DOCSLIB.ORG

Neuromodulation in Epilepsy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Neuromodulation in Epilepsy NEUROMODULATION IN EPILEPSY Colin Van Hook, M.D., M.P.H. Ochsner Medical Center Department of Neurology International Center for Epilepsy WHAT IS NEUROMODULATION??? • “The alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body.” INS definition • Chronic pain • Movement disorders • Psychiatric disorders • Stroke/Brain injury • Cardiovascular disease • Gastrointestinal disease • Genitourinary or colorectal disorders • Epilepsy NEUROMODULATION IN EPILEPSY: WHEN TO CONSIDER IT • Medically Refractory: In an analysis of 1,098 patients with newly diagnosed epilepsy at a one center between 1982 and 2006 (Brodie 2012) • 49% became seizure free on the first medication tried • 13% became seizure free on the second medication tried • 3.7% became seizure free on the third medication tried • 1/3 of patients remain medically refractory NEUROMODULATION IN EPILEPSY: WHEN TO CONSIDER IT • Non-Surgical candidates • Primary generalized epilepsy • Multiple seizure foci NEUROMODULATION IN EPILEPSY • VAGAL NERVE STIMULATOR (VNS) • RESPONSIVE NEUROSTIMULATOR (RNS/NEUROPACE) • DEEP BRAIN STIMULATION (DBS) VAGUS NERVE ANATOMY • CN X (VAGUS NERVE) • Exits jugular foramen with CN IX and CN XI then travels in the carotid sheath with the common carotid artery and the internal jugular vein • AFFERENT FIBERS = 80% • Solitary Nucleus and Spinal Trigeminal Nucleus • EFFERENT FIBERS = 20% • Originate in Dorsal Motor Nucleus and Nucleus Ambiguus • Parasympathetic fibers to the viscera • Right CNX provides significantly more innervation to heart compared to left (this is why VNS placed usually on left CN X) VAGUS NERVE ANATOMY • Projects to Nucleus Tractus Solitarius BILATERALLY (Henry, Neurology 2002) VAGUS NERVE PROJECTIONS • Vagus nerve works through Nucleus Tractus Solitarus(NTS) and Pontine Parabrahcial Nucleus (PBN) • Limbic • Amygdala: implicated in temporal lobe epilepsy • Insula: connections to orbitofrontal cortex • Autonomic • Connections to hypothalamus and periaqueductal gray (PAG) • Reticular structures • Thalamus Henry 2002. VAGUS NERVE AND SEIZURES • 1938 (Bailey and Bremer) • Stimulation of vagus nerve produced EEG changes in cats • 1952 (Zanchetti) • Intermittent vagal nerve stimulation decreased or eliminated chemically induced focal epileptiform discharges • 1960s • Repetitive stimulation of vagus nerve led to synchronize or desynchronize cortical electrical activity • Seizures caused by hypersynchronized cortical activity thus VNS could desynchronize • 1985 (Zabara) • Hypothesized that VNS antagonizes hypersynchronous states using animal studies VAGUS NERVE AND THE CORTEX • 3HZ spike-wave initiated in thalamus and propagated via pathways to the cortex • Hypothalamic hamartomas with gelastic seizures • Intracranial recordings of cerebellar dysplastic lesions show discharges originating in that structure • In several cases of frontal lobe epilepsy, seizures continued following cortical resection with subsequent seizure freedom following resection of deep structures with electrographic discharges originating in the striatum. VNS: CLINICAL EVIDENCE Design # patients Seizure type Results radomized E01/2 (1988-1992) Single-blinded 14 Partial 28% reduction in seizure frequency E03 (1990-1992) Randomized 114 Partial Mean 24.5% reduction in frequency double-blind with 31% having >50% reduction active control E04 (1991-1995) Open label, 116 Partial or Mean 21.5% reduction in frequency non-blinded generalized with 29.3% having >50% reduction E05 (1995-1996) Randomized 199 Partial Mean 27.9% reduction in frequency double-blind with 23.4% having >50% reduction active control VNS CLINICAL EVIDENCE • Reduction of seizure frequency > 50% (Morris and Mueller, Neurology 1999) • 1 year = 36.8% patients • 2 years = 43.2% patients • 3 years = 42.7% patients • Well tolerated • 75% patients continued therapy • There is a persistent VNS‐induced anticonvulsant effect and indicate that its efficacy is dependent on the cumulative stimulus duration (Takaya, Epilepsia 1996). VNS APPROVAL • In 1997, the FDA approved the VNS Therapy System for use as an adjunctive therapy in reducing the frequency of seizures in adults and adolescents over 12 years of age with partial onset seizures refractory to antiepileptic medications • In 2017, device was FDA approved for children as young as 4 due after data from Japan Post‐Approval Study (PAS) in which followed patients implanted between 2010 and 2012. • As of 2017, >100,000 patients treated with VNS VNS IN GENERALIZED EPILEPSY • Labar (Neurology 1999) showed >50% reduction in 11 of 24 patients with medically resistant IGE • Ng and Devinsky (Seizure 2004) compared seizure frequency reduced by > 50% in partial vs. symptomatic generalized vs. idiopathic generalized • Partial (PE)= 47.1% patients (N=138) • Symptomatic generalized (SGE)= 46.1% patients (N=13) • Idiopathic generalized (IGE) = 57.1% patients (N=14) • Furthermore, higher proportion of patients with IGEable to achieve 50% or greater reduction in seizure frequency and reduced antiepileptic drug • Partial = 9.4% • Symptomatic generalized = 7.7% • Idiopathic generalized = 35.7 VNS AND DEPRESSION • Reduction in depression scores was noted in E03/5 and two subsequent studies (Harden 2000 and Elger 2000) showed trend to depression reduction was INDEPENDENT of seizure reduction • One year trial of VNS for patients with depression (n=185) or bipolar I/II (n=20) refractory to at least 2 medications showed a significant reduction in symptoms on the 24 item Hamilton Rating Scale for Depression. (Rush 2005) • Five year open-label, non-randomized trial of patients with treatment resistant depression showed reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) in patients with VNS (n=494) versus treatment as usual (n=301). (Aaronson 2017) • In 2005 FDA approved VNS for adjunct treatment in depression but coverage denied by US Committee on Medicare and Medicaid Services VNS AND QUALITY OF LIFE • PuLsE (Open Prospective Randomized Long-term Effectiveness) trial showed significant improvement in Quality of Life in Epilepsy Inventory-89 total score (QOLIE-89) in 61 patients with VNS versus 61 patient with medical therapy only (Ryvlin 2017) • VNS patients with autism showed improved alertness, verbal communication, memory, and school performance (Levy 2010) VNS OPERATIONS • Battery powered device • Leads placed in carotid sheath around left vagus nerve and connected to subcutaneous programmable pacemaker • Typical battery life is 5-10 years based on settings VNS OPERATIONS Pulse width Signal frequency Output current Amount of electrical current delivered in a single pulse of stimulation Signal frequency Number of pulses per second (measured in Hz) Pulse width Duration of a single pulse within a stimulation period VNS OPERATIONS Parameter Units Range Typical Output current milliamps 0–3.5 1.25 Signal frequency hertz 1–30 20-30 Pulse width microseconds 130–1000 250-500 ON time seconds 7–60 30 OFF time minutes 0.2–180 5 Magnet Settings Output current milliamps 0–3.5 1.50 Pulse width microseconds 130–1000 500 ON time seconds 7–60 60 VNS OPERATIONS: CYCLING AND DUTY CYCLE • Initial settings typically: • Several small studies do not support increased efficacy for “Rapid Cycling” typically Output current 0.25mA • connotating 7 seconds “on” and 30 seconds • Signal frequency 30Hz “off” • Pulse Width 250-500 microseconds • Not recommended as this will wear down • “On” 30 seconds battery faster • “Off” 5 minutes • Duty cycle should be <50% ON time + 4 seconds ON time + OFF time VNS MAGNET • Patient or other swipes magnet on generator for 1 second which gives additional current/stimulation to stop or shorten seizure • Morris. Epilepsy and Behavior 2003. • Patients in E03 trial with active magnets were more likely to report improved seizure control than patients with inactive magnets • In the E04 trial, 22% of patients using the magnet reported seizure termination and 31% reported seizure diminution • Magnet output current should always be higher (usually 0.25mA higher) than parameter output VNS SAFETY • Side Effects • Data from E0S trials • Voice alteration/hoarseness 66.3 % • Cough 45.3% • Pharyngitis 34.7% • Dyspnea 24.2% • Most resolved after 1-2 years of continued treatment • Mild increase in hypopnea and apnea in patients with OSA, may unmask latent OSA (Marzed, Edwards, Sagher. Epilepsia 2003) VNS: MANAGING SIDE EFFECTS • Reduce pulse width from 500 to 250 • Reduce frequency from 30 to 20 • TAPE MAGNET OVER DEVICE TO AVOID VOICE CHANGE VNS AND MRI • Safe for brain, lumbar spine, and extremities! • NOT SAFE for cervical and thoracic spine • PRIOR to MRI reprogram • Output current = 0.0 • Magnet current = 0.0 • Autostimulation = 0.0 • AFTER imaging • Reset to previous parameters • Perform diagnostic, should show IMPEDENCE = OK TRANSCUTANEOUS VNS (T-VNS) • Stimulation applied to auricular branch of CNX at the tragus • 5 of 7 patients showed a reduction in seizure frequency at 9 months (Stefan 2012) • Randomized, double-blind controlled trial (cMPsE02) showed no statistical difference in change in seizure frequency between high and low stimulation groups at 20 weeks (Bauer 2016). • NEMOS system is approved in Europe • LOW THRESHOLD FOR APPROVAL – EFFICACY NOT NEEDED VNS: WHO TO CONSIDER? PRO CON • Option for anyone who is not a candidate for resection • Surgery required • No cognitive side effects • Battery replacement 5-10 years • Compliance is not an issue • Still need AEDs •
Load more

Recommended publications
  • From Human Emotions to Robot Emotions
    1 American Association for Artificial Intelligence – Spring Symposium 3/2004, Stanford University – Keynote Lecture. From Human Emotions to Robot Emotions Jean-Marc Fellous The Salk Institute for Neurobiological Studies 10010 N. Torrey Pines Road, la Jolla, CA 92037 [email protected] Abstract1 open a new window on the neural bases of emotions that may offer new ways of thinking about implementing robot- The main difficulties that researchers face in understanding emotions. emotions are difficulties only because of the narrow- mindedness of our views on emotions. We are not able to Why are emotions so difficult to study? free ourselves from the notion that emotions are necessarily human emotions. I will argue that if animals have A difficulty in studying human emotions is that here are emotions, then so can robots. Studies in neuroscience have significant individual differences, based on experiential as shown that animal models, though having limitations, have well as genetic factors (Rolls, 1998; Ortony, 2002; significantly contributed to our understanding of the Davidson, 2003a, b; Ortony et al., 2004). My fear at the functional and mechanistic aspects of emotions. I will sight of a bear may be very different from the fear suggest that one of the main functions of emotions is to experienced by a park-ranger who has a better sense for achieve the multi-level communication of simplified but high impact information. The way this function is achieved bear-danger and knows how to react. My fear might also be in the brain depends on the species, and on the specific different from that of another individual who has had about emotion considered.
    [Show full text]
  • Case Study: Right Temporal Lobe Epilepsy
    Case Study: Right temporal lobe epilepsy Group Members • Rudolf Cymorr Kirby P. Martinez • Yet dalen • Rachel Joy Alcalde • Siriwimon Luanglue • Mary Antonette Pineda • Khayay Hlaing • Luch Bunrattana • Keo Sereymonica • Sikanal Chum • Pyone Khant khant • Men Puthik • Chheun Chhorvy Advisers: Sudasawan Jiamsakul Janyarak Supat 2 Overview of Epilepsy 3 Overview of Epilepsy 4 Risk Factor of Epilepsy 5 Goal of Epilepsy Care 6 Case of Patient X Patient Information & Hx • Sex: Female (single) • Age: 22 years old • Date of admission: 15 June 2017 • Chief Complaint: Jerking movement of all 4 limbs • Past Diagnosis: Temporal lobe epilepsy • No allergies, family history & Operation Complete Vaccination. (+) Developmental Delay Now she can take care herself. Income: Helps in family store (can do basic calculation) History Workup Admission Operation ICU Female Surgery D/C 7 • Sex: Female Case of Patient X • Age: 22 years old • CC: Jerking movement of all 4 limbs History Past Present History Workup Admission Operation ICU Female Surgery D/C 8 • Sex: Female Case of Patient X • Age: 22 years old • CC: Jerking movement of all 4 limbs Past Present (11 mos) (+) high fever. Prescribed AED for 2-3 Treatment at Songkranakarin Hosp. mos. After AED stops, no further episode Prescribe AED but still with 4-5 ep/mos 21 yrs 6 yrs Present PTA PTA (15 y/o) (+) jerking movement (15 y/o) (+) aura as jerking Now 2-3 ep/ mos both arms and legs with LOC movement at chin & headache Last attack 2 mos for 5 mins. Drowsy after attack ago thus consult with no memory of attack 15-17 episode/ mos History Workup Admission Operation ICU Female Surgery D/C 9 • Sex: Female Case of Patient X • Age: 22 years old • CC: Jerking movement of all 4 limbs Past Present 2 months prior to admission, she had jerking movement both arms and legs, blinking both eyes, corner of the mouth twitch, and drool.
    [Show full text]
  • Anatomy of the Temporal Lobe
    Hindawi Publishing Corporation Epilepsy Research and Treatment Volume 2012, Article ID 176157, 12 pages doi:10.1155/2012/176157 Review Article AnatomyoftheTemporalLobe J. A. Kiernan Department of Anatomy and Cell Biology, The University of Western Ontario, London, ON, Canada N6A 5C1 Correspondence should be addressed to J. A. Kiernan, [email protected] Received 6 October 2011; Accepted 3 December 2011 Academic Editor: Seyed M. Mirsattari Copyright © 2012 J. A. Kiernan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Only primates have temporal lobes, which are largest in man, accommodating 17% of the cerebral cortex and including areas with auditory, olfactory, vestibular, visual and linguistic functions. The hippocampal formation, on the medial side of the lobe, includes the parahippocampal gyrus, subiculum, hippocampus, dentate gyrus, and associated white matter, notably the fimbria, whose fibres continue into the fornix. The hippocampus is an inrolled gyrus that bulges into the temporal horn of the lateral ventricle. Association fibres connect all parts of the cerebral cortex with the parahippocampal gyrus and subiculum, which in turn project to the dentate gyrus. The largest efferent projection of the subiculum and hippocampus is through the fornix to the hypothalamus. The choroid fissure, alongside the fimbria, separates the temporal lobe from the optic tract, hypothalamus and midbrain. The amygdala comprises several nuclei on the medial aspect of the temporal lobe, mostly anterior the hippocampus and indenting the tip of the temporal horn. The amygdala receives input from the olfactory bulb and from association cortex for other modalities of sensation.
    [Show full text]
  • The Neurobiology of Agrammatic Sentence Comprehension: a Lesion Study
    The Neurobiology of Agrammatic Sentence Comprehension: A Lesion Study Corianne Rogalsky1, Arianna N. LaCroix1, Kuan-Hua Chen2,3, Steven W. Anderson2, Hanna Damasio4, Tracy Love5, and Gregory Hickok6 Abstract ■ Broca’s area has long been implicated in sentence compre- average did not exhibit the expected agrammatic compre- hension. Damage to this region is thought to be the central hension pattern—for example, their performance was >80% source of “agrammatic comprehension” in which performance on noncanonical sentences in the sentence–picture matching is substantially worse (and near chance) on sentences with non- task. Patients with ATL damage (n = 18) also did not exhibit canonical word orders compared with canonical word order an agrammatic comprehension pattern. Across our entire sentences (in English). This claim is supported by functional patient sample, the lesions of patients with agrammatic com- neuroimaging studies demonstrating greater activation in prehension patterns in either task had maximal overlap in pos- Broca’s area for noncanonical versus canonical sentences. terior superior temporal and inferior parietal regions. Using However, functional neuroimaging studies also have frequently voxel-based lesion–symptom mapping, we find that lower per- implicated the anterior temporal lobe (ATL) in sentence pro- formances on canonical and noncanonical sentences in each cessing more broadly, and recent lesion–symptom mapping task are both associated with damage to a large left superior studies have implicated the ATL and mid temporal regions in temporal–inferior parietal network including portions of the agrammatic comprehension. This study investigates these ATL, but not Broca’s area. Notably, however, response bias in seemingly conflicting findings in 66 left-hemisphere patients plausibility judgments was significantly associated with damage with chronic focal cerebral damage.
    [Show full text]
  • What Can Be Learned from White Matter Alterations in Antisocial Girls Willeke M
    Menks WM, Raschle NM. J Neurol Neuromedicine (2017) 2(7): 16-20 Neuromedicine www.jneurology.com www.jneurology.com Journal of Neurology & Neuromedicine Mini Review Open Access What can be learned from white matter alterations in antisocial girls Willeke M. Menks1, Christina Stadler1 and Nora M. Raschle1 1Department of Child and Adolescent Psychiatry, University of Basel, Psychiatric University Hospital Basel, Switzerland. Article Info ABSTRACT Article Notes Antisocial behavior in youths constitutes a major public health problem Received: June 17, 2017 worldwide. Conduct disorder is a severe variant of antisocial behavior with higher Accepted: July 31, 2017 prevalence rates for boys (12%) as opposed to girls (7%). A better understanding *Correspondence: of the underlying neurobiological mechanisms of conduct disorder is warranted Dr. Willeke Menks, PhD to improve identification, diagnosis, or treatment. Functional and structural Department of Child and Adolescent Psychiatry (KJPK), neuroimaging studies have indicated several key brain regions within the limbic Psychiatric University Clinics Basel (UPK) system and prefrontal cortex that are altered in youths with conduct disorder. Schanzenstrasse 13, CH-4056 Basel, Switzerland Examining the structural connectivity, i.e. white matter fiber tracts connecting Tel. +41 61 265 89 76 these brain areas, may further inform about the underlying neural mechanisms. Fax +41 61 265 89 61 Diffusion tensor imaging (DTI) is a non-invasive technique that can evaluate the © 2017 Menks WM & Raschle NM. This article is distributed white matter integrity of fiber tracts throughout the brain. To date, DTI studies have under the terms of the Creative Commons Attribution 4.0 found several white matter tracts that are altered in youths with conduct disorder.
    [Show full text]
  • Long-Term Results of Vagal Nerve Stimulation for Adults with Medication-Resistant
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Seizure 22 (2013) 9–13 Contents lists available at SciVerse ScienceDirect Seizure jou rnal homepage: www.elsevier.com/locate/yseiz Long-term results of vagal nerve stimulation for adults with medication-resistant epilepsy who have been on unchanged antiepileptic medication a a, b a c a Eduardo Garcı´a-Navarrete , Cristina V. Torres *, Isabel Gallego , Marta Navas , Jesu´ s Pastor , R.G. Sola a Division of Neurosurgery, Department of Surgery, University Hospital La Princesa, Universidad Auto´noma, Madrid, Spain b Division of Neurosurgery, Hospital Nin˜o Jesu´s, Madrid, Spain c Department of Physiology, University Hospital La Princesa, Madrid, Spain A R T I C L E I N F O A B S T R A C T Article history: Purpose: Several studies suggest that vagal nerve stimulation (VNS) is an effective treatment for Received 15 July 2012 medication-resistant epileptic patients, although patients’ medication was usually modified during the Received in revised form 10 September 2012 assessment period. The purpose of this prospective study was to evaluate the long-term effects of VNS, at Accepted 14 September 2012 18 months of follow-up, on epileptic patients who have been on unchanged antiepileptic medication. Methods: Forty-three patients underwent a complete epilepsy preoperative evaluation protocol, and Keywords: were selected for VNS implantation. After surgery, patients were evaluated on a monthly basis, Vagus nerve increasing stimulation 0.25 mA at each visit, up to 2.5 mA. Medication was unchanged for at least 18 Epilepsy months since the stimulation was started.
    [Show full text]
  • God and the Limbic System from Phantoms in the Brain, by V.S
    Imagine you had a machine, a helmet of sorts that you could ... http://www.historyhaven.com/TOK/God and the Limbic Syst... God and the Limbic System From Phantoms in the Brain, by V.S. Ramachandran Imagine you had a machine, a helmet of sorts that you could simply put on your head and stimulate any small region of your brain without causing permanent damage. What would you use the device for? This is not science fiction. Such a device, called a transcranial magnetic stimulator, already exists and is relatively easy to construct. When applied to the scalp, it shoots a rapidly fluctuating and extremely powerful magnetic field onto a small patch of brain tissue, thereby activating it and providing hints about its function. For example, if you were to stimulate certain parts of your motor cortex, different muscles would contract. Your finger might twitch or you'd feel a sudden involuntary, puppetlike shrugging of one shoulder. So, if you had access to this device, what part of your brain would you stimulate? If you happened to be familiar with reports from the early days of neurosurgery about the septum-a cluster of cells located near the front of the thalamus in the middle of your brain-you might be tempted to apply the magnet there. Patients "zapped" in this region claim to experience intense pleasure, "like a thousand orgasms rolled into one." If you were blind from birth and the visual areas in your brain had not degenerated, you might stimulate bits of your own visual cortex to find out what people mean by color or "seeing." Or, given the well-known clinical observation that the left frontal lobe seems to be involved in feeling "good," maybe you'd want to stimulate a region over your left eye to see whether you could induce a natural high.
    [Show full text]
  • The Human Brain Hemisphere Controls the Left Side of the Body and the Left What Makes the Human Brain Unique Is Its Size
    About the brain Cerebrum (also known as the The brain is made up of around 100 billion nerve cells - each one cerebral cortex or forebrain) is connected to another 10,000. This means that, in total, we The cerebrum is the largest part of the brain. It is split in to two have around 1,000 trillion connections in our brains. (This would ‘halves’ of roughly equal size called hemispheres. The two be written as 1,000,000,000,000,000). These are ultimately hemispheres, the left and right, are joined together by a bundle responsible for who we are. Our brains control the decisions we of nerve fibres called the corpus callosum. The right make, the way we learn, move, and how we feel. The human brain hemisphere controls the left side of the body and the left What makes the human brain unique is its size. Our brains have a hemisphere controls the right side of the body. The cerebrum is larger cerebral cortex, or cerebrum, relative to the rest of the The human brain is the centre of our nervous further divided in to four lobes: frontal, parietal, occipital, and brain than any other animal. (See the Cerebrum section of this temporal, which have different functions. system. It is the most complex organ in our fact sheet for further information.) This enables us to have abilities The frontal lobe body and is responsible for everything we do - such as complex language, problem-solving and self-control. The frontal lobe is located at the front of the brain.
    [Show full text]
  • Function of Cerebral Cortex
    FUNCTION OF CEREBRAL CORTEX Course: Neuropsychology CC-6 (M.A PSYCHOLOGY SEM II); Unit I By Dr. Priyanka Kumari Assistant Professor Institute of Psychological Research and Service Patna University Contact No.7654991023; E-mail- [email protected] The cerebral cortex—the thin outer covering of the brain-is the part of the brain responsible for our ability to reason, plan, remember, and imagine. Cerebral Cortex accounts for our impressive capacity to process and transform information. The cerebral cortex is only about one-eighth of an inch thick, but it contains billions of neurons, each connected to thousands of others. The predominance of cell bodies gives the cortex a brownish gray colour. Because of its appearance, the cortex is often referred to as gray matter. Beneath the cortex are myelin-sheathed axons connecting the neurons of the cortex with those of other parts of the brain. The large concentrations of myelin make this tissue look whitish and opaque, and hence it is often referred to as white matter. The cortex is divided into two nearly symmetrical halves, the cerebral hemispheres . Thus, many of the structures of the cerebral cortex appear in both the left and right cerebral hemispheres. The two hemispheres appear to be somewhat specialized in the functions they perform. The cerebral hemispheres are folded into many ridges and grooves, which greatly increase their surface area. Each hemisphere is usually described, on the basis of the largest of these grooves or fissures, as being divided into four distinct regions or lobes. The four lobes are: • Frontal, • Parietal, • Occipital, and • Temporal.
    [Show full text]
  • Andrew Rosen the Architecture of the Nervous System: • Central Nervous
    Andrew Rosen The Architecture of the Nervous System: Central Nervous System (CNS) – Includes the brain and spinal cord Peripheral Nervous System (PNS) – All nerves elsewhere and are connected to the CNS via the spinal cord o Composed of the Somatic Nervous System (SNS), which has the efferent nerves that control the skeletal muscles and afferent nerves that carry information from the sense organs to CNS o Also composed of the Autonomous Nervous System (ANS), which has the efferent nerves that regulate the glands and smooth muscles of internal organs and vessels as well as afferent nerves that bring the CNS information about the internal systems . Divided into the sympathetic branch “Revs” body up for an action . Also divided into parasympathetic branch Restores the body’s internal activities to normal after an action Brain is in cerebrospinal fluid that acts as a shock absorber Anatomy of the Brain: Spinal cord that goes into brain forms the brain stem Medulla is at the bottom of the brain stem o Controls breathing, blood circulation, and maintains balance Pons is above the medulla o Controls attentiveness and governs sleep/dreaming Behind the brain stem is the cerebellum o Controls balance, coordination, and spatial reasoning The midbrain and thalamus are on top of the pons o Relay information to the forebrains o Midbrain regulates experience of pain and moods The forebrain is on top of all of these o Outer part of the forebrain is the cerebral cortex . High surface area . Deepest groove is the longitudinal fissure that splits the left cerebral hemisphere from the right .
    [Show full text]
  • Lecture 12 Notes
    Somatic regions Limbic regions These functionally distinct regions continue rostrally into the ‘tweenbrain. Fig 11-4 Courtesy of MIT Press. Used with permission. Schneider, G. E. Brain structure and its Origins: In the Development and in Evolution of Behavior and the Mind. MIT Press, 2014. ISBN: 9780262026734. 1 Chapter 11, questions about the somatic regions: 4) There are motor neurons located in the midbrain. What movements do those motor neurons control? (These direct outputs of the midbrain are not a subject of much discussion in the chapter.) 5) At the base of the midbrain (ventral side) one finds a fiber bundle that shows great differences in relative size in different species. Give examples. What are the fibers called and where do they originate? 8) A decussating group of axons called the brachium conjunctivum also varies greatly in size in different species. It is largest in species with the largest neocortex but does not come from the neocortex. From which structure does it come? Where does it terminate? (Try to guess before you look it up.) 2 Motor neurons of the midbrain that control somatic muscles: the oculomotor nuclei of cranial nerves III and IV. At this level, the oculomotor nucleus of nerve III is present. Fibers from retina to Superior Colliculus Brachium of Inferior Colliculus (auditory pathway to thalamus, also to SC) Oculomotor nucleus Spinothalamic tract (somatosensory; some fibers terminate in SC) Medial lemniscus Cerebral peduncle: contains Red corticospinal + corticopontine fibers, + cortex to hindbrain fibers nucleus (n. ruber) Tectospinal tract Rubrospinal tract Courtesy of MIT Press. Used with permission. Schneider, G.
    [Show full text]
  • White Matter Tracts - Brain A143 (1)
    WHITE MATTER TRACTS - BRAIN A143 (1) White Matter Tracts Last updated: August 8, 2020 CORTICOSPINAL TRACT .......................................................................................................................... 1 ANATOMY .............................................................................................................................................. 1 FUNCTION ............................................................................................................................................. 1 UNCINATE FASCICULUS ........................................................................................................................... 1 ANATOMY .............................................................................................................................................. 1 DTI PROTOCOL ...................................................................................................................................... 4 FUNCTION .............................................................................................................................................. 4 DEVELOPMENT ....................................................................................................................................... 4 CLINICAL SIGNIFICANCE ........................................................................................................................ 4 ARTICLES ..............................................................................................................................................
    [Show full text]