neurologic function 1 Flashcards
central nervous system
-brain
-brainstem
-cerebellum
-spinal cord
peripheral nervous system
-cranial nerves
-spinal nerves
cerebral cortex
-receives sensory info from skin, muscles, glands, and organs
-sends msgs to move skeletal muscles
-integrates incoming and outgoing nerve impulses
-performs associative acts such as thinking, learning, and remembering
basal nuclei
-play a role in the coordination of slow, sustained movements
-suppress useless patterns of movement
thalamus
-relays most sensory info from the spinal cord and certain parts of the brain to the cerebral cortex
-interprets certain sensory msgs such as those of pain, temp, and pressure
hypothalamus
-controls various homeostatic functions such as body temp, respiration, and heart rate
-directs hormone secretions of the pituitary
cerebellum
-coordinates subconscious movements of skeletal muscles
-contributes to muscle tone, posture, balance, and equilibrium
brainstem
-origin of many cranial nerves
-reflex center for movement of eyeballs, head, and trunk
-regulates heart rate and breathing
-plays a role in consciousness
-transmits impulses btwn brain and spinal cord
alterations in the NS may result in:
-impaired physical mobility
-chronic pain
-impaired social interaction
-altered thought process
-incontinence
-risk for injury
-self-care deficit
anything growing in the skull will do so at the expanse of neural tissue:
-tumor
-fluid
-blood
hydrocephalus
-“water on the brain”
-CSF accumulation w in the skull
-ventricles dilate and the brain and blood vessels become compressed
-pressure thins the cortex, causing severe brain damage
-may be present at birth or develop later in life
hydrocephalus causes
CSF flow disruption: obstructive hydrocephalus
CSF is not properly absorbed by the bloodstream
risk factors of hydrocephalus
prematurity, pregnancy complications, other congenital defects, nervous system tumors, CNS infections, and severe head injuries
***often fatal if left untreated
hydrocephalus in infants
-unusually large head
-rapid increase in the head size
-bulging fontanelle
-seizures, development delay
hydrocephalus in older children and adults
-headache followed by vomiting, nausea
-blurred vision or diplopia, sluggish pupil response to light
-uncoordinated movements, extreme fatigue, development delay
-memory loss, confusion, irritability, personality changes
spina bifida
-most common neural tube birth defect in the US
-the lumbar area of the vertebrae is most commonly the site
-can vary in severity from mild to debilitating
-the posterior spinous processes on the vertebrae fail to fuse, permitting the meninges and spinal cord to herniate
spina bifida maternal risk factors
family history of neural defects, folate deficiency, certain meds (e.g. antiseizure agents), diabetes mellitus
spina bifida complications
physical and neurologic impairments, hydrocephalus, meningitis, and learning problems
spina bifida occulta
-mildest form
-results in a small gap in one or more vertebrae
-the spinal nerves and meninges do not usually protrude through the opening
-usually no clinical manifestations and no neurologic deficits
-defect may not be evident other than a dimple, birthmark, or tuft of hair over the site
meningocele
-rare form that involves the same bony defect as in spina bifida occulta, but the meninges protrude through the vertebral opening
-the meninges and CSF form a sac on the surface of the back
-the spinal cord develops normally
-neurologic impairment is usually not present
myelomeningocele
-most severe from
-the spinal canal remains open along several vertebrae in the lower or middle back
-the meninges, spinal cord, spinal nerves, and CSF protrude through the large opening and form a sac on the infant’s back
-tissues and nerves are exposed in most cases, making the infant vulnerable to life-threatening infections
myelomeningocele complications
neurologic impairment (often including paralysis), bowel and bladder problems, seizures, and other medical complications
cerebral palsy
-a group of nonprogressive disorders that appear in infancy or early childhood and permanently affect motor movement and muscle coordination
-other cerebral functioning may be affected (e.g. cognition and communication)
-usually caused by damage to the cerebellum during the prenatal period or during childbirth, but can occur any time during the 3 yrs of life, when the brain is developing
contributing factos of cerebral palsy
prematurity, low birth weight, breech births, mult fetuses, hypoxia, cerebral hemorrhage, neurologic infections, head injury, maternal infections during pregnancy (e.g. rubella and varicella), maternal exposure to toxins during pregnancy (e.g. mercury)
manifestations of cerebral palsy
-persistence of early reflexes
-development delays
-ataxia, spasticity, flaccidity, hyperreflexia
-unusual positioning of limbs when resting or when help up
-excessive drooling, difficulty swallowing, impaired sucking, and difficulty w fine motor skills
-may or may not be evident at birth
-vary in severity
-may affect the entire body or one area
-may affect one side or both sides of the body
cerebral palsy complications
-balance and coordination issues, contractures
-atrophy below the waist
-speech delays
-learning or cognition difficulties, seizures
-urinary incontinence, constipation
-chronic pain, and injury
infections neurological disorders
meningitis, encephalitis, zika
meningitis
-inflammation of the meninges and subarachnoid space, usually resulting from an infection
-leading to swelling of the meninges and increased intracranial pressure
*** can be self-limiting (viral) or life-threatening (acute bacterial)
causes of meningitis
bacteria (e.g. group B Streptococcus), viruses (e.g. enterovirus, West Nile virus, influenza, human immunodeficiency virus (HIV), tumors, and allergens
manifestations of meningitis
-fever, chills
-mental status changes, decreased consciousness
-photophobia, severe headache, stiff neck
-agitation, bulging fontanelle
complications of meningitis
-permanent neurologic, paralysis
-seizures
-hearing loss, blindness, speech difficulties
-learning disabilities, behavior problems
-acute renal failure, cerebral edema, shock, and death
encephalitis
-inflammation of the brain and spinal cord usually resulting from an infection
-infection triggers the inflammatory response that causes vasodilation, increased capillary permeability, and leukocyte infiltration
-can cause nerve cell degeneration and diffuse brain destruction
*** most cases are mild and self-limiting, but can be severe and life threatening
causes of encephalitis
-virus (e.g. poliovirus, adenovirus, HSV, cytomegalovirus, West Nile virus, measles, and mumps)
-bacterial infections (e.g. Lyme disease, tuberculosis, and syphilis)
vulnerable groups that have more severe progression in encephalitis
immunocompromised persons, young children, older adults, those living in high-incidence areas
encephalitis complications and manifestations
complications: cerebral edema, cerebral hemorrhage, and brain damage
manifestations: similar to meningitis but w a more gradual onset; history of flu like symptoms
zika virus
-a growing worldwide health concern
-caused by a flavivirus
-several outbreaks in Africa, the Americas, Asia, and the Pacific: Brazil in 2015, large outbreak of Zika virus disease w more neurologic complications
transmission of zika virus
mosquito (primary), foreign travel, local mosquito spread, sexual transmission
other sources: mother to fetus, blood transfusion
manifestations & complications
manifestations: none usually; when present include flulike symptoms
complications: rare but severe w maternal–fetal transmission: ocular lesions, miscarriage, and microcephaly
prevention of zika virus
wearing protective covering, minimizing outdoor exposure, using insect repellant w DEET, using condoms
traumatic neurological disorders
brain injuries, increased intracranial pressure & spinal cord injuries
traumatic brain injuries (TBI)
-Usually caused by a sudden and violent blow or jolt to the head (closed injury) or a penetrating (open injury) head wound that disrupts the normal brain function
-The injury can bruise the brain, damage nerve fibers, and cause hemorrhaging. Varies from mild to severe
manifestations of traumatic brain injuries (TBI)
-May be vague and develop slowly, or may be sudden and severe
-Symptoms may improve and then suddenly worsen
-The outward appearance of the head is not an indication of the injury severity
closed TBIs: concussion
-momentary interruption of brain function
-usually results form a mild blow to the head that causes sudden movement of the brain, disrupting neurologic functioning
-may or may not lead to a loss of consciousness
-amnesia, confusion, sleep disturbances, and headaches any occur for weeks
closed TBIs: cerebral contusion (bruising of the brain)
-most often results from a blunt blow that causes the brain to make sudden impact w the skull
-coup: initial area where the brain impacts the skull
-countercoup: opposite side of the brain where it rebounds and impacts the skull
-Varies in severity depending on the extent of damage and the amount of bleeding
-Residual effects depend on severity
open TBIs
-fractures
-increased risk for infections
open TBIs fractures
inear skull fracture, a
comminuted skull fracture,
compound skull fracture,
depressed skull fracture,
basilar skull fracture
TBI manifestations
-not being able to recall event details
-indications of a concussion
-changes in or unequal pupil size
-seizures
-asymmetrical facial features
-fracture of skull or face
-bruising of face
-inability to move one or more limbs
irritability (especially in children)
-personality changes
-unusual behavior
-loss of consciousness
glasgow coma scale
-Assess and document level of consciousness in patients with head trauma
-Includes – Eye opening, verbal response, motor response, response to stimuli, posture
increased intracranial pressure
-Normal ICP =60-200
-increase volume in a limited space
-delicate pressure-volume relationship btwn skull contents
-CSF, Blood, Brain tissue
-blood vessels dilate to increase blood flow and constrict if ICP increases
Monro-Kellie Hypothesis
-an increase in one volume by a decrease in the volume of another
-accomplished mostly by shifts in the CSF and blood volume
-vasodilation/constriction
Cushing’s reflex
- increase sympathetic stimulation when the mean arterial pressure drops below the ICP
-Causes vasoconstriction, increased cardiac contractility, and increased cardiac output
-Cushing’s triad: increased blood pressure, bradycardia, and Cheyne-Stokes respirations
herniations
Complication of Increased Intracranial pressure
Various types affect different parts of the brain, brainstem or cerebellum
Compress neural tissue and cranial nerves
Manifestations depend on which region of the brain/nerves is compresed
Can lead to mild to severe issues
Compression of Reticular activation system in brainstem can lead to coma or death
intracranial hematomas
-A collection of blood in the tissue that develops from ruptured blood vessels
-Hematomas can develop immediately or slowly because of a TBI
-Bleeding leads to localized pressure on nearby tissue and increases ICP
-Blood may coagulate and form a solid mass
types of intracranial hematomas
subdural
intracranial
epidural
subarachnoid
epidural hematomas
-Result from bleeding between the dura and skull, usually caused by an arterial tear
-Manifestations include marked neurologic dysfunction that usually develops within a few hours of injury
-The typical symptom pattern of an epidural hematoma is a brief loss of consciousness, followed by a short period of alertness, then loss of consciousness again
subdural hematoma
-develop btwn the dura and arachnoid, frequently caused by small venous tear
-Generally develop slowly
-Manifestations are present within 24 hours of an injury
-Progresses rapidly and has a high mortality
-ICP increases over a period of about a week after the injury
-With chronic subdural hematomas, manifestations develop several weeks after the injury because of a slow leak; more common in elderly adults because of brain atrophy
intracerebral hematomas
-result from bleeding in the brain tissue itself
-caused by contusion or shearing injuries but can also result from hypertension, cerebral vascular accidents (strokes), aneurysms, or vascular abnormalities
Subarachnoid hemorrhage
-Results from bleeding in the space between the arachnoid and pia
-The primary clinical presentation is a severe headache with a sudden onset and that is worse near the back of the head
Spinal Cord Injuries
-Result from direct injury to the spinal cord or indirectly from damage to surrounding bones, tissues, or blood vessels
causes of spinal cord injuries
Causes: motor vehicle accidents, falls, violence, sports injuries, and weakening vertebral structures (e.g., rheumatoid arthritis or osteoporosis)
spinal shock (spinal cord injuries)
temporary suppression of neurologic function because of spinal cord compression; neurologic function gradually returns
autonomic hyperreflexia (spinal cord injuries)
a massive sympathetic response that can cause headaches, hypertension, tachycardia, seizures, stroke, and death; most commonly associated with injuries above T6
neurogenic shock (spinal cord injuries)
an abnormal vasomotor response secondary to disruption of sympathetic impulses
manifestations of spinal cord injuries
-loss of neurologic functioning
-varying degrees of paralysis
cervical/thoracic injuries
affect both the upper and lower extremities
include breathing difficulties, loss of normal bowel and bladder control, paresthesia, sensory changes, spasticity, pain, weakness, paralysis, blood pressure instability, temperature fluctuations, and diaphoresis
lumbar/sacral injuries
affect the lower extremities in varying degrees;
manifestations are similar to those of cervical injuries, with the exception of breathing difficulties
complications of spinal cord injuries
Respiratory failure
Effects of immobility (e.g., constipation, pulmonary infections, urinary infections, thrombus, impaired skin integrity, contractures)
Changes in bowel and bladder function
Sexual dysfunction
Chronic pain
Death
