 2005). Markam (1967) …

Understanding The Mystery Of Brain Death, Natalie A. Felter

Nursing Student Class Projects (Formerly MSN)

Lack of understanding of brain death has contributed to recent controversial cases (Copnell, 2014). The cases of Jahi McMath and Marlise Munoz were the focus of national news, causing an intense debate among the public and healthcare professionals (Copnell, 2014). The concept of brain death is a mystery to the public (Powell, 2014). Copnell (2014) found that 60% of family members who had been told their loved one was brain dead believed that they were still alive. Health professionals not having a clear grasp of brain death’s definition and assessment can lead to increased confusion in family members (Powell, 2014).

Role Of Astrocyte Network In Edema After Juvenile Traumatic Brain Injury, Andrew Minoru Fukuda

Loma Linda University Electronic Theses, Dissertations & Projects

Juvenile traumatic brain injury (jTBI) is the leading cause of death and disability in young children and adolescents. Despite its lasting detrimental effects on the developing brain, no pharmacological treatment exists. One of the pathological hallmarks of jTBI is edema. Astrocytes play a key role in the edema process, and have been hypothesized that numerous astrocyte networks allow communication and propagation of edema and secondary injury spread. Two key astrocyte proteins are hypothesized to have a central role in the edema process: Aquaporin 4 (AQP4) and Connexin 43 (Cx43). AQP4 is expressed extensively in astrocyte endfeet, which surrounds the blood …

Wirelesseeg: Data Aquisition + Handheld Device, Michael Dylan Snowden, Madeline Threatt, Brent Mcferrin, David Platillero, Karsten Solies, Lindsey Hopf

Chancellor’s Honors Program Projects

No abstract provided.

Pillow Talk: The Epigenetic And Physiological Effects Of Sleep Deprivation, Jennifer D. Cotter

Thinking Matters Symposium Archive

Circadian rhythms, or the 24-hour biological cycles of living cells, function as the body’s internal clock. Although circadian rhythms and sleep are very different processes, they are closely related to one another as these cycles play an important role in sleeping and waking patterns. Recent studies have shown that lack of sleep or sleep of poor quality can disrupt circadian rhythms and may actually cause cognitive disorders and memory loss, facilitate false memory production, and even alter gene expression in humans. This literature review is focused on identifying the epigenetic and physiological effects of disruptions and desynchronization in circadian rhythms …

Caveolins And Njks Influence Brain Endothelial Permeability After Juvenile Tbi, David Olufemi Ajao

Loma Linda University Electronic Theses, Dissertations & Projects

Disruption of blood-brain barrier (BBB) is a key secondary event that exacerbates brain damage following traumatic brain injury (TBI). BBB disruption is particularly damaging to the developing brain – which is highly vulnerable to various stress stimuli, resulting in increased brain swelling, disrupted cerebral blood flow (CBF) autoregulation, long-term disabilities and death following TBI in young demographic. Unsurprisingly, BBB disruption and the resultant cerebral edema have emerged as therapeutic targets in juvenile TBI. It is therefore important to understand the molecular players and mechanisms involved in TBI-induced BBB disruption in the juvenile brain. To this end, the endothelial caveolins and …

Secular Trends In Ischemic Stroke Subtypes, Chrysi Bogiatzi

Electronic Thesis and Dissertation Repository

Background: With an aging population and an increasing prevalence of therapy for atherosclerosis, it might be expected that stroke subtypes would be changing over time. Limited information exists on the ischemic stroke subtypes in adults in Canada.

Methods: Patients referred to the Urgent TIA Clinic, in London, Ontario, between 2002-2012 were included. Secular trends were analyzed using Poisson regression with spline trend function. Ischemic stroke subtype classification was validated.

Results: 3,445 consecutive patients (mean age + SD 64.8 + 14.9) were included. Cardioembolic strokes/TIAs increased from 21% in 2002 to 56% in 2012, whereas all other ischemic stroke subtypes …

Is Pramipexole Safe And Effective In Reducing Depressive Symptoms In Patients With Mild To Moderate Parkinson’S Disease And Depression?, Corinne J. Kern

PCOM Physician Assistant Studies Student Scholarship

OBJECTIVE: The objective of this selective EBM review is to determine whether or not pramipexole (Mirapex) is a safe and effective drug to treat depression in patients with mild to moderate Parkinson’s Disease (PD).

STUDY DESIGN: Review of three English language primary randomized controlled trials and one randomized prospective, observational study published between 2003-2010.

DATA SOURCES: Three randomized controlled trials and one randomized prospective, observational study comparing the efficacy of pramipexole to placebo, sertraline (an SSRI) and other dopamine agonists (pergolide) in the treatment of PD related depression symptoms were found using PubMed.

OUTCOME(S) MEASURED: Each of the …

Does Etravirine Decrease Central Nervous System (Cns)/Neuropsychiatric (Nps) Adverse Events Compared To Efavirenz, In Hiv Positive Patients?, Angelo D. T. Smith

PCOM Physician Assistant Studies Student Scholarship

OBJECTIVE: The objective of this selective EBM review is to determine whether or not Etravirine (ETR) decreases adverse reactions on the central nervous system (CNS) compared to Efavirenz (EFV) in Human Immunodeficiency Virus (HIV) positive patients.

STUDY DESIGN: Review of three, English language, primary randomized controlled trial studies published in 2011.

DATA SOURCES: Three randomized controlled trials studying the possible decrease of ADR’s in HIV positive patients who are taking Efavirenz compared to study medication Etravirine.

OUTCOME(S) MEASURED: Outcomes measured were by surveys from patients that assess the development or cessation of CNS ADR’s. The self …

Exercise-Induced Neuroprotection In A Hemiparkinsonian 6-Hydroxydopamine Rat Model, Merrill Russen Landers

UNLV Theses, Dissertations, Professional Papers, and Capstones

Outside of finding a cure, one of the preeminent goals of research in Parkinson's disease (PD) is finding a neuroprotective treatment that when applied prior to the onset of the disease will decrease the risk and severity of the subsequent disease. One such treatment that has potential as a neuroprotective agent in PD is exercise. Several studies have found forced exercise to be protective of Parkinson's disease in adult rodent models; however, few of these studies have used a design wherein voluntary exercise was evaluated. Moreover, no study has used a true neuroprotective design in which exercise was applied prior …

Effects Of Hyperthermia On Photochemical Internalization-Mediated Delivery Of Bleomycin, Christina Schlazer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Standard treatment protocols for high-grade gliomas, such as glioblastoma multiforme (GBM), are highly ineffective due to their inability to eradicate infiltrating tumor cells. Improvements in overall survival are likely to be realized only with the development of more effective localized therapies capable of eradicating tumor cells in the surgical resection margin and beyond. Photochemical internalization (PCI) is a localized light-based therapeutic modality that enhances the efficacy of therapeutic macromolecules including chemotherapeutic agents such as bleomycin. A number of studies have shown that this photodynamic therapy (PDT) - based modality may prove effective in the treatment of high-grade gliomas.

Three-dimensional multicell …

Short-Term Plasticity At The Schaffer Collateral: A New Model With Implications For Hippocampal Processing, Andrew Hamilton Toland

Dissertations and Theses

A new mathematical model of short-term synaptic plasticity (STP) at the Schaffer collateral is introduced. Like other models of STP, the new model relates short-term synaptic plasticity to an interaction between facilitative and depressive dynamic influences. Unlike previous models, the new model successfully simulates facilitative and depressive dynamics within the framework of the synaptic vesicle cycle. The novelty of the model lies in the description of a competitive interaction between calcium-sensitive proteins for binding sites on the vesicle release machinery. By attributing specific molecular causes to observable presynaptic effects, the new model of STP can predict the effects of specific …

Investigating The Impact Of Cd147 And Its Expression On Neurodegenaration And Alzheimer's Disease (Ad), Limbikani J. Kanyenda

Theses: Doctorates and Masters

CD147, also known as basigin, extracellular matrix metalloproteinase inducer, neurothelin, tumour cell-derived collagenase stimulatory factor, M6, HT7, OX47 or gp42, is a transmembrane glycoprotein of the immunoglobulin super-family. It is expressed in many neuronal and non-neuronal tissues with high expression in the hippocampus, pre-frontal cortex, thyroid, heart, early erythroid, amygdala and placenta. This protein is involved in various cellular and biological functions such as lymphocyte migration and maturation, tissue repair, cancer progression, T and B lymphocyte activation and induction of extracellular matrix metalloproteinase. The CD147 protein interacts with with cyclophilin A, cyclophilin B, sterol carrier protein, caveolin-1 and integrins, and …

Brain Activation And Connectivity In Non-Disabled Multiple Sclerosis Patients, Rene A. Colorado

Dissertations & Theses (Open Access)

Multiple sclerosis (MS) is the most common demyelinating disease affecting the central nervous system. There is no cure for MS and current therapies have limited efficacy. While the majority of individuals with MS develop significant clinical disability, a subset experiences a disease course with minimal impairment even in the presence of significant apparent tissue damage on magnetic resonance imaging (MRI). The current studies combined functional MRI and diffusion tensor imaging (DTI) to elucidate brain mechanisms associated with lack of clinical disability in patients with MS. Recent evidence has implicated cortical reorganization as a mechanism to limit the clinical manifestation of …

Effect Of Acute Administration Of Angiopoietin-1 In Experimental Traumatic Spinal Cord Injury: Magnetic Resonance Imaging And Neurobehavioral Studies, Chirag B. Patel

Dissertations & Theses (Open Access)

Spinal cord injury (SCI) is a devastating condition that affects people in the prime of their lives. A myriad of vascular events occur after SCI, each of which contributes to the evolving pathology. The primary trauma causes mechanical damage to blood vessels, resulting in hemorrhage. The blood-spinal cord barrier (BSCB), a neurovascular unit that limits passage of most agents from systemic circulation to the central nervous system, breaks down, resulting in inflammation, scar formation, and other sequelae. Protracted BSCB disruption may exacerbate cellular injury and hinder neurobehavioral recovery in SCI.

In these studies, angiopoietin-1 (Ang1), an agent known to reduce …