Ebook Textbook of clinical neurology: Part 1

(BQ) Part 1 book Textbook of clinical neurology has contents: A brief history of neurology, the neurological consultation, an overview over nervous system and muscles. technical investigations in neurology, strength and sensation, motor control,... and other contents.

Textbook of Clinical Neurology editors: J.B.M Kuks J.W Snoek Textbook of Clinical Neurology editors: J.B.M Kuks J.W Snoek Textbook of Clinical Neurology ISBN 978-90-368-2141-4 ISBN 978-90-368-2142-1 (eBook) https://doi.org/10.1007/978-90-368-2142-1 © Bohn Stafleu van Loghum is een imprint van Springer Media B.V., onderdeel van Springer Nature 2018 This work is subject to copyright All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed The use of general descriptive names, registered names, trademarks, service marks, etc in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations NUR 876 Basisontwerp omslag: Studio Bassa, Culemborg Automatische opmaak: Scientific Publishing Services (P) Ltd., Chennai, India Bohn Stafleu van Loghum Walmolen Postbus 246 3990 GA Houten www.bsl.nl V Preface This edition of the Textbook of Clinical Neurology is a translation of the original Dutch textbook edited back in the day by Prof H.J.G.H Oosterhuis It has proved highly useful over the years and we therefore decided to produce an English-language edition The textbook is intended for medical and paramedical students, clerks and registrars Clinical neurology builds on the foundation of basic sciences, hence in the first eleven chapters we have devoted attention to basic concepts and only referred to clinical pictures occasionally From Chapter 12 onwards we deal with the various areas of clinical neurology, referring back wherever necessary to the first eleven chapters The Dutch textbook has been constantly revised to reflect new developments and in response to comments by users – both teachers and students – thus keeping it up to date both neurologically and pedagogically We are aware that the book will be many readers’ first encounter with clinical neurology and have therefore ensured that neurological terms and concepts are introduced in such a way that, as far as possible, readers with as yet limited medical knowledge not need to have access to other reference works in order to continue reading without losing the thread Having both been active practitioners of general clinical neurology and lecturers and deans of education for many years, we trust we have succeeded in this The textbook is supported by a website where test questions for each chapter are provided It also includes some up-to-date references to reviews in the neurological literature We hope that this book will prove useful as a reference work for both students and medical practitioners in the broadest sense We welcome any questions and comments and will endeavour to respond swiftly J.B.M Kuks, MD PhD J.W Snoek, MD PhD Clinical Neurology Consultants University Medical Center Groningen The Netherlands j.b.m.kuks@umcg.nl Contents 1.1 1.2 1.3 1.4 1.5 A brief history of neurology Images from antiquity The middle ages 2 The development of present-day knowledge 2 Research into the nervous system 3 Clinical neurology and related medical specialisms 3 The neurological consultation 2.1 History-taking 6 2.1.1 The seven dimensions of the problem 2.1.2 Heteroanamnesis 2.1.3 Family history 2.1.4 Other diseases, intoxications 2.1.5 Social history 2.1.6 What does the patient think it could be? 2.2 Physical neurological examination: often carried out only where indicated 7 2.3 Diagnostic tests 8 2.3.1 A priori considerations 2.3.2 Diagnostic value 2.4 Organizing information 9 2.5 Diagnostic follow-up 9 An overview over nervous system and muscles Technical investigations in neurology 11 3.1 Structure of the nervous system 13 3.2 Visualizing the peripheral nervous system 14 3.2.1 Computed tomography (CT) 14 3.2.2 Magnetic resonance imaging (MRI) 14 3.2.3 Radioisotope scanning 15 3.2.4 Ultrasound 15 3.3 The nerve 16 3.3.1 Functional structure 16 3.3.2 Histology and metabolism 16 3.3.3 Physiology at rest 17 3.3.4 Nerve action potential 17 3.3.5 Interneuronal communication 18 3.3.6 Abnormal nerve activity 18 3.4 The muscle 18 3.4.1 Functional structure 18 3.4.2 Microscopic anatomy 19 3.4.3 Neuromuscular transmission 19 3.4.4 The muscle in action 19 3.4.5 Symptoms of muscular disorders 20 3.5 The motor unit 21 3.6 Electromyography 21 3.6.1 Needle EMG 21 3.6.2 Measuring nerve conduction 21 3.7 Physiological measurements of the central nervous system 23 3.7.1 Electroencephalography 23 3.7.2 The indications for EEG 23 3.7.3 Magnetoencephalography 24 3.8 Other diagnostic tests 25 3.8.1 Causes of neurological diseases 25 3.8.2 Blood tests 25 3.8.3 Neuropathological tests 25 VII Contents 4.1 4.1.1 4.1.2 4.1.3 4.1.4 4.1.5 4.1.6 4.1.7 4.1.8 4.1.9 4.2 4.2.1 4.2.2 4.2.3 4.3 4.4 4.5 Strength and sensation 27 Physiological background 28 The spinal reflex 28 Several types of spinal reflexes 28 Central control of spinal reflexes 28 Increased and depressed reflexes 29 Central paresis 30 Sensory feeling 30 Central sensory pathways 30 Somatotopy of the sensory system 32 Segmental distribution 32 Examination of the motor and sensory system 32 Examination of muscle function 33 Examination of reflexes 39 Testing sensation 41 Central hemiplegia 44 Non-Organic disorders 45 Measurement of central motor and sensory disturbances 46 Motor control 47 5.1 Central motor control 48 5.1.1 The parietal sensory cortex plays an important role in movement initiation 48 5.1.2 The basal ganglia 49 5.1.3 The cerebellum 53 5.1.4 The examination of central motor function 54 5.1.5 Inspection and observation 54 5.1.6 Eye movements 54 5.1.7 Dysarthria 55 5.1.8 Upper limb ataxia 55 5.1.9 Lower limb ataxia 55 5.1.10 Truncal movements 56 5.1.11 Muscle tone 56 5.1.12 Muscle stretch reflexes 56 5.2 Gait and stance 56 5.2.1 Postural reflexes 56 5.2.2 Examination 56 Brainstem and cranial nerves 59 6.1 Functional arrangement of the brainstem 61 6.1.1 Overview 61 6.1.2 Functions of the brainstem 61 6.1.3 Motor control in the event of brainstem disorder 64 6.2 The cranial nerves 64 6.2.1 Smell 65 6.2.2 Pupillary responses and eyelid movement 66 6.2.3 Eye movements 67 6.2.4 Facial sensation 70 6.2.5 Taste 70 6.2.6 Facial movement 71 6.2.7 Hearing 71 6.2.8 Balance 72 6.2.9 Chewing, speaking and swallowing 73 6.2.10 The special characteristics of the accessory nerve 73 Examination of the cranial nerves 73 6.3 6.3.1 Testing smell 73 6.3.2 Resting-state eye examination and pupillary response testing 73 6.3.3 Examination of eye movements 74 VIII Contents 6.3.4 6.3.5 6.3.6 6.3.7 6.3.8 6.3.9 6.3.10 6.4 6.5 6.6 6.7 6.7.1 6.7.2 6.7.3 6.7.4 Examination of facial sensation 75 Examination of taste sensation 75 Facial motor control 75 Hearing examination 75 Examination of the balance organ 76 Examination of the tongue and throat musculature 76 Examination of the accessory nerve 77 Examination of a comatose patient 77 Abnormal respiration associated with brainstem problems 79 Bulbar or pseudobulbar disorder? 79 Brainstem syndromes 80 Occlusion of the basilar artery 80 Locked-in syndrome 80 Wallenberg’s syndrome 80 Foville’s syndrome 81 Autonomic nervous system, hypothalamus and pituitary gland 83 7.1 The sympathetic and parasympathetic systems 85 7.1.1 The sympathetic system 85 7.1.2 The parasympathetic system 85 7.1.3 Afferent fibres of the autonomic nervous system 85 7.2 The hypothalamus 86 7.2.1 Temperature regulation 86 7.2.2 Regulation of blood osmolarity 86 7.2.3 Growth and sexual maturation 87 7.2.4 Sleep regulation 87 7.3 Pituitary gland 87 7.4 Autonomic regulation of blood pressure and heart action 88 7.5 Autonomic control of the eye 88 7.5.1 Regulation of pupil diameter 88 7.5.2 Sympathetic elevation of the eyelid 89 7.5.3 Horner’s syndrome 89 7.6 Micturition and defecation 89 7.6.1 Micturition 89 7.6.2 Neurogenic bladder disorders 90 7.6.3 Myogenic bladder disorders 91 7.6.4 Defecation 91 7.7 Sexual function disorder 91 8.1 8.1.1 8.1.2 8.1.3 8.1.4 8.1.5 8.2 8.2.1 8.2.2 8.2.3 8.2.4 8.2.5 8.3 8.4 8.4.1 8.5 8.6 The higher cerebral functions 93 The functions of the cerebellar cortex 95 Diffuse and local cortical disorders 95 Anatomical arrangement 95 Language dominance 96 Emotion and memory 96 Cortical functions are more or less localized 97 Aphasia 97 Language and speech 97 Fluent and non-fluent language disorders 97 Categorization of aphasia 97 The impact of aphasia 98 Reading, writing and arithmetic 98 Apraxia 98 Agnosia 99 Klüver-bucy syndrome 99 Aprosody 99 Spatial disorders 100 IX Contents 8.7 8.7.1 8.7.2 8.7.3 8.7.4 8.8 8.8.1 8.8.2 8.8.3 8.9 8.10 8.11 Memory 100 Short-term and long-term memory disorders 100 Amnestic syndrome 100 Wernicke’s encephalopathy 101 Transient global amnesia 101 Physical causes of psychological dysregulation 102 Organic psychosyndrome 102 The two forms of frontal psychosyndrome 102 Psychological phenomena associated with the posterior cortex 102 Delusions and hallucinations 102 Ill-defined symptoms 102 Testing of higher functions 103 The visual system 105 9.1 Vision and visual fields 106 9.1.1 From eye to cortex 106 9.1.2 Central visual information processing 106 9.1.3 Visual field defects 106 9.2 Higher visual disorders 108 9.2.1 Visual agnosia 108 9.2.2 Losing sight of things 109 9.2.3 Positive visual phenomena 109 9.3 Examination and testing of the visual system 110 9.3.1 Vision 110 9.3.2 Visual field test 110 9.3.3 Fundoscopy 111 10 Cerebral meninges and the cerebrospinal fluid system 113 10.1 Cerebral meninges 114 10.2 Production and drainage of fluid 114 10.3 Lumbar puncture 114 10.4 Measuring cerebrospinal fluid pressure 115 10.5 Cerebrospinal fluid analysis 115 10.6 Cerebrospinal fluid abnormalities 117 10.7 Cerebrospinal fluid circulation disorders 117 10.7.1 Hydrocephalus 117 10.7.2 Obstructive and communicating hydrocephalus 117 10.7.3 Acute and chronic hydrocephalus 119 10.7.4 Diagnosis of hydrocephalus 119 10.8 Clinical problems associated with fluid circulation disorders 119 10.8.1 Obstructive hydrocephalus 119 10.8.2 Communicating hydrocephalus 120 10.8.3 Idiopathic intracranial hypertension 120 10.8.4 Cerebrospinal fluid hypotension 121 The cerebrovascular system 123 11.1 The blood supply to the CNS 124 11.1.1 Arterial blood supply to the brain 124 11.1.2 Venous drainage 124 11.1.3 The blood-brain barrier 126 The cerebral blood flow 126 11.2 11.2.1 Physiology 126 11.2.2 Cerebral infarction 127 11.2.3 Relative hypoxia 127 11.2.4 Vasogenic cerebral oedema 128 11.2.5 Venous cerebral thrombosis 128 11 X Contents 11.3 Pathological vascular changes 128 11.3.1 Atherosclerosis 128 11.3.2 Aneurysm 128 11.3.3 Arteriovenous malformation 129 11.3.4 Dissection of an artery 129 11.4 Cerebrovascular diagnostics 130 11.4.1 Angiography 130 11.4.2 Ultrasonography 130 11.4.3 Perfusion and diffusion measurement 131 12 Diseases of the muscle and neuromuscular junction 133 12.1 Classification of neuromuscular disorders 135 12.2 Acquired and congenital disorders 135 12.3 Diagnostic tests 136 12.3.1 Strategy 136 12.3.2 Muscle biopsy 136 12.4 Congenital muscular diseases 137 12.4.1 Dystrophinopathy 137 12.4.2 Facioscapulohumeral muscular dystrophy 138 12.4.3 Myotonic dystrophy 139 12.4.4 Limb-girdle dystrophy 140 12.4.5 Channelopathies 140 12.4.6 Metabolic myopathies 140 12.5 Acquired myopathies 141 12.5.1 Inflammatory myopathies 141 12.5.2 Inclusion body myositis 142 12.5.3 Polymyalgia rheumatica 142 12.5.4 Non-inflammatory acquired muscular diseases 142 12.6 Diseases of the neuromuscular junction 142 12.6.1 Clinical signs 142 12.6.2 Myasthenia gravis 142 12.6.3 Lambert-Eaton myasthenic syndrome 144 12.6.4 Differential diagnosis of fluctuating muscle weakness 145 12.7 Causes of muscle cramp 145 12.8 Chronic tiredness without muscular disease 145 12.9 Muscular diseases in medical practice 146 13 Disorders of the motor neurons, nerve roots and peripheral nerves 147 13.1 Classification of nerve disorders 149 13.1.1 Symptoms and signs 149 13.1.2 Involuntary movements and neuropathic symptoms 149 13.1.3 Autonomic symptoms 149 13.1.4 Electromyography 150 13.1.5 Further tests for neuropathies 151 13.2 Diseases of the nerve cell body: neuronopathy 151 13.2.1 Symptoms 151 13.2.2 Spinal muscular atrophy 151 13.2.3 Amyotrophic lateral sclerosis 152 13.2.4 Less severe motor neuron diseases 153 13.3 Disorders of the nerve root: radiculopathy 153 13.3.1 Radiculopathy is often accompanied by radiating pain 153 13.3.2 Guillain-Barré syndrome 153 Mononeuropathy 154 13.4 13.4.1 Damage to a peripheral nerve 154 13.4.2 Causes 154 13.4.3 Surgery for peripheral nerve lesions 155 15.5.4 Ventral transdural spinal cord herniation – 190 15.5.5 Chiari malformation – 191 15.5.6 Treatment of non-traumatic spinal cord compression – 191 15.6 Myelopathy without compression – 192 15.6.1 Vascular disorders of the spinal cord – 192 15.6.2 Transverse myelitis – 193 15.6.3 Combined degeneration of the spinal cord – 193 15.6.4 Vacuolar myelopathy in AIDS – 194 15.6.5 Tropical spastic paraparesis – 194 181 15.1 · Anatomy of the spinal column and spinal cord Case 15.1 A 25-year-old man dives into a swimming pool where the depth is 1.5 metres He remembers the top of his head hitting the bottom and then lying there unable to move his arms and legs When bystanders fished him out of the water he was able to breathe, but his arms, legs and abdomen remained immobile, and he had no sensation below shoulder height In hospital he was found to have a fracture with dislocation of the C5–6 vertebrae Cranial traction was applied to reduce the dislocation He then underwent surgery with stabilization, fixation and osteosynthesis He remained completely paralysed below the shoulders for two weeks, after which he was gradually able to move his legs a little, but his arms remained paralysed Sensation returned to his chest above the nipples and to his buttocks, scrotum and penis It also returned to the outside of his upper arms, but not to the forearms, the inside of the upper arms and the armpits He was given intermittent catheterization to treat urinary retention; he was able to feel this clearly and often had erections Question 1: Why was he still able to breathe in spite of the extensive paralysis? Question 2: What explains the progression, with sensation in the buttocks, scrotum and penis quickly returning? Question 3: What can be expected over time as regards the reflexes? Question 4: What explains the phenomenon of erections due to catheterization? Online: 7Answers to case study questions 15.1 Case 15.2 A 63-year-old man with a history of diabetes and hypertension wakes up at five o’clock in the morning with a severe pain in the middle of his back Soon afterwards, when he tries to get out of bed, he notices that he cannot move his legs He is unable to urinate, but he does not feel a clear urge On examination he is found to have flaccid weakness of both legs with absent stretch reflexes He feels it when he is touched and when his legs are moved passively, but pain sensation is completely absent from the legs and trunk up to the navel Motor sensation in the big toe and even graphesthesia are intact Question 1: Which part of the spinal cord is affected and at what level? Question 2: What is the most likely explanation for this problem? Question 3: What is causing the severe back pain? Online: 7Answers to case study questions 15.2 15.1  natomy of the spinal column and spinal A cord 15.1.1 Location of the spinal cord The spinal cord segments are named after the vertebral bodies along which the spinal nerve root exits (.fig. 15.1) Each segment is higher than its corresponding vertebra The spinal cord has a number of long-tract systems, of which the following are important in clinical practice: the posterior columns (.fig. 15.2-1) the spinothalamic tract (.fig. 15.2-2) the corticospinal tract or pyramidal tract (.fig. 15.2-4) also the origin of the peripheral motor neuron, namely the anterior horn cell (.figs. 15.2-5 and 4.3) The spinal cord originates in the foramen magnum, with the highest sensory innervation in the C2 dermatome, covering the occiput and the lower edge of the jaw (.figs. 4.7 and 6.10) The spinal cord terminates approximately at the L1 vertebra, so there is a difference in level in particular between the lower spinal cord segments and the vertebrae with the same segmental names (ascending medulla) Some examples: the T5 vertebra corresponds to the T6–7 spinal cord segment and the T12 vertebra corresponds to the L3–4 spinal cord segment At the L1 vertebral level there are the sacral segments, the conus medullaris The collection of roots below the conus in the spinal canal is referred to as the ‘cauda equina’ (horse’s tail, fig. 15.1) 15.1.2 Loss of function due to spinal cord injury A permanent complete spinal cord injury at a particular level (e.g C7, due to a C6 vertebral injury) eventually results in (.fig. 15.2): damage to the posterior columns (funiculi) (.fig. 15.2-1): loss of epicritic sensation from the corresponding dermatome downwards (C7: the mid-forearm and hand and below: fig. 4.7); damage to the spinothalamic tract (.fig. 15.2-2): loss of protopathic sensation in the same area; loss of reflex arc function (.fig. 15.2-3) over the spinal cord segment affected (C7: triceps tendon reflex: tab. 4.4); damage to the pyramidal tract (.fig. 15.2-4): increase in the reflexes below that level, with pathological plantar reflexes due to interruption of the pyramidal tract (7sect. 4.1.4), loss of strength at and below the level of the spinal cord injury (C7: the patient is still able to flex his arms but not stretch them, hand motor function is lost, the legs are paralysed); damage to the anterior horn (.fig. 15.2-5): segmental muscular atrophy at the level of the injury due to loss of motor neuron function (C7: triceps muscle); damage to the lateral horn (.fig. 15.2-6) with sympathetic tracts and cell column: this particularly affects sweat secretion and blood pressure regulation; impaired bladder function (7sect. 7.6.2) and sexual function (7sect. 7.7) due to loss of sympathetic tract function and also control of the parasympathetic centres in the cauda equina The parasympathetic nervous system remains otherwise unimpaired, as the vagus nerve is not affected 15 Chapter 15 · Diseases of the spinal cord 182 roots cervical segments thoracic segments 1 2 3 76 7 6 7 15.2 15.2.1 Conventional X-ray examination 10 10 11 11 12 12 sacrococcygeal segments 2 3 cauda equina L(umbar) 5 15 S(acral)  Figure 15.1  Spinal cord segments, spinal column and exiting roots (lateral view) 10 Radiological diagnosis T(oracic) lumbar segments C(ervical) Incomplete spinal cord injuries can cause erratic and asymmetrical loss of function, e.g the following presentation due to an incomplete spinal cord injury at C7 with external compression: loss of epicritic sensation on the left below T2 and on the right below T6, loss of protopathic sensation in the right leg up to L1, spastic paralysis of both legs and loss of bladder control In the next three sections we discuss spinal cord disorders classified by cause: compression due to trauma (7sect. 15.3), non-traumatic compression (7sect. 15.5) and myelopathy without compression (7sect. 15.6) .Figure 15.3 gives an overview of the most common spinal cord disorders and their particular characteristics  Figure 15.2  Cross-section of the spinal cord at cervical level posterior columns, spinothalamic tract, segmental reflex arc, pyramidal tract, motor neuron, intermediolateral nucleus (lateral horn), dorsal ganglion with cell body, large fibre (deep sensation), dorsal ganglion with cell body, small fibre (pain, temperature), second-order neuron, anterolateral system in the dorsal horn, 10 interneuron Conventional (plain) X-ray examination is of very limited value It does have some value if a vertebral disorder is suspected, especially following a trauma The spinal column is then routinely X-rayed at all levels in two planes (anteroposterior and lateral) In the case of the cervical and lumbar spine, oblique (three-quarter) X-rays can be made in order to assess the foramina better In practice nowadays, however, in an initial trauma care setting a quick spiral CT scan of the entire spinal column will carried out in virtually all cases in order to show all the relevant parts of the bony spinal column The position and/or back of the vertebral bodies should be checked to see whether they form a continuous line (is there any dislocation?) Traumatic abnormalities are sometimes only seen once functional X-rays in maximum flexion and extension have been taken In the case of trauma the dens needs to be X-rayed and assessed separately Abnormalities on a conventional spinal column X-ray 5 5 5 vertebral body slippage due to ligament injury bone destruction and bone neoplasm spondylolysis, spondylolisthesis abnormal lordosis, kyphosis, scoliosis open arch destruction of intervertebral disc and surrounding tissue due to spondylitis or spondylodiscitis stenosis of intervertebral interstice Loss of intervertebral space is indicative of disc degeneration, but a prolapsed disc is not visible on a plain X-ray, and a normal intervertebral disc height certainly does not rule out a prolapsed disc 183 15.3 · Traumatic spinal cord injuries disease-sympton matrix of spinal cord injuries onset pyramidal tract disorder posterior funiculus disorder spinothalamic tract disorder anterior horn disorder pain sensory upper boundary abnormal CSF anterior spinal artery thrombosis + – + + + + – section 15.6.1 transverse myelitis herniated disc spondylitis extramedullary compression intramedullary tumour vitamine-B12-deficiency 2 3/4 4/5 + –/+ + + + –/+ + –/+ + + (+) + + –/+ + (+) (+) – + –/+ (+) (+) (+) – – + + + – – + + + + –/+ – 1,2,3,4 1+2 – – 15.6.2 14.3.2 15.5.1 15.5.1 15.5.1 15.6.3 multiple sclerosis tabes dorsalis vacuolar myelopathy tropical paraparesis 2/3/4 3/4 + – + + + + + –/+ – + – –/+ – – – – – + – – –/(+) – (+) – 3,4 1,3,4 1,2,3,4 24.2 23.8 15.6.4 15.6.5 ALS syringomyelia 4/5 + (+) – (+) – + + + – –/+ – – – – 13.2.3 15.5.3 spinocerebellar degeneration (+) + – –/+ – – – 25.3 + present; – absent; –/+ may be present or absent; (+) present to a small extent, e.g partial CSF blockage Onset: minutes-hours, hours-days, days-weeks, weeks-months, months-years Abnormal CSF: elevated cell count, elevated protein, abnormal IgG index, specific antibodies  Figure 15.3  Disease-symptom matrix of spinal cord injuries 15.2.2 MRI scan The spinal cord is generally scanned in the sagittal and transverse planes using MRI (7sect. 3.2.2) This clearly shows the nerve tissue and intervertebral discs with any abnormalities It is possible to examine a large part of the spinal canal at once, so abnormalities at a higher level than initially expected will not be overlooked 15.3 Traumatic spinal cord injuries 15.3.1 Transient and permanent loss of function An injury to the spinal column and/or spinal cord can be caused by a force acting perpendicular to the length (usually from behind), a force on the axis of the spinal column (com­ pression fracture due to a fall from a great height), forced flexion or extension (diving into shallow water), or powerful torsion/rotation of the trunk/pelvis (as can occur when falling off a horse, bicycle or motorcycle) In most cases (60 %) there will be a combination of vertebral injury and medullary contusion due to compression of the spinal cord (medullary compression), immediately resulting in complete or incomplete loss of function In other cases (20 %) there will be vertebral injury with no damage to neural structures Isolated spinal cord injuries without vertebral fractures are also found (20 %) In this case there may have been traumatic herniated disc or very brief compression at the time of the trauma In the best scenario this will cause brief transient loss of function of the spinal cord (or part of it), e.g due to a fall onto the buttocks or a back-and-forth motion of the cervical spinal column, e.g due to a rear-end collision or a sporting accident This can cause medullary concussion, resulting in minutes or hours of paraesthesia in the extremities, and possibly transient paresis Sometimes there initially appears to be only minor damage or none, and loss of function develops secondarily after a free interval This is due to the occurrence of small haemorrhages and oedema, as in the case of central haematomyelia (7sect. 15.3.2) Spinal epidural haematoma (7sect. 15.3.2) may also be a factor, but this is rare following a trauma 15 184 Chapter 15 · Diseases of the spinal cord Patients with a narrowed spinal column (spondylarthrosis, rheumatoid arthritis, 7sect. 15.5.2) can sustain a partial spinal cord injury even from relatively minor traumas, e.g falling forward onto the hands The lesion will almost always be cervical, and impaired blood supply is also likely to be a factor In the case of traumatic spinal cord syndromes it is best to an MRI scan immediately in order to detect e.g any traumatic herniated disc or compression by a bone fragment straight away d 15.3.2 Traumatic spinal cord syndromes Complete traumatic spinal cord injury 15 In the acute stage (the first few weeks) of a traumatic spinal cord injury there will be spinal shock (7sect. 6.1.3) below the level of the lesion After a while hyperreflexia will develop below that level, producing a presentation such as that described in 7case 15.1 In the case of a complete spinal cord injury the easiest way to determine the height of the lesion is by using pain stimuli As the spinal cord segments (especially the caudal ones) are higher than the corresponding vertebrae (ascending medulla, fig. 15.1), a vertebral injury always needs to be sought slightly higher than the clinical level of the loss of function: for instance, if the clinical/neurological level is C7 there is likely to be a spinal cord injury at the level of the C6 vertebra In many cases a cervical traumatic spinal cord injury will be located in the C6 and C7 segments, due to dislocation of the C5 vertebra in relation to the C6 vertebra Because of the partially intact biceps function (C5–6) and the paralysis of the triceps muscle (C7–8), the patient will be lying with his arms bent on his chest A complete spinal cord injury above the C5 segment is generally incompatible with life, as it makes diaphragm function (phrenic nerve, C3–5: fig. 13.2) insufficient and hypoventilation causes CO2 intoxication The practical consequence is that permanent artificial breathing support is needed to maintain body functions, so the patient will be dependent on a ventilator Symptoms and signs of acute traumatic spinal cord injury total flaccid paralysis below the level of the lesion complete areflexia (both tendon and skin reflexes) loss of bladder and rectal function (urinary retention and paralytic ileus) complete loss of sensation below the level of the lesion if the site is cervical: strong erection (priapism) Brown-Séquard syndrome Brown-Séquard syndrome (.fig. 15.4) is due to the protopathic system crossing over just above the level where it enters the spinal cord, whereas the epicritic system ascends ipsilaterally (7sect. 4.1.7) At the level of the abnormality an ipsilateral band-like area with analgesia, sometimes hyperpathia, may be found on careful examination This is caused by the pain c b hyperpathia or analgesia a epicritic protopathic  Figure 15.4  Brown-Séquard syndrome, T10 left fibres that enter ipsilaterally at the level affected being damaged before crossing over (the pathway shown in blue that enters the middle section at the right posterior in fig. 15.5) Damage to the anterior horn can also occur at the level of the lesion, eventually causing local muscle atrophy This syndrome seldom occurs in its pure form It was first described following bullet wounds (especially in the First World War), but nowadays it is usually caused by a tumour – e.g a metastasis or meningioma – compressing the spinal cord, or a bleed or infarction in the spinal cord The symptoms are often somewhat more extensive, e.g because the contralateral pyramidal tract is also affected Another cause of BrownSéquard syndrome is ‘ventral transdural spinal cord herniation’, a rare condition found only at the level of the thoracic spine (7sect. 15.5.4) An important clinical rule is that unilateral paralysis of a leg due to a spinal cord injury should not cause unilateral loss of protopathic sensation on the same side Brown-Séquard syndrome Below the lesion central paresis of the ipsilateral limb (or limbs) ipsilateral loss of epicritic sensation contralateral loss of protopathic sensation At the level of the lesion ipsilateral analgesia, hyperpathia ipsilateral loss of strength and atrophy 15 185 15.3 · Traumatic spinal cord injuries T4 10 T5 T8  Figure 15.6  Central cord syndrome posterior columns, spino­ thalamic tract, segmental reflex arc, pyramidal tract, motor neuron, intermediolateral nucleus (lateral horn), dorsal ganglion with cell body, large fibre (deep sensation), dorsal ganglion with cell body, small fibre (pain, temperature), second-order neuron, anterolateral system in the dorsal horn, 10 interneuron Central cord syndrome Central cord syndrome is caused by damage to the central grey matter in the cervical spinal cord, which is more vulnerable than the surrounding white matter with the long neural pathways There will often have been transient medullary compression following a pincer movement of the spinal column Sometimes the symptoms not develop until some time after the trauma, due to secondary bleeds and oedema They can increase to such an extent as to affect the surrounding long pathways in the spinal cord white matter as well The segmental symptoms are caused by interruption of the reflex arc in the centre of the spinal cord and the protopathic pathways that cross over (.fig. 15.6), and the distant symptoms by a disorder of the long pathways in the spinal cord Sensation in the S2–5 sacral dermatomes is often relatively unaffected, as the pathways ascending from this area are on the outside of the spinal cord (.fig. 4.6): this is referred to as ‘sacral sparing’ Because of the generally very severe peripheral loss of function in both arms, often with relatively little central loss of leg function, it is sometimes referred to as ‘man-in-the-barrel syndrome’ T9 L2 Central cord syndrome L3  Figure 15.5  Hemisection of the spinal cord The pathways shown in blue are interrupted as a result of the injury posterior column, spino­ thalamic tract, pyramidal tract, incoming large fibre with epicritic information, outgoing ventral root, incoming small fibre with protopathic information, axon crossing over the second-order neuron, not at the level of the segment but obliquely upwards: the axon joins the contralateral spinothalamic tract one or two levels higher hypotonic loss of strength in the arms (.fig. 15.6-5) hypertonic leg paresis (.fig. 15.6-4) segmental loss of protopathic sensation in the arms (.fig. 15.6-9) areflexia in the arms (.fig. 15.6-3) usually little loss of epicritic sensation (.fig. 15.6-1) sacral sparing (.fig. 15.7) Posterior cervical contusion Posterior cervical contusion is a transient syndrome that can develop following a trauma to the cervical spine, with no radiological abnormalities The patient complains of a severe burning pain in the neck and shoulders (the C3–4 dermatomes), sometimes in both arms and hands (C5–8) There is hyperpathia and dysaesthesia (7sect. 4.2.3): light touching is particularly painful, whereas firmly grasping e.g the neck muscles or 186 Chapter 15 · Diseases of the spinal cord by rapidly progressive symptoms of spinal cord compression Depending on the site of the bleed this causes spinal cord injury symptoms with loss of strength and sensation in the arms and/or legs, and possibly loss of sphincter function Use of anticoagulants is a risk factor, as is older age (the condition is more common in the over-50s) It is important to recognize and diagnose this condition quickly (.fig. 15.8) In most cases urgent surgical decompression (removal of the haematoma) is required, as this has the best chance of restoring function Iatrogenic spinal haematoma is a notorious complication for anaesthetists who have carried out an injection or puncture or installed a catheter in the spinal epidural space as part of a surgical procedure or in order to treat pain This is referred to as ‘traumatic spinal epidural haematoma’ Fortunately this is rare compared with the large number of epidural punctures carried out The source of a spinal epidural haematoma is the ‘spinal epidural venous plexus’, which is a venous network embedded in the epidural fatty tissue in the spinal column Injuries to the conus medullaris and cauda equina 15  Figure 15.7  Sacral sparing in C6 central cord syndrome The dark blue area shows the loss of sensation trapezius muscle is only painful to begin with; the pain stops once the examiner continues to hold these muscles without moving the skin There is generally no paresis, but the patient is unwilling to move because of the pain This is a typical example of neuropathic pain with damage causing abnormal nerve signals The prognosis is good: the severe pain sometimes clears up within a few hours and usually within a few days Spinal epidural haematoma There might be thought to be a link between back trauma and spinal epidural haematoma, but this is not the case In most cases there is no clear cause of the bleeding, so it ought really to be referred to as ‘spontaneous spinal epidural haematoma’ There is usually sudden neck or back pain with no apparent cause, with or without acute radiating pain in an arm or leg, generally followed The lower end of the spinal cord, the conus medullaris, usually terminates at or above the level of the L2 vertebra Therefore, if the problem is below this level there can never be pyramidal tract symptoms Another interesting point is that the outgoing fibres (L1–S5) are very close together They continue into the cauda equina, which gradually thins out until low in the sacrum (.fig. 15.1) Conus medullaris and cauda equina lesions are quite often found in combination, due to fractures of the T12 to L2 vertebrae The common symptomatology is loss of sensation in S2–5 (the saddle area: fig. 15.9), impaired bladder, rectal and sexual function and absent anal reflex (S5) If there is complete loss of function of all the sacral roots, motor function in the feet will also be lost If roots S1 and S2 remain relatively intact, motor function in the feet will not be particularly impaired, which can be misleading on superficial examination If only the caudal roots are affected, there will be spontaneous pain and stretching pain (positive Lasègue’s sign) and the loss of function will often be asymmetrical If the conus medullaris is damaged, the loss of function will be symmetrical and not normally painful Apart from vertebral fractures, acute cauda equina syndrome is generally caused by a herniated disc (7sect. 14.4.2, fig. 14.4), or sometimes by metastases or bleeds in the spinal column Conus medullaris/cauda equina syndrome site below the T11 vertebra, usually at the level of L1/2 (.fig. 15.1) hypotonic paresis of the legs, depending on the level of the loss of function loss of protopathic and epicritic sensation in the saddle area more extensive loss of sensation, depending on the site areflexia in the legs, depending on the site conus medullaris injury: not painful; cauda equina injury: pain due to irritation of the nerve roots conus medullaris injury symmetrical; cauda equina injury often asymmetrical impaired bladder and rectal function impaired sexual function 187 15.3 · Traumatic spinal cord injuries  Figure 15.8 T2-weighted MRI of the spinal column, with posterior compression of the spinal cord at the level of C6–T1 by an extradural (epidural) haematoma in the spinal column 15.3.3 The value of surgical intervention in traumatic spinal cord injuries The prognosis for complete spinal cord injuries above C5 almost always soon becomes poor because of ventilation disorders Lower spinal cord injuries that are complete from the outset rarely improve Other than we might intuitively expect, immediate surgery (decompression, correction of the abnormal position of the spinal column) has no effect on the progression of a complete spinal cord injury On the other hand, decompression may improve a complete cauda equina injury Other­ wise, epidural haematoma or traumatic HNP is of course a reason to operate, and radicular pain may also justify surgical intervention High doses of corticosteroids to reduce oedema and prevent secondary tissue damage have not been found worthwhile, just as in the case of cerebral injuries The survival prognosis in the case of a complete spinal cord injury will depend on whether complications (decubitus ulcers, urinary tract infections, pulmonary complications) can be prevented in the acute stage: these complications increase with patient age After weeks or months the flaccid paralysis turns into spastic paresis (central paralysis) and automatic bladder (7sect. 7.6.2) develops In the case of a complete cauda equina lesion any remaining weakness in the lower legs remains flaccid paresis/paralysis (PMN lesion) and bladder function does not return: atonic bladder develops, with urinary retention and incontinence In the case of conus medullaris lesions autonomic bladder develops at a later stage . Figure 15.9  Saddle anaesthesia in cauda equina syndrome (S2–5) The dark blue area shows the loss of sensation The acute stage (six to eight weeks) is followed by a rehabilitation period of one or two years in which the patient adapts to his disability as best he can Autonomic dysregulation (blood pressure fluctuations) and neuropathic pains merit special attention After months or years further loss of function can develop secondarily, due to post-traumatic syrinx (7sect. 15.5.3) 15.3.4 Late effects of cervical trauma It is fairly common for a stiff neck to develop after a fall onto or against the head, evidently due to distortion or soft tissue trauma Neck movements are initially painful in all directions An X-ray hardly ever shows any abnormalities 15 188 Chapter 15 · Diseases of the spinal cord Whiplash injury is caused by a rear-end collision with the head not properly supported The symptoms often not develop until after an interval of hours or days In many people they last for a few weeks or months, but they can sometimes last for a very long time (whiplash-associated disorder) A proportion of patients develop complex symptomatology, with dizziness, headache, poor concentration, blurred vision and hypersensitivity to sensory stimuli There is no satisfactory explanation as yet for this pattern, and it is also unclear what the best treatment is There are indications that active treatment strategies are more effective than passive ones There is certainly no indication that long-term wearing of a cervical collar is useful; on the contrary, it seems to delay recovery 15.4 Non-traumatic spinal cord injuries 15.4.1 Clinical approach The best way to determine the spinal cord level above which no neurological abnormalities can be found is sensory examination (of pain sensation, touch sensation, possibly temperature sensation and vibration sensation on the vertebrae) Pain in a nerve root area that is spontaneous or occurs when the pressure is increased may be an indication; if the level is lumbar or cervical, loss of motor function will give a useful indication of the site (.tab. 4.3) A careful search for throbbing pain, tenderness on and near the vertebrae and axial pain should be carried out at the expected level of the spinal cord problem 15.4.2 Imaging tests for myelopathy 15 Imaging should focus on the part of the spinal column corres­ ponding to the clinically affected spinal cord segment, taking the ascending medulla into account (.fig. 15.1), and also the fact that the impairment will actually be higher than indicated by the clinical level, as a partial spinal cord syndrome or vascularization disorder may have developed for which the collateral circulation at the level of the problem could be compensating An MRI scan can provide information on the vertebrae and the ‘soft tissue parts’, including intervertebral discs, muscle tissue and the contents of the spinal canal (epidural fat, dural sac, spinal cord, cauda equina) A sagittal MRI scan of the spinal column (in the longitudinal plane) usually has to be carried out in two stages, as the magnetic coil in the MRI is too short to cover the entire column at once The anatomical relationships between the vertebrae and the spinal cord and the amount of space left for the cerebrospinal fluid (CSF) around the cord are clearly shown in an MRI scan In the case of spinal cord compression abnormal signals reflecting myelopathy may be found Abnormalities such as a space-occupying process, syringomyelia, vascular malformation, MS plaques or vascular damage may also come to light A CT scan provides information particularly on the bone structures making up the spinal column; it is less suitable for providing information on the contents of the spinal canal In special cases a ‘CT myelogram’ can be carried out by injecting a contrast agent into the dural sac (usually via a lumbar puncture): this can help to distinguish between arachnoid cysts and other abnormalities around the spinal cord and in the dural sac A chest X-ray and/or chest CT is also routinely carried out in the case of a non-traumatic spinal cord problem (lung cancer resulting in vertebral metastases, tuberculosis resulting in spondylitis, aortic aneurysm resulting in loss of vascular function) If bone metastases are suspected a total skeletal isotope scan is worthwhile, or a PET/CT or MRIPET scan can be carried out 15.4.3 General supplementary tests Lab tests can provide indirect indications of the nature of the process, such as elevated ESR, elevated alkaline phosphatase and PSA (prostate-specific antigen) in the case of vertebral metastases from the prostate, abnormal protein spectrum in multiple myeloma (Kahler’s disease), hypochromic anaemia in the case of vitamin B12 deficiency, copper deficiency, and possibly a positive syphilis test 15.4.4 Examination of CSF If CSF passage is blocked because the width of the spinal cord does not correlate to that of the spinal canal, the protein level will often increase below the level of the problem, sometimes to such high values that the CSF turns yellow (protein-bound bilirubin) .Table 15.1 gives an overview of CSF disorders in various conditions Today’s sophisticated MRI techniques have rendered CSF testing far less valuable than it used to be, except where infectious/parainfectious and demyelinating disorders are suspected 15.5  pinal cord compression due to nonS traumatic causes 15.5.1 Clinical differences between extramedullary and intramedullary compression Table 15.1 gives an overview of the causes of non-traumatic spinal cord compression Extramedullary neoplasms often cause pain, which can be due to bone destruction in the case of vertebral disorders or to radicular irritation Intradural extramedullary neoplasms are generally more likely to cause radicular pains and radicular symptoms than spinal cord symptoms The first sensory impairment due to extramedullary neoplasms is loss of epi­ critic function due to compression of the posterior columns This often starts out asymmetrical, and develops in the legs first because the sacral fibres lie completely dorsally at the surface (.fig. 4.5) Brown-Séquard syndrome (7sect. 15.3.2) can also develop 189 15.5 · Spinal cord compression due to non-traumatic causes  Table 15.1  Causes of non-traumatic spinal cord compression spinal neoplasms non-malignant spinal column abnormalities: – cervical spondylosis deformans – congenital spinal stenosis – degenerative spinal stenosis – rheumatoid arthritis – osteoporosis (rarely spinal cord compression) – ankylosing spondylitis (formerly known as Bechterew’s disease) – Paget’s disease, achondroplasia – prolapsed disc (rarely thoracic) primary tumours and bone lesions – haemangioma – myelomas (e.g multiple myeloma, Kahler’s disease) – bone tumours (e.g chondrosarcoma) – osteomyelitis (Staphylococci, Escherichia coli, Brucella) – tuberculous spondylitis – vertebral metastases (spinal epidural metastasis: 7sect. 22.6) intraspinal epidural neoplasms – abscess – haematoma (usually spontaneous) intradural extramedullary neoplasms – meningioma (relationship with breast cancer) – neurofibroma – neurinoma – vascular malformation (usually without compression, however) – arachnoid cyst – ventral transdural spinal cord herniation – leptomeningeal metastases (lymphoma, leukaemia, breast cancer, melanoma, lung cancer, sarcoma, gastrointestinal cancer) – granulomatous infiltration of the leptomeninges (sarcoidosis) medullary neoplasms – glioma (astrocytoma, ependymoma) – syringomyelia – intramedullary metastases (especially lung and breast cancer, lymphoma) Intramedullary tumours are very slowly progressive over many years The loss of sensation is not usually clearly circumscribed Central cord syndrome as described in 7sect. 15.3.2 occurs, namely loss of segmental reflexes and temperature sensation; the sacral dermatomes remain relatively unaffected 15.5.2 Cervical spinal stenosis Cervical osteoarthritis (.fig. 15.10) is a common cause of myelopathy It is referred to in full as ‘cervical spondylotic myelop­ athy’ This is a combination of direct spinal cord compression and a chronic circulatory disorder of the spinal cord, as blood vessels are also compressed Often the mid and/or low cervical spinal canal is narrowed by bony protuberances (osteophytes)  Figure 15.10  MRI (T2) of the cervical spinal cord in a 60-year-old woman with pyramidal tract symptoms and loss of epicritic sensation There is narrowing of the cervical canal at C3–5 A signal change is found locally in the spinal cord, a manifestation of ischaemic damage due to the prolonged compression and protruding intervertebral discs There will often be preexisting congenital stenosis A common misapprehension is that this causes neck pain, and that neck movements are restricted, which is surprisingly not so much the case There is gradually progressive damage to and atrophy of the spinal cord It mainly affects the over-50s, who over a period of months start complaining of numbness and loss of strength in the fingers (making it more difficult to up buttons), sometimes a certain amount of radiating pain in one or both arms, wooden gait, imperative urinary urgency and impotence In particular, pyramidal tract and posterior column disorders are found in the legs, segmental disorders in the arms and posterior column disorders in the hands The symptoms are fairly variable and may be confined to long-tract symptoms in the legs Pure pyramidal tract syndromes and Brown-Séquard syndrome may also be found Rheumatoid arthritis is an unusual cause of anomalies in the upper cervical vertebrae Bony narrowing of the spinal canal due to granuloma formation (known as ‘pannus’) and subluxation of the dens can cause severe spinal cord compression 15 190 Chapter 15 · Diseases of the spinal cord As the spinal cord has little room for manoeuvre in the case of cervical spinal stenosis, a relatively minor trauma, e.g falling forwards, can cause extensive symptomatology This often takes the form of a traumatic central cord syndrome (7sect. 15.3.2) Lumbar spinal stenosis (7sect. 14.4.3) and lumbar disc protrusion (7sect. 14.4.2) not of course cause spinal cord syndromes but symptoms of caudal compression 15.5.3 Syringomyelia 15 Syringomyelia is a very slowly progressive disease of the spinal cord (usually cervical) A cavity (syrinx = pipe) develops in the spinal cord In the pure form there is widening – usually congenital – of the central canal Cavities can also form outside the canal, in which case the abnormality is often secondary to a spinal cord tumour (.fig. 15.11) or develops following a spinal cord trauma or infarction Sometimes the lower part of the medulla oblongata (bulb) is also affected, hence the term syringobulbia The condition manifests itself between the 20th and 45th year of life, is very slowly progressive (over dozens of years) and does not usually cause invalidity, or not until a very late stage It is sometimes discovered by chance It is not normally inherited Twice as many men as women are affected The syrinx causes a central spinal cord syndrome (7sect. 15.3.2) The first symptoms are usually minor burns to the fingers due to impaired temperature sensation At this stage there is generally loss of temperature and pain sensation in the hands, arms and often the shoulder dermatomes, initially asymmetrical, with absence of arm reflexes Epicritic sensation remains intact (dissociated loss of sensation) The loss of protopathic sensation and the spread of the process to the lateral horn of the spinal cord (sympathetic nervous system) cause tropic disorders affecting both the skin and the joints Horner’s syndrome (7sect. 7.5.3) can occur and will often be bilateral The skin sometimes becomes oedematous, thin and smooth, with ulcers that are not painful and heal poorly The elbow and shoulder joint cartilage can develop abnormal metabolism due to loss of autonomic function causing neurogenic arthropathy (Charcot joint) At an even later stage further spread affects the motor neurons, causing atrophy of the small hand muscles and arm muscles The white matter and long tracts then become involved in the process as well, and both pyramidal tract and posterior column symptoms can develop in the legs Spread to the lower part of the brainstem (syringobulbia) causes atrophy of the tongue and swallowing problems and further symptoms higher up Syringomyelia is usually (90 %) accompanied by abnorma­ lities in the craniovertebral junction, either basilar impression on its own or Chiari malformation (7sect. 15.5.5) This has led to the hypothesis that syringomyelia is due to abnormal CSF dynamics . Figure 15.11  Syringomyelia due to Chiari malformation T2-weighted craniocervical MRI scan, with the cerebellar tonsils descending to the superior margin of the C1 vertebral arch (arrow) There is also extensive accumulation of central CSF in the cervical spinal cord (cervical syringomyelia) 15.5.4 Ventral transdural spinal cord herniation A treatable cause of spinal cord compression is ventral trans­ dural spinal cord herniation This is a rare condition found only at the level of the thoracic spine The cause is not known It is more common in women and usually starts with a presentation similar to Brown-Séquard syndrome (7sect. 15.3.2) caused by spinal cord herniation due to a ventral dural defect This is usually lateral to the centre, initially causing herniation of the corresponding half of the spinal cord If it remains undiagnosed the herniation increases over time and the neurological pre­ sentation evolves into spastic paraparesis, often causing sphincter dysfunction as well The MRI pattern is often typical at this stage, with a clear kink in the spinal cord, which also appears to lie partly outside the dural sac (.fig. 15.12a) At an early stage of the condition it may be difficult to distinguish between 191 15.5 · Spinal cord compression due to non-traumatic causes 15.5.5 Chiari malformation A congenital defect of the craniovertebral junction can cause an abnormality in the base of the skull, with the lower part of the brainstem displaced caudally and part of the cerebellum descending into the cervical canal (.fig. 15.11) The dens can lie relatively high and cause impression in the medulla oblongata (basilar impression) This abnormality can occur in all degrees of severity and, as already mentioned, can be accompanied by syringomyelia or syringobulbia As a result there is relatively little space for the structures of the posterior cranial fossa (cerebellum, brainstem), which can cause symptoms such as swallowing problems, long-tract symptoms (abnormalities in the posterior columns and pyra­­ midal tract), eye movement disorders and ataxia The symptoms generally develop between the 10th and 30th year of life, sometimes manifesting themselves suddenly following a fairly minor skull or neck trauma An unusual symptom is cough headache (7sect. 21.7): the increased pressure in the head that always occurs when coughing briefly causes the cerebellar tonsils to descend further into the foramen magnum, and occlusion of the foramina between the fourth ventricle and the peripheral CSF spaces increases the CSF pressure This presentation is consistent with Chiari type malforma­ tion; if the malformation is combined with meningomyelocele and hydrocephalus it is referred to as a Chiari type malforma­ tion (7sect. 28.6.2) 15.5.6 Treatment of non-traumatic spinal cord compression  Figure 15.12  Ventral transdural spinal cord herniation a T2-weighted MRI of the thoracic spine, with the spinal cord at the level of T6–7 displaced forward and the CSF signal (white line), which should normally be between the anterior of the spinal cord and the posterior of the spinal column, absent This is due to the spinal cord bulging as a result of a defect in the dura mater b Intraoperative X-ray showing the dural defect and the distorted part of the spinal cord bulging outward due to the defect spinal cord herniation and an arachnoid cyst Both problems sometimes occur simultaneously The precise problem can usually only be diagnosed by surgical exploration Surgery for spinal cord herniation aims to remove the herniation and cover the dural defect (to prevent reherniation) (.fig. 15.12b) If there is an arachnoid cyst the treatment will consist in removing the cyst and exposing the spinal cord The aim will generally be to relieve the spinal cord compression by laminectomy (removing a number of vertebral arches) and removing the space-occupying process This produces good results in the case of meningiomas and neurinomas if the neurological symptoms are not yet severe Spinal cord compression due to an earlier vertebral fracture or stenosis also often responds well to decompression The treatment of spinal epidural metastases is discussed in 7sect. 22.6 Surgery can also produce good results in the case of intramedullary tumours These operations are always performed using an operating microscope (microsurgical resection), with intraoperative neurophysiological monitoring (IONM) of spinal cord function during the procedure This increases the safety of the operation, thus limiting the chances of new postoperative loss of function Complete resection of a spinal cord tumour is only possible if the cancerous tissue can be clearly differentiated from the surrounding spinal cord Decompressive laminectomy can produce good results in cervical myelopathy due to osteoarthritis (7sect. 15.5.2, fig. 15.10) by improving the sensory impairments and motor symptoms The structural damage to the spinal cord caused at the time of the compression is of course no longer reparable Residual symptoms usually remain after surgery; the value of decompression lies mainly in preventing further deterioration The younger the patient the better the prognosis and the shorter the symptoms will last 15 Chapter 15 · Diseases of the spinal cord 192 S L dorsal root T C posterior spinal artery C S lateral corticospinal tract C S spinothalamic tract ventral root radicular artery anterior spinal artery  Figure 15.13  Vascularization of the spinal cord The dotted line shows the area supplied by the anterior spinal artery Somatotopy in the various tract systems: C cervical, T thoracic, L lumbar, S sacral Treatment for syringomyelia or hydromyelia depends on the cause One possibility is to install a shunt, a small drain from the cavity into the spinal CSF space If the cavitation is post-traumatic or post-infectious it may be worthwhile to remove any adhesions that have developed between the spinal cord and the dural sac surgically, so as to restore normal CSF passage If there is a defect at the level of the craniocervical junction (basilar impression, Chiari malformation, fig. 15.11) it is worthwhile to perform decompression surgery (atlantooccipital decompression) to remove the blockage of CSF passage at that level 15 15.6 Myelopathy without compression Causes of myelopathy without compression demyelinating disorders – MS – neuromyelitis optica (Devic’s syndrome) infections – following vaccination or infection – viral (polio, herpes zoster, rabies, HIV, human T-cell lymphotropic virus type 1) – bacterial (e.g TB, syphilis, borreliosis) toxic and physical damage – spinal anaesthetics – radiation metabolic disorders – diabetes – vitamin B12 deficiency, copper deficiency vascular disorders – aneurysm or aortic dissection – arteriosclerosis – arteriovenous malformation – c omplication of aortic angiography – vasculitis paraneoplastic abnormalities – 7section 22.7 15.6.1 Vascular disorders of the spinal cord Spinal cord vascular disorders are relatively rare, compared with cerebrovascular accidents (strokes) This is probably due to the good anastomoses of the spinal cord arteries, both along the spinal cord and in each segment Vascular disorders in the spinal cord occur mainly in the mid-thoracic segments This is because the arterial supply (from the aorta) to the spinal cord comes mainly from the great radicular artery (artery of Adam­ kiewicz, usually originating somewhere between spinal segments T8 and L1) and a low cervical/high thoracic radicular artery The mid-thoracic segments are most distant from this in a ‘watershed area’ (7sect. 11.1) and will suffer the most damage if there is a drop in blood pressure This kind of spinal cord infarction is found mainly in patients with generalized atherosclerosis and/or diabetes The loss of function usually develops fairly suddenly, may be accompanied by severe back pain and/ or radiating pain (root ischaemia) and is sited in the anterior two-thirds of the spinal cord segment (supplied by the ante­ rior spinal artery); epicritic sensation then remains unaffected (.fig. 15.13) The weakness is initially flaccid with areflexia (spinal shock, 7sect. 6.1.3) and there is sphincter dysfunction Less extensive syndromes can also develop The prognosis need not be poor, but some loss of function often remains 193 15.6 · Myelopathy without compression Another type of spinal cord circulatory disorder can be caused by a spinal dural arteriovenous fistula This is an acquired arteriovenous anomaly that usually develops in middle age It is more common in men and sited mainly at the level of the thoracic spinal cord The loss of function is usually gradually progressive but can also develop quickly or be subject to sudden exacerbations The loss of function depends on the part of the spinal cord affected, and the severity is determined by the degree of swelling/congestion in the spinal cord The MRI pattern is fairly typical, with swelling of the spinal cord and distended, tortuous blood vessels (the arterialized spinal cord veins) on the outside of the spinal cord (.fig. 15.14) Venous congestion causing ischaemia (‘venous congestion myelopathy’) probably explains the loss of function in the case of a spinal dural arteriovenous fistula The treatment consists in surgical disconnection or embolization (endovascular closure) of the arteriovenous fistula 15.6.2 Transverse myelitis Transverse myelitis is a rare syndrome that can sometimes develop following a viral infection (measles, herpes zoster, herpes simplex, HIV) or microbial infection (Borrelia, Mycoplasma pneumoniae), in systemic diseases (Sjögren’s syndrome, SLE) or following vaccination (smallpox, rabies) The cause is unknown in 20 % of cases The symptoms can develop acutely at a single spinal cord injury level, or they can gradually increase (ascending progression), reaching a maximum after several weeks They are often preceded by pain and radicular irritation If one or both optic nerves are affected the condition is referred to as neuromyelitis optica (7sect. 24.7.3) MS can start out as transverse myelitis High doses of corticosteroids are thought to have a beneficial effect, but this is not proven 15.6.3 Combined degeneration of the spinal cord Myelopathy caused by vitamin B12 deficiency generally develops gradually, with loss of epicritic sensation and paraesthesia in the legs, and examination reveals symptoms of posterior column disorders Polyneuropathy often develops in the legs as well Pyramidal tract disorders develop later, hence the term combined degeneration of the spinal cord It is important to remember that pathological plantar reflexes and absent stretch reflexes co-exist here Mental changes (pseudodementia) may accompany the neurological abnormalities Vitamin B12 deficiency also causes haematological abnormalities, but often these not run in parallel with the neurological symptoms Multi-vitamin supplements can prevent the blood picture from becoming pathological, but larger doses of parenteral vitamin B12 are needed to treat the neurological abnormalities . Figure 15.14  Spinal dural arteriovenous fistula a T2-weighted MRI of the thoracic spine, with the entire thoracic spinal cord swollen, with a high signal (oedema) due to venous congestion (congestive myelopathy) The distended venous plexus can be seen on the outside around the spinal cord The fistula can be seen on the angiogram (inset photo), with a radicular artery short-circuiting an efferent spinal cord vein (arrow) As a result the arterial blood from the arteriole is propelled retrograde into the efferent venous system, causing venous outflow resistance with spinal cord congestion and swelling b Intraoperative X-ray showing the distended venous plexus of the spinal cord and the place where the arteriole shortcircuits the venous system at the junction with the dura (arrow), just below the exiting thoracic nerve root 15 194 Chapter 15 · Diseases of the spinal cord 15.6.4 Vacuolar myelopathy in AIDS This syndrome develops in some 20 % of patients in the final stage of AIDS, due to damage to the white matter, especially at thoracic level The symptoms are loss of epicritic sensation in the legs, spastic paresis and micturition problems 15.6.5 Tropical spastic paraparesis This rare form of chronic myelitis is caused by human T-cell lymphotropic virus type (HLTV-1) It develops very gradually in middle age, with stiffness and paresis in the legs, followed at a later stage by bladder dysfunction The sensory impairments are not so pronounced and may even be absent The CSF generally displays a mild lymphocytic response, elevated protein and gamma globulin Specific antibodies are found in the serum and CSF These antibodies in fact occur in 5–20 % of the popu­ lation in endemic regions (particularly North Africa and the Caribbean) There is no specific treatment 15 ... 16 6 14 14 .1 14.2 14 .2 .1 14.2.2 14 .2.3 14 .2.4 14 .3 14 .3 .1 14.3.2 14 .3.3 14 .4 14 .4 .1 14.4.2 14 .4.3 14 .5 14 .6 15 15 .1 15 .1. 1 15 .1. 2 15 .2 15 .2 .1 15.2.2 15 .3 15 .3 .1 15.3.2 15 .3.3 15 .3.4 15 .4... 2 61 20.7.4 Chronic traumatic encephalopathy 2 61 21 21. 1 21. 2 21. 2 .1 21. 2.2 21. 2.3 21. 2.4 21. 3 21. 3 .1 21. 3.2 21. 3.3 21. 3.4.. .Textbook of Clinical Neurology editors: J.B.M Kuks J.W Snoek Textbook of Clinical Neurology ISBN 978-90-368- 214 1-4 ISBN 978-90-368- 214 2 -1 (eBook) https://doi.org /10 .10 07/978-90-368- 214 2 -1 ©