Tegmental Pontine Hemorrhages: Clinical Features and Prognostic Factors
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Imaging of the Confused Patient: Toxic Metabolic Disorders Dara G
Imaging of the Confused Patient: Toxic Metabolic Disorders Dara G. Jamieson, M.D. Weill Cornell Medicine, New York, NY The patient who presents with either acute or subacute confusion, in the absence of a clearly defined speech disorder and focality on neurological examination that would indicate an underlying mass lesion, needs to be evaluated for a multitude of neurological conditions. Many of the conditions that produce the recent onset of alteration in mental status, that ranges from mild confusion to florid delirium, may be due to infectious or inflammatory conditions that warrant acute intervention such as antimicrobial drugs, steroids or plasma exchange. However, some patients with recent onset of confusion have an underlying toxic-metabolic disorders indicating a specific diagnosis with need for appropriate treatment. The clinical presentations of some patients may indicate the diagnosis (e.g. hypoglycemia, chronic alcoholism) while the imaging patterns must be recognized to make the diagnosis in other patients. Toxic-metabolic disorders constitute a group of diseases and syndromes with diverse causes and clinical presentations. Many toxic-metabolic disorders have no specific neuroimaging correlates, either at early clinical stages or when florid symptoms develop. However, some toxic-metabolic disorders have characteristic abnormalities on neuroimaging, as certain areas of the central nervous system appear particularly vulnerable to specific toxins and metabolic perturbations. Areas of particular vulnerability in the brain include: 1) areas of high-oxygen demand (e.g. basal ganglia, cerebellum, hippocampus), 2) the cerebral white matter and 3) the mid-brain. Brain areas of high-oxygen demand are particularly vulnerable to toxins that interfere with cellular respiratory metabolism. -
Efficacy And/Or Effectiveness of Portable Neuromodulation Stimulator (Pons®) As Treatment for Traumatic Brain Injury (TBI)”
Evidence-Based Practice Group Answers to Clinical Questions “Efficacy and/or Effectiveness of Portable Neuromodulation Stimulator (PoNS®) as Treatment for Traumatic Brain Injury (TBI)” A Rapid Systematic Review By WorkSafeBC Evidence-Based Practice Group Dr. Craig Martin Manager, Clinical Services Chair, Evidence-Based Practice Group October 2019 Clinical Services – Worker and Employer Services Efficacy and/or Effectiveness of Portable Neuromodulation Stimulator (PoNS®) as Treatment for Traumatic Brain Injury (TBI) i About this report Efficacy and/or Effectiveness of Portable Neuromodulation Stimulator (PoNS®) as Treatment for Traumatic Brain Injury (TBI) Published: October 2019 About the Evidence-Based Practice Group The Evidence-Based Practice Group was established to address the many medical and policy issues that WorkSafeBC officers deal with on a regular basis. Members apply established techniques of critical appraisal and evidence-based review of topics solicited from both WorkSafeBC staff and other interested parties such as surgeons, medical specialists, and rehabilitation providers. Suggested Citation WorkSafeBC Evidence-Based Practice Group, Martin CW. Efficacy and/or Effectiveness of Portable Neuromodulation Stimulator (PoNS®) as Treatment for Traumatic Brain Injury (TBI). Richmond, BC: WorksafeBC Evidence- Based Practice Group; October 2019. Contact Information Evidence-Based Practice Group WorkSafeBC PO Box 5350 Stn Terminal Vancouver BC V6B 5L5 Email [email protected] Phone 604 279-7417 Toll-free 1 888 967-5377 -
Overview of the Reticular Formation (RF)
TeachSheet Reticular Formation & Diffuse modulatory system Overview of the Reticular Formation (RF) The term reticular formation refers to the neuronal network within the brainstem, although it continues rostrally into the thalamus and hypothalamus and caudally into the propriospinal network of the spinal cord. A “coordinating system” (like the Limbic system) with “connections” to sensory, somatic motor and visceral motor systems Organization can be subdivided into two neuronal cell “columns” (medial to lateral) as well as on the basis of their neurotransmitter release Neuronal columns (many nuclei and names, but these are some of the major ones): o “Medial tegmental field” (large-celled nuclei) . Origin of the reticulospinal pathway . Role in coordinating posture, eye and head movements. o “Lateral tegmental field” (smaller and fewer cells, shorter local projections) . Extends from the medulla to the pons . Coordinate autonomic and limbic functions (e.g. micturition, swallowing, mastication and vocalization) The functions of the reticular formation include their ability to coordinate motor and sensory brainstem nuclei: o Pattern generator . Eye movements; horizontal (PPRF) and vertical (riMLF) . Rhythmical chewing movements (pons) . Posture and locomotion (midbrain and pons) . Swallowing, vomiting, coughing and sneezing (medulla) . Micturition (pons) o Respiratory control (medulla); expiratory, inspiratory, apneustic and pneumotaxic o Cardiovascular control (medulla); vasomotor pressor/depressor, cardioacceleratory and inhibitory. Afferents arise from baroreceptors (carotid sinus and aortic arch), chemoreceptors (carotid sinus, lateral reticular formation chemosensitive area in the medulla) and stretch receptors (lung and respiratory muscles) . Efferents arise from reticular formation neurons within the pons and medulla o Sensory modulation or “gate” control . The term “gating” refers to “modulation” of synaptic transmission from one set of neurons to the next. -
The Portable Neuromodulation Stimulator (Pons)
The Portable Neuromodulation Stimulator (PoNS™) FACT SHEET What is the PoNS? The Portable Neuromodulation Stimulator (PoNS) device is an investigational medical device being studied for the treatment of neurological symptoms caused by disease or trauma. The PoNS is currently being studied in the United States for the treatment of balance disorder related to mild to moderate Traumatic Brain Injury (mTBI), and in Canada for the treatment of gait and balance disorder for patients with Multiple Sclerosis (MS). It represents the first in a series of non-invasive devices -- based on the patented PoNS platform -- designed to amplify the brain’s powerful ability to heal itself. This is part of a new approach being studied for “symptom treatment” for the rising number of patients who have experienced loss of function as a result of neurological disease or trauma. What is the potential impact of the PoNS? As a result of their disease or injury, many patients are left with disrupted neural networks in the brain that are unable to carry neural impulses completely or efficiently. Neural impulses are the signals responsible for directing the functions of the body, such as movement control or sensory perception. Researchers believe that significantly increasing the activation of these neurons through electrical stimulation, combined with targeted functional therapy, may help reorganize and reactivate the networks responsible for those functions. While physicians and patients turn to available options to manage a host of neurological symptoms today, for millions living with these chronic disorders, there exists limited treatment options that actually help patients rehabilitate lost functions. The PoNS device is being studied as new potential option for the treatment of these chronic neurological symptoms of disease or trauma. -
Orienting Head Movements Resulting from Electrical Microstimulation of the Brainstem Tegmentum in the Barn Owl
The Journal of Neuroscience, January 1993, 13(l): 351370 Orienting Head Movements Resulting from Electrical Microstimulation of the Brainstem Tegmentum in the Barn Owl Tom Masino and Eric I. Knudsen Department of Neurobiology, Stanford University, Stanford, California 943055401 The size and direction of orienting movements are repre- movement latency, duration, velocity, and size each dem- sented systematically as a motor map in the optic tectum of onstrated dependencies on stimulus amplitude, frequency, the barn owl (du Lac and Knudsen, 1990). The optic tectum and duration. projects to several distinct regions in the medial brainstem The data demonstrate directly that at the level of the mid- tegmentum, which in turn project to the spinal cord (Masino brain tegmentum there exists a three-dimensional Cartesian and Knudsen, 1992). This study explores the hypothesis that representation of head-orienting movements such that hor- a fundamental transformation in the neural representation izontal, vertical, and roll components of movement are en- of orienting movements takes place in the brainstem teg- coded by anatomically distinct neural circuits. The data sug- mentum. Head movements evoked by electrical microstim- gest that in the projection from the optic tectum to these ulation in the brainstem tegmentum of the alert barn owl were medial tegmental regions, the topographic code for orienting cataloged and the sites of stimulation were reconstructed movement that originates in the tectum is transformed into histologically. Movements elicited from the brainstem teg- this Cartesian code. mentum were categorized into one of six different classes: [Key words: optic tectum, superior colliculus, saccadic saccadic head rotations, head translations, facial move- head movement, brainstem tegmentum, interstitial nucleus ments, vocalizations, limb movements, and twitches. -
Optogenetic Activation of Cholinergic Neurons in the PPT Or LDT Induces REM Sleep
Optogenetic activation of cholinergic neurons in the PPT or LDT induces REM sleep Christa J. Van Dorta,b,c,1, Daniel P. Zachsa,b,c, Jonathan D. Kennya,b,c, Shu Zhengb, Rebecca R. Goldblumb,c,d, Noah A. Gelwana,b,c, Daniel M. Ramosb,c, Michael A. Nolanb,c,d, Karen Wangb,c, Feng-Ju Wengb,e, Yingxi Linb,e, Matthew A. Wilsonb,c, and Emery N. Browna,b,d,f,1 aDepartment of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114; and bDepartment of Brain and Cognitive Sciences, cPicower Institute for Learning and Memory, eMcGovern Institute for Brain Research, fHarvard-MIT Division of Health Sciences and Technology, and dInstitute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139 Contributed by Emery N. Brown, December 3, 2014 (sent for review September 19, 2014; reviewed by Helen A. Baghdoyan and H. Craig Heller) Rapid eye movement (REM) sleep is an important component of REM sleep regulation, a method that can modulate specific cell the natural sleep/wake cycle, yet the mechanisms that regulate types in the behaving animal is needed. Optogenetics now pro- REM sleep remain incompletely understood. Cholinergic neurons vides this ability to target specific subpopulations of neurons in the mesopontine tegmentum have been implicated in REM sleep and control them with millisecond temporal resolution (30). regulation, but lesions of this area have had varying effects on REM Therefore, we aimed to determine the role of cholinergic sleep. Therefore, this study aimed to clarify the role of cholinergic neurons in the PPT and LDT in REM sleep regulation using neurons in the pedunculopontine tegmentum (PPT) and laterodor- optogenetics. -
Brainstem Dental 2012.Doc
Dental Neuroanatomy January 12 and 19, 10-12, 2012 Suzanne S. Stensaas, Ph.D. Dear Students: Please print these notes and bring them with you. My style is to use a Tablet PC and I draw on either a Word or pdf copy with colors. Be prepared to draw. Have at least 5 colors. Please try to look at the notes AHEAD OF TIME for each lecture in this course. This way you can see the direction and organization of the lecture and be more familiar with the terms. There will be a quiz (that does not count) at the beginning to cover topics in the two gross anatomy lectures by Dr. Morton in Phase 1. They are G 17B and GL 18 Waxman, S Clinical Neuroanatomy, 26th ed.2010. THE OLD EDITION IS FINE TOO. Review Ch 5 on the spinal cord organization, but not the tracts in the middle or lesions at the end of the chapter. Also review the basic concept of a reflex. Review or skim Ch 12 on the vascular supply of the brain. Just look at pictures and legends for the clinical part at the end. NEW material: Chapter 7 Waxman, Brainstem, but not the cerebellum part. NEW material: Chapter 8 Waxman, Cranial nerves, all of it including autonomic. BEWARE THE CRANIAL NERVES ARE KILLERS! There are about 50 copies of the following bright yellow paperback book, which can be checked out from the Eccles Health Sciences Library and kept for the duration of the course. They are on reserve as: Cranial nerves: anatomy and clinical comments Linda Wilson-Pauwels, 1988 Toronto; Philadelphia: B.C. -
Isolated Necrosis of Central Tegmental Tracts Due to Neonatal Hypoxic-Ischemic Encephalopathy: MRI Findings
Journal of Neurology & Stroke Case Report Open Access Isolated necrosis of central tegmental tracts due to neonatal hypoxic-ischemic encephalopathy: MRI findings Abstract Volume 11 Issue 1 - 2021 Perinatal hypoxia is an old entity that still prevails today and may lead to neurological Tomás de Andrade Lourenção Freddi, Luiz sequelae that can go unnoticed until a certain age, generating many costs for public health. In this case report, we demonstrate on magnetic resonance imaging an unusual pattern of Fellipe Curvêlo Ciraulo Santos, Nelson Paes perinatal hypoxia in a preterm 5-month-old infant, involving the central tegmental tracts Fortes Diniz Ferreira, Felipe Diego Gomes and briefly discuss its possible pathophysiology. Dantas Department of Radiology, Hospital do Coração, Brazil Keywords: magnetic resonance imaging, asphyxia, hypoxic-ischemic encephalopathy, tegmentum, neonates, brainstem Correspondence: Tomás de Andrade Lourenção Freddi, Hospital do Coração, 147 Desembargador Eliseu Guilherme Street, São Paulo, SP, 04004-030, Brazil, Tel +5511976059280, Email Received: May 25, 2020 | Published: Febrauary 15, 2021 Abbreviations: MRI, magnetic resonance imaging; HII, that connect the red nucleus and the inferior olivary nucleus, being hypoxic-ischemic injury; FLAIR, fluid-attenuated inversion recovery; part of the dentato-rubro-olivary system, called Guillain–Mollaret CTT, central tegmental tract; VGB, vigabatrin triangle.3–5 Introduction Hypoxic-ischemic injury (HII) is one of the most important causes of encephalopathy in neonates, irrespective of gestational age, and may occur in the uterus or during delivery by different intrapartum conditions. In preterm or very low birth weight infants, brain magnetic resonance imaging (MRI) can demonstrate multiple different findings, which a detailed description is beyond the scope of this article, although being periventricular leukomalacia the most frequent (seen in at least 50% of cases). -
Chapter 128: Basic Mechanisms of Sleep: New Evidence On
128 BASIC MECHANISMS OF SLEEP: NEW EVIDENCE ON THE NEUROANATOMY AND NEUROMODULATION OF THE NREM-REM CYCLE EDWARD F. PACE-SCHOTT J. ALLAN HOBSON The 1990s brought a wealth of new detail to our knowledge NREM sleep (noradrenergic, serotonergic, and cholinergic of the brain structures involved in the control of sleep and systems damped), and REM sleep (noradrenergic and sero- waking and in the cellular level mechanisms that orchestrate tonergic systems off, cholinergic system undamped) (1–4). the sleep cycle through neuromodulation. This chapter pre- sents these new findings in the context of the general history Original Reciprocal Interaction Model: An of research on the brainstem neuromodulatory systems and Aminergic-Cholinergic Interplay the more specific organization of those systems in the con- trol of the alternation of wake, non–rapid eye movement The model of reciprocal interaction (5) provided a theoretic (NREM), and REM sleep. framework for experimental interventions at the cellular and Although the main focus of the chapter is on the our molecular level that has vindicated the notion that waking own model of reciprocal aminergic-cholinergic interaction, and REM sleep are at opposite ends of an aminergically we review new data suggesting the involvement of many dominant to cholinergically dominant neuromodulatory more chemically specific neuronal groups than can be ac- continuum, with NREM sleep holding an intermediate po- commodated by that model. We also extend our purview to sition (Fig. 128.1). The reciprocal interaction hypothesis the way in which the brainstem interacts with the forebrain. (5) provided a description of the aminergic-cholinergic in- These considerations inform not only sleep-cycle control terplay at the synaptic level and a mathematic analysis of per se, but also the way that circadian and ultradian rhythms the dynamics of the neurobiological control system. -
Reticular Formation and Sleep/Wakefulness
Reticular Formation and Sleep/Wakefulness Maureen Riedl Department of Neuroscience University of Minnesota 1 Reticular Formation • The reticular formation is the oldest part of our nervous system phylogenetically. • It is present throughout the midbrain, pons and medulla. • Typically, the reticular formation is regions of the brainstem between clearly defined nuclei and tracts • It is groups of neurons embedded in a seeming disorganized mesh of axons and dendrites. 2 Reticular Formation • Although seemingly disorganized, over 100 groups of neurons related by function and connections have been identified in the reticular formation. 3 Reticular Formation Locus Coeruleus Cortex Spinal Cord Amygdala Superior Colliculus Reticular Formation Motor Nuclei Cerebellum Hippocampus Hypothalamus Periaqueductal Gray Thalamus 4 Reticular Formation • The reticular formation receives input from all parts of the nervous system… every sensory system, all parts of the motor system, thalamus, hypothalamus, cortex, etc. • The output of the reticular formation is as diverse as its input. • Many of the neurons in the reticular formation have large, highly branched dendrites that receive diverse information. 5 Reticular Formation • The reticular formation has a major role in regulation of: • Motor control • Sensory attention • Autonomic nervous system • Eye movements • Sleep and wakefulness 6 Reticulospinal & Reticulbulbar Projections • Reticular formation (RF) in the lower pons and medulla receives motor information from premotor cortex, motor cortex and cerebellum as well as proprioceptive and vestibular sensory information. • RF sends axons to cranial nerve motor nuclei and to ventral horn of the spinal cord via the reticulospinal tracts. 7 Reticulospinal & Reticulbulbar Projections • Reticular formation (RF) initiates ‘accompanying’ movements. • Accompanying movements are subconscious and are needed in support of a consciously initiated movement. -
Brain Anatomy
BRAIN ANATOMY Adapted from Human Anatomy & Physiology by Marieb and Hoehn (9th ed.) The anatomy of the brain is often discussed in terms of either the embryonic scheme or the medical scheme. The embryonic scheme focuses on developmental pathways and names regions based on embryonic origins. The medical scheme focuses on the layout of the adult brain and names regions based on location and functionality. For this laboratory, we will consider the brain in terms of the medical scheme (Figure 1): Figure 1: General anatomy of the human brain Marieb & Hoehn (Human Anatomy and Physiology, 9th ed.) – Figure 12.2 CEREBRUM: Divided into two hemispheres, the cerebrum is the largest region of the human brain – the two hemispheres together account for ~ 85% of total brain mass. The cerebrum forms the superior part of the brain, covering and obscuring the diencephalon and brain stem similar to the way a mushroom cap covers the top of its stalk. Elevated ridges of tissue, called gyri (singular: gyrus), separated by shallow groves called sulci (singular: sulcus) mark nearly the entire surface of the cerebral hemispheres. Deeper groves, called fissures, separate large regions of the brain. Much of the cerebrum is involved in the processing of somatic sensory and motor information as well as all conscious thoughts and intellectual functions. The outer cortex of the cerebrum is composed of gray matter – billions of neuron cell bodies and unmyelinated axons arranged in six discrete layers. Although only 2 – 4 mm thick, this region accounts for ~ 40% of total brain mass. The inner region is composed of white matter – tracts of myelinated axons. -
Pons Treatment™: Restoring Balance and Gait Through Noninvasive Neuromodulation1-4
Introducing PoNS™ (Portable Neuromodulation Stimulator) PoNS Treatment™: Restoring balance and gait through noninvasive neuromodulation1-4 The PoNS™ device is intended for use as an acute treatment of chronic balance deficit due to mild-to- moderate traumatic brain injury (mmTBI), and is to be used in conjunction with physical therapy (PT). The device is limited to prescription use. Contraindications The PoNS™ device delivers electrical stimulation directly to the surface of the tongue. Precautions for use are similar to those for transcutaneous electrical nerve stimulation (TENS). Electrical stimulation SHOULD NOT be used: if there is an active or suspected malignant tumor, in areas of recent bleeding or open wounds, or in areas that lack normal sensation. PoNS™ has not been tested on, and thus should not be used by, individuals under the age of 18 or who are pregnant. PoNS™ should not be used in patients sensitive to nickel, gold, or copper. PoNS™ is an authorized medical device and commercially available in Canada. PoNS™ is an investigational device under review for EU clearance by an EU notified body and by TGA in Australia; PoNS™ is not commercially available in the US, EU, or Australia. ™ HEALING IN MIND In patients who have experienced an mmTBI Chronic balance deficit is prevalent5-8 ~350 people in Canada are living with chronic balance deficit THOUSAND after an mmTBI5-7 ~13 new cases of chronic balance deficit from mmTBI THOUSAND are reported annually in Canada6-8 Rehabilitation therapy (physical therapy, occupational therapy,