Chapter10 patho.pptx

Chapter 10 Altered Neural Function Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Neuron #1 Components  Cell body  Dendrites  Axon-carries impulses Copyright © 2023 Wolters Kluwer · All Rights Reserved Neuron #2 Functional types o Sensory (afferent)o Motor (efferent)o In...

Chapter 10 Altered Neural Function Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Neuron #1 Components  Cell body  Dendrites  Axon-carries impulses Copyright © 2023 Wolters Kluwer · All Rights Reserved Neuron #2 Functional types o Sensory (afferent)o Motor (efferent)o InterneuronSupporting cells Copyright © 2023 Wolters Kluwer · All Rights Reserved Membrane Potential #1 Is Difference in electrical charge between the inside and outside of the cell It regulates Action potential o Electrical event that travels along entire neuron o Allows neurons to communicate o Three components  Resting membrane potential Depolarization phase-rapid movement of sodium into the cell  Repolarization phase Copyright © 2023 Wolters Kluwer · All Rights Reserved Membrane Potential #2 image of whole repolarization phase Copyright © 2023 Wolters Kluwer · All Rights Reserved Neural Communication Information from one neuron Flows to another neuron of information across a synapse o Electrical o Chemical Synapse structures (three types of synapse structures) o Presynaptic terminal o Synaptic cleft o Postsynaptic membrane Copyright © 2023 Wolters Kluwer · All Rights Reserved Action Potential Copyright © 2023 Wolters Kluwer · All Rights Reserved Processes of Neural Injury// mature neurons don’t divide when damaged/lost Injury types include: o Chromatolysis- swelling o Atrophy o Neuronophagia o Intraneuronal inclusions Copyright © 2023 Wolters Kluwer · All Rights Reserved Developmental Considerations Embryo  Neural tube develops Newborn  All needed neurons are present Age 2 years  Brain 80% of adult size With aging the characteristics include:  Decrease in number of neurons  Enlargement of ventricle system  Widening of sulci  Decreased brain volume and weight  Sensory changes Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #1 Central nervous system  Brain  4 Lobes – frontal lobe, parietal lobe, temporal lobe, occipital lobe (get info on which does what from book)  2 Hemispheres  Left –speech and language / would cause speech impairment, logical issues,  Right hemipheres – vision and what else. Think about different lobes Copyright © 2023 Wolters Kluwer · All Rights Reserved Coronal View of Brain Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #2 Central nervous system o Spinal cord- pathway for communication from peripheral to brain. Controls reflexes.  Ventral horns-anterial extensions and contains Anterior extensions Efferent motor neurons leaving cord  Dorsal horns are: Posterior extensions and contains Sensory neurons receiving afferent impulses Copyright © 2023 Wolters Kluwer · All Rights Reserved Spinal Cord Structures white matter contains myelinated axons.. Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #3 Central nervous system o Tissue composition  White matter (controls voluntary) Axons and dendrites  Gray matter Cell bodies Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #4 Central nervous system o Pyramidal motor system  Extends from the sensorimotor areas of the brain to the motor neurons of the ventral horn of the spinal cord  Controls voluntary movement o Extrapyramidal system  Basal ganglia  Fine-tunes and stabilizes movement Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Protection Central nervous system  Cerebrovascular circulation  Blood–brain barrierallows low lipids. ??? why  Cerebrospinal fluid (CSF) Copyright © 2023 Wolters Kluwer · All Rights Reserved Neural Injury #1 Injury responses o Astrogliosis o Microglial nodules o Axonal degeneration o Axonal regeneration o Neuropathy o Demyelination Copyright © 2023 Wolters Kluwer · All Rights Reserved Neural Injury #2 Mechanisms of injury to the CNS o Traumatic  Brain injury  Spinal cord injury o Ischemic o Excitation o Pressure Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #5 Peripheral nervous system o Somatic  Motor and sensory impulses between the central nervous system and the periphery Cranial nerves Spinal nerves Dermatomes Plexus formation Copyright © 2023 Wolters Kluwer · All Rights Reserved Dermatomes Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #6 Peripheral nervous system (cont.) o Somatic (voluntary movement) in your:  Peripheral nerves o Autonomic (involuntary) include:  Preganglionic neurons  Autonomic ganglion  Postganglionic neurons Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #7 Peripheral nervous system (cont.) o Autonomic  Sympathetic Fiber lengths Short preganglionic Long postganglionic fibers Spinal nerves exit between T1 and L2 Copyright © 2023 Wolters Kluwer · All Rights Reserved Distribution of Sympathetic Nerve Fibers Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #8  Peripheral nervous system (cont.) o Autonomic  Sympathetic  Increased heart rate, contractility, blood pressure, respiratory rate  Bronchial smooth muscle relaxation  Vascular smooth muscle constriction  Decreased bladder tone and peristalsis of gastrointestinal smooth muscle  Constriction of anal and urinary sphincters Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #9  Peripheral nervous system (cont.) o Autonomic  Parasympathetic  Fiber lengths Long preganglionic Short postganglionic  Neuron exit sites Cranial nerves between midbrain and medulla Spinal nerves between S2 and S4 Copyright © 2023 Wolters Kluwer · All Rights Reserved Distribution of Parasympathetic Nerve Fibers Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Organization #10  Peripheral nervous system (cont.) o Autonomic  Parasympathetic  Decreased heart rate, contractility, velocity of conduction, blood pressure, respiratory rate  Bronchial smooth muscle constriction  Vascular smooth muscle relaxation  Increased constriction of bladder and peristalsis of gastrointestinal smooth muscle  Relaxation of anal and bladder sphincter Copyright © 2023 Wolters Kluwer · All Rights Reserved Nervous System Integration Reflex arc Copyright © 2023 Wolters Kluwer · All Rights Reserved Basic Responses of Peripheral Nerve Fibers to Injury Copyright © 2023 Wolters Kluwer · All Rights Reserved Neural Injury Copyright © 2023 Wolters Kluwer · All Rights Reserved Application of the Concepts of Alteration in Neural Transmission Cerebral palsy Multiple sclerosis Hydrocephalus Incomplete spinal cord transection Parkinson disease Copyright © 2023 Wolters Kluwer · All Rights Reserved Cerebral Palsy Pathophysiology Clinical manifestations Diagnostic criteria Treatment Copyright © 2023 Wolters Kluwer · All Rights Reserved Cerebral Palsy Pathophysiology Group of neuromuscular disorders Cause: event during the antenatal or postnatal periods damaging upper motor neurons Copyright © 2023 Wolters Kluwer · All Rights Reserved Cerebral Palsy Pathophysiology: Classification Motor dysfunction type Anatomic involvement  Spastic  Hemiplegia  Athetoid/dyskinetic  Diplegia  Ataxic  Quadriplegia Copyright © 2023 Wolters Kluwer · All Rights Reserved Cerebral Palsy Clinical Manifestations Variable severity o Limited fine motor skills o Lack of coordination and balance o Impaired cognitive function o Speech disorder o Seizure disorder Copyright © 2023 Wolters Kluwer · All Rights Reserved Seizure Activity in the Brain Copyright © 2023 Wolters Kluwer · All Rights Reserved Cerebral Palsy Diagnostic Criteria Diagnosis of exclusion o History o Physical exam  Neurologic exam Motor skills Reflexes  Developmental milestones Copyright © 2023 Wolters Kluwer · All Rights Reserved Cerebral Palsy Treatment No known cure Supportive treatment for signs and symptoms o Pharmacologic  Control seizures  Reduce muscle spasms o Assistive devices  Enhance ability to complete activities of daily living Copyright © 2023 Wolters Kluwer · All Rights Reserved Multiple Sclerosis (MS) Pathophysiology Clinical manifestations Diagnostic criteria Treatment Copyright © 2023 Wolters Kluwer · All Rights Reserved MS Pathophysiology Central nervous system demyelination Etiology combines o Genetics o Environmental factors o Triggering event o Autoimmunity o Regional variation Copyright © 2023 Wolters Kluwer · All Rights Reserved Process of Demyelination Copyright © 2023 Wolters Kluwer · All Rights Reserved World Distribution of MS Copyright © 2023 Wolters Kluwer · All Rights Reserved MS Clinical Manifestations Related to slowed nerve conduction Clinical course variation o Clinically isolated syndrome o Relapsing-remitting o Primary progressive o Secondary progressive Copyright © 2023 Wolters Kluwer · All Rights Reserved MS Diagnostic Criteria Based on clinical manifestations o History o Physical examination  Neurologic o Imaging  MRI o Laboratory  Lumbar puncture and CSF analysis Copyright © 2023 Wolters Kluwer · All Rights Reserved MS Treatment Pharmacologic o Disease-modifying drugs Nonpharmacologic o Balanced rest and activity o Assistive devices Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus #1 Pathophysiology Clinical manifestations Diagnostic criteria Treatment Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus Pathophysiology #1 Increased ventricular accumulation of CSF o Ventricular enlargement o Increased intracranial pressure Classifications o Noncommunicating o Communicating o Congenital o Acquired Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus Pathophysiology #2 Causes o Intraventricular hemorrhage o Neural tube defect o Brain tumor o Meningitis o Traumatic injury o CSF flow obstruction o Impaired CSF absorption Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus Clinical Manifestations #1 Age-dependent o Infant  Enlarged head with bulging fontanels  Scalp vein distention  Difficulty feeding  High, shrill cry o Older children/adults  Impaired motor and cognitive function  Incontinence Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus #2 Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus Clinical Manifestations #2 Increased intracranial pressure o Increased blood pressure o Altered heart rate o Headache o Vomiting o Decreased level of consciousness o Papilledema Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus Diagnostic Criteria Head circumference measurement Transillumination Imaging studies Copyright © 2023 Wolters Kluwer · All Rights Reserved Hydrocephalus Treatment Establishment and maintenance of normal CSF volumes and intracranial pressure o Ventriculoperitoneal shunt o Ventriculoatrial shunt o Endoscopic third ventriculostomy Copyright © 2023 Wolters Kluwer · All Rights Reserved Ventriculoperitoneal Shunt Copyright © 2023 Wolters Kluwer · All Rights Reserved Incomplete Spinal Cord Transection Pathophysiology Clinical manifestations Diagnostic criteria Treatment Spinal cord transection refers to a spinal cord injury due to a partial or complete tear within the spinal cord. Spinal segmental level, type of injury, and degree of cord transection contribute to the manifestations and complications associated with spinal cord injury. Copyright © 2023 Wolters Kluwer · All Rights Reserved Incomplete Spinal Cord Transection Pathophysiology  Spinal cord injury (SCI) is due to nerve root or myelinated tract damage, impairing the transduction of afferent or efferent neural impulses. Damage to the gray matter of the central cord may result in loss of motor neurons and interneurons.  Spinal cord injury altering neuronal transmission  Categories o Complete transection - In complete injury, sensation and motor function below the level of injury are lost o Partial transection -Partial cord transections can be categorized into three types of syndromes  Central cord syndrome  Anterior cord syndrome  Brown-Séquard syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved Incomplete Spinal Cord Transection Clinical Manifestations Variable o Spinal segmental level o Type of injury o Degree of cord transection Copyright © 2023 Wolters Kluwer · All Rights Reserved Central Cord Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved Anterior Cord Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved Brown-Séquard Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved Incomplete Spinal Cord Transection Diagnostic Criteria Physical examination test for: o Cognitive function o Motor function o Sensory function Imaging studies include: Commonly used tests to diagnose SCI include radiograph, CT scan, MRI, and myelography (imaging after injection of dye into the spinal canal). Copyright © 2023 Wolters Kluwer · All Rights Reserved Incomplete Spinal Cord Transection Treatment Immobilization of the spine o Traction- to stabilize the spine to prevent further damage Surgery o To correct fractures and decompress spinal cord Promotion of functional abilities Copyright © 2023 Wolters Kluwer · All Rights Reserved Parkinson Disease Pathophysiology Clinical manifestations Diagnostic criteria Treatment Copyright © 2023 Wolters Kluwer · All Rights Reserved Parkinson Disease Pathophysiology Chronic, progressive neurologic condition Degeneration of pigmented dopaminergic neurons of the basal ganglia Impaired transport of dopamine Presence of Lewy bodies (protein) Neuronal injury from oxidative damage is suspected Copyright © 2023 Wolters Kluwer · All Rights Reserved Parkinson Disease Clinical Manifestations Tremor Rigidity o Jerky movements o Flat affect Bradykinesia (slowed movement) o Shuffling gate and stooped posture Postural instability Copyright © 2023 Wolters Kluwer · All Rights Reserved Parkinson Disease Diagnostic Criteria History and physical examination Hoehn and Yahr scale o Stage 1: mild, unilateral o Stage 2: bilateral, posture and gait affected o Stage 3: slowed movements, impaired balance o Stage 4: severe, limited walking, rigidity o Stage 5: cachectic, total disability Copyright © 2023 Wolters Kluwer · All Rights Reserved Parkinson Disease Treatment Pharmacologic o Dopamine replacement (levodopa) o Anticholinergics o Dopamine agonists Surgical o Pallidotomy o Deep brain stimulation Copyright © 2023 Wolters Kluwer · All Rights Reserved