Cerebral Vascular Accidents and Infections Flashcards
(24 cards)
Cerebrovascular Disorders
Ischemic stroke: TIA, thrombotic, embolic
Hemorrhagic stroke
Headaches
Infections of the CNS: meningitis, encephalitis
Ischemic Stroke
Obstruction of blood flow to the brain caused by a thrombus, embolus, or hypoperfusion –decreased blood volume or heart failure
Decreased blood flow causes ischemia and can cause infarction – death of tissue
Transient Ischemic Attack
Lasting < 1 hour
Focal cerebral ischemia
S&S – weakness, numbness, sudden confusion, loss of balance, or sudden severe headache –resolves within an hour
Thrombotic Stroke
Arterial occlusions caused by a blood clot (thrombi) that develops in the blood vessels inside the brain
Risk factors – increased coagulation or inadequate cerebral perfusion
Develops most often from atherosclerosis
Clot forms over time, 20 -30 years
- can also form quickly from a clot detaching elsewhere in the body and traveling to the cerebral circulation – embolic stroke
Embolic Stroke
Fragments that break from a blood clot (thrombus) formed outside the brain – heart, aorta, common carotid artery
Can also be from fat, air, tumour, bacteria, foreign body
Usually small brain vessels – obstructs at a bifurcation
Hemorrhagic Stroke
-Intracranial aneurysms due to arteriosclerosis, -congenital abnormality, cocaine use, trauma, inflammation.
-Most located at bifurcation or near circle of willis, vertebrobasilar arteries, or carotid arteries
Signs and symptoms:
Arteriovenous Malformation (AVM)
Congenital
Mass of dilated vessels instead of capillary bed
Abnormal structure
Abnormally thin
Complex growth and remodelling patterns
Direct shunting of arterial blood into the venous system
Signs and symptoms:
-Chronic headache
-50% have seizures
Subarachnoid Hemorrhages
Escape of blood from a damaged or injured vessel into the subarachnoid space
Blood can ooze into the subarachnoid space. If vessel tears, blood is pumped into subarachnoid space
Increase in intracranial volume. Leaked blood irritates tissue. Impairs CSF circulation and CSF reabsorption
Similar to primary TBI. Increases in size, compresses and displaces brain tissue causing increased ICP, decreased cerebral blood flow, BBB breakdown, edema, cell death - secondary brain injury occurs.
Mortality 50% in 1 month. Vasospasms in 40-60% of people.
S&S: headache and changes in mental state in early stages. When ruptured: sudden throbbing, explosive headache, visual disturbance, Nausea and vomiting, motor defects, decreased LOC, neck stiffness, blurred vision
Risk factors: intracranial aneurysm, AVM, HTN, family hx, head injury
Outcomes of stroke on LEFT side
-Right sided weakness or paralysis
-Problems with speech (speaking and understanding)
-Visual: cant see right side field of vision in both eyes
-Depression
-Impaired cognition
-Memory issues
Outcomes of stroke on RIGHT side
-Left sided weakness or paralysis
-Denial of paralysis: reduced insight into condition -“left neglect” – lack of response to stimuli on the left side
-Visual: can’t see the left side
-Depth perception
-Recognition of body parts
-Memory problems
-Depression, inappropriate behaviours, impulsivity
Levels of prevention
Primary: education, yearly checkups
Secondary: F.A.S.T.
Tertiary: Ischemic stroke: fibrinolytic
Hemorrhagic stroke: surgery to stop bleed
Migraine
One sided
severe
May have aura (visual, sensory, motor)
Triggers
Can last hours to days
Premonitory phase: Hrs to days before onset. Tiredness, irritability, inability to concentrate, stiff neck
Headache phase: Throbbing, spreading to the entire head. Accompanied by nausea, vomiting, fatigue, and dizziness
Recovery phase: irritability, fatigue and depression - lasts hours to days
Cluster headache
-Occur in the autonomic division of cranial nerve 5: trigeminal nerve
-One side of head
-Mostly men 20-50 yrs
-Severe, stabbing, throbbing
-Occurs in clusters: up to 8X day, lasting minutes to hours
-Unilateral trigeminal distribution of severe pain
-Tearing, drooping of eyelid
-Consider location of trigeminal nerve to remember symptoms
Tension headache
-Most common
-Teenage yrs average age onset
-Gradual onset of a tight band around the head
-May last several hours or several days
Meningitis
-Inflammation of the meninges of the brain or spinal cord
-Can involve all 3 membranes (dura, arachnoid, pia)
-Tissues swell causing increased ICP and reduced cerebral blood flow
-Mortality in untreated meningitis is 70-100%
-Good prognosis if treated
-Infants and adults are more at risk
Types of meningitis
bacterial
viral
fungal
parasite
(only focusing on bacterial and viral)
Meningitis onset categories
Acute: < 1 day
Subacute: 1-7 days
Chronic: > 7 days
Bacterial Meningitis
Rapid onset
Young individuals (15-24) and those over 40 at risk
Organisms vary
Risk factors:
Lumbar puncture, craniotomy
Skull fracture, trauma
Secondary to respiratory/ear infection
Overcrowded living conditions
Aseptic Viral Meningitis
Slow onset
Self-limiting: managed with anti-virals
Can’t kill
Direct contact or secondary infection
Causes:
Enteroviral virus
Mumps
Herpes simplex 2
Epstein Barr Virus
Influenza type A and B
Risk factors: infants, children, older adults, malnourished, immunosuppression, CNS trauma
Signs and symptoms:
Neuro signs (changes in LOC, focal deficits, seizures), infectious signs (fever, tachycardia, chills), Clinical signs (stiff neck, headache, photophobia, petechia rash, kernig’s sign, Brudzinski’s sign)
Brudzinski’s sign
Severe neck stiffness causes hips and knees to flex when the neck is flexed
Kernig’s sign
Severe stiffness of hamstrings cause an inability to straighten the leg when the hip is flexed to 90 degrees
Meningitis complications
Hearing loss - most common
Seizures
Increased ICP
Cerebral edema
hydrocephalus (accumulation of CSF)
Altered mental status
Cerebrovascular damage
Intellectual deficit
Encephalitis
Inflammation of the parenchyma of the brain or spinal cord due to infection (IN the brain, whereas meningitis is not in brain)
Similar to meningitis but patients are usually sicker with encephalitis
Virus or bacteria invades the brain tissue and causes degeneration of the neurons
Caused by bacteria, virus, fungi, or parasites
Arteriovenous Malformation (AVM)
-Congenital vascular lesion
-Mass of dilated vessels instead of capillary bed
-Abnormally thin
-Complex growth and remodelling patterns
-If large enough, can shunt blood to deprive surrounding tissues
S&S: chronic headache. 50% have seizures
