Trochlear-Oculomotor Synkinesis
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Cranial Nerve Palsy
Cranial Nerve Palsy What is a cranial nerve? Cranial nerves are nerves that lead directly from the brain to parts of our head, face, and trunk. There are 12 pairs of cranial nerves and some are involved in special senses (sight, smell, hearing, taste, feeling) while others control muscles and glands. Which cranial nerves pertain to the eyes? The second cranial nerve is called the optic nerve. It sends visual information from the eye to the brain. The third cranial nerve is called the oculomotor nerve. It is involved with eye movement, eyelid movement, and the function of the pupil and lens inside the eye. The fourth cranial nerve is called the trochlear nerve and the sixth cranial nerve is called the abducens nerve. They each innervate an eye muscle involved in eye movement. The fifth cranial nerve is called the trigeminal nerve. It provides facial touch sensation (including sensation on the eye). What is a cranial nerve palsy? A palsy is a lack of function of a nerve. A cranial nerve palsy may cause a complete or partial weakness or paralysis of the areas served by the affected nerve. In the case of a cranial nerve that has multiple functions (such as the oculomotor nerve), it is possible for a palsy to affect all of the various functions or only some of the functions of that nerve. What are some causes of a cranial nerve palsy? A cranial nerve palsy can occur due to a variety of causes. It can be congenital (present at birth), traumatic, or due to blood vessel disease (hypertension, diabetes, strokes, aneurysms, etc). -
MR Imaging of Primary Trochlear Nerve Neoplasms
707 MR Imaging of Primary Trochlear Nerve Neoplasms Lindell R. Gentry 1 We present the clinical, anatomic, and MR imaging findings in six patients with seven Rahul C. Mehta 1 primary trochlear nerve neoplasms, as well as the MR and clinical criteria that serve to Richard E. Appen2 establish the diagnosis of these rare cranial nerve neoplasms. Three patients had a Joel M. Weinstein2 history of neurofibromatosis and five patients had clinical evidence of a trochlear nerve palsy. Six of seven neoplasms produced localized, fusiform enlargement of the proximal cisternal segments of the trochlear nerves. The lesions that were visible on noncontrast MR scans (T1-, T2-, and proton density-weighted) had signal intensities that were virtually identical to normal brain parenchyma. All lesions showed intense, homogeneous enhancement on contrast-enhanced scans. Contrast-enhanced imaging was necessary for the detection of five of seven lesions and greatly increased the value of the MR study in all six patients. AJNR 12:707-713, July/August 1991; AJR 157: September 1991 Primary neoplasms arising from pure motor cranial nerves such as the trochlear nerve are rare. To our knowledge just nine primary trochlear nerve neoplasms have been reported in the literature [1-7), only one of which was imaged with MR [1). Over the last 6 years, since we began to use MR as the primary imaging method for evaluating patients with cranial nerve palsies , we have noticed a striking increase in the number of primary trochlear nerve neoplasms over those encountered during the CT era. We believe this is due to a much greater sensitivity of MR in detecting these typically small lesions. -
Congenital Oculomotor Palsy: Associated Neurological and Ophthalmological Findings
CONGENITAL OCULOMOTOR PALSY: ASSOCIATED NEUROLOGICAL AND OPHTHALMOLOGICAL FINDINGS M. D. TSALOUMAS1 and H. E. WILLSHA W2 Birmingham SUMMARY In our group of patients we found a high incidence Congenital fourth and sixth nerve palsies are rarely of neurological abnormalities, in some cases asso associated with other evidence of neurological ahnor ciated with abnormal findings on CT scanning. mality, but there have been conflicting reports in the Aberrant regeneration, preferential fixation with literature on the associations of congenital third nerve the paretic eye, amblyopia of the non-involved eye palsy. In order to clarify the situation we report a series and asymmetric nystagmus have all been reported as 1 3 7 of 14 consecutive cases presenting to a paediatric associated ophthalmic findings. - , -9 However, we tertiary referral service over the last 12 years. In this describe for the first time a phenomenon of digital lid series of children, 5 had associated neurological elevation to allow fixation with the affected eye. Two abnormalities, lending support to the view that con children demonstrated this phenomenon and in each genital third nerve palsy is commonly a manifestation of case the accompanying neurological defect was widespread neurological damage. We also describe for profound. the first time a phenomenon of digital lid elevation to allow fixation with the affected eye. Two children demonstrated this phenomenon and in each case the PATIENTS AND METHODS accompanying neurological defect was profound. The Fourteen children (8 boys, 6 girls) with a diagnosis of frequency and severity of associated deficits is analysed, congenital oculomotor palsy presented to our paed and the mechanism of fixation with the affected eye is iatric tertiary referral centre over the 12 years from discussed. -
Anatomy of the Extraneural Blood Supply to the Intracranial
British Journal of Ophthalmology 1996; 80: 177-181 177 the extraneural blood to the Anatomy of supply Br J Ophthalmol: first published as 10.1136/bjo.80.2.177 on 1 February 1996. Downloaded from intracranial oculomotor nerve Mark Cahill, John Bannigan, Peter Eustace Abstract have since been classified as extraneural vessels Aims-An anatomical study was under- as they arise from outside the nerve and ramify taken to determine the extraneural blood on the surface ofthe nerve. In 1965, Parkinson supply to the intracranial oculomotor attempted to demonstrate and name the nerve. branches of the intracavernous internal carotid Methods-Human tissue blocks contain- artery.3 One of these branches, the newly titled ing brainstem, cranial nerves II-VI, body meningohypophyseal trunk was seen to pro- of sphenoid, and associated cavernous vide a nutrient arteriole to the oculomotor sinuses were obtained, injected with con- nerve in the majority of dissections. The infe- trast material, and dissected using a rior hypophyseal artery was also seen to arise stereoscopic microscope. from the meningohypophyseal trunk. Seven Results-Eleven oculomotor nerves were years earlier McConnell had demonstrated dissected, the intracranial part being that this vessel provided a large portion of the divided into proximal, middle, and distal pituitary blood supply.4 (intracavernous) parts. The proximal part Asbury and colleagues provided further of the intracranial oculomotor nerve anatomical detail in 1970.5 They set out to received extraneural nutrient arterioles explain the clinical findings of diabetic oph- from thalamoperforating arteries in all thalmoplegia on a pathological basis. Using a specimens and in six nerves this blood serial section technique, they demonstrated an supply was supplemented by branches intraneural network of small arterioles within from other brainstem vessels. -
Cranial Nerve Disorders: Clinical Manifestations and Topographyଝ
Radiología. 2019;61(2):99---123 www.elsevier.es/rx UPDATE IN RADIOLOGY Cranial nerve disorders: Clinical manifestations and topographyଝ a,∗ a b c M. Jorquera Moya , S. Merino Menéndez , J. Porta Etessam , J. Escribano Vera , a M. Yus Fuertes a Sección de Neurorradiología, Hospital Clínico San Carlos, Madrid, Spain b Servicio de Neurología, Hospital Clínico San Carlos, Madrid, Spain c Neurorradiología, Hospital Ruber Internacional, Madrid, Spain Received 17 November 2017; accepted 27 September 2018 KEYWORDS Abstract The detection of pathological conditions related to the twelve cranial pairs rep- Cranial pairs; resents a significant challenge for both clinicians and radiologists; imaging techniques are Cranial nerves; fundamental for the management of many patients with these conditions. In addition to knowl- Cranial neuropathies; edge about the anatomy and pathological entities that can potentially affect the cranial pairs, Neuralgia; the imaging evaluation of patients with possible cranial pair disorders requires specific exami- Cranial nerve palsy nation protocols, acquisition techniques, and image processing. This article provides a review of the most common symptoms and syndromes related with the cranial pairs that might require imaging tests, together with a brief overview of the anatomy, the most common underlying processes, and the most appropriate imaging tests for different indications. © 2018 SERAM. Published by Elsevier Espana,˜ S.L.U. All rights reserved. PALABRAS CLAVE Sintomatología derivada de los pares craneales: Clínica y topografía Pares craneales; Resumen La detección de la patología relacionada con los doce pares craneales representa Nervios craneales; un importante desafío, tanto para los clínicos como para los radiólogos. Las técnicas de imagen Neuropatía de pares craneales; son fundamentales para el manejo de muchos de los pacientes. -
Clinical Anatomy of the Cranial Nerves Clinical Anatomy of the Cranial Nerves
Clinical Anatomy of the Cranial Nerves Clinical Anatomy of the Cranial Nerves Paul Rea AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Academic Press is an imprint of Elsevier 32 Jamestown Road, London NW1 7BY, UK The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Radarweg 29, PO Box 211, 1000 AE Amsterdam, The Netherlands 225 Wyman Street, Waltham, MA 02451, USA 525 B Street, Suite 1800, San Diego, CA 92101-4495, USA First published 2014 Copyright r 2014 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangement with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. -
Cranial Nerves
Cranial Nerves Cranial nerve evaluation is an important part of a neurologic exam. There are some differences in the assessment of cranial nerves with different species, but the general principles are the same. You should know the names and basic functions of the 12 pairs of cranial nerves. This PowerPage reviews the cranial nerves and basic brain anatomy which may be seen on the VTNE. The 12 Cranial Nerves: CN I – Olfactory Nerve • Mediates the sense of smell, observed when the pet sniffs around its environment CN II – Optic Nerve Carries visual signals from retina to occipital lobe of brain, observed as the pet tracks an object with its eyes. It also causes pupil constriction. The Menace response is the waving of the hand at the dog’s eye to see if it blinks (this nerve provides the vision; the blink is due to cranial nerve VII) CN III – Oculomotor Nerve • Provides motor to most of the extraocular muscles (dorsal, ventral, and medial rectus) and for pupil constriction o Observing pupillary constriction in PLR CN IV – Trochlear Nerve • Provides motor function to the dorsal oblique extraocular muscle and rolls globe medially © 2018 VetTechPrep.com • All rights reserved. 1 Cranial Nerves CN V – Trigeminal Nerve – Maxillary, Mandibular, and Ophthalmic Branches • Provides motor to muscles of mastication (chewing muscles) and sensory to eyelids, cornea, tongue, nasal mucosa and mouth. CN VI- Abducens Nerve • Provides motor function to the lateral rectus extraocular muscle and retractor bulbi • Examined by touching the globe and observing for retraction (also tests V for sensory) Responsible for physiologic nystagmus when turning head (also involves III, IV, and VIII) CN VII – Facial Nerve • Provides motor to muscles of facial expression (eyelids, ears, lips) and sensory to medial pinna (ear flap). -
Central Fourth Nerve Palsies Mitchell S.V
RESIDENT &FELLOW SECTION Pearls and Oy-sters: Section Editor Central fourth nerve palsies Mitchell S.V. Elkind, MD, MS Daniel R. Gold, DO CLINICAL PEARLS Lesions of the fourth (trochlear) Clinical features suggestive of bilateral fourth nerve Robert K. Shin, MD cranial nerve cause vertical or oblique diplopia by impair- palsies include right hypertropia in left gaze, left hyper- Steven Galetta, MD ing the ability of the superior oblique muscle to intort tropia in right gaze, and alternating hypertropia with and depress the eye. This binocular diplopia worsens in head tilt to either side (i.e., right hypertropia with right downgaze and lateral gaze away from the affected eye. tilt and left hypertropia with left head tilt).8 Correspondence & reprint Because intorsion is necessary to maintain fusion in ocu- requests to Dr. Gold: [email protected] lar counter-roll, this diplopia also worsens with head tilt CASE REPORTS Case 1. A20-year-oldmanpresented 1,2 toward the affected eye. to the emergency department complaining of 6 days of Diagnosis of a superior oblique palsy can be made binocular vertical diplopia and a left eyelid droop. He using the Parks-Bielschowsky 3-step test: 1) determine had noted fatigue, bilateral eye pain, and flu-like symp- which eye is hypertropic, 2) determine if the hypertro- toms 2 to 4 weeks prior to presentation. pia worsens in left or right gaze, and 3) determine if the Left-sided ptosis and miosis were present on exam- hypertropia worsens in right or left head tilt. In a supe- ination, along with a left adduction deficit. -
What Causes Microvascular Cranial Nerve Palsy? It Is Not Always Clear What Causes the Blockage in the Tiny Blood Vessels to the Cranial Nerves
MICROVASCULAR CRANIAL NERVE PALSEY Microvascular Cranial Nerve Palsy (MCNP) is one of the most common causes of acute double vision in the older population. It occurs more often in patients with diabetes and high blood pressure. MCNP is sometimes referred to as a “diabetic” palsy. This condition almost always resolves on its own without leaving any double vision. Six muscles move your eyes. Four of these muscles attach to the front part of your eye (just behind the iris, or the colored portion of the eye). The two muscles that attach to the back of your eye are responsible for some of the up-and-down (vertical) movement and most of the twisting movement of each eye. These six muscles receive their signals from three cranial nerves that begin in the brain stem. What is Microvascular Cranial Nerve Palsy? A nerve cannot function properly when its blood flow is blocked. If the 6th cranial nerve (also called the abducens nerve) is affected, your eye will not be able to move to the outside and you will be aware of double vision, seeing side-by-side images. If the 4th cranial nerve (also called the trochlear nerve) is affected, you will be aware of vertical double vision (one image on top of another). You may be able to eliminate or decrease the double vision by tilting your head towards the opposite shoulder. The 3rd cranial nerve (also called the oculomotor nerve) supplies four of the six eye muscles. These are some of the muscles that control the eyelid and the size of the pupil. -
Occurrence of Oculomotor Dysfunctions in Acquired Brain Injury: a Retrospective Analysis
Optometry (2007) 78, 155-161 Occurrence of oculomotor dysfunctions in acquired brain injury: A retrospective analysis Kenneth J. Ciuffreda, O.D., Ph.D., Neera Kapoor, O.D., M.S., Daniella Rutner, O.D., M.S., Irwin B. Suchoff, O.D., D.O.S., M.E. Han, O.D., and Shoshana Craig, O.D. State University of New York State College of Optometry, Raymond J. Greenwald Rehabilitation Center, New York, New York. KEYWORDS Abstract Acquired brain injury; BACKGROUND: The purpose of this retrospective study was to determine the frequency of occurrence Traumatic brain of oculomotor dysfunctions in a sample of ambulatory outpatients who have acquired brain injury injury; (ABI), either traumatic brain injury (TBI) or cerebrovascular accident (CVA), with associated vision Cerebrovascular symptoms. accident; METHODS: Medical records of 220 individuals with either TBI (n ϭ 160) or CVA (n ϭ 60) were Stroke; reviewed retrospectively. This was determined by a computer-based query spanning the years 2000 Oculomotor through 2003, for the frequency of occurrence of oculomotor dysfunctions including accommodation, dysfunction; version, vergence, strabismus, and cranial nerve (CN) palsy. Strabismus; RESULTS: The majority of individuals with either TBI (90%) or CVA (86.7%) manifested an Accommodation; oculomotor dysfunction. Accommodative and vergence deficits were most common in the TBI Eye movements; subgroup, whereas strabismus and CN palsy were most common in the CVA subgroup. The frequency Cranial nerve palsy of occurrence of versional deficits was similar in each diagnostic subgroup. CONCLUSION: These new findings should alert the clinician to the higher frequency of occurrence of oculomotor dysfunctions in these populations and the associated therapeutic, rehabilitative, and quality-of-life implications. -
Cranial Nerves. Sensory Organs
Kharkiv National Medical University, Department of Human Anatomy CRANIAL NERVES. SENSORY ORGANS. The cranial nerves are: CN I - Olfactory Nerve CN II - Optic Nerve CN III - Oculomotor Nerve CN IV - Trochlear Nerve CN V - Trigeminal Nerve CN VI - Abducens Nerve CN VII - Facial Nerve CN VIII - Vestibulocochlear Nerve CN IX - Glossopharyngeal Nerve CN X - Vagus Nerve CN XI - Accessory Nerve CN XII - Hypoglossal Nerve Classification of the Cranial Nerves It is possible to describe a cranial nerve in terms of its function and embryological origin, initially cranial nerves can be subdivided into being either: Motor (efferent) Sensory (afferent) And from there further categorization can occur. Motor (efferent) Cranial nerves -Somatic motor (general somatic efferent) (III, IV, VI, XII) These cranial nerves are so called because they innervate muscles derived from the occipital somites, such as the extra ocular and extrinsic tongue muscles. Sensory (afferent) cranial nerves -Visceral sensory special visceral afferent- (VII, IX, X) general visceral afferent- (IX, X) The name is related to the fact that it detects sensation from visceral organs. They are divided into special visceral, referring to the rostral portion of the nucleus which contributes to the special sensation of taste. Whilst the general visceral portion is named as such due to this caudal portion receiving general sensory impulses such as cardiac, respiratory . - General somatic sensory (general somatic afferent) (V, VII, IX, X) These nuclei detect general sensation, such as touch, pain, vibration from the face, sinuses and meninges - Special somatic sensory (special somatic) (VIII) This carries information from the special sensation of hearing and balance. -
Peripheral Nervous System Peripheral Nervous System Comprises: A) Cranial Nerves: 12 in Number, Arise Mainly from Brain Stem
Peripheral nervous system Peripheral nervous system comprises: A) Cranial nerves: 12 in number, arise mainly from brain stem. B) Spinal nerves: arise from spinal cord, varies in number according to species. C) Autonomic nervous system : 1-Sympathetic (thoracolumbar) division. 2-Parasympathetic (craniosacral) division. Cranial nerves They are 12 pairs General features: – They are known by roman numbers from (rostral to caudal) . – Some nerves take their names according to: * Function as olfactory and abducent * Distribution as facial and hypoglossal * Shape as trigeminal. - All cranial nerves have superficial origins on ventral aspect of brain except trochlear nerve originates from dorsal aspect of brain. -All cranial nerves except first one originate from brain stem. - Each nerve emerges from cranial cavity through a foramen. - All cranial nerves except vagus distributed generally in head region. - 3,7,9,10 cranial nerves carry parasympathetic fibers. - Classification of cranial nerves: - They are classified according to the function into: 1-Sensory nerves: 1,2,8. 2-Motor nerves: 3,4,6,11,12. 3-Mixed nerves: 5,7,9,10. I- Olfactory nerves Type: • Sensory for smell. • Represented by bundles of nerve fibers, not form trunk. Origin: • Central processes of olfactory cells of olfactory region of nasal cavity. Course: • They pass though cribriform plate to join olfactory bulb. Vomeronasal nerve: • It arises from vomeronasal organ ,passes through medial border of cribriform plate to terminate in olfactory bulb. II- Optic nerve Type: • Sensory for vision. Origin: • Central processes of ganglion cells of retina. Course: • Fibers converge toward optic papilla forming optic nerve, emerges from eyeball. • Then passes through optic foramen and decussates with its fellow to form optic chiasma.