DOCSLIB.ORG

Conduction Aphasia Elicited by Stimulation of the Left Posterior Superior Temporal Gyrus

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Conduction Aphasia Elicited by Stimulation of the Left Posterior Superior Temporal Gyrus J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.66.3.393 on 1 March 1999. Downloaded from J Neurol Neurosurg Psychiatry 1999;66:393–396 393 SHORT REPORT Conduction aphasia elicited by stimulation of the left posterior superior temporal gyrus Mark Quigg, Nathan B Fountain Abstract Case report Objective—Disruption of fascicular tracts A 35 year old right handed woman had intrac- that connect Wernicke’s to Broca’s areas is table complex partial seizures consisting of the classic mechanism of conduction parosmias, tachycardia, and confusion of a aphasia. Later work has emphasised corti- year’s duration. Biopsy of the left temporal pole cal mechanisms. at another institution had disclosed a left fron- Methods—To determine the distribution totemporal oligodendroglioma. of language on dominant cortex, electrical The patient presented to the comprehensive cortical stimulation was performed using epilepsy program 4 months later with contin- implanted subdural electrodes during ued seizures. Neurological examination was brain mapping before epilepsy surgery. normal with findings of intact comprehension, Results—A transient, isolated deficit in repetition, and naming. Brain MRI disclosed a repetition was elicited with stimulation of large, non-enhancing, low intensity lesion in the posterior portion of the dominant the left frontotemporal region abutting the superior temporal gyrus. insula and extending to the basal ganglia Conclusion—This finding suggests that (figure (A–C)). The arcuate fasciculus ap- cortical dysfunction, not just white matter peared compromised anteriorly. Continuous disruption, can induce conduction aphasia. EEG with video monitoring showed seizure (J Neurol Neurosurg Psychiatry 1999;66:393–396) onset in the left temporal region. Speech was fluent on the preoperative Keywords: language; brain mapping; aphasia neuropsychological battery. On the Reitan- Indiana aphasia screening test the patient transposed syllables when repeating the word Conduction aphasia is thought to result from “episcopal” forming “ecispolal.” lesions of the arcuate fasciculus that disconnect For seizure localisation and cortical map- http://jnnp.bmj.com/ receptive from expressive language regions. It ping, intracranial monitoring with subdural consists of impaired repetition with preserved grids and occipitally inserted hippocampal comprehension, naming, and reading. Literal depth electrodes was performed before left paraphasias are frequent, and ideomotor temporal lobectomy and partial subfrontal apraxias can also be present. tumour resection. Subsequent histopathology The lesions that most often produce conduc- confirmed the presence of oligodendroglioma. tion aphasia involve the white matter underly- Four months postoperatively the patient was 1–3 tested with the Boston aphasia severity rating on September 27, 2021 by guest. Protected copyright. Department of ing the dominant supramarginal gyrus. The Neurology, disconnection between expressive and recep- scale. Impaired repetition with mixed parapha- Comprehensive tive cortical regions was hypothesised by sic errors became evident only when tested Epilepsy Program, Wernicke and led to the first description of with complex, low probability vocabulary. University of Virginia, conduction aphasia. However, it has been Charlottesville, VA, reported in lesions that spare white matter, and USA M Quigg is unexpectedly absent in some cases involving Methods 4–7 N B Fountain the classic lesion. Some of these diYculties in Informed consent was obtained before proce- localisation have arisen because naturally dures were carried out. Subdural grids and Correspondence to: occurring lesions may indiscriminately involve Dr Mark Quigg, Department strips (intercontact distance=1 cm) were of Neurology, both white and grey matter. These inconsisten- placed on the left frontal lobe and temporal Comprehensive Epilepsy cies, in part, support an alternative hypothesis lobe as shown on the figure (D and E). We Program, Box 394, Health that conduction aphasia may be mediated by a stimulated adjacent pairs of contacts using a 50 Sciences Center, University 8 of Virginia, Charlottesville, specific region of cortex. Hz square wave signal starting at a duration of VA 22908, USA. Telephone We report a case of transient conduction 2 seconds and an intensity of 4.5 mA. We 001 804 924 5312; fax aphasia elicited by electrical cortical stimula- 001 804 982 1726; increased duration to 5 seconds and increased email [email protected] tion of the posterior superior temporal gyrus. current by 1 mA increments until (1) a The selective and reversible impairment of a response occurred, (2) an afterdischarge or Received 17 July 1998 specific region of cortex shows that conduction clinical seizure occurred, or (3) no response and in revised form 14 September 1998 aphasia may be induced by means other than was achieved at a stimulus of 12.5 mA/5 Accepted 16 September 1998 disconnection. seconds. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.66.3.393 on 1 March 1999. Downloaded from 394 Quigg, Fountain http://jnnp.bmj.com/ (A) Axial, (B) sagittal, and (C) coronal views of a T1 weighted, uncontrasted MRI taken before placement of subdural on September 27, 2021 by guest. Protected copyright. electrodes demonstrates the large, frontotemporal cystic mass of the dominant hemisphere. The arcuate fasciculus is intact posteriorly but is diYcult to identify anteriorly near Broca’s region. (D) Coronal view after electrode placement confirming location of electrode STS 4 upon the superior temporal gyrus (white arrow). (E) Three dimensional MRI reconstruction showing the array of subdural electrodes. Stimulation at pairs LG4, 5, and 10 caused either global or non-fluent aphasia, and stimulation at STS3,4 caused conduction aphasia. STS and ITS=superior and inferior temporal strip; UG and LG=upper and lower grid; SF=sylvian fissure. Results charges were elicited. Stimulations at other Stimulation in adjacent contact pairs (lower sites had no clinical manifestations. grid electrodes 4, 5, and 10 in the figure (E)) induced anomia and speech arrest in Broca’s Discussion region. Stimulations of 5 seconds duration and Our finding of an isolated deficit of repetition 6 mA intensity at electrodes 3 and 4 of the elicited by electrical cortical stimulation is rel- superior temporal strip (figure (E)) induced a evant because it runs counter to the prevailing language disorder similar to conduction apha- view that disconnection of a white matter tract sia: (1) recitation was normal; (2) naming is necessary for conduction aphasia. The “thumb,” “index finger,” and “tie” was normal; precise localisation oVered by cortical stimula- (3) command following—“show me your tion suggests that a focal region of the posterior thumb”—was normal; and (4) repetition— superior temporal gyrus of the language domi- “Bill Clinton”, “Commonwealth of nant hemisphere can mediate language dys- Virginia”—was reproducibly impaired. No function most consistent with conduction paraphasic errors were found. No afterdis- aphasia. Because practical considerations limit J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.66.3.393 on 1 March 1999. Downloaded from Conduction aphasia by cortical stimulation 395 complex testing during intracranial electrical addition to its connecting white matter tracts is stimulation, we were only able to test the basic necessary to mediate repetition. Two findings abilities of naming, recitation, repetition, and support this conclusion. Firstly, the large fron- command following. We were not able to test totemporal tumour compromised the arcuate other findings that define the full syndrome of fasciculus but spared the overlying cortex (fig- conduction aphasia.2 ure). Despite the white matter lesion, the The arcuate fasiculus is a white matter tract patient had no preoperative evidence of a that runs from Wernicke’s area in the posterior significant conduction aphasia (although sub- superior temporal gyrus, arches around the tle findings were disclosed after partial resec- sylvian fissure, and runs anteriorly from the tion). Secondly, electrical stimulation of the inferior parietal lobe to the inferior frontal lobe superior temporal gyrus elicited transient con- of Broca’s region.3 Wernicke postulated that a duction aphasia, specifically demonstrating lesion of the arcuate fasciculus that discon- that cortical function is necessary for normal nected receptive from expressive centres would repetition. produce a deficit in repetition, or “conduction The large frontotemporal tumour could aphasia”. Others have proposed that a single confound our interpretation. It is theoretically cortical centre was responsible for integration possible that eloquent cortex was abnormally of receptive and expressive regions yet was represented as a consequence of a chronic mass independent of them.8 lesion. By this “remapping” process, stimula- Evidence from subjects with conduction tion of a makeshift language area may have aphasia usually supports the concept of discon- unexpectedly resulted in conduction aphasia, nection. In these studies (usually patients with even though this region might not normally strokes), disruption of the arcuate fasciculus is mediate this function in other subjects. This obligate with variable involvement of adjacent process seems unlikely as the tumour displaced regions of suprasylvian or subsylvian cortex.13 no other language functions, such as expressive Circumscribed lesions of the arcuate fasciculus language in Broca’s region.
Load more

Recommended publications
  • Conduction Aphasia, Sensory-Motor Integration, and Phonological Short-Term Memory – an Aggregate Analysis of Lesion and Fmri Data ⇑ Bradley R
    Brain & Language 119 (2011) 119–128 Contents lists available at ScienceDirect Brain & Language journal homepage: www.elsevier.com/locate/b&l Conduction aphasia, sensory-motor integration, and phonological short-term memory – An aggregate analysis of lesion and fMRI data ⇑ Bradley R. Buchsbaum a, , Juliana Baldo b, Kayoko Okada d, Karen F. Berman e, Nina Dronkers b, ⇑ Mark D’Esposito c, Gregory Hickok d, a Rotman Research Institute, Toronto, Ontario, Canada b VA Northern California Health Care System, Center for Aphasia and Related Disorders, Martinez, CA, USA c Department of Psychology, University of California, Berkeley, CA, USA d Department of Cognitive Sciences, University of California, Irvine, CA, USA e Section on Integrative Neuroimaging, National Institute of Mental Health, Bethesda, MD, USA article info abstract Article history: Conduction aphasia is a language disorder characterized by frequent speech errors, impaired verbatim Accepted 11 December 2010 repetition, a deficit in phonological short-term memory, and naming difficulties in the presence of other- Available online 21 January 2011 wise fluent and grammatical speech output. While traditional models of conduction aphasia have typi- cally implicated white matter pathways, recent advances in lesions reconstruction methodology Keywords: applied to groups of patients have implicated left temporoparietal zones. Parallel work using functional Conduction aphasia magnetic resonance imaging (fMRI) has pinpointed a region in the posterior most portion of the left pla- Working memory num temporale, area Spt, which is critical for phonological working memory. Here we show that the Speech production region of maximal lesion overlap in a sample of 14 patients with conduction aphasia perfectly circum- Planum temporale Brain lesion scribes area Spt, as defined in an aggregate fMRI analysis of 105 subjects performing a phonological work- Sensorimotor integration ing memory task.
    [Show full text]
  • Effects of Vocal Training in a Musicophile with Congenital Amusia
    Effects of vocal training in a musicophile with congenital amusia Jonathan M. P. Wilbiks, Dominique T. Vuvan, Pier-Yves Girard, Isabelle Peretz, and Frank A. Russo Volume 22, Issue 6, pp 526-537, Neurocase DOI: https://doi.org/10.1080/13554794.2016.1263339 Running head: Training in congenital amusia 1 Effects of vocal training in a musicophile with congenital amusia Jonathan M. P. Wilbiks 1, 2 Dominique T. Vuvan 3, 4 Pier-Yves Girard 4, 5 Isabelle Peretz 4, 5 Frank A. Russo 1 1 Ryerson University, Toronto, Canada 2 Mount Allison University, Sackville, Canada 3 Skidmore College, Saratoga Springs, USA 4 International Laboratory for Brain, Music and Sound Research (BRAMS) 5 Université de Montréal, Montreal, Canada Address : Department of Psychology, Ryerson University 350 Victoria Street Toronto, Ontario, M5B 2K3 Telephone : (001) 416-979-5000 x2647 Corresponding Author: Frank A. Russo ([email protected]) Running head: Training in congenital amusia 2 Abstract Congenital amusia is a condition in which an individual suffers from a deficit of musical pitch perception and production. Individuals suffering from congenital amusia generally tend to abstain from musical activities. Here we present the unique case of Tim Falconer, a self- described musicophile who also suffers from congenital amusia. We describe and assess Tim’s attempts to train himself out of amusia through a self-imposed 18-month program of formal vocal training and practice. We tested Tim with respect to music perception and vocal production across seven sessions including pre-training and post-training assessments. We also obtained diffusion-weighted images of his brain to assess connectivity between auditory and motor planning areas via the arcuate fasciculus.
    [Show full text]
  • Correlation of CT Cerebral Vascular Territories with Function: 3. Middle Cerebral Artery
    161 Correlation of CT Cerebral Vascular Territories with Function: 3. Middle Cerebral Artery Stephen A. Berman 1 Schematic displays are presented of the cerebral territories supplied by branches of L. Anne Hayman2 the middle cerebral artery as they would appear on axial and coronal computed Vincent C. Hinck 1 tomographic (CT) scan sections. Companion diagrams of regional cortical function and a discussion of the fiber tracts are provided to simplify correlation of clinical deficits with coronal and axial CT abnormalities. This report is the third in a series designed to correlate cerebral vascular territories and functional anatomy in a form directly applicable to computed tomog­ raphy (CT). The illustrations are intended to simplify analysis of CT images in terms of clinical signs and symptoms and vascular territories in everyday practice. The anterior and posterior cerebral arteries have been described [1 , 2] . This report deals with the middle cerebral arterial territory. Knowledge of cerebral vascular territories can help in differentiating between infarction and other pathologic processes. For example, if the position and extent of a lesion and the usual position and extent of a vascular territory are incongruous, infarction should receive relatively low diagnostic priority and vice versa. Knowledge of vascular territories can also facilitate correct interpretation of cerebral angio­ grams by pinpointing specific vessels for particularly close attention. Knowledge of functional neuroanatomy applied to a patient's clinical findings can improve detection of subtle lesions by pinpointing specific areas for special attention on CT and specific vessels for attention on angiograms. Discussion The largest area of the brain that is normally supplied by the vessel(s) of the middle cerebral territory is indicated in figures 1 and 2.
    [Show full text]
  • Abadie's Sign Abadie's Sign Is the Absence Or Diminution of Pain Sensation When Exerting Deep Pressure on the Achilles Tendo
    A.qxd 9/29/05 04:02 PM Page 1 A Abadie’s Sign Abadie’s sign is the absence or diminution of pain sensation when exerting deep pressure on the Achilles tendon by squeezing. This is a frequent finding in the tabes dorsalis variant of neurosyphilis (i.e., with dorsal column disease). Cross References Argyll Robertson pupil Abdominal Paradox - see PARADOXICAL BREATHING Abdominal Reflexes Both superficial and deep abdominal reflexes are described, of which the superficial (cutaneous) reflexes are the more commonly tested in clinical practice. A wooden stick or pin is used to scratch the abdomi- nal wall, from the flank to the midline, parallel to the line of the der- matomal strips, in upper (supraumbilical), middle (umbilical), and lower (infraumbilical) areas. The maneuver is best performed at the end of expiration when the abdominal muscles are relaxed, since the reflexes may be lost with muscle tensing; to avoid this, patients should lie supine with their arms by their sides. Superficial abdominal reflexes are lost in a number of circum- stances: normal old age obesity after abdominal surgery after multiple pregnancies in acute abdominal disorders (Rosenbach’s sign). However, absence of all superficial abdominal reflexes may be of localizing value for corticospinal pathway damage (upper motor neu- rone lesions) above T6. Lesions at or below T10 lead to selective loss of the lower reflexes with the upper and middle reflexes intact, in which case Beevor’s sign may also be present. All abdominal reflexes are preserved with lesions below T12. Abdominal reflexes are said to be lost early in multiple sclerosis, but late in motor neurone disease, an observation of possible clinical use, particularly when differentiating the primary lateral sclerosis vari- ant of motor neurone disease from multiple sclerosis.
    [Show full text]
  • Right Arcuate Fasciculus Abnormality in Chronic Fatigue Syndrome1
    Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. ORIGINAL R Right Arcuate Fasciculus ESEARCH Abnormality in Chronic Fatigue n Syndrome1 NEURORADIOLOGY Michael M. Zeineh, MD, PhD Purpose: To identify whether patients with chronic fatigue syndrome James Kang, MD (CFS) have differences in gross brain structure, micro- Scott W. Atlas, MD scopic structure, or brain perfusion that may explain their Mira M. Raman, MS symptoms. Allan L. Reiss, MD Jane L. Norris, PA Materials and Fifteen patients with CFS were identified by means of Ian Valencia, BS Methods: retrospective review with an institutional review board– Jose G. Montoya, MD approved waiver of consent and waiver of authorization. Fourteen age- and sex-matched control subjects provided informed consent in accordance with the institutional review board and HIPAA. All subjects underwent 3.0-T volumetric T1-weighted magnetic resonance (MR) imag- ing, with two diffusion-tensor imaging (DTI) acquisitions and arterial spin labeling (ASL). Open source software was used to segment supratentorial gray and white matter and cerebrospinal fluid to compare gray and white matter volumes and cortical thickness. DTI data were processed with automated fiber quantification, which was used to compare piecewise fractional anisotropy (FA) along 20 tracks. For the volumetric analysis, a regression was per- formed to account for differences in age, handedness, and total intracranial volume, and for the DTI, FA was com- pared piecewise along tracks by using an unpaired t test. The open source software segmentation was used to com- pare cerebral blood flow as measured with ASL.
    [Show full text]
  • The Nomenclature of Human White Matter Association Pathways: Proposal for a Systematic Taxonomic Anatomical Classification
    The Nomenclature of Human White Matter Association Pathways: Proposal for a Systematic Taxonomic Anatomical Classification Emmanuel Mandonnet, Silvio Sarubbo, Laurent Petit To cite this version: Emmanuel Mandonnet, Silvio Sarubbo, Laurent Petit. The Nomenclature of Human White Matter Association Pathways: Proposal for a Systematic Taxonomic Anatomical Classification. Frontiers in Neuroanatomy, Frontiers, 2018, 12, pp.94. 10.3389/fnana.2018.00094. hal-01929504 HAL Id: hal-01929504 https://hal.archives-ouvertes.fr/hal-01929504 Submitted on 21 Nov 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. REVIEW published: 06 November 2018 doi: 10.3389/fnana.2018.00094 The Nomenclature of Human White Matter Association Pathways: Proposal for a Systematic Taxonomic Anatomical Classification Emmanuel Mandonnet 1* †, Silvio Sarubbo 2† and Laurent Petit 3* 1Department of Neurosurgery, Lariboisière Hospital, Paris, France, 2Division of Neurosurgery, Structural and Functional Connectivity Lab, Azienda Provinciale per i Servizi Sanitari (APSS), Trento, Italy, 3Groupe d’Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives—UMR 5293, CNRS, CEA University of Bordeaux, Bordeaux, France The heterogeneity and complexity of white matter (WM) pathways of the human brain were discretely described by pioneers such as Willis, Stenon, Malpighi, Vieussens and Vicq d’Azyr up to the beginning of the 19th century.
    [Show full text]
  • Language & the Brain Broca's Aphasia Wernicke's Aphasia the ARCUATE FASCICULUS Bilinguals: a Neural Signature?
    10/8/2009 Language & The Brain Broca’s Aphasia Dr. Gardner: “Were you in the Broca’s Coast Guard?” Area Broca’s Area Mr. Ford (patient): “No, er, yes, yes … ship … Massachu … chusetts … Coastguard…years”. He held up his hand twice indicating 19. Gardner H. The Shattered Mind. New York: Vintage Books, 1974, pp 60-61 Posterior Speech 1. Language Comprehension (good) Areas Including Wernicke’s Area 2. Speech Production (impaired): • Nonfluent • Words improperly formed Posterior Speech Areas • Slow and slurred Including Wernicke’s • Paraphasic errors: “purnpike” Area (for turnpike) Wernicke’s Aphasia THE ARCUATE FASCICULUS Dr. Gardner: “What brings you to Broca’s the hospital?” I asked the 72- Area year-old retired butcher four weeks after his admission to the hospital. White Matter Tract that connects Broca’s Area and Mr. Gorgan (patient): Wernicke’s Area “Boy, I’m sweating, I’m awful nervous, you know, once in a while I get caught up, I can’t mention the tarripoi, a month agok, quite a Damage: Conduction Aphasia Posterior Speech little, I’ve done a lot well, I Areas Including impose a lot, while on the other 1. Language Comprehension: Wernicke’s Area hand, you know what I mean, I intact In 97% of people, both Broca's Area and have to run around, look it over, Wernicke's Area only on left hemisphere. 2. Fluent speech with some trebbin and all that sort of stuff. 1. Language Comprehension (poor) paraphasic errors Gardner H. The Shattered Mind. New York: Vintage Books, 3. Inability to repeat words 2. Speech fluent but nonsensical 1974, pp 67-68 3.
    [Show full text]
  • 26 Aphasia, Memory Loss, Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders - - 8/4/17 12:21 PM )
    1 Aphasia, Memory Loss, 26 Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders M.-Marsel Mesulam CHAPTER The cerebral cortex of the human brain contains ~20 billion neurons spread over an area of 2.5 m2. The primary sensory and motor areas constitute 10% of the cerebral cortex. The rest is subsumed by modality- 26 selective, heteromodal, paralimbic, and limbic areas collectively known as the association cortex (Fig. 26-1). The association cortex mediates the Aphasia, Memory Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders Loss, integrative processes that subserve cognition, emotion, and comport- ment. A systematic testing of these mental functions is necessary for the effective clinical assessment of the association cortex and its dis- eases. According to current thinking, there are no centers for “hearing words,” “perceiving space,” or “storing memories.” Cognitive and behavioral functions (domains) are coordinated by intersecting large-s- cale neural networks that contain interconnected cortical and subcortical components. Five anatomically defined large-scale networks are most relevant to clinical practice: (1) a perisylvian network for language, (2) a parietofrontal network for spatial orientation, (3) an occipitotemporal network for face and object recognition, (4) a limbic network for explicit episodic memory, and (5) a prefrontal network for the executive con- trol of cognition and comportment. Investigations based on functional imaging have also identified a default mode network, which becomes activated when the person is not engaged in a specific task requiring attention to external events. The clinical consequences of damage to this network are not yet fully defined. THE LEFT PERISYLVIAN NETWORK FOR LANGUAGE AND APHASIAS The production and comprehension of words and sentences is depen- FIGURE 26-1 Lateral (top) and medial (bottom) views of the cerebral dent on the integrity of a distributed network located along the peri- hemispheres.
    [Show full text]
  • Role of Oligodendrocytes and Myelin in the Pathophysiology of Autism Spectrum Disorder
    brain sciences Review Role of Oligodendrocytes and Myelin in the Pathophysiology of Autism Spectrum Disorder Alma Y. Galvez-Contreras 1,* , David Zarate-Lopez 2,3 , Ana L. Torres-Chavez 2,3 and Oscar Gonzalez-Perez 2,* 1 Department of Neuroscience, Centro Universitario de Ciencias de la Salud, University of Guadalajara, Guadalajara 44340, Mexico 2 Laboratory of Neuroscience, School of Psychology, University of Colima, Colima 28040, Mexico; [email protected] (D.Z.-L.); [email protected] (A.L.T.-C.) 3 Physiological Sciences PhD Program, School of Medicine, University of Colima, Colima 28040, Mexico * Correspondence: [email protected] (A.Y.G.-C.); [email protected] (O.G.-P.) Received: 9 November 2020; Accepted: 2 December 2020; Published: 8 December 2020 Abstract: Autism Spectrum Disorder (ASD) is an early neurodevelopmental disorder that involves deficits in interpersonal communication, social interaction, and repetitive behaviors. Although ASD pathophysiology is still uncertain, alterations in the abnormal development of the frontal lobe, limbic areas, and putamen generate an imbalance between inhibition and excitation of neuronal activity. Interestingly, recent findings suggest that a disruption in neuronal connectivity is associated with neural alterations in white matter production and myelination in diverse brain regions of patients with ASD. This review is aimed to summarize the most recent evidence that supports the notion that abnormalities in the oligodendrocyte generation and axonal myelination in specific brain regions are involved in the pathophysiology of ASD. Fundamental molecular mediators of these pathological processes are also examined. Determining the role of alterations in oligodendrogenesis and myelination is a fundamental step to understand the pathophysiology of ASD and identify possible therapeutic targets.
    [Show full text]
  • High-Yield Neuroanatomy, FOURTH EDITION
    LWBK110-3895G-FM[i-xviii].qxd 8/14/08 5:57 AM Page i Aptara Inc. High-Yield TM Neuroanatomy FOURTH EDITION LWBK110-3895G-FM[i-xviii].qxd 8/14/08 5:57 AM Page ii Aptara Inc. LWBK110-3895G-FM[i-xviii].qxd 8/14/08 5:57 AM Page iii Aptara Inc. High-Yield TM Neuroanatomy FOURTH EDITION James D. Fix, PhD Professor Emeritus of Anatomy Marshall University School of Medicine Huntington, West Virginia With Contributions by Jennifer K. Brueckner, PhD Associate Professor Assistant Dean for Student Affairs Department of Anatomy and Neurobiology University of Kentucky College of Medicine Lexington, Kentucky LWBK110-3895G-FM[i-xviii].qxd 8/14/08 5:57 AM Page iv Aptara Inc. Acquisitions Editor: Crystal Taylor Managing Editor: Kelley Squazzo Marketing Manager: Emilie Moyer Designer: Terry Mallon Compositor: Aptara Fourth Edition Copyright © 2009, 2005, 2000, 1995 Lippincott Williams & Wilkins, a Wolters Kluwer business. 351 West Camden Street 530 Walnut Street Baltimore, MD 21201 Philadelphia, PA 19106 Printed in the United States of America. All rights reserved. This book is protected by copyright. No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews. Materials appearing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above-mentioned copyright. To request permission, please contact Lippincott Williams & Wilkins at 530 Walnut Street, Philadelphia, PA 19106, via email at [email protected], or via website at http://www.lww.com (products and services).
    [Show full text]
  • Neurophysiology of Communication
    Neurophysiology of Communication Presented by: Neha Sharma MD Date: October 11, 2019 What is Communication? Ø The imparting or exchange of information Ø Auditory, Language, Speech, and Comprehension Ø Focus of presentation – how language and speech are perceived and comprehended by the brain Neurophysiology of Hearing Neurophysiology of Hearing Ø Frequency of sound as speech (sound waves) Ø Frequency of speech is 60-500 Hz Ø Males – 85-180 Hz; Female – 165-255 Hz Ø Ear picks up 20-20,000 Hz Animal Frequencies Animal Vocal Frequency (Hearing Frequency) Elephants 14-24 Hz (14-12,000 Hz) Dogs 1,000-2,000 Hz (67-45,000 Hz) Birds 1,000-8,000 Hz (200-8,500 Hz) Ants 1,000 Hz (500-1500 Hz) Mice/Rats 20,000-100,000 Hz (1,000-100,000 Hz) Cow 70-7,000 Hz (16-40,000 Hz) Bats 50,000-160,000 Hz (2,000-110,000 Hz) Torrent Frog 128,000 Hz (38,000 Hz) Katydid 138,000 Hz-150,000 Hz (15,000-50,000 Hz) Dolphins 175,000 Hz (75-150,000 Hz) Wax Moth 300,000 Hz (300,000 Hz) Auditory Anatomy https://endoplasmiccurriculum.wordpress.com/2012/03/09/internal-ear-anatomy/ Neurophysiology of Hearing Ø Sound waves transmit through the air to the ear Ø Travels through external acoustic meatus to auditory canal to tympanic membrane Ø Oscillate against the ossicles which causes vibration of the oval window Ø Stimulating the cochlea which converts the vibration into electrical signals Ø Hair cells move upwards and forwards causing depolarization of the basilar membrane Ø Due to perturbation of basilar membrane against tectorial membrane Ø Inner hair cells – discriminate
    [Show full text]
  • Comparative Primate Neurobiology and the Evolution of Brain Language Systems
    Available online at www.sciencedirect.com ScienceDirect Comparative primate neurobiology and the evolution of brain language systems 1,2,3,4,5 James K Rilling Human brain specializations supporting language can be our capacity for language. As discussed below, compara- identified by comparing human with non-human primate tive studies of primate neurobiology have helped to brains. Comparisons with chimpanzees are critical in this identify some of these specializations. Comparisons with endeavor. Human brains are much larger than non-human our closest living relative, the chimpanzee, have been primate brains, but human language capabilities cannot be crucial in this endeavor, for we cannot conclude that a trait entirely explained by brain size. Human brain specializations has uniquely evolved in humans unless we also demon- that potentially support our capacity for language include firstly, strate its absence in modern chimpanzees [4]. wider cortical minicolumns in both Broca’s and Wernicke’s areas compared with great apes; secondly, leftward Brain size asymmetries in Broca’s area volume and Wernicke’s area The human brain averages 1330 cc in size, a value that far minicolumn width that are not found in great apes; and thirdly, exceeds that for the brain of any other living primate arcuate fasciculus projections beyond Wernicke’s area to a species [5]. Rhesus macaque brains average only 88 cc [6]. region of expanded association cortex in the middle and inferior Chimpanzee brains average 405 cc and gorilla brains temporal cortex involved in processing word meaning. average 500 cc [5]. These numbers suggest the possibility Addresses that our unique capacity for language is simply a product 1 Department of Anthropology, Emory University, 1557 Dickey Drive, of our large brain size.
    [Show full text]