DOCSLIB.ORG

Micturitional Disturbance in Herpetic Brainstem Encephalitis; Contribution of the Pontine Micturition Centre

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
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. Brain MRI oped band-like headaches around the bilateral Department of showed right side dominant, bilateral Neurology occipitotemporal area which responded par- R Sakakibara pontine segmental lesions extending tially to analgesia but continued for five weeks, T Hattori slightly to the midbrain and medulla. changing to a persistent throbbing headache in T Fukutake After two weeks he was able to urinate but the bilateral frontal area. A week after onset he M Mori showed nocturnal urinary frequency, uri- was admitted to our hospital. On admission his nary incontinence, and voiding diYculty. body temperature was normal, and he was alert Department of Urodynamic studies showed a residual Urology, Chiba and responded well, although his neck was stiff University School of urine volume of 350 ml and detrusor and the Kernig sign was positive. The ocular Medicine, Chiba, hyporeflexia on voiding. Micturitional fundi, pupils, extraocular muscles, and other Japan disturbance gradually disappeared to- cranial nerves were intact, and coordination of T Yamanishi gether with the neurological signs. The the limbs was normal. Tendon reflexes were K Yasuda bilateral pontine tegmental lesions in this active and symmetric with no extensor planter patient are similar to those in previous Department of responses. Sensations to pin prick and position Neurology, Kashima findings on brainstem strokes, evidence of were normal. The second day after admission Rosai Hospital, the presence of a pontine micturition cen- he gradually became somnolent. On the fourth Kashima, Japan tre in humans. day he was comatose and had no oculocephalic R Sakakibara (J Neurol Neurosurg Psychiatry 1998;64:269–272) reflex, hiccup-like dysrhythmic breathing, and T Fukutake ° M Mori Keywords: brainstem encephalitis; herpes simplex virus a fever of 38.5 C. An indwelling urinary cath- type 1 (HSV-1); urinary retention; urodynamic study; eter was used to monitor urinary volume, and Correspondence to: pontine micturition centre he was placed on assisted ventilation. Periph- Dr R Sakakibara, eral blood analysis showed normal findings. An Department of Neurology, Chiba University EEG showed diVuse slowing, without periodic 1–8–1 Inohana, Chuo-Ku, The pontine tegmentum, also called the synchronous discharge. Brain CT detected dif- Chiba 260 Japan. Telephone pontine micturition centre, has an essential fuse brain swelling, particularly in the posterior 0081 43 226 2129; fax 0081 43 226 2160; email function in urinary evacuation. Lesioning and fossa, and bilateral subdural eVusion with [email protected] electrical or chemical stimulations in animals1–3 niveau. Examination of CSF showed a low Received 30 May 1997 show that the pontine micturition centre is opening pressure of 90 cm H2O, mild mononu- Accepted 9 July 1997 located adjacent to,3 or includes,2 the locus clear pleocytosis of 10 /mm3, and increased 270 Sakakibara, Hattori, Fukutake, et al Figure 1 MRI (A Axial plane R–L, B sagittal plane; T2 weighted image, TR 2500,TE100). Abnormally high signal intensities present in the right side dominant, bilateral pontine tegmentum, and extend slightly to the midbrain and medulla. total protein of 93 mg/dl. Antibody values protein of 44 g/dl. At this time, after removal of against HSV-1 in the CSF and the serum the urinary catheter, he had left trochlear nerve respectively were 0.583 and 1.864 in the IgG palsy, left corectopia, ageusia, and urinary enzyme immunoassay and 1:32 and 1:256 in retention, and needed clean, intermittent cath- the complement fixation test.9 The antibody eterisation. Brain MRI showed right side index was 8.5 (albumin 60 mg/dl in CSF and dominant, bilateral pontine segmental lesions 4100 mg/dl in serum). Herpetic encephalitis, extending slightly to the midbrain and medulla predominantly in the brainstem, was diag- (fig 1), but no apparent cerebral lesion. He nosed. gradually became able to urinate and to walk to Aciclovir (1200 mg/day) was started, but was the toilet. On the 44th day, as he still had noc- without benefit. On treatment with 900 mg turnal frequency, urinary incontinence and vidarabine/day, 24 mg dexamethasone/day, and voiding diYculty, urodynamic studies were 900 ml mannitol/day, he gradually regained made. normal consciousness on the 32nd day. Brain The methods and definitions used for the oedema and subdural eVusion had disappeared urodynamic studies conformed to the stand- on the follow up brain CT. A CSF examination ards proposed by the International Continence gave a normal opening pressure of 150 cm Society.10 Neither urinary tract infection nor H2O, no pleocytosis, and mildly increased total organic obstructive urological disease were Figure 2 Results of urodynamic studies. Simultaneous recordings of intravesical pressure (Pves) and external urethral sphincter EMG. Bladder volume at first desire to void (FDV) was 200 ml and at maximum desire to void (MDV) 500 ml. There is no detrusor hyperreflexia. During voluntary micturition (VOID), the detrusor pressure rise was insuYcient, evidence of hypocontractile bladder on voiding. EMG activity has disappeared, and there is no detrusor-sphincter dyssynergia (DSD). Micturitional disturbance in human herpetic brainstem encephalitis 271 Locus coeruleus petic encephalitis, particularly in the brainstem type,11 12 corresponds to a low CSF pressure.13 Superior cerebellar peduncle Micturitional disturbance has rarely been described in herpetic brainstem encephalitis, Medial parabrachial nucleus probably because serious clinical features, such Pontine reticular nucleus and as disturbed consciousness or respiratory reticular formation arrest, usually mask this disturbance. Antiviral chemotherapy with steroids and ventilatory Medial leminiscus support ameliorated the acute signs of our patient, but he showed urinary retention which changed to nocturnal urinary frequency, uri- nary incontinence and voiding diYculty. Uro- dynamic study results showed the presence of 350 ml residual urine volume, and detrusor hyporeflexia on voiding, evidence of a severe evacuating disorder. Detrusor areflexia occurs in peripheral nerve lesions. Our patient, however, had neither the decreased tendon Abducens nucleus reflexes nor disturbed sensation in the limbs Trigeminal sensory nucleus that indicate peripheral neuropathy. Detrusor areflexia also occurs in cerebral diseases within Reticular formation several months during the shock phase,14 and 6 Facial nucleus may persist for years. Detrusor hypoflexia in our patient indicates a supranuclear type of Medial leminiscus pelvic nerve dysfunction as has been reported in vascular diseases6 and tumours15 16 of the Spinothalamic tract brainstem. Other than micturitional disturbance, our patient had coma, hiccup-like dysrhythmic Figure 3 Suspected pontine micturition centre in humans. The dotted circle (pontine breathing, absence of the oculocephalic reflex, micturition centre) includes the pontine reticular nucleus, the reticular formation adjacent to and left trochlear palsy with corectopia after- 6 the medial parabrachial nucleus, and the locus coeruleus. (Cited from Sakakibara et al. ) wards, suggestive of brainstem tegmental found by digital examination of the prostate lesion. Ageusia reflects a lesion of the central and cystourethrography. He had a residual gustatory pathway, which travels in the medial urine volume of 350 ml. Water cystometry part of the medial leminiscus or of the reticular showed a bladder volume of 200 ml at first formation.17 18 MRI showed right sided domi- desire to void, and 500 ml at maximum desire nant, bilateral pontine tegmental
Load more

Recommended publications
  • 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.
    [Show full text]
  • Localization and Network of Coma- Causing Brainstem Lesions: Evidence for a Human Consciousness Network
    Localization and Network of Coma- Causing Brainstem Lesions: Evidence for a Human Consciousness Network The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Fischer, David B. 2016. Localization and Network of Coma-Causing Brainstem Lesions: Evidence for a Human Consciousness Network. Doctoral dissertation, Harvard Medical School. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:27007725 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Abstract Focal brainstem lesions can disrupt arousal and cause coma, yet the exact location of the brainstem region critical to arousal and its associated network are unknown. First, we compare brainstem lesions between 12 patients with coma and 24 patients without coma to identify a region specific to coma-causing lesions. Second, we determine the network connectivity of this brainstem region and each individual coma- causing lesion using resting state functional connectivity MRI data acquired from 98 healthy subjects. Third, we evaluate the functional connectivity of this network in patients with disorders of consciousness (51 patients versus 21 controls). These analyses reveal a small, coma-specific region in the left pontine tegmentum, near the medial parabrachial nucleus. This brainstem region, and each individual coma-causing lesion, is functionally connected to the left agranular, anterior insula (AI), and pregenual anterior cingulate cortex (pACC). These cortical sites align poorly with previously defined functional networks but match the distribution of von Economo neurons (VENs).
    [Show full text]
  • Clinicoradiological Aspects of Pontine
    Published online: 2021-07-26 NEURORADIOLOGY & HEAD AND NECK IMAGING Clinicoradiological aspects of pontine tegmental cap dysplasia: Case report of a rare hindbrain malformation Aanchal Bhayana, Sunil K Bajaj, Ritu N Misra, S Senthil Kumaran1 Department of Radiodiagnosis, Safdarjung Hospital and VM Medical College, 1Department of Nuclear Medical Resonance, All India Institute of Medical Sciences, New Delhi, India Correspondence: Dr. Aanchal Bhayana, Department of Radiodiagnosis, Safdarjung Hospital and VM Medical College, New Delhi - 110 029, India. E-mail: [email protected] Abstract Malformations involving the brainstem are very rare and present with a varied spectrum of clinical symptoms due to multiple cranial nerve palsies and pyramidal tract involvement. Of these, pontine tegmental cap dysplasia is a very unusual malformation, characterized by ventral pons hypoplasia and an ectopic dorsal band of tissue, projecting into the fourth ventricle, from dorsal pontine tegmentum. A 4‑year‑old male child, presenting with left facial nerve palsy, revealed hypoplastic ventral pons and an ectopic structure on magnetic resonance imaging (MRI). The ectopic structure was isointense to pons, arose from the left side of dorsal pontine tegmentum, at pontomedullary junction and protruded into the fourth ventricle, impinging upon the left seventh and eighth cranial nerves. Diffusion tensor imaging (DTI) depicted abnormal white matter tracts in ectopic tissue with absent transverse pontine fibres and abnormal middle and superior cerebellar peduncles.
    [Show full text]
  • Traumatic Transection of the Brainstem
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.44.12.1156 on 1 December 1981. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry 1981 ;44:1156-1158 Short report Traumatic transection of the brainstem BRIAN HARDING, MAGDA ERDOHAZI From the Department of Neuropathology, The National Hospital for Nervous Diseases, London SUMMARY A case of nearly complete transection of the lower brainstem following skull fracture with detailed histological study is presented. Brainstem lesions are a well recognised cause of parietal bones and the squamous part of the occipital coma and early death following severe head injuryl-3 bone. The main fracture line continued forwards along but massive lower brainstem laceration resulting the right temporal bone, turning medially at the base, and injury is highly unusual.45 We was seen to reach the medial end of the petrous bone. from closed head Some epidural haemorrhage was present mainly on the report here one such case which in addition had some right side, but subdural haemorrhage was much more unexpected histological features. extensive and bilateral. There were large areas of con- tusion of both frontal lobes, mainly on their orbital Case report and over both temporal poles, and this was more surfaces, Protected by copyright. An 8-year-old boy was in good health until his injury. extensive on the left side than the right. The posterior While playing on the roof of a local technical college, he temporal lobes and the lateral and inferior surfaces of the tried to jump on to a lower roof and fell through a closed occipital lobes were also contused, but here the damage glass sky-light on to the floor of a laboratory workshop was more severe on the right.
    [Show full text]
  • Pontine Tegmental Cap Dysplasia: MR Imaging and Diffusion Tensor Imaging Features of ORIGINAL RESEARCH Impaired Axonal Navigation
    Pontine Tegmental Cap Dysplasia: MR Imaging and Diffusion Tensor Imaging Features of ORIGINAL RESEARCH Impaired Axonal Navigation P. Jissendi-Tchofo BACKGROUND AND PURPOSE: Malformations of the brain stem are uncommon. We present MR D. Doherty imaging and diffusion tensor imaging (DTI) features of 6 patients with pontine tegmental cap dysplasia, characterized by ventral pontine hypoplasia and a dorsal “bump,” and speculate on potential mecha- G. McGillivray nisms by which it forms. R. Hevner D. Shaw MATERIALS AND METHODS: Birth and developmental records of 6 patients were reviewed. We reviewed MR imaging studies of all patients and DTIs of patient 3. Potential developmental causes G. Ishak were evaluated. R. Leventer RESULTS: All patients were born uneventfully after normal pregnancies except patient 6 (in utero A.J. Barkovich growth retardation). They presented with multiple cranial neuropathies and evidence of cerebellar dysfunction. Variable hypotonia and motor dysfunction were present. Imaging revealed ventral pontine hypoplasia and mild cerebellar vermian hypoplasia, in addition to an unusual rounded to beaklike “bump” on the dorsal surface of the pons, extending into the fourth ventricle. Color fractional anisotropy maps showed the bump to consist of a bundle of axons directed horizontally (left-right). The bump appeared, on morphologic images, to be continuous with the middle cerebellar peduncles (MCPs), which were slightly diminished in size compared with those in healthy infants. Analysis of the DTI was, however, inconclusive regarding the connections of these axons. The decussation of the MCPs, transverse pontine fibers, and longitudinal brain stem axonal pathways was also abnormal. CONCLUSIONS: Our data suggest that the dorsal transverse axonal band in these disorders results from abnormal axonal pathfinding, abnormal neuronal migration, or a combination of the 2 processes.
    [Show full text]
  • An Anatomic, Imaging, and Clinical Review of the Medial Longitudinal
    www.clinicalimagingscience.org Journal of Clinical Imaging Science Neuroradiology/Head and Neck Imaging Review Article An Anatomic, Imaging, and Clinical Review of the Medial Longitudinal Fasciculus Peter Fiester1, Saif Ahmed Baig1, Jeet Patel1, Dinesh Rao1 1Department of Neuroradiology, University of Florida Health Jacksonville, Jacksonville, Florida, United States. ABSTRACT e medial longitudinal fasciculus (MLF) is a paired, highly specialized, and heavily myelinated nerve bundle responsible for extraocular muscle movements, including the oculomotor reflex, saccadic eye movements an smooth pursuit, and the vestibular ocular reflex. Clinically, lesions of the MLF are classically associated with internuclear ophthalmoplegia. However, clinical manifestations of a lesion in the MLF may be more complex and variable. We provide an overview of the neuroanatomy, neurologic manifestations, and correlative examples of the *Corresponding author: imaging findings on brain MRI of MLF lesions to provide the clinician and radiologist with a more comprehensive Saif Ahmed Baig, understanding of the MLF and potential clinical manifestations for an MLF lesion. Department of Neuroradiology, University of Florida Health Keywords: Medial longitudinal fasciculus, Internuclear opthalmoplegia, Trochlear syndrome, One-and-a-half Jacksonville, Jacksonville, syndrome, Wall-eyed bilateral internuclear opthalmoparesis syndrome Florida, United States. [email protected] INTRODUCTION Received : 07 April 2020 Internuclear opthalmoplegia is defined as the lack of adduction of the ipsilateral eye with Accepted : 10 November 2020 preserved abduction of the contralateral eye with nystagmus. It is the result of a lesion Published : 18 December 2020 affecting the medial longitudinal fasciculus (MLF) – a paired, highly specialized, and heavily DOI: myelinated nerve bundle traveling in a craniocaudid direction near the midline within 10.25259/JCIS_49_2020 the tegmentum of the midbrain and dorsal pons.
    [Show full text]
  • Premonitory Symptoms of Stroke in Evolution to the Locked-In State
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.46.3.221 on 1 March 1983. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry 1983 ;46:221-226 Premonitory symptoms of stroke in evolution to the locked-in state JOHN LIU, STANLEY TUHRIM,* JESSE WEINBERGER,* SUN K. SONG,t PAUL J ANDERSONt From the Department ofNeurology* and Division ofNeuropathologyt The Mount Sinai School ofMedicine, City University ofNew York, and the Division ofNeuropathology, City Hospital Centre at Elmhurstt, New York, USA SUMMARY Three patients, who subsequently developed the locked-in state characterised by quadriplegia and mutism with an alert sensorium, initially had mild dysarthria and uncrossed hemisensory or hemimotor deficits involving the face and ipsilateral extremities. Case one ini- tially mimicked a left cerebral lesion with right hemisensory deficits, a mild right facial paresis and a right homonymous field deficit. Case two initially developed both left hemimotor and hemisen- sory deficits and later developed a paresis of right conjugate gaze. Case three presented with left hemimotor deficit, and mild paresis of conjugate gaze to the right. All three patients died. Rostral were brainstem infarctions found at necropsy in cases one and two. Case three had a radiolucent Protected by copyright. area of the brainstem demonstrated by CT Scan. Hemisensory and hemimotor deficits also have been noted to precede reported cases of pontine infarction with the locked-in state. Acute onset of uncrossed hemisensory and hemimotor deficits with dysarthria may be caused by infarction of the pons which may predispose to the locked-in state. The locked-in state is a devastating neurological ler infarction in the midventral pons was found.
    [Show full text]
  • Lab 3. Pons & Midbrain
    Lab 3. Pons & Midbrain Lesion Lessons Lesion 4.1 Anne T. Pasta i) Location ii) Signs/symptoms (Slice of Brain © 993 Univs. of Utah and Washington; E.C. Alvord, Jr., Univ. of Washington) iii) Cause: Lesion 4.2 Colin S. Terase i) Location ii) Signs/symptoms (Slice of Brain © 993 Univs. of Utah and Washington; M.Z. Jones, Michigan St. Univ.) iii) Cause: Medical Neuroscience 4– Pontine Level of the Facial Genu Locate and note the following: Basilar pons – massive ventral structure provides the most obvious change from previous med- ullary levels. Question classic • pontine gray - large nuclear groups in the basilar pons. Is the middle cerebellar peduncle composed – origin of the middle cerebellar peduncle of climbing or mossy • pontocerebellar axons - originate from pontine gray neurons and cross to form the fibers? middle cerebellar peduncle. • corticopontine axons- huge projection that terminates in the basilar pontine gray. • corticospinal tract axons – large bundles of axons surrounded by the basilar pontine gray. – course caudally to form the pyramids in the medulla. Pontine tegmentum • medial lemniscus - has now assumed a “horizontal” position and forms part of the border between the basilar pons and pontine tegmentum. Question classic • central tegmental tract - located just dorsally to the medial lemniscus. What sensory modali- – descends from the midbrain to the inferior olive. ties are carried by the • superior olivary nucleus - pale staining area lateral to the central tegmental tract. medial and lateral – gives rise to the efferent olivocochlear projection to the inner ear. lemnisci? • lateral lemniscus - lateral to the medial lemniscus. – composed of secondary auditory projections from the cochlear nuclei.
    [Show full text]
  • Substance P in the Descending Cholinergic Projection to REM Sleep
    European Journal of Neuroscience, Vol. 15, pp. 176±196, 2002 ã Federation of European Neuroscience Societies Substance P in the descending cholinergic projection to REM sleep-induction regions of the rat pontine reticular formation: anatomical and electrophysiological analyses Kristi A. Kohlmeier,1* Joan Burns,2 Peter B. Reiner1² and Kazue Semba2 1Kinsmen Laboratory of Neurological Research, Department of Psychiatry, School of Medicine, University of British Columbia, Vancouver, B.C., V6T 1Z3 Canada 2Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4H7 Canada Keywords: immunohistochemistry, mesopontine tegmentum, tract tracing, whole-cell patch-clamp recording Abstract Release of acetylcholine within the pontine reticular formation (PRF) from the axon terminals of mesopontine cholinergic neurons has long been hypothesized to play an important role in rapid eye movement (REM) sleep generation. As some of these cholinergic neurons are known to contain substance P (SP), we used anatomical, electrophysiological and pharmacological techniques to characterize this projection in the rat. Double immuno¯uorescence demonstrated that 16% of all cholinergic neurons within the mesopontine tegmentum contained SP; this percentage increased to 27% in its caudal regions. When double immuno¯uorescence was combined with retrograde tracing techniques, it was observed that up to 11% of all SP-containing cholinergic neurons project to the PRF. Whole-cell patch-clamp recordings from in vitro brainstem slices revealed that SP administration depolarized or evoked an inward current in a dose-dependent manner in all PRF neurons examined, and that these effects were antagonized by a SP antagonist. The amplitude of the SP-induced inward current varied with changes in the Na+ concentration, did not reverse at the calculated K+ or Cl± equilibrium potentials, and was not attenuated in the presence of tetrodotoxin, low Ca2+ concentration or caesium ions.
    [Show full text]
  • Subjective of Brain Stem
    Brain Disorders & Therapy Editorial Subjective of Brain Stem Samy McFarlane* Department of Medicine and Endocrinology, Osaka University, New York, USA EDOTRIAL NOTE ON BRAIN STEM METENCEPHALON The midbrain (mesencephalon) contains the atomic complex of The pons (metencephalon) comprises of two sections: the the oculomotor nerve just as the trochlear core; these cranial tegmentum, a phylogenetically more seasoned part that contains nerves innervate muscles that move the eye and control the state the reticular development, and the pontine cores, a bigger part of the focal point and the breadth of the student. Also, between made out of masses of neurons that lie among enormous heaps the midbrain reticular arrangement (referred to here as the of longitudinal and cross over nerve filaments. Filaments tegmentum) and the crus cerebri is a huge pigmented core called beginning from neurons in the cerebral cortex end upon the the substantia nigra. The substantia nigra comprises of two pontine cores, which thusly task to the contrary side of the sections, the standards reticulata and the standards compacta. equator of the cerebellum. These gigantic crossed strands, called Cells of the standards compacta contain the dim shade melanin; crus cerebri, structure the center cerebellar peduncle and fill in these cells integrate dopamine and undertaking to either the as the scaffold that associates each cerebral side of the equator caudate core or the putamen. By restraining the activity of huge with the contrary portion of the cerebellum. The filaments aspiny striatal neurons in the caudate core and the putamen beginning from the cerebral cortex establish the corticopontine (depicted above in the segment Basal ganglia), the dopaminergic lot.
    [Show full text]
  • A Review of Facial Nerve Anatomy
    A Review of Facial Nerve Anatomy Terence M. Myckatyn, M.D.1 and Susan E. Mackinnon, M.D.1 ABSTRACT An intimate knowledge of facial nerve anatomy is critical to avoid its inadvertent injury during rhytidectomy, parotidectomy, maxillofacial fracture reduction, and almost any surgery of the head and neck. Injury to the frontal and marginal mandibular branches of the facial nerve in particular can lead to obvious clinical deficits, and areas where these nerves are particularly susceptible to injury have been designated danger zones by previous authors. Assessment of facial nerve function is not limited to its extratemporal anatomy, however, as many clinical deficits originate within its intratemporal and intracranial components. Similarly, the facial nerve cannot be considered an exclusively motor nerve given its contributions to taste, auricular sensation, sympathetic input to the middle meningeal artery, and parasympathetic innervation to the lacrimal, submandibular, and sublingual glands. The constellation of deficits resulting from facial nerve injury is correlated with its complex anatomy to help establish the level of injury, predict recovery, and guide surgical management. KEYWORDS: Extratemporal, intratemporal, facial nerve, frontal nerve, marginal mandibular nerve The anatomy of the facial nerve is among the components of the facial nerve reminds the surgeon that most complex of the cranial nerves. In his initial descrip- the facial nerve is composed not exclusively of voluntary tion of the cranial nerves, Galen described the facial motor fibers but also of parasympathetics to the lacrimal, nerve as part of a distinct facial-vestibulocochlear nerve submandibular, and sublingual glands; sensory innerva- complex.1,2 Although the anatomy of the other cranial tion to part of the external ear; and contributions to taste nerves was accurately described shortly after Galen’s at the anterior two thirds of the tongue.
    [Show full text]
  • 14 Motor Nucleus of Cranial Nerve Vii (Motor Vii)
    263 Brain stem Motor VII 14 MOTOR NUCLEUS OF CRANIAL NERVE VII (MOTOR VII) Before turning to the motor VII, you should note that the pons consists of two zones, a dorsal portion called the tegmentum of the pons and a ventral zone called the basilar pons. The tegmentum contains cranial nerve nuclei and ascending pathways such as the medial lemniscus, lateral lemniscus, ALS (spinothalamic tract), STT (solitariothalamic tract) and TTT (trigeminothalamic tract). The basilar region contains the pontine grey nuclei and massive groups of descending fibers, including the corticospinal, corticobulbar, and corticopontine tracts. Brain stem 264 Motor VII The motor nucleus VII contains motor neurons (branchiomotor) that innervate the muscles of facial expression including the orbicularis oculi (CLOSES eyelid), the stapedius, the stylohyoid and the posterior belly of the digastric. Neurons comprising motor VII possess axons that pursue a rather circuitous route in order to exit the brain stem. Initially they pass dorsally and medially to loop over the abducens nucleus. The fibers then course ventrally and laterally to exit the brain stem. The bump in the floor of the fourth ventricle caused by the motor fibers of C.N. VII looping over the abducens nucleus is called the FACIAL COLLICULUS. A unilateral lesion interrupting the axons of C.N. VII results in the following: On the ipsilateral side, the forehead is immobile, the corner of the mouth sags, the nasolabial folds of the face are flattened, facial lines are lost, and saliva may drip from the corner of the mouth. The patient is unable to whistle or puff the cheek because the buccinator muscle is paralyzed.
    [Show full text]