Week 5: Alterations in Cerebral Function Flashcards
Agnosia
can’t recognize familiar objects
Agnosognosia
fail to recognize themself. May not recognize half the body, or that they’ve even had a stroke.
Aphasia
inability to understand and speak
apraxia
the inability to move purposefully
ataxia
impaired gait
dysphagia
impaired swallowing
hemianopsia
ex: right sided stroke, can’t see on left vision field
hemiplegia
half of body has paralysis or weakness
pneumbra
around where the ischemia is. It’s the area we hope we can salvage
subluxation
partial dislocation of the shoulder on the opposite side of the stroke
non-modifiable risk factors of stroke
- AGE: 55 and older – incidence doubles every decade
- GENDER: Men
- RACE: African Americans 2X more likely than Caucasians
modifiable cva risk factors
- Hypertension – major risk factor
- A-Fib
- Hyperlipidemia
- Diabetes
- Smoking
- Carotid Stenosis, valvular heart disease
- Obesity
- ETOH – excessive consumption
- Periodontal Disease
- Sudden loss of function resulting from disruption of the blood supply to the brain
- Accounts for 80% of Brain Attacks
- Needs to be treated early to have fewer stroke symptoms, less loss of function, less permanent loss, etc.
- Causes – 1. atherosclerotic plaques in the large blood vessels of the brain result in thrombus formation and occlusion at site, and result in ischemia and infarction
Type of CVA?
ischemic brain attack
ISCHEMIC BRAIN ATTACK – CAUSES
- several small vessels affected, but they are ones that penetrate deeper into the brain (small penetrating artery thrombotic attack)
- heart can throw clots (a-fib, etc.)
- other causes: some are just unknown, illicit drug use, coagulopathies, spontaneous dissection of the carotid artery
- Disruption of cerebral blood flow because of an obstruction of a blood vessel
- This starts a series of events known as the Ischemic Cascade
Type of cerebral attack?
Thrombus related cerebral attack
THE ISCHEMIC CASCADE, describe?
- Blood flow decreases to a point where neurons are no longer able to maintain aerobic respiration
- So the mitochondria in the cells switch to anaerobic respirations (less efficient)
- Anaerobic respirations causes a large amount of lactic acid to be produced
- The large amount of lactic acid causes a change in the pH level (acidosis)
- Anaerobic respirations cause less ATP to be produced (because it is less efficient system), and depolarization of the cells is inhibited
- Ultimately the process leads to cellular death
Penumbra
- an area of low cerebral blood flow around the site of the infarction
- It is an area of ischemic brain tissue that can be saved with timely intervention
If ischemic cascade continues?
- it threatens the area of the penumbra also, causing cell death in that area and enlarging the infarction
- If this happens , it is called “extending the stroke”
Clinical manifestations of stroke
- Symptoms depend upon the location and size of the affected area
- Numbness or weakness of face, arm, or leg, especially on one side - Hemiplegia, Hemiparesis
- Aphagia, Drooping of 1 side of mouth
- Confusion or change in mental status
- Trouble speaking or understanding speech – Dysarthria, Aphasia (expressive vs. receptive)
- Difficulty in walking, dizziness, or loss of balance or coordination, Apraxia
- Sudden, severe headache (more hemmorrhagic)
- Perceptual disturbances – Hemianopsia, Agnosia
Spot a stroke saying?
FAST
- facial drooping
- arm weakness
- speech difficulty
- time to call 911
- Temporary neurological deficit resulting from a temporary impairment of blood flow
- “Warning of an impending stroke”
- Diagnostic work-up is required to treat and prevent irreversible deficit
Type of stroke?
TIA: transient ischemic attack
Medical managment of stroke
- ABC’s, stabilizing the pt., and preventing complications
- Mainly focusing on preventing extending the attack, and secondary prevention
- t-PA Tx
- Carotid Stents
- Carotid Endarterectomy
- Medications
- Innovations in Treatment: Clot removal catheter, Laser Treatments to the prenumbra
TPA what it does, time frame, contraindications
- Dissolves the clot - Works by binding fibrin, and converts plasminogen to plasmin, which stimulates fibrinolysis of the clot
- Must be given within 3 hrs of the onset of the attack
- Revascularization of necrotic tissue (>3 hrs) increases the risk for cerebral edema and hemorrhage
- Leads to a decrease in the size of the attack and an overall improvement in outcome
TPA dosage, side effects, and nursing indications
Dosage
- is based on weight –
- 10% is given as a bolus
- other 90% over 1 hr
Side effect :
- Bleeding is the most common
- 6.4% have intracranial bleeding
Nursing:
- watch IV site for bleeding
- no NG tubes, suction, foleys
- frequent neuro checks (Q 15 minutes)
CONTRAINDICATIONS TO T-PA
- SBP > 185 or DBP > 110 mm Hg, or aggressive treatment (IV medication) necessary to achieve these limits
- CT findings suggesting ICH, SAH, or established major acute stroke
- Suspicion of subarachnoid hemorrhage (even if head CT is negative for hemorrhage)
- Seizure at onset (If rapid diagnosis of vascular occlusion can be made, treatment may begiven.)
- Recent intracranial or spinal surgery, head trauma, or stroke (less than 3 months)
- History of intracranial hemorrhage or brain aneurysm or vascular malformation or brain tumor
- Major surgery or trauma within 3 months
- Recent active internal bleeding (less than 22 days) (including arterial puncture at a non-compressible site)
- Platelets < 100,000; heparin use within 48 hours with PTT > 40 (or exceeding upper limitsof normal range); INR > 1.7
- Known bleeding diathesis or other major disorder associated with increased bleeding risk
Carotid endarterectomy nursing care
*Watch for complications: brain attack, cranial nerve injuries, infection, hematoma
*Maintain adequate blood pressure
- Hypotension- cerebral ischemia and thrombosis
- Hypertension – cerebral hemorrhage, edema, and hemorrhage at the surgical site
*Neuro flow sheets
*Edema in neck is normal, but watch for airway obstruction
-should have emergency airway supplies at bedside
Nursing management for acute phase of ischemic attack
- Ongoing/frequent monitoring of all systems including vital signs, neurologic assessment: LOC, motor, speech, and eye symptoms
- Monitor for potential complications including: swallowing difficulties, respiratory problems, signs and symptoms of increased ICP
- 15-20% of attacks
- Mortality rate up to 43%
- Usually have more severe deficits, and a longer recovery time
- Caused by bleeding into brain tissue, ventricles, or subarachnoid space
Type of CVA?
HEMORRHAGIC BRAIN ATTACK
amyloid angiopathy
- Cause unknown, sometimes passed down through families
- Persons with this condition have deposits of amyloid protein in the walls of the brain arteries. The protein is usually not deposited anywhere else in the body.
- The major risk factor is increasing age. It is more often seen in those older than 60.
Hemmorrhagic brain attack causes
Spontaneous rupture of small vessels primarily related to:
- hypertension
- subarachnoid hemorrhage due to a ruptured aneurysm
Intracerebral hemorrhage related to:
- amyloid angiopathy
- arterial venous malformations (AVMs)
- intracranial aneurysms
- medications such as anticoagulants
Pathophysiology of Hemorrhagic brain attack
- Brain metabolism is disrupted by exposure to blood
- ICP increases due to blood in the subarachnoid space
- Compression or secondary ischemia from reduced perfusion
- vasoconstriction injures to brain tissue and cranial nerves
- when blood vessels lyse, releases proteints, cause irritant to tissue around it gets inflammed, vessels around it get damaged leading to further hemmorrhagic strokes
- Similar to other kinds of strokes
- Severe headache
- Early and sudden changes in LOC
- Vomiting
Manifestations of what type of stroke?
hemorrhagic stroke
Medical management of hemmorrhagic stroke
*Goal – allow the brain to recover
- prevent rebleeding
- prevent Tx complications
*Usually not treated surgically unless hematoma is at least 3 cm
- Surgical evacuation of hematoma
- isolate the aneurysm
*Bed rest with sedation
Acute phase complications of hemmorrhagic stroke
*I_CP = Increased Intracranial Pressure_
- Causes a decrease in cerebral perfusion, stimulates further swelling, and can cause death by shifting brain tissue through openings in dura,
- or by causing so much loss in cerebral blood flow
- Can occur with ischemic attack, but almost always with a hemorrhagic attack
- Occurs during acute phase, but may also develop in the recovery phase
- Also occurs tumors, head injuries, etc.
Nursing management of complications with hemmorrhagic stroke
Complications
_Vasospasms: _occur 4-14 days after the event
Narrowing of the blood vessels
- leads to vascular resistance-
- Impedes blood flow
- ischemia
- infarction
Nursing Management
- Monitor ICP
- Watch for and manage Hypertension,
Seizures, Rebleeding, Hyponatremia – IV Tx, Hydrocephalus (CSF cannot drain) - shunt
Long Term Medications for Strokes
- Warfarin (Coumadin) – esp. useful for afib or cardioembolitic attacks – the target INR= 2.5
- If warfarin is contradicted –ASA (don’t give within 24 hours of thrombolytic agents)
- Clopidogrel (Plavix)
- Ticlopidine (Ticlid)
- Statins – Zocor, Crestor, Lipitor
- Antihypertensives
What is a seizure?
- SpontaneousaAbnormal neuronal activity
- A sudden biochemical imbalance at the cell membrane
- Repeated abnormal electrical discharges
- Seen clinically as changes in motor control, sensory perception and/or autonomic function
Clinical presentations of seizure
- Feeling nauseous
- Feeling odd or peculiar
- Losing control of bowel or bladder
- Feeling numbness, tingling
- Experiencing odd smells or sounds
Precipitators of seizures?
- Dehydration
- Fatigue
- Flashing lights
- Hypoxia
- Stress
- Monthly hormonal fluctuations
- Head injury
- Electrolyte imbalances
Absence seizure
- Brief alteration in consciousness 5–30 seconds
- • Staring
- • Mild increase or decrease in muscular tone
- • Automatisms—chewing, rapid eye-blinking, lip-smacking
- • No postictal phase
Tonic-clonic seizures
- May have aura or vocalize a sudden cry from forced expiration 3–5 minutes
- • Loss of consciousness, stertorous respirations
- • 30–60 second tonic phase
- • Apnea and cyanosis may occur until end of tonic phase
- • Clonic phase of rhythmic, synchronous, jerky movements
- Dilated pupils, hypertension, tachycardia
- • Bilateral Babinski
- • May bite tongue, become incontinent
- • Postictal fatigue, memory loss, headache, confusion (minutes to hours)
myoclonic seizure
Quick symmetrical muscular, jerky movement of body, face, trunk extremity or entire body;
may be bilateral or unilateral
seconds seizure
- Violent (may fall and hit objects)
- • Impaired consciousness Seconds
Atonic (drop attack) seizure
- Abrupt loss of muscle tone (may fall and injure self)
- • Unconsciousness during episode
- • Short postictal phase—can resume activity
Simple Partial seizure
- Conscious, but without control Seconds to minutes
- • Twitching, jerky, unilateral movements of an extremity, eyes or face
- • Todd paralysis of involved area may occur
Generalized seizures, vs. complex and simple
Generalized
- Involves BOTH hemispheres of the brain
- Always involves loss of consciousness
- Types: Tonic or clonic movements or combination (grand mal), Absence (petit mal), Myoclonic, Atonic (e.g., drop attacks), Infantile spasms
Complex
- May have aura
- Involves motor* or autonomic# symptoms with altered level of consciousness
- May generalize
Simple
- No impaired consciousness
- Can involve motor,* autonomic# or somatosensory+ symptoms
- May generalize
motor symptoms of seizure
head/eye deviation, jerking, stiffening
autonomic symptoms of seizure
pupils dilatation, drooling, pallor, change in heart rate or respiratory rate
Somatosensory symptoms of seizure
smells, alteration of perception (déjà vu)
Complex partial
- Loss of consciousness, unresponsive Minutes
- • Impaired awareness (confused, unfocused), blank stare
- • May have aura
- • Unusual sensations—memory flashbacks, depersonalization of surroundings, “out of body”
- experience, visual or auditory distortions, rage, terror, elation, sadness
- • Automatisms—lip-smacking, chewing, picking up objects, aimless walking, removing clothing,
- repeating phrases
- • Unaware of danger such as traffic, fire, heights
- • Postictal confusion and amnesia of event
- Secondarily generalized • Any partial seizure that becomes generalized with loss of consciousnes
Seizure phases
Aura
- actually a small partial seizure that is often followed by a larger event.
- Alterations in senses.
Ictus.
- The seizure event.
Postictal state.
- After the ictus phase.
- Drowsiness and confusion are commonly experienced during this phase.
- The postictal state is the period in which the brain recovers from the insult it has experienced.
diagnostic tests for seizures
- Laboratory tests for electrolyte balance, blood glucose, and anticonvulsant levels
- CT scan
- EEG
Collaborative care for seizures
Anticonvulsants
- Phenytoin (Dilantin)
- 10-20 mg/kg loading dose
- Mix with NS not dextrose
- 25-50 mg/min IVP
- Monitor MP and Heart Rate x 30 min: May use Fosphenytoin children (SIVP or IM)*
-Benzodiazepine: Given emergent with Dilantin
Keatogenic Diet: High fat, low carb, low protein
Vagus Nerve Stimullator: implanatble device that stimulates the vagus nerve. Done after trying 3 or more meds
nursing care for seizure pts
- Make certain that the patient has the following equipment: Nasal cannula and tubing, Oxygen flow meter; , Suction gauge, Suction canister, Suction tubing to connect to canister
- Assign patient to room in close proximity to the nurses station
- Maintain continuous observation via video monitor or sitter
- Pad side rails of bed
- Keep bed in low position with all side rails up at all times
- Keep unnecessary equipment out of patients room
- Instruct patient not to get out of bed without assistance
- Assure that call bell is always within patients reach. Make sure that the family knows where it is and how to use it
- Avoid use of restraints
- Check vital signs every fifteen minutes and maintain airway patency during the post ichtal phase (period of time immediately following the seizure, during which the patient remains comatose or stuperous).
pt. education on what to do if a seizure occurs
- DO NOT restrain.
- DO NOT place anything between the person’s teeth during a seizure.
- DO NOT move the person unless they are in danger or near something hazardous.
- DO NOT try to make the person stop convulsing.
- DO NOT give the person anything by mouth until the convulsions have stopped and the person is fully awake and alert.
- DO NOT start CPR unless the seizure has clearly stopped and the person is not breathing or has no pulse.
STATUS EPILEPTICUS
*A sustained seizure lasting 5 minutes
*150, 000 each year experience SE
*40,000 die as a result
-Surge of catecholamines
-HTN
-Tachycardia
-Cardiac arrhythmias
-Hyperthermia
*Results in increase neuronal metabolic needs and ultimate neuronal death
Management of seizure pt.
*Stay with Patient!
*Secure Airway/Oxygenation
*Establish IV access with NS or D5 (if hypoglycemic)
*Drug of choice:
- Benzodiazepine (Lorazepam) 2-4 mg IVP over 1 minute
- Phenytoin IV drip
Febrile seizures risk/cause, types, meds
- Most common neurological condition in childhood
- 2-5% of all children experience between 6-60 months
- Cause unknown: Associated with viral infections, Family hx, Premature birth
- 1% Long Term risk for developing epilepsy
Types
- Simple: No hx of previous seizure, High fever, Tonic-clonic, Less than 15 minutes
-
Complex: Previous hx of seizures
Greater than 15 minutes
Treatment
- safety till resolved
- Acetaminophen for fever
- Diazepam IV or rectal if seizure continues
