HLTH 2501: acute neurologic problems Flashcards
what can tumors be called in the brain?
space-occupying lesions
gliomas
are the largest category of primary malignant tumors and these arise from one of the glial cells (the parenchymal cells in the CNS); these can be further subdivided because of the cell of derivation
most common type of glioma
astrocytomas
types of brain tumors
gliomas, meningioma, or adenoma (pituitary gland)
what are secondary brain tumors often a result of?
breast or lung tumors
diagnosis for brain tumors
stereotactic biopsy or MRI
what do primary malignant brain tumors appear as?
not well-defined margins (project into adjacent tissue) and are surrounded by an area of inflammation
what brain tumors are common in young children?
brainstem and cerebellar tumors
where do brain tumors often develop in adults?
in the cerebral hemispheres
signs of brain tumors
morning headaches, vomiting, lethargy, irritability, personality changes, seizures, paralysis, visual problems, and adenomas will cause endocrinologic signs
why are there no systemic signs associated with brain tumors?
because they do not metastasize outside of the CNS and will cause death before this can occur
brain tumor treatment
surgery is often the treatment of choice, but chemo and radiation may also be used
2 origins of vascular disorders
hemorrhagic or ischemic
global cerebral ischemia
may develop secondary to severe shock or cardiac arrest and occurs when impaired perfusion of the entire brain results in loss of function and generalized cerebral edema
mild signs of global cerebral ischemia
will cause confusion and neurologic dysfunction but recovery will occur with no permanent damage
severe or prolonged global cerebral ischemia signs
significant diffuse necrosis or infarction will result in a deep doma
causes of a transient ischemic attack
results from temporary localized reduction of blood flow in the brain (partial occlusion of an artery, atherosclerosis, a small embolus, a vascular spasms, or local loss of autoregulation)
TIA
transient ischemic attack
what may a TIA predict?
a stroke
signs of a TIA
short episodes of impaired function (such as muscle weakness), visual disturbances, numbness, paresthesia, and transient aphasia
paresthesia
abnormal sensation of the skin or pins and needles
another name for a stroke
cerebrovascular accidents
stroke
is an infarction of brain tissue that results from lack of blood
two main causes of a stroke
2 ways; the brain tissue may become necrosis, leading to a total occlusion of a vessel by atheroma or embolus, which causes ischemia; it may also be the result of a ruptured vessel, causing a hemorrhage and increased ICP
how long of ischemia does it take to cause cell damage?
5 minutes
what is the result of ischemia in the brain?
a central area of necrosis develops, surrounded by inflammation, in which the tissue liquifies, leaving a cavity in the brain
three types of cerebrovascular accidents
thrombus, embolus, or hemorrhage
most common cause of a stroke
occlusion of an artery by an atheroma that often develop in large arteries
obstruction by an embolus leading to a stroke
may be lodged in a cerebral artery or in the heart, and may result from tumors, air, or infection
hemorrhage causing a stroke
usually is caused by the rupture of a cerebral artery is a patient with severe hypertension and cause increased ICP
most severe type of stroke
hemorrhage because they affect large portions of the brain
secondary effects of a hemorrhage stroke
the bleeding may result in vasospasms, electrolyte imbalances, acidosis, and cellular edema
what are strokes diagnosed with?
an MRI
what are neurons replaced with after a stroke?
residual scar tissue and cysts
secondary complications of strokes
recurrent strokes, contractures as a result of paralysis, and secondary problems related to immobility like pneumonia, aspiration, and constipation
contracture meaning
A permanent tightening of the muscles, tendons, skin, and nearby tissues that causes the joints to shorten and become very stiff
risk factors for a stroke
diabetes, hypertension, lupus, elevated cholesterol, hyperlipidemia, atherosclerosis, a history of TIA, increasing age, obstructive sleep apnea, oral contraceptives, cigarette smoking, and heart disease
warning signs of a stroke
sudden weakness, numbness or tingling in the face, arm or leg, or on one side of the body, loss of speech, confusion, sudden loss of vision, severe headache, and unusual dizziness or unsteadiness
stroke scale
created by the national institute of health and includes commands to determine capacity for speech, level of consciousness, motor abilities, and assessment of eye movement
small infarctions and strokes
small infractions may make a ‘silent stroke’ in which there are not obvious signs until several small infarctions have occured
evolving stroke
is a stroke that develops slowly over a period of hours
paralysis for a stroke
flaccid paralysis will first occur, and spastic paralysis will develop weeks later
what are the signs of a hemorrhagic stroke
severe headache and increasingly severe neurologic defects
signs of a stroke resulting from occlusion of an anterior cerebral artery
this affects the frontal lobe so signs are contralateral muscle weakness or paralysis, sensory loss in the leg, confusion, loss of problem-solving skills, and personality changes
signs of a stroke resulting from occlusion of an middle cerebral artery
affects the central hemisphere so contralateral paralysis and sensory loss of the upper body and arm occur; as well, aphasia when the dominant hemisphere of the brain is affected, or spatial relationships are impacted if it is the right lobe
signs of a stroke resulting from occlusion of the posterior cerebral artery
vision loss as the occipital lobe is affected
clot-busting agents
are tissue-plasminogen activator which reduces the effects of the stroke
function of glucocorticoids for a stroke
reduce cerebral edema
treatment for stroke
can be clot-busting agents, surgery to relieve obstruction, glucocorticoids, O2 supply, getting the patient to stand up to maintain muscle tone, PT, OT, speech therapy, and treating the underlying problem ex. hypertension
what is an aneurysm?
a localized dilation in an artery caused by the force of blood (hypertension) leading to a bulging in the wall
where do cerebral aneurysms occur?
at the points of bifurcation on the circle of Willis, specifically at points of weakness in the wall, often where branching occurs
development of an aneurysm
initially they are asymptomatic and develop very gradually until they compress a nearby structure or until rupture occurs
what does an aneurysm rupture result from?
a sudden increase in BP during exertion, causing bleeding to occur into the subarachnoid space and the CSF
blood in the meninges
is irritating and will cause an inflammatory response and an irritation of the nerve roots passing through here; it can also cause a vasospasm in the cerebral arteries, as well as a hemorrhage which will cause increased ICP
signs of an aneurysm that is creating pressure
pressure on the surrounding structures such as the optic chiasm or the cranial nerves can lead to the loss of the visual fields and it can also result in a headache
signs of small leak aneurysm
headache, photophobia, and intermittent periods of dysfunction such as confusion, slurred speech, or weakness, and a stiff neck (nuchal rigidity)
phototopia
increased sensitivity of the eyes to light
nuchal rigidity
is a stiff neck that develops as a response to escaped blood that irritates the spinal nerve roots and causes contractions in the neck
signs of a massive rupture aneurysm
immediate and severe blinding headache, vomiting, photopia, and sometimes seizures of a loss of consciousness; death may also occur
treatment for an aneurysm
is often treated with surgery through clipping or tying it off, while also focusing on reducing increased ICP and cerebral vasospasm
how do microorganisms arrive at the brain through the blood?
they can bind to nasopharyngeal cells, cross the mucosal barrier, attach to the choroid plexus, and enter the CSF
what does the brain look like when infected by meningitis?
inflamed and swollen (there is increased ICP as a result), blood vessels appear dilated, and purulent exudate covers the surface, filling in the sulci causing them to appear flat
meningococcus other name
neisseria meningitidis
meningococcus
is the classic meningitis pathogen and enters in the nasopharynx of carriers; it is spread by respiratory droplets and occurs more often in the late winter and early spring
treatment for meningococcus organism
prophylactic treatment
E coli and meningitis
commonly affects neonates and is common is those with a neural tube defect, premature rupture of the amniotic membranes, or a difficult delivery
haemophilus influenzae and meningitis
commonly occurs in the autumn or winter and often affects young children
meningitis in elderly people
is often caused by streptococcus pneumoniae
common organisms causing meningitis
streptococcus pneumoniae, haemophilus influenzae, E coli, and meningococcus (neisseria meningitidis)
other causes of meningitis
can be secondary to other infections like sinusitis or otitis, may result from an abscess that spreads, or can be a result of viral infections like mumps or measles
signs of meningitis (specifically meningeal irritation)
severe headache, back pain, photophobia, nuchal rigidity, kernig sign, and brudzinski sign
kernig sign
resistance to leg extension when lying with the hip flexed
brudzinski sign
neck flexion cause flexion of hip and knee
signs of meningitis (specifically for increased ICP)
vomiting, irritability, lethargy, and seizures
signs of meningitis (specifically for infection)
fever, chills, leukocytosis, and a rose-colored petechial rash over the body
signs of meningitis in a newborn
feeding problems, irritability, lethargy, a high-pitched cry, and bulging fontanelles (soft spots on head)
potential complications of meningitis
hydrocephalus, cranial nerve damage, mental retardation, seizures, or motor impairment
fulminant meaning
rapidly progressive and severe
fulminant meningitis
is caused by highly virulent organisms, causing intravascular coagulation or hemorrhage of the adrenal glands, resulting in vascular collapse or shock and death
diagnosis for meningitis
lumbar puncture; CSF is cloudy and contains an increased number of WBCs if infection is present
treatment for meningitis
aggressive antimicrobial therapy (ex. ampicillin) along with treatment of ICP and seizures if needed, and glucocorticoids for inflammation
vaccines available for meningitis
are available for S. pneumoniae and H. influenzae
brain abscess
is a localized infection frequently occuring in the frontal or temporal lobes; necrosis of brain tissue and edema are usually also present
where do brain abscesses usually result from?
the spread of infections from the ear, throat, lung, or sinus infections, as well as endocarditis
common causative organisms for brain abscesses
staphylococci, streptococci, and pneumococci
signs of brain abscess
neurologic deficits and increasing ICP
treatment for brain abscess
antimicrobial therapy and surgical drainage
encephalitis
is an infection of the parenchymal or CT in the brain and spinal cord, particularly of the basal ganglia; inflammation and necrosis develop in the brain tissue
early signs of encephalitis
severe headache, stiff neck, lethargy, vomiting, seizures, and fever
western equine encephalitis
is an arboviral infection spread by mosquitoes and is common in children and summer
St Louis encephalitis
is found throughout the US and affects older persons more seriously
West Nile fever
is a form of encephalitis that is caused by a flavivirus and is spread by mosquitoes and uses birds as an intermediate host
signs of west nile fever
low-grade fever, headache, confusion, and tremors
another name for lyme
neuroborreliosis
what causes lyme
a spirochete called borrelia burgdorferi that is transmitted by tick bites
what does a tick bite look like?
red with a pale centre that gradually increases in size to form the unique marker lesion the ‘bull’s eye’
signs of lyme
first sore throat, dry cough fever, and headache; this is followed by cardiac arrhythmias, neurological abnormalities, and pain and swelling in large joints that may persist to chronic arthritis
treatment for lyme
prolonged therapy with antimicrobials like doxycycline
herpes simplex encephalitis
arises from the spread of herpes simplex virus type 1 from the trigeminal nerve ganglion; causes extensive necrosis and hemorrhage in the brain
treatment for herpes simplex encephalitis
acyclovir antiviral drugs
amoebic meningoencephalitis causative organism
the amoeba Naegleria fowleri which thrives in warm water and is found in southern US
amoebic meningoencephalitis
rare infection that results in inflammation and swelling of the brain or spinal cord; is almost always fatal
types of encephalitis
western equine encephalitis, St louis encephalitis, west nile fever, lyme, herpes simplex encephalitis, and amoebic meningoencephalitis
other infections that can target the CNS or PNS
rabies, tetanus, poliomyelitis, candida albicans or toxoplasma gondii
rabies other name
hydrophobia
rabies
is a virus that is transmitted by the bite or a rapid animal; the virus travels along the peripheral nerves to the NS, where is causing severe inflammation and necrosis, particularly in the brainstem and basal ganglia
signs of rabies
headache, fever nervous hyperirritability (including sensitivity to touch and seizures), difficulty swallowing, foaming at the mouth, and respiratory failure
treatment for rabies
immediate cleansing of the bite area and prophylactic immunization
another name for tetanus
lockjaw
what is tetanus caused by?
clostridium tetani which is a spore-forming bacillus
signs of tetanus
the exotoxin enters the nervous system, causing tonic muscle spasms causing jaw stiffness, difficulty swallowing, stiff neck, headache, skeletal muscle spasm, and even respiratory failure
treatment for tetanus
an antitoxin, mechanical respiration, and immunization
poliomyelitis other name
infantile paralysis
poliomyelitis
the virus reproduces in the lymphoid tissue in the oropharynx and digestive tract, then enters the blood and the CNS and targets the motor neurons of the spinal cord and medulla
signs of poliomyelitis
fever, headache, vomiting, stiff neck, flaccid paralysis and sometimes respiratory failure
what may cause infections in the brain of immune-suppressed people
candida albicans or toxoplasma gondii
herpes zoster other name
shingles
what is herpes zoster caused by?
varicella-zoster virus (chickenpox) and it occurs years after this primary infection
what does herpes zoster affect?
one cranial nerve or one dermatome on one side of the body
dermatone
a cutaneous area innervated by a spinal nerve
signs of herpes zoster
pain, paresthesia (pins and needles), and a vesicular rash develop in a line, unilaterally usually on the face or hip
prognosis of herpes zoster
the lesions usually clear up in a few weeks but some older individuals experience pain after these disappear and sometimes they spread for autoimmune individuals
treatment for herpes zoster
antiviral medications like acyclovir or the vaccine zostavax
postpolio syndrome
occurs 10 to 40 years after the original infection recovery and is progressive fatigue, weakness, pain and muscle atrophy
what percentage of those with polio develop postpolio syndrome?
25-50%
why does postpolio syndrome develop?
because the surviving motor neurons developed new additional axon branches to serve muscle cells as a compensation but could not maintain them, and end up dying
what causes reye syndrome?
is not fully understood but is linked to a viral infection like influenza in young children who have been treated with aspirin
what happens in reye syndrome?
a noninflammatory cerebral edema develops, leading to increased ICP; the liver also enlarges, developing fatty changes and progress to acute failure; kidneys may also be affected
serum levels in Reye syndrome
high ammonia, high serum liver enzymes (jaundice not present), low glycogen, and high lactic acid
signs of Reye syndrome
lethargy, headache, vomiting, disoreration, hyperreflexia, hyperventilation, seizures, stupor, or coma
treatment for Reye syndrome
no cure so treatment focuses on metabolic imbalances and cerebral edema
other names for Guillain Barre syndrome
postinfectious polyneuritis, acute idiopathic polyneuropathy, and acute infectious polyradiculoneuritis
guillian-barre syndrome
is an inflammatory condition of the PNS
cause of guillian-barre syndorme
unknown but it may be an abnormal immune response precipitated by a preceding viral infection or immunization
what occurs during guillian-barre syndrome
local inflammation, accumulated lymphocytes, demyelination, and axon destruction; this causes impaired nerve conduction, mostly motor but also sensory
what body parts does guillain-barre syndrome affect?
initially the legs, then the spinal nerves involving the trunk and neck, and then the cranial nerves; critical period develops when the diaphragm and respiratory muscles are affected
recovery for guillian-barre syndrome
occurs spontaneously and in the reverse order, so the motor function is regained first
signs of guillian-bare syndrome
progressive muscle weakness and areflexia, which leads to flaccid paralysis, accompanied by paresthesia (pins and needles) and general muscle aching; vision, speech, swallowing, and respiration may be affected
treatment for guillian-bare syndrome
ventilator, immunoglobulin therapy, PT, OT, and respiratory therapy
immunoglobulin therpay
is when the immunoglobulin G (IgG) is separated and removed from the patients blood
types of brain injuries
may be skull fractures, hemorrhage, edema, or direct injury to brain tissue
another name for concussion
mild traumatic brain injury
concussion
is a reversible interference with brain function, in which neurologic dysfunction and a loss of consciousness may be experienced; memory loss and headaches may also temporarily occur
amnesia
memory loss
contusion
is bruising of brain tissue with rupture of small blood vessels and edema that usually result from a blunt blow to the head
closed head injury
occur when the skull is not fractured in the injury, but the brain tissue is injured and blood vessels may be ruptured
open head injuries
are those involving fractures or penetration of the brain by missiles or sharp objects
compound brain fracture
involve trauma in which the brain tissue is exposed to the environment and is likely to be severely damaged because bone fragments may penetrate the tissue, thus the risk of infection is high
basilar fracture
occurs at the base of the skull and are often accompanied by leaking of CSF through the ears or nose; often occur when a forehead hits a car windshield; cranial nerve damage and dark discoloration around the eyes are common
contrecoup injury
occurs when an area of the brain contralateral to the site of damage in injured as the brain bounces off the skull, so are secondary injuries; damage is usually minor
primary brain injuries
are direct injuries such as lacerations or crushing of the neurons, glial cells, and vessels resulting from a piece of bone or foreign object, as well as ruptures of vessels
shearing injury
is when the lobes of the brain move against eachother
how does a primary brain injury heal?
after the bleeding and inflammation subside, some recovering of the neurons may occur and the central area of damage undergoes necrosis and is replaced by scar tissue or a cyst
secondary brain injuries
result from the additional effects of cerebral edema, hemorrhage, hematoma, cerebral vasospasm, infection, and ischemia related to systemic factors
hematoma
is a collection of blood in the tissue that develops from ruptured blood vessels
4 types of hematomas
epidural, subdural, subarachnoid, and intracerebral
epidural hematoma
results from bleeding between the dura and the skull, usually caused by tearing of the middle meningeal artery in the temporal region
subdural hematoma
develops between the dura and the arachnoid; frequently these are caused by a small tear in a vein, in which blood slowly accumulates; can be acute or subacute
hygroma
is a tear in the arachnoid that can allow CSF to leak into the subdural space and this creates pressure
subarachnoid hemorrhage
is between the arachnoid and pia and is associated with traumatic bleeding from the blood vessels at the base of the brain; because blood mixes with circulating CSF, a hematoma cannot form
intracerebral hematoma
results from contusions or shearing injuries
what may arise secondary to a hematoma?
local pressure on adjacent tissues and a general increase in ICP; this is due to blood accumulating, then undergoing hemolysis which draws in water due to osmosis and thus creating pressure; this may also cause vasospasm, leading to ischemia and further dmage
alcohol and brain injuries
alcohol is a common factor leading to injuries and tends to delay the onset of cerebral edema and elevation of ICP, but this leads to a greater increase at a later time
signs in someone with a head injury
seizures, cranial nerve impairment, otorrhea and rhinorrhea, fever, or stress ulcers
rhinorrhea
is the leaking of CSF from the ear or nose
otorrhagia
is the leaking of blood through the ear through a fracture site with torn vessels and meninges
how are brain injuries diagnosed?
CT and MRI
treatment for brain injuries
glucocorticoid agents and antibiotics for infection, surgery for ICP, O2 to protect the remaining tissue, head injury assessments by family and friends, PT and OT
simplified head injury test
is done by a family or friend and involves checking for reactive pupils, watching for vomiting, change in movement, sensation, or behaviour
what do spinal cord injuries usually result from?
fracture or dislocation of the vertebrae which compresses, stretches or tears the spinal cord; supporting ligaments and the discs may also be damaged
where do most spinal cord injuries occur?
in the areas that provide more mobility and less support; C1-C7 and T12-L2
4 types of spinal cord injuries
hyperextension or hyperflexion of the neck, dislocation of any vertebrae, compression fractures, and penetration injuries
hypertension/hyperextension spinal cord injuries
occur in the cervical spine and sometimes include fracture; usually there is damage to the disc and ligaments, which leads to dislocation, loss of alignment and compression or stretching of the spinal cord
dislocation of the vertebrae
may crush or compress the spinal cord and compromise the blood supply
compression fractures to the spinal cord
cause injuries when great force is applied to the top of the skull or to the feet, and is transmitted to the spine; this results in shattered bone that exerts horizontal pressure against the cord and sharp edges may tear nerves or vessels
spinal cord penetration injuries
may result form a bullet wound
4 types of vertebrae fractures
simple, compression, wedge, or dislocation
wedge fracture
a displaced angular section of bone
nerve damage from spinal cord injuries
may be temporary or permanent as nerves cannot undergo mitosis, only axonal regrowth; nerves are affected at or below the level of injury (except for C3-C5 that projects up)
secondary effects of spinal cord injuries
bruising, edema, minor bleeding, and ischemia; released enzymes also cause vasoconstriction, leading to more ischemia and inflammation, and possibly necrosis; longer effects may cause contractures, decubitus ulcers, and urinary infections
when may respiration be impaired from a spinal cord injury?
if it occurs in the cervical region, inflammation may extend up to C3-C5, interfering with phrenic nerve innervation to the diaphragm
spinal shock
occurs initially and is when conduction of impulses ceases in the nerve tracts and grey matter; reflexes are also absent
how do spinal cord injuries heal?
inflammation subsides, phagocytes remove damaged tissue, and scar tissue begins to form
two stages in the posttraumatic period of spinal cord injuries
spinal shock and recovery
spinal shock signs
flaccid paralysis, hyperreflexia, sensory loss, absence of reflexes, and loss of motor control; if injury is in the cervical area, loss of motor control includes blood pressure, diaphoresis, body temperature, and emptying; urinary retention and paralytic ileus and present
how is spinal cord injury recovery tested?
via a check of the dermatone response
what is damaged in a cervical spine injury?
motor and sensory function in the arms, trunk, and legs, respiratory function, SNS function, and sacral parasympathetic fibres
quadriplegia
paralysis of all four extremities
paraplegia
refers to paralysis of the lower part of the trunk and legs
autonomic dysreflexia
occurs in a cervical spine injury and is the triggering of a massive SNS reflex that cannot be controlled by the brain; causes distention of bladder, vasoconstriction, severe headache, and visual impairment; prolonged period of this can result in stroke or heart failure
sex and spinal cord injuries
sexual and reproductive function is often impaired; men may have neurogenic reflex erections and may also be infertile is the injury is higher
international standards for neurological classification of spinal cord injury
developed by the american spinal injury association and includes criteria A-E
‘A’ spinal damage criteria
complete, no motor or sensory function is preserved in the sacral segments S4-S5
‘B’ spinal damage criteria
incomplete; sensory, but not motor function is preserved below the neurologic level, and includes the sacral segments S4-S5
‘C’ spinal damage criteria
incomplete; motor function is preserved below the neurologic level and more than half of the key muscles below that level have a muscle grade less than 3
‘D’ spinal damage criteria
incomplete; motor function is preserved below the neurologic level and at least half of the key muscles below the level have a muscle grade of 3 or more
‘E’ spinal damage criteria
normal, motor and sensory function are normal
treatment for spinal cord injuries
immobilizing the spin, maintaining breathing and preventing shock; more specifically, can be traction, surgery, glucocorticoids (methylprednisolone), OT, PT, respiratory therapists, psychotherapists, and myriad assistive devices
leading cause of spinal cord injury death
pneumonia, followed by renal failure
