final first half Flashcards
ischemic stroke
- most common sites of thrombotic stroke: branches of cerebral arteries, circle of willis
- thrombus or embolus obstructs a blood vessel
- thrombus- blood clot or cholesterol plaque that forms in the artery
- embolus- clot or plague that forms elsewhere and than breaks off, and obstructs blood flow when it becomes lodged in an artery
- more common
hemorrhagic stroke
-diseased or damaged vessel rupture
hemiparesis
- unilateral weakness on opposite side is stroke
- strokes in middle cerebral artery produce hemiparesis
- usually weakness more in arm/face than leg
anterior cerebral artery stroke
- altered mental status
- impaired judgement
- contralateral weakness more in leg
posterior cerebral artery stroke
-impaired thought/memory, visual field deficits
risk factors of stroke
- atherosclerosis leads to turbulent blood flow, increased risk of clot
- blood disorders- sickle cell anemia, polycythemia
TPA
- TPA- tissue plasminogen activator
- TPA is a medication that is given to dissolve clot that is causing the stroke
- TPA can cause bleeding (many risk factors)
- must be given within 3 hours of LKWT
FAST / cincinnati stroke scale
- Face drooping
- Arm weakness
- Speech Difficulty
- Time to call 911
- CINCINNATI STOKE SCALE:
- facial droop
- arm drift
- abnormal speech
- if one sign out of 3 is abnormal the probability of stroke is 72%
stroke treatment
- place pt in low-fowlers or supine position with head slightly raised if ischemic stroke suspected
- regulate BP to maintain MAP at least 60mmHg
- so first they use non contrast -> if there is no bleed use a contrast CT
- fibrinolytic agents at hospital (TPA)
- mechanical thrombectomy
cerebrum
- conscious thought, memory storage and processing, sensory processing, regulation of skeletal muscle contraction
- Cerebrum divided into two cerebral hemispheres
- Superficial layer of gray matter is the cerebral cortex.
cerebellum
- coordination, balance, modulation of motor commands from cerebral cortex
- second largest area of brain
diencephalon
-link between cerebrum and CNS
brain stem
- processes visual and auditory info maintains consciousness, somatic and visceral motor control, regulates autonomic function
- autonomic control**
- midbrain, pons, medulla
meninges
- meninges- 3 layers of membranes
- dura mater- outer, strong white fibrous tissue (inner layer of cranial bones’ periosteum)
- arachnoid mater- arachnids: spiders, cobweb-like middle layer.
- pia mater- innermost meninge, adheres to the outer surface of brain and spinal cord, contains blood vessels.
delirium / excited / agitated delirium
- ACUTE alteration in cognition with impairment of awareness and orientation
- sometimes associated with hallucinations
- more often in women and with illness of very young or older than 60
- appearance, vitals, hydration, evidence of trauma
- check serum glucose levels
- causes: intoxication, infection, trauma, seizure, organ failure, stroke, shock, endocrine disorders or intracranial bleeding, and tumors
- dementia is CHRONIC loss of brain function (different than delirium
- agitated delirium:
- characterized by agitation, aggression, acute distress and sudden death, often in the pre-hospital care setting.
- typically associated with the use of drugs that alter dopamine processing, hyperthermia, and, most notably, sometimes with death of the affected person in the custody of law enforcement.
- Subjects typically die from cardiopulmonary arrest.
frontal lobe
- frontal association area
- speech
- motor cortex
parietal lobe
- speech
- taste
- somatosensory cortex
- somatosensory association area
- reading
temporal lobe
- smell
- hearing
- auditory association area
causes of vertigo
- central vertigo may be caused by stroke, concussion, tumors, infection, migraine, MS, toxic ingestion/inhalation
- vertigo is a symptom- originates in CNS or vestibular organs
- benign paroxysmal positional vertigo (BPPV) -> migraine headache
- menieres disease -> multiple sclerosis
- labyrinthitis -> mal de debarquement syndrome
- ototoxicity -> cerebellar hemorrhage and infarct
- superior canal dehiscence syndrome -> vertebrobasilar insufficiency, vertebral artery dissection, neoplasm
peripheral vs central vertigo
PERIPHERAL
-sudden onset
-intermittent with severe symptoms
-affected by head position and movement
-nausea and vomiting more frequent and severe
-motor function, gait and coordination typically intact
CENTRAL
-gradual onset
-constant with milder symptoms
-unaffected by head position and movement
-nausea and vomiting less predictable
-motor function, gait instability and loss of coordination frequent
headache
- This can be a vague and puzzling symptom
- Note associated symptoms:
- > vision changes (ipsilateral may be temporal arteritis)
- > photophobia, phonophobia, “flashing lights”
- Trauma followed by headache may indicate subdural/epidural hematoma or vertebral artery dissection
- Severe h/a w/sudden onset may be subarachnoid bleeding
- Co-morbidities hypertension, vascular issues, may indicate brain bleeding or aneurysm
- Look for abnormal vital signs: fever could indicate meningitis
- GAIT!
- worry about aneurism and hemorrhage
intracranial hypertension
-↑ Intracranial pressure (ICP) can compromise brain perfusion
-May be due to mass effect (hemorrhage or edema) or malfunction of ventriculoperitoneal shunt
-pupils dilate
-brain may herniate through foramen magnum (high mortality): with signs of unilateral blown pupil and loss of consciousness
TREATMENT
-A ventriculoperitoneal (VP) shunt is a medical device that relieves pressure on the brain caused by fluid accumulation
-hyperventilation: must be performed carefully, with monitoring patient’s neurological status
1. hyperventilating decreases amount of CO2 in blood which induces cerebral vasoconstriction
2. vasoconstriction decreases blood volume in brain which reduces ICP
- however vasoconstriction also ↓ perfusion to brain, so this must be carefully considered
subarachnoid hemorrhage
- Arteries on brain’s surface bleed into subarachnoid space
- Caused by cerebral aneurysm, trauma or rupture of arteriovenous malformation
- Sudden & severe h/a, possible loss of consciousness
- Five grades of hemorrhage:
1. mild h/a with or w/out meningeal irritation
2. severe h/a with or w/out pupillary change
3. mild alteration in neurological exam
4. depressed level of consciousness
5. comatose with or w/out posturing
subdural hematoma
- Collection of blood between dura and arachnoid meninges
- May be acute, subacute, or chronic (2-3 weeks post-injury)
- Mortality rate: 20%, mostly in pt’s over 60 y/o
- Trauma or deceleration injury: tearing of veins between cerebral cortex & venous sinuses
- blood clots in subdural space
coup-countercoup head injury: subdural hematoma
- coup (blow) causes trauma to brain, brain recoils after blow and is injured on opposite side after it rebounds
- bleeding/damage to both sides of brain
- Signs/symptoms: loss of consciousness after head trauma, amnesia, personality changes, h/a, visual changes, vomiting, hemiparesis, hemiplegia
epidural hematoma
- Accumulation of blood between inner layer of skull and dura mater
- Usually from trauma to subcranial arteries resulting in high-pressure mass effect
- Usually an associated skull fracture
- 80% in temporo-parietal region
- Prompt surgical decompression for pt’s with significant neurological dysfunction
- patient may not lose consciousness or may lose it and then awaken (lucid interval) before becoming unresponsive
- may have severe h/a, vomiting, seizures
- QUIZ
- increased ICP may cause Cushing’s triad ***(patient unresponsive w/imminent death):
1. systolic hypertension
2. bradycardia
3. irregular respiratory pattern
head hematoma treatment
- Protect C-spine
- CT or MRI at hospital
- May need lumbar puncture: blood in CSF
- IV line, administer oxygen, cardiac monitor, do not administer fluids unless BP is low -> mostly for epidural hematoma
bells palsy
- can mimic strokes
- Unilateral facial paralysis that may mimic a stroke
- Cranial nerve VII (Facial)
- Unknown origin or infection (herpes simplex)
- In stroke: only lower half of face is weak, forehead and upper eyelid have normal motor function
- inability to wrinkle brow, drooping eyelid, inability to puff cheeks, drooping mouth
Guillain barre syndrome
- A group of acute immune-mediated polyneuropathies
- Demyelinating disorders causing weakness, numbness, or paralysis throughout body
- Can occur at any age
- Autoimmune response to recent infection
- Antibodies formed against peripheral nerves
- paralysis starts at legs and goes up -> goes to lung cavity
- can lead to pneumonia!*
- intubate and ventilate
- Patients may require mechanical ventilation at some point in their illness to compensate for respiratory muscle weakness (Pneumonia is a common side effect)
- Lack of deep tendon reflexes is strong indicator of Guillain-Barre
- Parasthesia in feet and hands
- May have loss of vibratory sense, proprioception and touch
- Most patients at their worst 12 days
- progressive weakness of 2 or more limbs due to neuropathy
- disease course < 4 weeks
- relatively symmetrical weakness
- facial or other cranial nerve involvement
- absence of fever
5 categories of stimuli
- insects
- food
- plants
- medication
- chemicals