Downloaded 88 times
More Related Content
Similar to Neurologic Pathophysiology
Neurologic Pathophysiology
- 1.
- 2. Four Primary Functionsof the Nervous System ■ Sensing the world ■ Transmitting information ■ Processing information ■ Producing a response
- 3. The Nervous System ■Central Nervous System – Brain and spinal cord ■ Peripheral Nervous System – Cranial nerves and spinal nerves – Brings information to the central nervous system – Divisions of PNS ■ Somatic Nervous System ■ Autonomic Nervous System – Sympathetic Nervous System – Parasympathetic Nervous System
- 5. Central Nervous System ■CNS receives, interprets, and sends signals to PNS ■ Brain – Main control center ■ Spinal Cord – Connects and relays nerve impulses to the brain – “Information superhighway”
- 6. Parts of theBrain ■ 4 lobes – Frontal Lobe processes logic and reasoning, planning, and taking responsibility – Parietal Lobe processes all sensory information except for vision, hearing, and smell – Occipital Lobe processes visual information – Temporal Lobe processes auditory information and interprets sense of smell
- 7. Parts of theBrain ■ Cerebellum – Coordinates all movement – Helps maintain posture, muscle control, and balance ■ Cerebrum – Voluntary activity – Memory, language – Receives and responds to sensory signals – Controls motor functions
- 9. Parts of theBrain ■ Cortex – top layer of the brain that stores experiences and learning – Frontal Cortex – behavior, emotion – Parietal Cortex – sensory information, concerning touch – Occipital Cortex - vision – Temporal Cortex – memory, emotion, speech, hearing
- 10. Parts of theBrain ■ Brain Stem – Swallowing, coughing, sneezing, and vomiting ■ Medulla Oblongata – Damage in this area will kill you ■ Pons – Regulates breathing, heart rate, and internal organs
- 11. Parts of theBrain ■ Limbic System – Controls emotions and memories – Damage to the limbic system can lead to amnesia or emotional disturbances
- 12. Peripheral Nervous System: SomaticNervous System ■ Controls voluntary activities such as the activation of skeletal muscles ■ Balance, movement
- 13. Peripheral Nervous System: AutonomicNervous System ■ Regulates the activity of cardiac muscle, smooth muscle, and glands ■ “Involuntary Nervous System” because it controls body activities automatically ■ Very important in maintaining homeostasis for the body ■ Two Divisions: – Sympathetic Nervous System – Parasympathetic Nervous System
- 14. Divisions of the AutonomicNervous System ■ Sympathetic Nervous System – “Fight or flight” – Norepinephrine and epinephrine are released – Increase in heart rate and blood flow – Decrease in digestion ■ Parasympathetic Nervous System – “Rest and digest” – Acetylcholine is released – Increase in salivation and digestion – Decrease in heart rate and other sympathetic responses
- 16. Two Types ofNervous Tissue ■ Neurons – Nerve cells: fundamental unit of structure/function – Receptive to stimuli: convert stimuli to action potentials ■ Neuroglia – Supportive cells capable of division – Do not support action potentials – Found in both CNS and PNS
- 17. The Neuron ■ Neuronsare highly specialized, non-mitotic cells that conduct impulses through the parasympathetic nervous system and the sympathetic nervous system
- 18. Parts of theNeuron: Nerve Cell ■ Myelin Sheath is the fatty covering over neurons that insulates them to speed up conduction ■ Dendrites are part of the neurons that detect the stimulus ■ Cell Body is the part of the neuron that contains most of the cytoplasm and the nucleus ■ Axons send a nerve impulse away from the cell body ■ Axon Terminal releases neurotransmitters of the pre- synaptic cell
- 19. Three Types ofNeurons ■ Sensory Neurons detect stimuli ■ Interneurons relay sensory signals to the brain, then return the message back to motor neurons ■ Motor Neurons pass messages from the brain to the rest of the body for a muscle response ■ Reflex Arc is the term for this coordinated pathway
- 20. Neuroglia ■ CNS Neuroglia –Astrocytes cling to neurons and bring them blood supply – Oligodendrocytes produce myelin sheath – Ependymal Cells line the CNS cavities and cilia moves CSF around – Microglia Cells dispose of cellular debris and bacteria ■ PNS Neuroglia – Schwann Cells form myelin sheath around neurons – Satellite Cells protect, nourish, and cushion neurons
- 22. Nerve Impulse ■ Anerve impulse is a progressive wave of electrical and chemical activity along a nerve fiber that stimulates or inhibits the action of a muscle, gland, or other nerve cell. ■ This is how the information moves from sensory neurons to interneurons to motor neurons
- 23. Impulse Generation ■ Depolarization– sodium influx ■ Action Potential ■ Repolarization – outward movement of potassium into its normal position by the sodium-potassium pump
- 24. Action Potential ■ Awave of electricity that travels down the axon of a neuron, from the cell body to the axon terminals ■ Usually a brief change in the resting membrane potential of the neuron from -70mV to +35mV. ■ Opens membrane gates for Na+, and then for K+ ■ Makes neuron cell membrane more permeable to Na+, then to K+ ■ Change in the numbers of plus charges inside and outside the cell, changing the cell membrane potential
- 25. Generation of ActionPotential ■ When stimulated, the nerve conducts the impulse along its length ■ The nerve has to reach the threshold voltage to initiate conduction down the length of the axon
- 26. Functions of Chemical Neurotransmitters ■Once stimulated, they are released into the synaptic cleft ■ They can be inactivated by enzymes or reuptake ■ Depending on the neurotransmitters involved, either the postsynaptic neuron dendrites or cell bodies will depolarize
- 27. Types of ChemicalNeurotransmitters ■ Acetylcholine – Excitatory/inhibitory – Located in the neuromuscular junction, autonomic nervous system, peripheral nervous system, and central nervous system
- 28. Types of ChemicalNeurotransmitters ■ Catecholamines are excitatory and present in the brain – Norepinephrine is found at the neuromuscular junction and sympathetic nervous system – Epinephrine is found at the sympathetic nervous system – Dopamine
- 29. Types of ChemicalNeurotransmitters ■ Serotonin – Excitatory; located in the CNS in the brain and in the GI tract – Regulates behavior, attention, and digestive processes – Implicated in mood changes ■ Glutamate – Excitatory ■ GABA – Inhibitory; located in the brain
- 30.
- 31. Increased Intracranial Pressure ■Expansion of fluids and tissues increases pressure ■ Produces ischemia and infarction
- 32. Herniation ■ Displacement ofbrain tissue caused by a large mass, like a clot or a tumor
- 33. Brain Tumors ■ Lesionscause increased intracranial pressure ■ If the tumor is accessible, then removing it is the standard treatment
- 34. Vascular Disorders –Types of Strokes ■ Hemorrhagic – increased intracranial pressure ■ Ischemic – atherosclerosis
- 35. Transient Ischemic Attacks(TIA) ■ Temporary reduction of blood flow in the brain ■ Small mini-strokes occur continually ■ Connected to dementia
- 37. Cerebrovascular Accidents ■ Infarctionof the brain due to a lacking blood supply ■ Treatment: clot busting agents, surgery, and glucocorticoids
- 38. Cerebral Aneurysm ■ Localizeddilation in the wall of an artery ■ Treatment: surgery (before rupture) or anti-hypertensive drugs
- 39. Meningitis ■ Bacterial infectionin the meninges of the CNS ■ Treatment: antimicrobial therapy, glucocorticoids, and vaccines
- 40. Brain Abscess ■ Localizedinfection and necrosis of tissue ■ Treatment: surgical drainage or anti-microbial therapy
- 41. Encephalitis ■ Infection ofthe parenchymal or connective tissue in the brain or spinal cord ■ Treatment: anti-microbial therapy or anti-viral drugs, depending on the cause
- 43. Guillain-Barre Syndrome ■ Inflammatorycondition of the parasympathetic nervous system ■ Recovery is spontaneous ■ Provide supportive care
- 45. Infections ■ Rabies –viral, transmitted by a bite of a rabid animal or transplantation of contaminated tissues. Treat with prophylactic immunizations. ■ Tetanus – infection via puncture wound; immunization advised ■ Poliomyelitis – polio virus; attacks motor neurons of the spinal cord and medulla; immunizations available – Post-Polio Syndrome – occurs 10 to 40 years after initial poliomyelitis infection ■ Herpes-Zoster – Shingles, caused by varicella-zoster in adults – Vaccine available for 60 y/o and up
- 46. Infections ■ Reye Syndrome –Viral infection – Linked to children treated with aspirin – No immediate cure
- 47.
- 48. Hydrocephalus ■ Excess cerebrospinalfluid within the skull ■ Non-Communicating – Flow of cerebrospinal fluid through the ventricular system is blocked ■ Communicating – Absorption of cerebrospinal fluid through the subarachnoid villi is impaired
- 50. Spina Bifida ■ Failureof the posterior spinous processes to fuse ■ Meninges and spinal cord herniated ■ Diagnostic Tests: alpha- fetoprotein (AFP) elevated, ultrasounds ■ Surgical Repair with OT/PT afterwards
- 51. Cerebral Palsy ■ Mostimpairment is due to brain damage – Intellectual function, behavior, visual/hearing deficits – Communication/speech, seizures ■ Causes – Genetic mutations, abnormal fetal formation, brain damage, hypoxia/ischemia ■ Treatment – Speech therapy, PT/OT, assistive devices ■ Types – Spastic Paralysis – hyperreflexia – Dyskinetic – loss of coordination w/fine movement – Ataxia – loss of balance and coordination
- 53. Multiple Sclerosis ■ Progressivede-myelination of neurons in the brain, spinal cord, and cranial nerves ■ Cause unknown ■ Signs/Symptoms: blurred vision, diplopia, scotoma, weakness in legs, progressive weakness or paralysis, paresthesia, dysarthria, loss of coordinaiton, bowel/bladder/sexual dysfunction, and chronic fatigue ■ Diagnosis: MRI ■ Research Treatments: interferon beta, glucocorticoids, and muscle relaxants
- 55. Parkinson’s Disease ■ Progressivedegeneration in the basal nuclei producing an imbalance between excitation and inhibition ■ Excess stimulation affects movement and posture ■ Signs/Symptoms: resting tremors, muscular rigidity, difficulty initiating movement, postural instability, decreased flexibility, fatigue, lack of facial expressions, propulsive gait, and bradykinesia ■ Treatment: removal of cause (if known), dopamine replacement therapy, anticholinergic drugs, speech therapy, PT/OT, respiratory infection treatment, and UTI treatment
- 57. Amyotrophic Lateral Sclerosis (LouGehrig’s Disease) ■ Progressive degenerative disease affecting motor neurons and producing muscle wasting ■ Cause unknown ■ Unaffected: cognition, sensory neurons, neurons of the eye ■ Loss of Motor Neurons – Upper Motor Neurons – spastic paralysis, hyperreflexia – Lower Motor Neurons – flaccid paralysis, decreased muscle tone, and decreased reflexes ■ Treatment: moderate exercise, rest; no specific treatment to slow degeneration
- 59. Myasthenia Gravis ■ Autoimmunedisorder in which there are auto-antibodies to acetylcholine receptors at the neuromuscular junction ■ Signs/Symptoms: muscle weakness in face/eyes/arms/trunk, impaired speech/vision, difficulty chewing/swallowing, head drooping, and frequent upper respiratory infections ■ Diagnostic Tests: EMG, serum antibody test, acetylcholine esterase inhibitor ■ Treatment: anti-acetylcholine esterase agents, glucocorticoids, plasmaphoresis, thymectomy
- 61. Huntington’s Disease ■ Rapid,jerky movements ■ Chronic progressive neurodegenerative chorea ■ Presents around 40 y/o; hereditary and autosomal dominant ■ Progressive atrophy of the brain ■ Signs/Symptoms: mood swings, personality changes, restlessness, choreiform movements in arms/face, and intellectual impairments ■ Diagnostic Test: DNA analysis ■ Treatment: no therapy to slow progress
- 63. Dementia ■ Intellectual deteriorationthat interferes with occupational or social function ■ Signs/Symptoms: impaired cognitive skills, impaired thinking/learning/judgment, memory loss, confusion, and behavioral/personality changes ■ Causes: vascular disease, infections, toxins, or genetic disorders
- 64. Alzheimer’s Disease ■ Progressivecortical atrophy of neurofibrillary tangles and amyloid plaques ■ Cause unknown ■ Insidious onset ■ Signs/Symptoms: behavioral changes, gradual loss of memory and lack of concentration, impaired learning, poor judgment, decline in cognitive function, change in food intake, inability to recognize family, environmental unawareness, and incontinence ■ Diagnostic Tests: none available ■ Treatment: anti-acetylcholine esterase drugs, OT/PT, psychologist, speech therapy
- 65. Stages of Alzheimer’sDisease ■ First Stage – Short term memory loss – Social withdrawal – No sense of humor ■ Second Stage – General confusion, wandering – Sundown syndrome ■ Third Stage – Terminal stage – Incontinent, apathetic, and institutionalized
- 67. Creutzfeld-Jacob Disease ■ MadCow Disease ■ Rapidly progressive; fatal - dead in 6 months ■ Cause: prion is ingested or transmitted through contaminated blood ■ Signs/Symptoms: memory loss, behavioral changes, motor dysfunction, progressive disorders, and dementia ■ Diagnostic Tests: blood tests
- 68. AIDS-related Dementia ■ Commonin later stages of AIDS when the virus begins to invade brain tissue ■ Gradual loss of memory and cognitive ability ■ Impaired motor function
- 69.
- 70. Pain ■ Nociception isthe sensory nervous systems response to harmful stimuli ■ Pain is the perception of nociception that is not directly measurable ■ Pain Behavior is the observed consequence of a painful experience – the distress response: verbal, vocal, facial, physical, social
- 71. Classifications of Pain ■Benign Pain – not associated w/terminal illness ■ Malignant Pain – associated w/terminal illness ■ Acute Pain – recent onset of <3 months ■ Chronic Pain – onset of >3 months
- 72. Complex Regional PainSyndrome (CRPS) ■ Pathogenesis – Abnormal activity of the sympathetic nervous system – Gate control theory – Reflexive muscle spasm
- 73. Stages of CRPS ■Acute, stage 1 – Right after injury, lasts up to 3 months – Excess sympathetic activity, persistent burning pain with swelling ■ Dystrophic, stage 2 – Persistent pain and stiffness, lasts up to 6 months – Trophic skin changes, muscle atrophy, edematous limbs ■ Atrophic, stage 3 – Lasts 6 months. Pain can increase or decrease. – Progressive atrophy of skin, subcutaneous tissue, muscle, and bone
- 74. Classification of CRPS ■Definite CRPS – Pain and tenderness in extremities, signs and symptoms of vasomotor instability, swelling, and dystrophic skin changes ■ Probable CRPS – Pain and tenderness OR swelling. Dystrophic skin changes are often present. ■ Possible CRPS – Vasomotor instability AND/OR swelling. NO pain. Tenderness. Dystrophic skin changes are occasional. ■ Doubtful CRPS – Unexplained pain and tenderness in an extremity.
- 76.
- 77. Seizure ■ The abnormaldischarge of a group of cortical or subcortical neurons ■ Inappropriate electrical activity ■ Transient neurological signs ■ Altered consciousness, involuntary movements, and disturbed perceptions often occur ■ Defined by EEG patterns and neurological signs/symptoms
- 78. Epilepsy ■ Syndrome characterizedby recurrent seizures. ■ Seizures occur with little or no provocation. ■ Individual or multiple seizure types and characteristics change with age. ■ Defined by EEG, the spectrum of seizure types, and the setting
- 80. Phases of aSeizure ■ Aura: Pre-ictal/Prodromal – subjective sensation or motor phenomenon that precedes a seizure ■ Ictal Period – period of abnormal EEG activity where signs/symptoms are evident ■ Post-Ictal Period – period of confusion following the acute seizure; EEG returns to normal ■ Status Epilepticus – Series of rapidly repeated epileptic convulsions without any period of consciousness between them
- 81. Etiology of Seizures ■Genetic – Inherited metabolic abnormalities – Lowered threshold to electrical activity ■ Structural – Disturbed cerebral flow – Disorders of blood composition ■ Environmental – Anoxia, toxins, drug withdrawal, or head trauma – Idiopathic causes
- 82. Seizure Triggers ■ Visuallyinduced ■ Movement induced ■ Hyperventilation ■ Trauma ■ Emotions ■ Dehydration ■ Electrolyte imbalance ■ Fever or illness ■ Lack of sleep ■ Premenstrual period
- 83. Seizure Diagnosis ■ MedicalHistory ■ Diagnostic Tests: lab studies, X-rays, lumbar puncture, CT, MRI, EEG, and clinical observation
- 84. Differential Diagnosis forSeizures ■ Disorders of cerebral blood flow ■ Disorders of blood constitution ■ Structural disorders ■ Psychiatric conditions ■ Migraine headaches
- 85. Seizure Treatment ■ Drugs ■Surgery ■ Diet ■ Microcomputers ■ Education