Neurology Commons^™

Characteristic Dynamic Functional Connectivity During Sevoflurane-Induced General Anesthesia, J. Miao, M. Tantawi, Mahdi Alizadeh, Sara Thalheimer, Faezeh Vedaei, Victor Romo, Feroze B. Mohamed, Chengyuan Wu

Department of Neurosurgery Faculty Papers

General anesthesia (GA) during surgery is commonly maintained by inhalational sevoflurane. Previous resting state functional MRI (rs-fMRI) studies have demonstrated suppressed functional connectivity (FC) of the entire brain networks, especially the default mode networks, transitioning from the awake to GA condition. However, accuracy and reliability were limited by previous administration methods (e.g. face mask) and short rs-fMRI scans. Therefore, in this study, a clinical scenario of epilepsy patients undergoing laser interstitial thermal therapy was leveraged to acquire 15 min of rs-fMRI while under general endotracheal anesthesia to maximize the accuracy of sevoflurane level. Nine recruited patients had fMRI acquired during …

Idiopathic Intracranial Hypertension: A Case Report, Christopher Bugajski Od

Optometric Clinical Practice

Background: Optic nerve head edema is a serious finding for which multiple etiologies need to be considered. When optic nerve head edema is observed bilaterally, among the top differentials is idiopathic intracranial hypertension (IIH), also known as primary pseudotumor cerebri. An emergent magnetic resonance image with and without contrast as well as venography and lumbar puncture with opening pressure measurement must be performed to diagnose and determine management. Case Report: This case specifically features a 30-year-old Caucasian female with bilateral optic disc edema secondary to IIH. In addition to discussing the details regarding this patient’s case, this report …

Association Of Brain Age, Lesion Volume, And Functional Outcome In Patients With Stroke, Sook-Lei Liew, Nicolas Schweighofer, James H. Cole, Artemis Zavaliangos-Petropulu, Bethany P. Lo, Laura K.M. Han, Tim Hahn, Lianne Schmaal, Miranda R. Donnelly, Jessica N. Jeong, Zhizhuo Wang, Aisha Abdullah, Jun H. Kim, Alexandre Hutton, Giuseppe Barisano, Michael R. Borich, Lara A. Boyd, Amy Brodtmann, Cathrin M. Buetefisch, Winston D. Byblow, Jessica M. Cassidy, Charalambos C. Charalambous, Valentina Ciullo, Adriana Bastos Conforto, Rosalia Dacosta-Aguayo, Julie A. Dicarlo, Martin Domin, Adrienne N. Dula, Natalia Egorova-Brumley, Wuwei Feng, Fatemeh Geranmayeh, Chris M. Gregory, Colleen A. Hanlon, Kathryn Hayward, Jess A. Holguin, Brenton Hordacre, Neda Jahanshad, Steven A. Kautz, Mohamed Salah Khlif, Hosung Kim, Amy Kuceyeski, David J. Lin, Jingchun Liu, Martin Lotze, Bradley J. Macintosh, John L. Margetis, Maria Mataro, Feroze B. Mohamed, Emily R. Olafson, Gilsoon Park, Fabrizio Piras, Kate P. Revill, Pamela Roberts, Andrew D. Robertson, Nerses Sanossian, Heidi M. Schambra, Na Jin Seo, Surjo R. Soekadar, Gianfranco Spalletta, Cathy M. Stinear, Myriam Taga, Wai Kwong Tang, Greg T. Thielman, Daniela Vecchio, Nick S. Ward, Lars T. Westlye, Carolee J. Winstein, George F. Wittenberg, Steven L. Wolf, Kristin A. Wong, Chunshui Yu, Steven C. Cramer, Paul M. Thompson

Department of Neurology Faculty Papers

BACKGROUND AND OBJECTIVES: Functional outcomes after stroke are strongly related to focal injury measures. However, the role of global brain health is less clear. In this study, we examined the impact of brain age, a measure of neurobiological aging derived from whole-brain structural neuroimaging, on poststroke outcomes, with a focus on sensorimotor performance. We hypothesized that more lesion damage would result in older brain age, which would in turn be associated with poorer outcomes. Related, we expected that brain age would mediate the relationship between lesion damage and outcomes. Finally, we hypothesized that structural brain resilience, which we define in …

Prediction Of Rapid Early Progression And Survival Risk With Pre-Radiation Mri In Who Grade 4 Glioma Patients, Walia Farzana, Mustafa M. Basree, Norou Diawara, Zeina Shboul, Sagel Dubey, Marie M. Lockheart, Mohamed Hamza, Joshua D. Palmer, Khan Iftekharuddin

Electrical & Computer Engineering Faculty Publications

Rapid early progression (REP) has been defined as increased nodular enhancement at the border of the resection cavity, the appearance of new lesions outside the resection cavity, or increased enhancement of the residual disease after surgery and before radiation. Patients with REP have worse survival compared to patients without REP (non-REP). Therefore, a reliable method for differentiating REP from non-REP is hypothesized to assist in personlized treatment planning. A potential approach is to use the radiomics and fractal texture features extracted from brain tumors to characterize morphological and physiological properties. We propose a random sampling-based ensemble classification model. The proposed …

Atlas-Based Shared-Boundary Deformable Multi-Surface Models Through Multi-Material And Two-Manifold Dual Contouring, Tanweer Rashid, Sharmin Sultana, Mallar Chakravarty, Michel Albert Audette

Electrical & Computer Engineering Faculty Publications

This paper presents a multi-material dual “contouring” method used to convert a digital 3D voxel-based atlas of basal ganglia to a deformable discrete multi-surface model that supports surgical navigation for an intraoperative MRI-compatible surgical robot, featuring fast intraoperative deformation computation. It is vital that the final surface model maintain shared boundaries where appropriate so that even as the deep-brain model deforms to reflect intraoperative changes encoded in ioMRI, the subthalamic nucleus stays in contact with the substantia nigra, for example, while still providing a significantly sparser representation than the original volumetric atlas consisting of hundreds of millions of voxels. The …

Amplitude Synchronization Of Spontaneous Activity Of Medial And Lateral Temporal Gyri Reveals Altered Thalamic Connectivity In Patients With Temporal Lobe Epilepsy, Anish V. Sathe, Michael Kogan, Kichang Kang, Jingya Miao, Mashaal Syed, Isaiah Ailes, Caio M. Matias, Devon Middleton, Feroze B. Mohamed, Scott Faro, Joseph Tracy, Ashwini Sharan, Mahdi Alizadeh

Department of Neurosurgery Faculty Papers

In this study, we examined whether amplitude synchronization of medial (MTL) and lateral (LTL) temporal lobes can detect unique alterations in patients with MTL epilepsy (mTLE) with mesial temporal sclerosis (MTS). This was a retrospective study of preoperative resting-state fMRI (rsfMRI) data from 31 patients with mTLE with MTS (age 23-69) and 16 controls (age 21-35). fMRI data were preprocessed based on a multistep preprocessing pipeline and registered to a standard space. Using each subject's T1-weighted scan, the MTL and LTL were automatically segmented, manually revised and then fit to a standard space using a symmetric normalization registration algorithm. Dual …

Pineal Cyst Apoplexy And Memory Loss: A Novel Complication, Areez Shafqat, Hanin Jaber Algethami, Shameel Shafqat, Syed Shafqat Ul Islam

Medical College Documents

An 8-year-old boy presented to our hospital complaining of a bilateral headache associated with episodes of anterograde amnesia. He had a road traffic accident 3 years ago when a computed tomography (CT) scan revealed traumatic brain injury. In addition, a small pineal cyst (PC) was noted with minor intramural calcifications. A follow-up CT a day later demonstrated increased density in the pineal gland of 60 Hounsfield Units, suggestive of apoplectic changes in the PC. However, the patient was lost to follow-up and presented with memory loss a year and a half later, upon which CT and magnetic resonance imaging revealed …

Detecting Primary Progressive Aphasia Atrophy Patterns: A Comparison Of Visual Assessment And Quantitative Neuroimaging Techniques, Stephanie Franczak, Jessica Pommy, Greta Minor, Chandler Zolliecoffer, Manav Bhalla, Mohit Agarwal, Andrew Nencka, Yang Wang, Andrew Klein, Darren O'Neill, Jude Henry, Glass Umfleet

Journal Articles

BACKGROUND: There are now clinically available automated MRI analysis software programs that compare brain volumes of patients to a normative sample and provide

OBJECTIVE: To address this gap in the literature, we examined Neuroreader

METHODS: lvPPA or aMCI patients who underwent MRI with Neuroreader

RESULTS: Cohen's Kappa coefficients were significant in 10 of the 28 computations (

CONCLUSION: Overall, our results indicated moderate to low interrater reliability, and raters never agreed that left asymmetry was present. While lower

Water Exchange Rate Across The Blood-Brain Barrier Is Associated With Csf Amyloid-Β 42 In Healthy Older Adults, Brian T. Gold, Xingfeng Shao, Tiffany L. Sudduth, Gregory A. Jicha, Donna M. Wilcock, Elayna R. Seago, Danny J. J. Wang

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: We tested if water exchange across the blood-brain barrier (BBB), estimated with a noninvasive magnetic resonance imaging (MRI) technique, is associated with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and neuropsychological function.

METHODS: Forty cognitively normal older adults (67–86 years old) were scanned with diffusion‐prepared, arterial spin labeling (DP‐ASL), which estimates water exchange rate across the BBB (k_w). Participants also underwent CSF draw and neuropsychological testing. Multiple linear regression models were run with kw as a predictor of CSF concentrations and neuropsychological scores.

RESULTS: In multiple brain regions, BBB kw was positively associated with CSF amyloid …

Hyperglycemia Followed By An Abrupt Decrease Of Blood Glucose Is A Rare Cause Of Posterior Reversible Encephalopathy Syndrome (Pres), Liza Garabet Diramerian, Nabila Ashraf, Admir Syla, Armen Malkhasian, Jason Madey

HCA Healthcare Journal of Medicine

Introduction

Posterior Reversible Encephalopathic Syndrome (PRES) is a clinical syndrome of headache, confusion or decreased level of consciousness, visual changes, seizures and focal neurologic signs associated with characteristic neuroimaging findings of posterior cerebral white matter edema. In most cases, PRES is precipitated by sudden increase in blood pressure; however, in the case presented here, the etiology was different as it was secondary to extreme changes in glucose levels.

Case Presentation

A 49-year-old female with a past medical history of hypertension and diabetes mellitus, type 2 was brought to the emergency room with a chief complaint of visual changes for 1 …

Microhemorrhages In Professional Motocross Athletes: A Case Series, Brianna Millsaps, Phillip R. Worts, Scott O. Burkhart, David C. Berg

HCA Healthcare Journal of Medicine

Introduction: Motocross is a sport in which riders race 250–450 cc four-stroke dirt bikes and are potentially subjected to a high frequency of head injuries starting at a very young age. The objective of this case series is to present the findings following gradient echo T2-weighted MRI (SWI) upon clinical evaluation after a concussion in 4 young professional motocross racers.

Clinical Findings: Microhemorrhages were found in 2 of 4 riders. Areas of microhemorrhages were not aligned with a previously positive CT finding from a prior concussion in 1 rider.

Conclusions: Microhemorrhages were found in 2 young motocross riders following a …

Cardiorespiratory Fitness Diminishes The Effects Of Age On White Matter Hyperintensity Volume, Nathan F. Johnson, Ahmed A. Bahrani, David K. Powell, Gregory A. Jicha, Brian T. Gold

Physical Therapy Faculty Publications

White matter hyperintensities (WMHs) are among the most commonly observed marker of cerebrovascular disease. Age is a key risk factor for WMH development. Cardiorespiratory fitness (CRF) is associated with increased vessel compliance, but it remains unknown if high CRF affects WMH volume. This study explored the effects of CRF on WMH volume in community-dwelling older adults. We further tested the possibility of an interaction between CRF and age on WMH volume. Participants were 76 adults between the ages of 59 and 77 (mean age = 65.36 years, SD = 3.92) who underwent a maximal graded exercise test and structural brain …

Understanding Water Diffusion In Experimental Spinal Cord Injury Remote From Injury Epicenter, Alice Motovylyak

Dissertations (1934 -)

Diffusion tensor imaging (DTI) has demonstrated success as a biomarker of spinal cord injury (SCI) severity as shown from numerous preclinical studies. However, artifacts from stabilization hardware at the lesion have precluded its use for longitudinal assessments. Previous research has documented ex vivo diffusion changes in the spinal cord both caudal and rostral to the injury epicenter. The aim of this dissertation was to quantify the structural changes that lead to different diffusion measures in the rat cervical spinal cord after a thoracic contusion injury in an attempt to find a biomarker of injury. Animals received a thoracic contusion injury …

Use Of Preoperative Apparent Diffusion Coefficients To Predict Brain Tumor Grade, Aneela Darbar, Muhammad Waqas, Syed Faaiz Enam, Shaikh D. Mahmood

Section of Neurosurgery

Introduction: The apparent diffusion coefficient (ADC) sequence is based on the diffusion properties of water molecules within tissues and correlates with tissue cellularity. ADC may have a role in predicting tumor grade for gliomas, and may in turn assist in identifying tumor biopsy sites. The purpose of this investigation was to assess the competence of preoperative ADC values in predicting tumor grades.
Methods: This was a retrospective investigation. We calculated the ADC values in the areas of greatest restriction in solid tumor components, and we recorded the pattern of contrast enhancement. Pathology reports masked to the imaging results were reviewed …

A Comprehensive Review Of Medical Imaging Equipment Used In Cadaveric Studies., Emily Simonds, Charlotte Wilson, Joe Iwanaga, Tyler Laws, Gary Holley, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Medical imaging techniques have led to great advances in clinical anatomy and forensic pathology. New and emerging technologies allow healthcare professionals to view and understand the human body from different perspectives. This gives way to new and improved interventions, treatment plans, and an overall understanding of the human body. Herein, we present a comprehensive review of the various medical imaging equipment used in cadaveric studies along with their individual strengths and limitations.

A Clinical Practice Guideline For The Management Of Patients With Acute Spinal Cord Injury: Recommendations On The Role Of Baseline Magnetic Resonance Imaging In Clinical Decision Making And Outcome Prediction, Michael G. Fehlings, Allan R. Martin, Lindsay A. Tetreault, Bizhan Aarabi, Paul Anderson, Paul M. Arnold, Darrel Brodke, Anthony S. Burns, Kazuhiro Chiba, Joseph R. Dettori, Julio C. Furlan, Gregory Hawryluk, Langston T. Holly, Susan Howley, Tara Jeji, Sukhvinder Kalsi-Ryan, Mark Kotter, Shekar Kurpad, Brian K. Kwon, Ralph J. Marino, Eric Massicotte, Geno J. Merli, James W. Middleton, Hiroaki Nakashima, Narihito Nagoshi, Katherine Palmieri, Anoushka Singh, Andrea C. Skelly, Eve C. Tsai, Alexander R. Vaccaro, Jefferson R. Wilson, Albert Yee, James Harrop

Department of Rehabilitation Medicine Faculty Papers

Introduction: The objective of this guideline is to outline the role of magnetic resonance imaging (MRI) in clinical decision making and outcome prediction in patients with traumatic spinal cord injury (SCI). Methods: A systematic review of the literature was conducted to address key questions related to the use of MRI in patients with traumatic SCI. This review focused on longitudinal studies that controlled for baseline neurologic status. A multidisciplinary Guideline Development Group (GDG) used this information, their clinical expertise, and patient input to develop recommendations on the use of MRI for SCI patients. Based on GRADE (Grading of Recommendation, Assessment, …

The Brain Imaging Data Structure, A Format For Organizing And Describing Outputs Of Neuroimaging Experiments, Krzysztof Gorgolewski, Tibor Auer, Vince Calhoun, R Cameron Craddock, Samir Das, Eugene Duff, Guillaume Flandin, Tristan Glatard, Yaroslav Halchenko

Dartmouth Scholarship

The development of magnetic resonance imaging (MRI) techniques has defined modern neuroimaging. Since its inception, tens of thousands of studies using techniques such as functional MRI and diffusion weighted imaging have allowed for the non-invasive study of the brain. Despite the fact that MRI is routinely used to obtain data for neuroscience research, there has been no widely adopted standard for organizing and describing the data collected in an imaging experiment. This renders sharing and reusing data (within or between labs) difficult if not impossible and unnecessarily complicates the application of automatic pipelines and quality assurance protocols. To solve this …

Peripheral (Deep) But Not Periventricular Mri White Matter Hyperintensities Are Increased In Clinical Vascular Dementia Compared To Alzheimer's Disease, Charles D. Smith, Eleanor S. Johnson, Linda J. Van Eldik, Gregory A. Jicha, Frederick A. Schmitt, Peter T. Nelson, Richard J. Kryscio, Richard R. Murphy, Clinton V. Wellnitz

Neurology Faculty Publications

Background and purpose: Vascular dementia (VAD) is a complex diagnosis at times difficult to distinguish from Alzheimer's disease (AD). MRI scans often show white matter hyperintensities (WMH) in both conditions. WMH increase with age, and both VAD and AD are associated with aging, thus presenting an attribution conundrum. In this study, we sought to show whether the amount of WMH in deep white matter (dWMH), versus periventricular white matter (PVH), would aid in the distinction between VAD and AD, independent of age. Methods: Blinded semiquantitative ratings of WMH validated by objective quantitation of WMH volume from standardized MRI image acquisitions. …

Disruption Of White Matter Integrity In Adult Survivors Of Childhood Brain Tumors: Correlates With Long-Term Intellectual Outcomes, Tricia Z. King, Liya Wang, Hui Mao

Psychology Faculty Publications

Background

Although chemotherapy and radiation treatment have contributed to increased survivorship, treatment-induced brain injury has been a concern when examining long-term intellectual outcomes of survivors. Specifically, disruption of brain white matter integrity and its relationship to intellectual outcomes in adult survivors of childhood brain tumors needs to be better understood.

Methods

Fifty-four participants underwent diffusion tensor imaging in addition to structural MRI and an intelligence test (IQ). Voxel-wise group comparisons of fractional anisotropy calculated from DTI data were performed using Tract Based Spatial Statistics (TBSS) on 27 survivors (14 treated with radiation with and without chemotherapy and 13 treated without …

A Comparative Study Of Two Prediction Models For Brain Tumor Progression, Deqi Zhou, Loc Tran, Jihong Wang, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.)

Electrical & Computer Engineering Faculty Publications

MR diffusion tensor imaging (DTI) technique together with traditional T1 or T2 weighted MRI scans supplies rich information sources for brain cancer diagnoses. These images form large-scale, high-dimensional data sets. Due to the fact that significant correlations exist among these images, we assume low-dimensional geometry data structures (manifolds) are embedded in the high-dimensional space. Those manifolds might be hidden from radiologists because it is challenging for human experts to interpret high-dimensional data. Identification of the manifold is a critical step for successfully analyzing multimodal MR images.

We have developed various manifold learning algorithms (Tran et al. 2011; Tran et al. …

A Case Report Of Joubert Syndrome In Adult Presenting With Seizures, Ramla Nayaib Hashmi, Umm Ul Kiram

Pakistan Journal of Neurological Sciences (PJNS)

Joubert syndrome (JS) is rare autosomal recessive condition characterized by hypotonia, ataxia, psychomotor delay, and variable occurrence of oculomotor apraxia and neonatal breathing abnormalitie,intellectual disability, and specific mid-hindbrain malformation (“molar tooth sign”, MTS) We reportthe case of Joubert syndrome in a 32 years old female patient presenting with intellectual impairment, breathing abnormal breathing patterns like tachypnea followed by apnea ataxia, and seizures. She was diagnosed on the basis of Magnetic Resonance Imaging (MRI) and clinical features. JoubertSyndrome should be considered in all patients presenting with hypotonia, ataxia, nystagmus, breathing abnormalities and developmental delay. Its neuroimaging hallmarks include molar tooth sign …

A Descriptive Study To Find Possible Correlation Between Mri Findings Of Pituitary Gland And Serum Prolactin Level, Muhammad Azeemuddin, Rohana Naqi, Mohammad Wasay

Department of Medicine

Objective: To explore equation, if any, between findings of magnetic resonance imaging of pituitary gland and serum prolactin level.

Methods: The retrospective, descriptive study was conducted at the Department of Radiology, Aga Khan University Hospital, Karachi, and related to patients\' records from April 19, 2006 to April 23, 2009. Seventy patients underwent magnetic resonance imaging of brain for pituitary gland. Inclusion criteria were all patients referred with relevant clinical symptoms or deranged serum prolactin level. Patients who were claustrophobic or had a pacemaker, aneurysm clip, metallic foreign body in the orbit or with no laboratory investigation were excluded from the …

Data Sharing In Neuroimaging Research, Jean-Baptiste Poline, Janis L. Breeze, Satrajit Ghosh, Krzysztof Gorgolewski, Yaroslav O. Halchenko

Dartmouth Scholarship

Significant resources around the world have been invested in neuroimaging studies of brain function and disease. Easier access to this large body of work should have profound impact on research in cognitive neuroscience and psychiatry, leading to advances in the diagnosis and treatment of psychiatric and neurological disease. A trend toward increased sharing of neuroimaging data has emerged in recent years. Nevertheless, a number of barriers continue to impede momentum. Many researchers and institutions remain uncertain about how to share data or lack the tools and expertise to participate in data sharing. The use of electronic data capture (EDC) methods …

Histogram Analysis Of Adc In Brain Tumor Patients, Debrup Banerjee, Jihong Wang, Jiang Li, Norbert J. Pelc (Ed.), Ehsan Samei (Ed.), Robert M. Nishikawa (Ed.)

Electrical & Computer Engineering Faculty Publications

At various stage of progression, most brain tumors are not homogenous. In this presentation, we retrospectively studied the distribution of ADC values inside tumor volume during the course of tumor treatment and progression for a selective group of patients who underwent an anti-VEGF trial. Complete MRI studies were obtained for this selected group of patients including pre- and multiple follow-up, post-treatment imaging studies. In each MRI imaging study, multiple scan series were obtained as a standard protocol which includes T1, T2, T1-post contrast, FLAIR and DTI derived images (ADC, FA etc.) for each visit. All scan series (T1, T2, FLAIR, …

Prediction Of Brain Tumor Progression Using Multiple Histogram Matched Mri Scans, Debrup Banerjee, Loc Tran, Jiang Li, Yuzhong Shen, Frederic Mckenzie, Jihong Wang, Ronald M. Summers (Ed.), Bram Van Ginneken (Ed.)

Electrical & Computer Engineering Faculty Publications

In a recent study [1], we investigated the feasibility of predicting brain tumor progression based on multiple MRI series and we tested our methods on seven patients' MRI images scanned at three consecutive visits A, B and C. Experimental results showed that it is feasible to predict tumor progression from visit A to visit C using a model trained by the information from visit A to visit B. However, the trained model failed when we tried to predict tumor progression from visit B to visit C, though it is clinically more important. Upon a closer look at the MRI scans …

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 …

White Matter Diffusion Alterations In Normal Women At Risk Of Alzheimer's Disease, Charles D. Smith, Himachandra Chebrolu, Anders H. Andersen, David A. Powell, Mark A. Lovell, Shuling Xiong, Brian T. Gold

Neurology Faculty Publications

Increased white matter mean diffusivity and decreased fractional anisotropy (FA) has been observed in subjects diagnosed with mild cognitive impairment (MCI) and Alzheimer's disease (AD). We sought to determine whether similar alterations of white matter occur in normal individuals at risk of AD. Diffusion tensor images were acquired in 42 cognitively normal right-handed women with both a family history of dementia and at least one apolipoprotein E4 allele. These were compared with images from 23 normal women without either AD risk factor. Group analyses were performed using tract-based spatial statistics. Reduced FA was observed in the fronto-occipital and inferior temporal …

Resting State Default-Mode Network Connectivity In Early Depression Using A Seed Region-Of-Interest Analysis: Decreased Connectivity With Caudate Nucleus, Robyn Bluhm, Peter Williamson, Ruth Lanius, Jean Théberge, Maria Densmore, Robert Bartha, Richard Neufeld, Elizabeth Osuch

Philosophy Faculty Publications

Aim: Reports on resting brain activity in healthy controls have described a default-mode network (DMN) and important differences in DMN connectivity have emerged for several psychiatric conditions. No study to date, however, has investigated resting-state DMN in relatively early depression before years of medication treatment. The objective of the present study was, therefore, to investigate the DMN in patients seeking help from specialized mental health services for the first time for symptoms of depression.

Methods: Fourteen depressed subjects and 15 matched controls were scanned using 4-T functional magnetic resonance imaging while resting with eyes closed. All but one subject was …

Magnetic Resonance Imaging (Mri) Findings In White Matter Disease Of Brain, Humera Ahsan, Muhammad Zafar Rafique, Fozia Ajmal, Mohsin Wahid, Muhammad Azeemuddin, Farah Iqbal

Department of Radiology

Demyelinating and dysmyelinating white matter diseases are important components of neurological problems. Recently, Magnetic Resonance Imaging (MRI) has played a key role in diagnoses of white matter diseases. Therefore, the purpose of the current study is to evaluate the usefulness of MRI in determining the type and frequency of white matter disease. We studied 35 patients who visited the Radiology Department of the Aga Khan University Hospital (AKUH) for MRI with suspected demyelinating/dysmyelinating disorder from January 2003 to December 2005. Multiple Sclerosis (MS) (17; 48%) and leukodystrophies (10; 29%) were the most common diseases. The MRI helped identify the sites …

Continuous Asl Perfusion Fmri Investigation Of Higher Cognition: Quantification Of Tonic Cbf Changes During Sustained Attention And Working Memory Tasks, Junghoon Kim, John Whyte, Jiongjiong Wang, Hengyi Rao, Kathy Z. Tang, John A. Detre

Department of Rehabilitation Medicine Faculty Papers

Arterial spin labeling (ASL) perfusion fMRI is an emerging method in clinical neuroimaging. Its non-invasiveness, absence of low frequency noise, and ability to quantify the absolute level of cerebral blood flow (CBF) make the method ideal for longitudinal designs or low frequency paradigms. Despite the usefulness in the study of cognitive dysfunctions in clinical populations, perfusion activation studies to date have been conducted for simple sensorimotor paradigms or with single-slice acquisition, mainly due to technical challenges. Using our recently developed amplitude-modulated continuous ASL (CASL) perfusion fMRI protocol, we assessed the feasibility of a higher level cognitive activation study in twelve …