Stroke (Ischemic) Flashcards
Transient Ischemic Attack is a temporary focal loss of neurological function last less than
24 hours
Carotid arteries involvement
Transient loss of vision on one eye
Hemiparesis
Inability to speak
Vertebrobasilar arteries involvement
Tinnitus
Vertigo and blurring vision
Hemiparesis
Definition of Ischemia
a reduction in blood flow that can last for several seconds to a
few minutes
Infarction
If there is cessation of flow for than a few minutes, infarction of
brain tissue occurs
Pathophysiology in Ischemic Stroke
Reduce blood flow in the arteries can be thrombosis or embolism
Reduction in blood flow deprives the cells of O2 and glucose
Lack of energy causes membrane dysfunction and entry of ions
Edema of cells occurs, followed by death of cells
Vascular changes aggravate edema
Causes of thrombosis
Arterial disease
Atherosclerosis, arteritis
Blood disorders
Thrombocytosis, polycythemia
Definition of Embolism
Thrombosis occurs in other parts of the body
A part of the thrombus detaches and travel to the brain through the
arteries
Causes of embolism
Embolic strokes are usually caused by a blood clot that forms elsewhere
in the body (embolus) and travels through the bloodstream to the brain.
Embolic strokes often result from heart disease or heart surgery and
occur rapidly and without any warning signs.
About 15% of embolic
strokes occur in people with atrial fibrillation, a type of abnormal heart
rhythm in which the upper chambers of the heart do not beat effectively
Clinical presentation of Ischemic stroke
Transient Ischemic Attacks (TIA)
Any neurological dysfunction that lasts for a few seconds to a
few minutes
Should recover within 24 hours
Pathogenesis of TIA
Low-flow states in vascular obstruction
Small emboli which get dissolved later
Recognition of TIA helps in prevention of major stroke
Established stroke
Infarction of brain tissue occurs due lack of blood. Deficit is permanent
Increasing obstruction may involve a proximal branch of the artery and increase the deficit: stroke-in-evolution
Edema occurs in surrounding tissue
Resolution of edema after the acute stage may restore some
function
Clinical presentation of Ischemic stroke (site)
Depend on the site of obstruction
the artery or its branch involved
the brain area supplied by the artery
Depend on the state of circulation
Presence of good arteries in the adjacent area may provide collateral
circulation
Also on the state of general circulation
Onset
Embolism - sudden, during exertion
Thrombosis - slow, during rest time
Anterior Cerebral Artery
Involvement of Superficial branches signs and symptoms
Prefrontal lobe: confusion, disorientation
Medial surface: paralysis and sensory loss in the opposite leg
Apraxia, abulia and urinary incontinence in bilateral lesions
Anterior Cerebral Artery
Involvement of Deep Branches
Obstruction is well tolerated because of collateral flow
Middle Cerebral Artery
Involvement Deep branches
Corticospinal fibers in internal
capsule - paralysis of opposite side
Middle Cerebral Artery
Involvement of Superficial
branches
Superior division:
Superior division: paralysis of face
and hand, conjugate gaze paralysis,
motor aphasia
Middle Cerebral Artery
Involvement of Superficial
branches
Inferior division:
Inferior division: conduction or
sensory aphasia, construction or
dressing apraxia
Vertebro-basilar territory
Presence of cerebellar symptoms
What are the cerebellar sx?
Presence of brain lesion
What are the brain lesion sx?
Presence of cerebellar symptoms
Ataxia, Intention tremor, In-coordination
Presence of brain lesion
Crossed paralysis and sensory loss
Posterior cerebral artery
Superficial branches
Deep branches
Visual loss, memory loss, agraphia
Thalamic syndromes
Ipsilateral lesion
Cerebellar ataxia
Wide-based, staggering unsteady gait
Vermis lesions produce truncal ataxia
Intention tremor
Incoordination of arm and leg on voluntary movement
Worse when approaching target, diminishes with rest
Finger-nose test, heel-shin test
Dysmetria
Error in judging distance resulting in overshooting
May be accompanied by tremor
Rebound phenomenon
Difficulty in stopping the movement when resistance is withdrawn suddenly
Dysdiadochokinesia
Inability to perform rapid alternating opposite movements
Pronation-supination, ankle flexion-extension
Decomposition of movements
Inability to perform actions that involve more than one joint
simultaneously
Movement are broken into many components, one joint at a
time
Robotic movement
Nystagmus
due to incoordination of extraocular muscles
Scanning speech
Words are broken into many component sounds
‘Staccato’ speech
Hypotonia
Decreased muscle tone and tendon reflexes
Asthenia
Muscles affected are weaker and tire more easily than normal muscles
Treatment for Ischemic stroke
Clot busters
IV tissue Plasminogen
Activator (tPA)
Preventive Treatment for Ischemic stroke
Anticoagulants/Antiplatelets
Antiplatelet: aspirin
Anticoagulants: warfarin
Carotid Endarterectomy
-Surgically remove plaque
Angioplasty/Stents
- Use balloon angioplasty
- Implant stents reduce fatty buildup
Warfarin Counseling
blood thinner
Prevent formational of blood clots
Treatment duration varies
Modification diet: Be consistent, avoid sudden reduction
of Vit K in diet
Need monitor INR and make sure within therapeutic
range 2-3
Monitor for side effects
Special precautions
