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Topics: care of the neurological patient. Head trauma Spinal cord injury Cranial nerve evaluation. Part One: Head Trauma (Traumatic Brain Injury aka TBI). Physical injury to brain tissue Temporary or permanent impairment of brain function All involve some form of structural damage
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Topics: care of the neurological patient Head trauma Spinal cord injury Cranial nerve evaluation
Part One: Head Trauma(Traumatic Brain Injury aka TBI) • Physical injury to brain tissue • Temporary or permanent impairment of brain function • All involve some form of structural damage • Nursing involvement is critical for • Support of respiration and oxygenation • Support of blood pressure • Prevent further injury • Rehabilitation
Head injury National Head Injury Foundation: • Traumatic insult to the brain… • Capable of producing physical, intellectual, emotional, social, and vocational changes • Highest risk individuals are • Those 15-24 years • Infants • School aged children • Elderly
Rates of TBI-related Emergency Department Visits, Hospitalizations, and Deaths by Sex — United States, 2001–2010
Mechanism and force of injury • The mechanism and force determines the degree of structural damage:
Concussion • Posttraumatic alteration in mental status • Transient, reversible • From seconds to minutes • Defined as <6 hours (arbitrary) • No gross structural brain lesions
Diffuse axonal injury (DAI) • Caused by deceleration • Causes shear-type forces • Damage to axonal fibers and myelin sheaths
Diffuse axonal injury (DAI) • Edema from injury increases intracranial pressure • Sometimes defines as loss of consciousness >6 hours • Typically underlying injury in Shaken Baby Syndrome
Brain contusion • Bruise of the brain • Can occur with open, penetrating, or closed injury • Can impair wide range of brain functions
Brain hematoma • Collection of blood in or around the brain • Can occur with penetrating or closed injury • May be epidural, subdural, or intracerebral • Subarachnoid hemorrhage (SAH) is common in TBI
Skull fractures • Penetrating injuries involve fractures by definition • Closed injuries may also cause skull fractures • Presence of fracture suggests significant force was involved
Pathophysiology of TBI • Trauma produces direct damage to brain tissue • Edema produced in damaged tissues • Cranial vault is fixed in size • Fluid (CSF) is noncompressible • Brain tissue is somewhat compressible • Intracranial pressure increases • Cerebral perfusion pressure decreases • Brain tissue can become ischemic
Treatment of TBI • Focused on restoring normal ICP • Evacuation of hematoma through burr holes • Ligation of bleeding vessels • May allow hematoma to reabsorb slowly • Debridement of traumatized tissue in open head injury to prevent infection • Steroids to minimize swelling, diuretics • Cranioplasty, possible grafting
Monitoring intracranial pressure • Catheter placed in OR or at bedside in ICU • Assist physician with placement • Maintain asepsis • Monitor pressure at appropriate intervals • Drain CSF as indicated • Monitor patient tolerance • Monitor of neuro status • Rezero at least every 12 hours • Maintain at level of tragus to correspond with Foramen of Monro
Markedly increased ICP • Hypertension • Bradycardia • Respiratory depression • Decorticate or decerebrate posturing are bad prognostic signs
Herniation • Brain is squeezed across skull structures • Caused by TBI, intracranial hemorrhage, or brain tumor • Extreme pressure placed on parts of the brain at site of herniation • Blood supply cut off • Often fatal
Part 2: Spinal Cord Trauma • Trauma may produce injuries to spinal cord, vertebrae, or both • 40% cord injuries from motor vehicle accidents • 25% from violent crime • 35% from falls, sports, work-related accidents • 80% of patients are male
Level of injury and resulting dysfunction • Spinal cord level identified by corresponding vertebrae • Vertebrae can be grouped into segments • The higher the injury, the greater potential dysfunction
High cervical nerves: C1-4 • Most severe • Paralysis of upper and lower extremities, trunk • No breathing control, no cough • No bowel, bladder control • Dependent for all ADLs • 24/7 care required
Low cervical nerves: C5-8 • Nerves control arms and hands • May be able to breathe independently • May be able to speak
C-5 Injury • Person can raise arms, bend elbows • Some or total paralysis of wrists, hands, trunk, legs likely • Can speak, use diaphragm, but breathing is weak • ADL assistance required • Can use power wheelchair
C-6 Injury • Wrist extension affected • Paralysis of hands, trunk, legs usual • May be able to bend wrists back • Can speak, breathing is weak • May be able to use equipment to move in & out of wheelchair, bed • May be able to drive adapted vehicle • Little to no control of bowel or bladder, may be able to use adaptive equipment
C-7 Injury • Elbow extension, finger extension • Usually can straighten arm, normal shoulder movement • Can perform most ADLs, may need assistance with more difficult tasks • May be able to drive an adapted vehicle • Little, no voluntary control of bowel or bladder
C-8 Injury • Some hand movement • Able to grasp, release objects • Can perform most ADLs, may need assistance with more difficult tasks • May be able to drive an adapted vehicle • Little, no voluntary control of bowel or bladder
T1-5 Injury • Nerves affect upper chest, mid-back, abdominal muscles • Arm, hand function usually normal • Affect the trunk, legs(paraplegia) • May use manual wheelchair • Can drive a modified car • Can stand in standing frame, may walk with braces
T6-12 Injury • Nerves affect muscles of the trunk • Usually paraplegia • Normal upper-body movement • Able to control, balance trunk while seated • Usually can cough productively • Little, no voluntary control of bowel or bladder • Can use manual wheelchair • Can drive a modified car • Can stand in standing frame, may walk with braces
L1-5 Injury • Some loss of function in the hips, legs • Little, no voluntary control of bowel or bladder • May need wheelchair, braces
S1-5 Injury • Some loss of function in the hips and legs. • Little or no voluntary control of bowel or bladder • Most likely will be able to walk
Part 3: Cranial nerves • 12 pairs of nerves—above level of C-1 • Emerge from brain or brainstem • Seen on ventral surface of brain • Some are sensory • Some are motor • Some connected to glands or other organs
Mnemonics for memorizing CNs • Standard: “On old Olympus’ towering top, a Finn and German viewed some hops.” • Sensory, motor, or both: “Some say marry money, but my brother says big brains matter more.”* (*Rude version also available)
More fun mnemonic • “Oh, Oh, Oh, They Traveled And Found Voldermort* Guarding Very Secret Horcruxes” (*vestibulocochlear aka auditory) • Sensory, motor, or both: “Severus Snape Meets Malfoy, But Mad Bellatrix Stays Behind Bushes Misusing Magic”
Testing cranial nerves • Part of any complete physical assessment • Often CN I dismissed clinically • Charted as, “CN II-XII intact” • Particularly important in head trauma • Testing pupils alone is not enough!
CN I: Olfactory Nerve • Fibers originate from nasal olfactory epithelium • Purely sensory • Carries impulses for sense of smell • HOW TO TEST: Ask patient to sniff something aromatic—vanilla, coffee, cloves
CN 2: Optic • Fibers originate in retina • Purely sensory • Carries impulse for vision • HOW TO TEST: Visual acuity and visual field
CN 3, 4, 6: Oculomotor, Trochlear, and Abducens • Tested together • CN 3 and 4 emerge from midbrain, exit skull to eye • CN 6 leaves from pons, exits to eye • Oculomotor—superior, inferior, medial rectus muscles of eye • Trochlear—superior oblique muscles of eye • Abducens—lateral rectus muscles of eye • HOW TO TEST: pupil reaction, cardinal positions
CN 5: Trigeminal • Exit from pons, form 3 divisions on face • Both motor and sensory for face • Sensory impulses from mouth, nose, surface of eyes • Fibers stimulate chewing muscles • HOW TO TEST: Safety pin on skin surface, corneal reflex with cotton wisp; ask to clench teeth, open mouth against resistance, move jaw side to side
CN 7: Facial • Origin in pons, through temporal bone to face • Both motor and sensory • Expression • Lacrimal and salivary glands • Taste • HOW TO TEST: Can ask to taste substances; ask to squint, smile, whistle; may test tearing with ammonia
CN 8: Acoustic (Vestibulocochlear) • Originates in inner ear, enters brainstem • Purely sensory • Sense of equilibrium, hearing • HOW TO TEST: Air and bone conduction with tuning fork
CN 9 and 10: Glossopharyngeal and Vagus • Glossopharyngeal fibers leave midbrain to throat, vagus fibers leave medulla throughneck into thorax and abdomen • Both motor and sensory—pharynx and salivary glands, impulses from pharynx, pressure receptors from carotid artery; vagussupples smooth muscles of abdominal organs • HOW TO TEST: Gag, swallow, cough, speak
CN 11: Spinal accessory • Originates in medulla and superior spinal cord, travels to muscles of neck and back • Both sensory and motor • Sternocleidomastoid and trapezius muscles • HOW TO TEST: Ask to rotate head, shrug shoulders against resistance
CN 12: Hypoglossal • Arise from medulla to tongue • Motor to muscles of tongue, sensory from tongue to brain • HOW TO TEST: Ask to stick out tongue
Principles of CN testing • Indicates specific neurological dysfunction rather than a systemic disorder • Develop your own method of testing quickly and efficiently • In normal, healthy patient, may screen with less detail • Regardless, important to know structure and function as you perform CN testing!