Stroke Flashcards
Stroke definition
a sudden onset of neurological dysfunction due to cerebrovascular abnormality that results in an area of brain infarction
What is the most common form of stoke?
Ischemic
Are males or females more affected by stroke?
Males
What are the risk factors of a stroke?
-Hypertension
-Diabetes
-Hypercholesterolemia
-Smoking
-Heavy alcohol consumption
-Oral contraceptive use
What are the two categories of stroke?
-Ischemic: embolic and thrombotic
-Hemorrhagic
What are the signs and symptoms of a stroke?
-Numbness or weakness of the face, arm or leg (contralateral)
-Confusion, trouble speaking or understanding others
-Visual disturbances in one or both eyes
-Dizziness, loss of balance, and difficulty with walking
-Severe headache
What happens during an ischemic stroke?
-A sudden occlusion of the cerebral artery- thrombus or emboli
-Produces recognizable symptoms
Thrombotic strokes are associated with:
Atherosclerosis and coagulopathies
How long does it take for symptoms to evolve in thrombotic strokes?
usually several minutes and may be preceded by trans ischemic attacks
What arteries do thrombotic strokes usually affect?
-Internal carotid artery
-Middle cerebral artery
-Basilar artery
What are most ischemic strokes caused by?
Lipohyalinosis
What are the most common affected vessels of ischemic stroke?
-Lenticulostriate arteries
-Small branches of the middle cerebral, basilar, and posterior arteries
Occlusions of the arteries affected by ischemic stroke can cause:
lacunar infarctions
What are the common affected areas of lacunar infarctions:
IMPORTANT
-Thalamus (pure sensory stroke)
-Internal capsule or pons ( pure motor stroke)
-Caudate
-Putame
-Cerebellum
What are embolic strokes usually associated with:
cardiac dysfunction or dysrhythmias (a.fib)
What arteries are affected by embolic strokes:
-Middle cerebral artery
-Basilar artery
-Posterior cerebral arteries
Are the signs and symptoms of hemorrhagic stroke more or less predictable than in ischemic stroke?
LESS
Do hemorrhagic strokes affect areas closer to or farther away from the hemorrhage?
Farther away
What do hemorrhagic strokes do to the brain?
-Increased intracranial pressure
-Edema
-Compression
-Rupture of blood into the ventricles of the subarachnoid space
What are the 3 types of hemorrhagic strokes?
-Epidural hemorrhage
-Subdural hematomas
-Subarachnoid hemorrhage
What causes an epidural hemorrhage and where is it most common?
Usually secondary to head trauma and damage to an artery
Most common in the middle meningeal artery
What causes a subdural hematoma?
Rupture of small cortical veins, caused by small trauma in the elderly
What causes subarachnoid hemorrhage?
Results from head trauma.
Extension of blood from another compartment into the subarachnoid space.
Rupture of an arterial aneurysm (Berry Aneurism)
Hemorrhage within the brain parenchyma usually occurs:
secondary to severe chronic hypertension
Where do hemorrhages occur within the brain parenchyma:
most occur in basal ganglia or thalamus and less common in the cerebellum
Other causes of intraparenchymal hemorrhage:
-vascular malformations
-glioblastoma multiforme
-platelet and coagulation disorders
-drugs (amphetamines and cocaine)
-Cerebral amyloid angiopathy (Alzheimer’s)
What are the normal glutamate metabolism steps:
- Glutamate is released at excitatory synapses
- Taken up by glia cells and converted to glutamine by glutamine synthetase (ATP)
- Glutamine release and uptake by neurons (Na+ reuptake systems)
- Neurons store glutamine in vesicles for subsequent release
What are the steps of cell death-excitotoxicity
- Glia cell ischemia causes low O2 glucose (ATP)
- Affects transmembrane Na+ gradient causes increased intracellular Na
3.Decreased glutamate uptake and conversion to glutamine
4. Increased extracellular levels of glutamate
5. Overstimulation of glutamate receptors leads to cell death
Motor deficits due to stroke
-Initially flaccidity or paralysis then spasticity
-Active/passive range of motion exercises
-Intensive rehabilitation
Sensory disturbances due to stroke
-Occur in the same locations as motor paralysis
-Involve neglect or visual impairment
-Assess fall risk
-Adaptive behaviours and techniques commonly needed to prevent injury
Two types of language deficits that can occur due to stroke
Broca aphasia and Wernicke aphasia
What area of the brain is damaged causing language deficits?
dominant cerebral hemisphere
Broca aphasia definition
verbal motor/expressive. It consists of poor articulation and sparse vocabulary
Wernicke aphasia
sensory, acoustic, and receptive. Characterized by impaired auditory comprehension and speech that is fluent by does not make sense.
