The Clinical Science of Neurologic Rehabilitation, Second Edition BRUCE H. DOBKIN, M.D. OXFORD UNIVERSITY PRESS ix Contents Part I. Neuroscientific Foundations for Rehabilitation 1. ORGANIZATIONAL PLASTICITY IN SENSORIMOTOR AND COGNITIVE NETWORKS 3 SENSORIMOTOR NETWORKS 4 Overview of Motor Control • Cortical Motor Networks • Somatosensory Cortical Networks • Pyramidal Tract Projections • Subcortical Systems • Brain Stem Pathways • Spinal Sensorimotor Activity STUDIES OF REPRESENTATIONAL PLASTICITY 39 Motor Maps • Sensory Maps BASIC MECHANISMS OF SYNAPTIC PLASTICITY 44 Hebbian Plasticity • Cortical Ensemble Activity • Long-Term Potentiation and Depression • Molecular Mechanisms • Growth of Dendritic Spines • Neurotrophins • Neuromodulators COGNITIVE NETWORKS 52 Overview of the Organization of Cognition • Explicit and Implicit Memory Network • Working Memory and Executive Function Network • Emotional Regulatory Network • Spatial Awareness Network • Language Network SUMMARY 64 2. BIOLOGIC ADAPTATIONS AND NEURAL REPAIR 76 TERMS FOR IMPROVEMENT AFTER INJURY 79 Compensation • Restitution and Substitution • Impairment and Disability INTRINSIC BIOLOGIC ADAPTATIONS 81 Spontaneous Gains • Activity in Spared Pathways • Sensorimotor Representational Plasticity • Spasticity and the Upper Motor Neuron Syndrome • Synaptogenesis • Denervation Hypersensitivity • Axon Regeneration and Sprouting • Axon Conduction • Growth Factors • Neurogenesis POTENTIAL MANIPULATIONS FOR NEURAL REPAIR 99 Activity-Dependent Changes at Synapses • Stimulate Axonal Regeneration • Deploy Neurotrophins • Cell Replacement • Pharmacologic Potentiation MUSCLE PLASTICITY 113 Exercise • Atrophy • Regeneration • Combined Approaches EXPERIMENTAL INTERVENTIONS FOR REPAIR OF SPINAL CORD INJURY 118 Prevent Cell Death • Increase Axonal Regeneration • Remyelination • Other Transplantation Strategies • Retraining the Spinal Motor Pools x Contents RELEVANCE OF ANIMAL MODELS OF REPAIR TO CLINICAL TRIALS 129 Eight Potential Pitfalls of Animal Models SUMMARY 134 3. FUNCTIONAL NEUROIMAGING OF RECOVERY 147 NEUROIMAGING TECHNIQUES 148 Positron Emission Tomography • Single Photon Emission Computerized Tomography • Functional Magnetic Resonance Imaging • Transcranial Magnetic Stimulation • Magnetoencephalography • High Resolution Electroencephalography • Intrinsic Optical Imaging Signals • Near-Infrared Spectroscopy • Magnetic Resonance Spectroscopy • Transcranial Doppler • Combined Methods LIMITATIONS OF FUNCTIONAL NEUROIMAGING STUDIES 160 General Limitations • Subtraction Studies • Timing of Studies METABOLIC IMAGING AT REST AFTER INJURY 163 Stroke • Aphasia • Traumatic Brain Injury • Persistent Vegetative State ACTIVATION STUDIES: FUNCTIONAL REORGANIZATION AFTER INJURY 167 Sensorimotor Reorganization After Central Nervous System Lesion • Peripheral Nerve Transection TRAINING-INDUCED REORGANIZATION 176 Sensorimotor Training • Aphasia • Cognition • Cross-Modal Plasticity NEUROPHARMACOLOGIC MODULATION 184 Monaminergic Agents • Other Agents SUMMARY 185 4. NEUROSTIMULATORS AND NEUROPROSTHESES 193 PERIPHERAL NERVOUS SYSTEM DEVICES 194 Functional Neuromuscular Stimulation • Nerve Cuffs CENTRAL NERVOUS SYSTEM DEVICES 198 Neuroaugmentation • Spinal Cord Stimulators • Brain–Machine Interfaces • Sensory Prostheses ROBOTIC AIDS 203 Upper Extremity • Lower Extremity TELETHERAPY 206 SUMMARY 206 Part II. Common Practices Across Disorders 5. THE REHABILITATION TEAM 213 THE TEAM APPROACH 213 The Rehabilitation Milieu Contents xi PHYSICIANS 215 Responsibilities • Interventions NURSES 218 Responsibilities • Interventions PHYSICAL THERAPISTS 219 Responsibilities • Interventions for Skilled Action OCCUPATIONAL THERAPISTS 231 Responsibilities • Interventions for Personal Independence SPEECH AND LANGUAGE THERAPISTS 235 Responsibilities • Interventions for Dysarthria and Aphasia NEUROPSYCHOLOGISTS 242 SOCIAL WORKERS 243 RECREATIONAL THERAPISTS 243 OTHER TEAM MEMBERS 244 SUMMARY 244 6. APPROACHES FOR WALKING 250 NORMAL GAIT 250 NEUROLOGIC GAIT DEVIATIONS 252 Hemiparetic Gait • Paraparetic Gait • Gait with Peripheral Neuropathy • Gait with Poliomyelitis QUANTITATIVE GAIT ANALYSIS 258 Temporal Measures • Kinematics • Electromyography • Kinetics • Energy Expenditure APPROACHES TO RETRAINING AMBULATION 262 Conventional Training • Task-Oriented Training • Assistive Devices SUMMARY 268 7. ASSESSMENT AND OUTCOME MEASURES FOR CLINICAL TRIALS 271 PRINCIPLES OF MEASUREMENT 272 Types of Measurements • Reliability and Validity • Choosing Measurement Tools MEASURES OF IMPAIRMENT 275 Consciousness • Cognition • Speech and Language • Sensorimotor Impairment Scales BEHAVIORAL MEASURES 288 Behavioral Modification • Neurobehavioral Scales MEASURES OF DISABILITY 289 Activities of Daily Living • Instrumental Activities of Daily Living • Mixed Functional Scales xii Contents MEASURES OF HEALTH-RELATED QUALITY OF LIFE 298 Instruments • Adjustment Scales • Style Of Questions MEASURES OF HANDICAP 302 MEASURES OF COST-EFFECTIVENESS 303 STUDY DESIGNS FOR REHABILITATION RESEARCH 303 Ethical Considerations • Types of Clinical Trials • Confounding Issues in Research Designs • Statistical Analyses SUMMARY 314 8. ACUTE AND CHRONIC MEDICAL MANAGEMENT 323 DEEP VEIN THROMBOSIS 323 Prevention ORTHOSTATIC HYPOTENSION 324 THE NEUROGENIC BLADDER 325 Pathophysiology • Management BOWEL DYSFUNCTION 329 Pathophysiology • Management NUTRITION AND DYSPHAGIA 330 Pathophysiology • Assessment • Treatment PRESSURE SORES 334 Pathophysiology • Management PAIN 336 Acute Pain • Chronic Central Pain • Weakness-Associated Shoulder Pain • Neck, Back, and Myofascial Pain DISORDERS OF BONE METABOLISM 348 Heterotopic Ossification • Osteoporosis SPASTICITY 348 Management CONTRACTURES 357 MOOD DISORDERS 358 Posttraumatic Stress Disorder • Depression SLEEP DISORDERS 363 SUMMARY 364 Part III. Rehabilitation of Specific Neurologic Disorders 9. STROKE 375 EPIDEMIOLOGY 375 Fiscal Impact • Stroke Syndromes Contents xiii MEDICAL INTERVENTIONS 377 Frequency of Complications • Secondary Prevention of Stroke INPATIENT REHABILITATION 385 Eligibility for Rehabilitation • Trials of Locus of Treatment • Discharge OUTPATIENT REHABILITATION 389 Locus of Treatment • Pulse Therapy • Sexual Function • Community Reintegration OUTCOMES OF IMPAIRMENTS 392 Overview of Outcomes • The Unaffected Limbs • Impairment-Related Functional Outcomes OUTCOMES OF DISABILITIES 399 Overview of Outcomes • Upper Extremity Use • Ambulation • Predictors of Functional Gains CLINICAL TRIALS OF FUNCTIONAL INTERVENTIONS 404 Trials of Schools of Therapy • Task-Oriented Approaches • Concentrated Practice • Assistive Trainers • Adjuvant Pharmacotherapy • Functional Electrical Stimulation • Biofeedback • Acupuncture TRIALS OF INTERVENTIONS FOR APHASIA 420 Rate of Gains • Prognosticators • Results of Interventions • Pharmacotherapy TRIALS FOR COGNITIVE AND AFFECTIVE DISORDERS 425 Memory Disorders • Visuospatial and Attentional Disorders • Affective Disorders SUMMARY 436 10. ACUTE AND CHRONIC MYELOPATHIES 451 EPIDEMIOLOGY 451 Traumatic Spinal Cord Injury • Nontraumatic Disorders MEDICAL REHABILITATIVE MANAGEMENT 458 Time of Onset to Start of Rehabilitation • Specialty Units • Surgical Interventions • Medical Interventions SENSORIMOTOR CHANGES AFTER PARTIAL AND COMPLETE INJURY 466 Neurologic Impairment Levels • Evolution of Strength and Sensation • Changes in Patients with Paraplegia • Changes in Patients with Quadriplegia • Mechanisms of Sensorimotor Recovery FUNCTIONAL OUTCOMES 473 Self-Care Skills • Ambulation TRIALS OF SPECIFIC INTERVENTIONS 477 Mobility • Strengthening and Conditioning • Upper Extremity Function • Neural Prostheses • Spasticity LONG-TERM CARE 485 Aging • Sexual Function • Employment • Marital Status • Adjustment and Quality of Life SUMMARY 489 xiv Contents 11. TRAUMATIC BRAIN INJURY 497 EPIDEMIOLOGY 498 Economic Impact • Prevention PATHOPHYSIOLOGY 499 Diffuse Axonal Injury • Hypoxic-Ischemic Injury • Focal Injury • Neuroimaging NEUROMEDICAL COMPLICATIONS 503 Nutrition • Hypothalamic-Pituitary Dysfunction • Pain • Seizures • Delayed-Onset Hydrocephalus • Acquired Movement Disorders • Persistent Vegetative State ASSESSMENTS AND OUTCOME MEASURES 510 Stages of Recovery • Disability PREDICTORS OF FUNCTIONAL OUTCOME 513 Level of Consciousness • Duration of Coma and Amnesia • Neuropsychologic Tests • Population Outcomes LEVELS OF REHABILITATIVE CARE 515 Locus of Rehabilitation • Efficacy of Programs REHABILITATION INTERVENTIONS AND THEIR EFFICACY 519 Overview of Functional Outcomes • Physical Impairment and Disability • Psychosocial Disability • Cognitive Impairments • Neurobehavioral Disorders • Neuropsychiatric Disorders SPECIAL POPULATIONS 535 Pediatric Patients • Geriatric Patients • Mild Head Injury ETHICAL ISSUES 537 SUMMARY 538 12. OTHER CENTRAL AND PERIPHERAL DISORDERS 547 DISORDERS OF THE MOTOR UNIT 548 Muscle Strengthening • Respiratory Function • Motor Neuron Diseases • Neuropathies • Myopathies PARKINSON’S DISEASE 557 Interventions MULTIPLE SCLEROSIS 559 Epidemiology of Disability • Pathophysiology • Rehabilitative Interventions • Clinical Trials PEDIATRIC DISEASES 565 Cerebral Palsy • Myelomeningocele BALANCE DISORDERS 567 Frailty and Falls in the Elderly • Vestibular Dysfunction ALZHEIMER’S DISEASE 570 EPILEPSY 570 CONVERSION DISORDERS WITH NEUROLOGIC SYMPTOMS 570 Contents xv CHRONIC FATIGUE SYNDROME 571 ACQUIRED IMMUNODEFICIENCY SYNDROME 571 SUMMARY 571 INDEX 579 PART I NEUROSCIENTIFIC FOUNDATIONS FOR REHABILITATION [...]... The direction of an upper extremity movement may be coded by the sum of the vectors of the single cell activities in motor cortex in the direction of the movement.40 The activity of a single corticomotoneuron can differ from the activity of an assembly of neighboring motoneurons When a small assembly of cells becomes active, the discharge pattern of a neuron within that population may change with the. .. motor regions, inform the cerebellar cortex of the place and rate of movement of the limbs These fibers put the motor intention generated by the cerebral cortex into the context of the status of the body at the time the movement is executed.120 Purkinje cells may encode some of the experience-dependent computations, such as position, velocity, acceleration, and inherent viscous forces of a moving limb,... understand the behavior of other people may have evolved from the interaction of superior temporal sulcus neurons with neurons along the border between the rostral anterior cingulate and medial prefrontal cortices.76 The medial prefrontal region is involved in the explicit representation of states of the self Along with the temporal region’s representation of the intentional actions of others, the two regions... performs The mental steps of the dance gradually disappear from consciousness, replaced by implicit memory, a striatal sequence of breathing and releasing with movement phrases of the dance tied to the bars of the music, like an athlete in the zone, like the singer whose lyrics meld into melody, or like the actor expressing words without thinking about the lines of the play The choreographer’s actions, the. .. about other aspects of actions, including how the environment, the properties of objects such as their shape and weight, and the demands of the task all interact with movement, perception, and experience Most experimental studies support the observations of Mountcastle and others that the sensorimotor system learns and performs with the overriding objective of achieving movement goals All but the simplest... contingencies raised by the environment and the biomechanical characteristics of the limbs interact with stored programs or with chains of reflexes A more elegant theory of motor control, perhaps first suggested by Bernstein in the 1960s, tried to account for how the nervous system manages the many degrees of freedom of movement at each joint.7 He hypothesized that lower levels of the CNS control the synergistic... movements They may be critical for the earliest learning of movements from parents Thus, the brain’s representation of a movement includes the mental content that relates to the goal or consequences of an action, as well as the neural operations that take place before the action starts (see Experimental Case Study 1–1) In a sense, the cognitive systems of the brain can be thought of as an outgrowth of the. .. codes the duration of the movement Velocity correlates with the amount of muscle activation The force exerted by muscles is a summed average of the ouput of single cells that fire at variable rates and the synchronization of assemblies of M1 neurons during specific phases of a motor task.39 Single cell activity in the motor cortex is most intense for reaching at a particular magnitude and direction of. .. modeling for the generation of a reaching movement have been offered.12,13 Much work has gone into what small groups of cortical cells in the primary motor cortex (M1) encode The activity of these neurons may encode the direction or velocity of the hand as it Plasticity in Sensorimotor and Cognitive Networks moves toward a target14 or the forces at joints or the control of mechanical properties of muscles... connections modulate the use-dependent integrations of these ensembles.32 Intermingled functional connections among these small ensembles of neurons offer a distributed organization that provides a lot of flexibility and storage capacity for aspects of movement These assemblies manage the coordination of multijoint actions, the velocity and direction of movements, and process the order of stimuli on which . the duration of the movement. Velocity correlates with the amount of muscle activation. The force exerted by muscles is a summed average of the ouput of. direction of force. 14 The direction of an upper extremity movement may be coded by the sum of the vectors of the single cell activ- ities in motor cortex in the