An Anatomic, Imaging, and Clinical Review of the Medial Longitudinal
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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 -
Telovelar Approach to the Fourth Ventricle: Microsurgical Anatomy
J Neurosurg 92:812–823, 2000 Telovelar approach to the fourth ventricle: microsurgical anatomy ANTONIO C. M. MUSSI, M.D., AND ALBERT L. RHOTON, JR., M.D. Department of Neurological Surgery, University of Florida, Gainesville, Florida Object. In the past, access to the fourth ventricle was obtained by splitting the vermis or removing part of the cere- bellum. The purpose of this study was to examine the access to the fourth ventricle achieved by opening the tela cho- roidea and inferior medullary velum, the two thin sheets of tissue that form the lower half of the roof of the fourth ven- tricle, without incising or removing part of the cerebellum. Methods. Fifty formalin-fixed specimens, in which the arteries were perfused with red silicone and the veins with blue silicone, provided the material for this study. The dissections were performed in a stepwise manner to simulate the exposure that can be obtained by retracting the cerebellar tonsils and opening the tela choroidea and inferior medullary velum. Conclusions. Gently displacing the tonsils laterally exposes both the tela choroidea and the inferior medullary velum. Opening the tela provides access to the floor and body of the ventricle from the aqueduct to the obex. The additional opening of the velum provides access to the superior half of the roof of the ventricle, the fastigium, and the superolater- al recess. Elevating the tonsillar surface away from the posterolateral medulla exposes the tela, which covers the later- al recess, and opening this tela exposes the structure forming -
A Small Dorsal Pontine Infarction Presenting with Total Gaze Palsy Including Vertical Saccades and Pursuit
Journal of Clinical Neurology / Volume 3 / December, 2007 Case Report A Small Dorsal Pontine Infarction Presenting with Total Gaze Palsy Including Vertical Saccades and Pursuit Eugene Lee, M.D., Ji Soo Kim, M.D.a, Jong Sung Kim, M.D., Ph.D., Ha Seob Song, M.D., Seung Min Kim, M.D., Sun Uk Kwon, M.D. Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine aDepartment of Neurology, Seoul National University, Bundang Hospital A small localized infarction in the dorsal pontine area can cause various eye-movement disturbances, such as abducens palsy, horizontal conjugate gaze palsy, internuclear ophthalmoplegia, and one-and-a-half syndrome. However, complete loss of vertical saccades and pursuit with horizontal gaze palsy has not been reported previously in a patient with a small pontine lesion. We report a 67-year-old man with a small dorsal caudal pontine infarct who exhibited total horizontal gaze palsy as well as loss of vertical saccades and pursuit. J Clin Neurol 3(4):208-211, 2007 Key Words : Ophthalmoplegia, Pontine infarction, Omnipause neurons A small localized dorsal pontine infarction can to admission he had experienced sudden general produce abducens palsy, horizontal conjugate gaze weakness for approximately 20 minutes without loss palsy, internuclear ophthalmoplegia (INO), and one- of consciousness while working on his farm. The and-a-half syndrome by damaging the abducens nucleus following day, the patient experienced dysarthric and its fascicle, the paramedian pontine reticular speech and visual obscuration, and his family members formation (PPRF), or the medial longitudinal fasciculus noticed that his eyes were deviated to one side. -
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. -
Micturitional Disturbance in Herpetic Brainstem Encephalitis; Contribution of the Pontine Micturition Centre
J Neurol Neurosurg Psychiatry 1998;64:269–272 269 SHORT REPORT Micturitional disturbance in herpetic brainstem encephalitis; contribution of the pontine micturition centre Ryuji Sakakibara, Takamichi Hattori, Toshio Fukutake, Masahiro Mori, Tomonori Yamanishi, Kosaku Yasuda Abstract coeruleus14 and lateral dorsal tegmental Micturitional disturbance is rarely men- nucleus.5 A pontine storage centre also exists tioned in human herpetic brainstem en- just ventromedial or lateral to the pontine mic- cephalitis although the pontine turition centre. Recently, we found micturi- tegmentum, called the pontine micturi- tional disturbance in patients with brainstem tion centre, seems to regulate the lower stroke.6 Their MRI showed that the responsible urinary tract in experimental animals. sites are comparable with those reported in The case of a 45 year old man, who devel- experimental studies.1–3 Herpes simplex virus oped subacute coma and hiccup-like dys- type 1 (HSV-1) infection also causes brainstem rhythmic breathing, and needed assisted lesions78characterised by acute onset of multi- ventilation is reported. Examination of ple cranial nerve palsies, ataxia, and pyramidal CSF showed mononuclear pleocytosis and tract involvement. Disturbances of conscious- antibody against herpes simplex virus ness and respiration are not uncommon. type 1, but the opening pressure was 90 cm Micturitional disturbance is rarely reported in this disease. We here describe the micturitional H2O. Brain CT showed brain swelling, predominantly in the posterior fossa, and disturbance of a patient with herpetic brain- bilateral subdural eVusion. Herpetic stem encephalitis who showed bilateral pontine brainstem encephalitis was diagnosed, tegmental lesions on MRI. and he received 900 mg/day vidarabine. On regaining consciousness, he had left Case report trochlear nerve palsy, left corectopia, A 45 year old, previously healthy man devel- ageusia, and urinary retention. -
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. -
Lipoma of the Midbrain
LIPOMA OF THE MIDBRAIN POST-MORTEM FINDING IN A PATIENT WITH BREAST CANCER VERÔNICA MAIA GOUVEA * — MYRIAM DUMAS HAHN ** — LEILA CHIMELLI ** SUMMARY — Intracranial lipomas are rare, usually do not have clinical expression and are located mare frequently in the corpus callosum. Other locations include the spinal cord, midbrain tectum, superior vermis, tuber cinereum, infundibulum and more rarely cerebello pontine angle, hypothalamus, superior medullary velum and insula. We report the case of a lipoma of the left inferior colliculus which was a post-mortem finding in a woman who died of breast cancer. Although there are reports of intracranial lipomas in patients with malignant tumors there is no explanation for the co-existence of the two tumors. The present tumor also includes a segment of a nerve which is not uncommon, but a less common finding was the presence of nests of Schwann cells within it, shown by immunohistochemistry. Lipoma do mesencéfalo: achado de necrópsia, em paciente com câncer da mama. RESUMO — Lipomas intracranianos são raros, em geral sem expressão clínica, localizados mais freqüentemente no corpo caloso. Outras localizações incluem medula espinhal, teto mesencefálico, vermis superior, tuber cinereum, infundibulum e mais raramente o ângulo ponto-cerebelar, hipotálamo, véu medular superior e insula. Relatamos o achado de necrópsia de um lipoma do colículo inferior esquerdo em uma mulher com câncer de mama. Embora haja relatos de lipomas intracranianos em pacientes com tumores malignos não há explicação para a co-existência dos dois tumores. O presente tumor também inclui o segmento de um nervo, o que não é incomum, mas um achado menos comum foi a presença de ninhos de células de Schwann no tumor, mostradas por imuno-histoquímica. -
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).