Stroke Lecture 1st Lecture Flashcards
What are the 2 types of stroke?
Ischemic - blood clot blocks flow
Hemorrhagic - Ruptured blood vessels cause leakage
How long do neurologic deficits need to last for it to be classified as a stroke?
24 hours
How long do spontaneous recovery last?
about 3 weeks
Name the 3 etiological categories for a stroke?
Thrombosis - formation of clot within brain
Embolus - bits of matter formed elsewhere that break loose and travel to the brain
Hemorrhage
Where does stroke rank on cause of long-term disability among adults in the US?
1st
Which type of stroke accounts for the most deaths?
Hemorrhagic (37-38%)
Ischemic (8-12%)
Name a major contributor to cerebrovascular disease.
Atherosclerosis
What are the most common sites for atherosclerotic plaques to form?
Origin of common carotid or transition to middle cerebral artery
Main bifurcation of the middle cerebral artery
Junction of the vertebral artery with basilar artery
What are the 3 types of hemorrhagic stroke?
Intracerebral Hemorrhage (rupture of cerebral vessel, usually occurs in small blood vessels) Subarachnoid hemorrhage (Typically from saccular or berry aneurysm affecting large blood vessels, congentinal, linked to chronic hypertension) Arteriovenous Malformation - Congenital defect (tangle of arteries or veins failure to develop (agenesis)
Name some major risk factors for stroke.
Hypertension (BP of 140/90 or higher)
Heart disease
Disorders of heart rhythm
Diabetes Mellitus
Name some other risk factors not major but important to notice for stroke?
High LDL and low HDL
Cardiac disorders (heart valve disease, endocarditis, or CABG increase embolic stroke)
A-Fib (5 fold increase in risk)
End stage renal disease
How does sleep apnea increase the risk of stroke?
Prevents restful sleep and is associated with HTN, arrhythmia, stroke and heart failure
What are some risk factors for women specifically for having a stroke?
Early menopause (before 42)
Use of estrogen plus progestin (increase ischemic stroke)
Pregnancy, birth and the 1st 6 weeks post-artum
Name some modifiable risk factors for stroke prevention?
Smoking
Physical activity
Obesity
Diet
What are the early warning signs for a stroke?
FAST Face drooping Arm Weakness Speech Difficulty Time to Call 911
How soon does a tPA need to be administered for an ischemic stroke?
Within 3 hours of onset of symptoms
What is the ischemic cascade?
- Release of excess neurotransmitters produces progressive disturbance of energy metabolism and anoxic depolarization
- Results in inability of brain cells to produce ATP (energy)
- Followed by excess influx of Ca ions and pump failure of the neuronal membrane
- Excess Ca reacts with intracellular phospholipids to form free radicals
- Ca influx also stimulates the release of NO2 and cytokines, further damaging brain cells
Describe the process of edema forming after ischemic strokes.
- Accumulation of fluids within brain begin within minutes of the insult (reaches maximum by 3-4 days)
- Result of tissue necrosis and widespread rupture of cell membranes with movement of fluid from the blood into brain tissues
- Swelling gradually subsides and disappears by 2-3 weeks
What are some clinical signs of elevating intracranial pressures?
Decreasing level of consciousness Increased HR Irregular respiration Vomiting Unreacting pupils Papilledema (swelling of optic disk, flickering, blurred or double vision)
Describe a TIA
Temporary interruption of blood supply to brain
Symptoms last no longer than 24 hours
No evidence of residual brain damage
Is a precurser to susceptibility for both cerebral infarction and myocardial infarction
Name some other management categories.
Major Stroke - presence of stable, usually severe, impairments
Deteriorating Stroke - Patients whose neurological status deteriorates after admission to the hospital
Young Stroke - Stroke affecting a person younger than 45
How much of a vessel needs to be restricted from atherosclerosis before changes are generally seen?
80% restricted
Name some factors that contribute to the severity and symptoms of a stroke.
Location of the ischemic process
Size of the ischemic area
Nature of the functions of the structures involved
Availability of collateral blood flow (rapid occlusion vs slow occlusion)
What does the anterior cerebral artery supply?
Medial aspect of cerebral hemisphere (frontal and parietal lobes), subcortical structures, including basal ganglia, anterior fornix, and anterior four-fifths of the corpus callosum
What are the most common characteristics of ACA syndrome?
Contralateral hemiparesis and sensory loss with greater involvement of lower extremity than the upper extremity
Which artery is the most common site of occlusion for a stroke?
Middle cerebral artery
What does the middle cerebral artery supply?
Entire lateral aspect of the cerebral hemisphere (frontal, temporal, and parietal lobes), subcortical structures such as internal capsule, corona radiate, globus pallidus, caudate nucleus, and the putamen
What are some common characteristics of MCA syndrome?
Contralateral hemiparesis
Sensory Loss of the face and UE
Face and UE more involved than LE
Lesions of the parieto-occiptal cortex of dominant hemisphere produce aphasia
Lesions of right parietal lobe of the non-dominant produce perceptual deficits (neglect, anosognosia, apraxia, spatial disorganization
Homonymous Hemianopsia
What is common with Internal Carotid Artery Syndrome?
Extensive cerebral infarction in areas of MCA and ACA
Significant edema forms and cause uncal herniation
Life-threatening situation
What does the posterior cerebral artery supply?
Occipital lobe and medial and inferior temporal lobe
Upper brainstem, midbrain, and posterior diencephalon, including most of the thalamus
What does occlusion of the thalamic branches of the posterior erebral artery cause?
Contralateral sensory loss (hemianestheisa)
Central post-stroke (thalamic) pain
What does occipital infarction produce?
Homonymous hemianopsia,
visual agnoisa
prospagnosia,
If bilateral cortical blindness
What does temporal lobe ischemia result in?
Amnesia
What happens if you have a stroke in the cerebral peduncle?
produces contralateralhemiplegia
Where is the lesion if there is a loss of vision (homonymous hemianopsia) on the right side?
Left side
contralateral
What is Visual Agnosia?
Loss of the ability to recognize objects, faces, voices, or places
What is Prosopagnosia?
Called “face blindness” an impairment in the recognition of faces
What is a Lacunar Stroke?
Caused by small vessel disease deep in the cerebral white matter
What is NOT seen in a lacunar stroke?
deficits in: consciousness, language, visual fields
Does vertebrobasilar artery syndrome cause contralateral or ipsilateral signs?
Both
some tracts in the brainstem will have crossed and others will not
What are some general signs and symptoms of Verebrobasilar Artery Syndrome?
Numerous cerebellar and cranial nerve abnormalities
Nystagmus, sensory changes or weakness in facial muscles
Vertigo, nausea, vomiting
Ataxia
Describe Locked-in Syndrome.
Occurs with basilar artery thrombosis and bilateral infarction of ventral pons
Sudden onset
Acute hemiparesis rapidly progressing to tetraplegia and lower bulbar paralysis (CN V-XII)
Initially dysarthric and dysphonic but progresses to mutism
Preserved consciousness and sensation
Vertical eye movement remains intact
Which hemisphere is most likely affected if there are speech and language deficits?
DOMINANT (usually left)
What is Aphasia?
General term used to describe an acquired communication disorder
What are the types of aphasia?
Fluent (Wernicke’s/sensory/receptive)
Nonfluent (Broca’s/exrpessive)
Global aphasia
Describe Fluent Aphasia (Wernickes)
Auditory comprehension is impaired (reading and writing usually affected as well)
Difficulty comprehending spoken language
Speech flows smoothly and melody speech is preserved
Usually minimal physical impairment
(can’t understand but can still make words)
Describe Nonfluent aphasia.
Flow of speech is slow and hesitant, vocabulary is limited
Speech production is labored or lost
Comprehension is intact
Pre-motor area of left frontal lobe (often has motor impairments as well)
What is dysarthria?
Volitional and automatic movement of jaw and tongue causing slurred speech
What is dysphagia?
Inability to swallow or difficulty swallowing
-occurs in about 51% of patients
What is Aspiration?
The penetration of food, liquid, saliva, or gastric reflux into the airway
What is it called when a person fills memory gaps with inappropriate words or fabricated stories?
Confabulation
What is perseveration?
It’s continued repetition of words, thoughts or acts not related to current context (get stuck and repeats words or acts)
What are executive functions?
Abilites that enable a person to engage in purposeful behaviors, include volition, planning, purposeful action and effect performance
What is Multi-infarct dementia?
Results from small infarcts of the brain
Scattered areas of brain are invovled
Gradual onset
How is delirium characterized?
Clouding of consciousness or dulling of cognitive processes and impaired alertness
(patient is inattentive, incoherent, and disorganized with fluctuating levels of consciousness)
-Hallucinations and agitation are also common
Describe the Pseudobulbar Affect.
Characterized by emotional outburst or uncontrolled or exaggerated laughing or crying that is inconsistent with mood.
What is apathy?
Shallow effect and blunted emotional responses
-Frequently miscontrued as depression or poor motivation
What is the term for exaggerated feelings of well-being?
Euphoria
When is depression most seen in post-stroke patients?
Seen in lesions in left frontal lobe (acute) and right parietal lobe (sub-acute)
Period of 6 months to 2 years after CVA
Left Hemisphere may experience more frequent and severe depression then right hemisphere
Name some common behavioral differences with left hemisphere lesions.
Difficulties in communication
Cautious, anxious and disorganized
More hesitant when trying new tasks (frequent feedback & support needed)
Tend to be more realistic in their appraisal of their existing problems
Name some common behavioral differences with right hemisphere lesions.
Difficulty with spatial-perceptual tasks
Difficulty grasping whole idea of task
Quick, impulsive
Tend to overestimate abilities while being unaware of deficits
Lack of insight and concreteness impairs ability to participate
Safety can be a big issue due to poor judgement
Often cant attend to visuospatial cues
When are you likely to see visual-perceptual deficits?
Lesions in right parietal cortex
Seen more often with left hemiplegia than right
What are some other complications of stroke?
Seizures (more common in acute)
Bladder and bowel dysfunction (acute)
Cariovascular or pulmonary dysfunction
DVT and pulmonary embolus (complication of immobility)
Osteoporosis and fracture risk (immobility and limited weight bearing)
