Strokes
Causes of a blockage in ischemic strokes
A blood clot either a thrombus or in emboli, or from stenosis of a vessel caused by a buildup of plaque
When maximum neurological deficit from a stroke in evolution has been reached usually by three days the condition is called
A completed a stroke
Client may also experience amaurosis fugax with a TIA
A fleeting blindness of one I described as a shading coming down over vision with the affected eye
Transient ischemic strokes
A mini stroke, is a brief period of localized cerebral ischemia that causes neurological deficit's lasting for less than 24 hours
Contralateral deficit
A stroke in the right hemisphere of the brain is manifested by deficits in the left side of the body and vice versa
Antiplatelet agents often used to treat clients with TIAs or those who had a previous stroke such as
Aspirin, clopidogrel, dipyridamole, ticlopidine
Ischemic thrombotic stroke
Caused by occlusion of a large cerebral vessel by a thrombus
If BP levels greater than 185/110 then
Client cannot be treated with IV TPA
Deficits that occur with TIA
Contralateral numbness or weakness of the leg hand and forearm and corner of the mouth, aphasia visual disturbances
TPA or tissue plasminogen activator
Converts Plasminogen to Plasmin resulting in fibrinolysis of the clot
These drugs have been used to treat cerebral edema but the results are not always positive
Corticosteroids such as prednisones or dexamethasone
In a lumbar puncture test Frank blood may be seen in the CSF if the patient had this type of stroke
Hemorrhagic stroke
Most common cause of a hemorrhagic stroke
Hypertension
Monitor clients body temperature as this may develop
Hyperthermia
Lacunar strokes which are thrombotic stroke affecting the smaller cerebral vessels
Leaves a small cavity or lake in the brain tissue
Hemianopia
Loss of half of the visual field of one or both eyes
If client has increased intracranial pressure hyper all smaller solutions such as these may be administered
Mannitol or diuretics
Sensory perception all deficits in patients who had a stroke
May include deficits in vision, hearing, equilibrium, taste and sense of smell also the ability to perceive vibration pain warmth called and pressure may be impaired
A thrombus
May remain in place and continue to enlarge occluding the lumen of the vessel or it may break off and become an embolus
Warfin sodium
Maybe given orally
Sodium heparin
Maybe given subcutaneously or by continuous IV drip
Lumbar puncture
Maybe performed to obtain CSF if there is no danger of increased intracranial pressure
Hemorrhagic stroke can also occur due to this
Aneurysm that ruptured is releasing blood into the brain
Do not dissolve and existing clot, they prevent further extension of the clot and formation of new clots
Anticoagulants
These are never administered to a client with a hemorrhagic stroke
Anticoagulants
Autoregulation
Allows the brain to maintain a constant blood flow despite changes in systemic blood pressure
Flaccidity
Absence of muscle tone hypotonia
Hemorrhagic stroke most often occurs in these individuals
Assisting increased in systolic and diastolic blood pressure
Most frequent sites of cerebral emboli
At bifurcations of vessels, particularly those of the carotid and middle cerebral artery's
Not effective when systemic blood pressure falls below 50 MMHG or rises above 160 MMHG
Autoregulation
Carotid angioplasty
Balloon catheter inserted through an artery in the clients arm or leg and advanced to the area of the carotid artery he stenosis, a small filter is inserted to catch any clots or pieces of debris that might break loose. Balloon is inflated to widen the artery and a permanent stent is inserted
If increased intracranial pressure causes seizures anticonvulsants may be prescribed such as these
Barbiturates and phenytoin(dilantin)
Reason that strokes lead to loss of sensormotor functions on the side of the body opposite the side of the brain that is damaged
Because the motor pathways cross at the junction of the medulla and spinal cord
Subarachnoid hemorrhage results from
Bleeding into the spaces around the brain
Intracerebral hemorrhage results from
Bleeding within the brain
Proprioception
Body's senses of its position in space this is lost sometimes in a patient has a stroke
Cerebral infarction's visible within 6 to 8 hours post stroke can be seen on this
CT scan
Diagnostic test useful in distinguishing the type of stroke
CT scan
Hemorrhage strokes visible immediately on this
CT scan
Survival of penumbra
Depends on a timely return of adequate circulation
If embolus breaks up into smaller fragments and is absorbed by the body the manifestations will
Disappear in a few hours to a few days
When a completed stroke occurs the brain tissue is
Edamatous and necrotic
Given concurrently with an anticoagulant used to treat thrombotic stroke
Fibrinolytic therapy or TPA
CT scan
First imaging technique used to demonstrate the presence of hemorrhage, tumors, aneurysm, ischemia, Adema and tissue necrosis
To be effective TPA should be given
IV within three hours of the onset of manifestations after CT scan to confirm the occurrence of an ischemic stroke
Apraxia
Inability to carry out some motor pattern
Agnosia
Inability to recognize one or more subjects that were previously familiar
Alterations in mental status and level of consciousness in movement indicate this
Increased intracranial pressure which is the major cause of death in the acute phase of a stroke
Spasticity
Increased muscle tone or hypertonia
Etiology of TIA
Inflammatory artery disorders, sickle cell disease, atherosclerotic changes in cerebral blood glasses, thrombosis, emboli
Anti-thrombotic drugs such as aspirin and dipyridamole
Inhibits platelet face of clot formation so used as a preventative measure for clients at risk for embolic and thrombotic stroke
Most common location of thrombi
Internal carotid artery he, vertebral arteries, and the junction of the vertebral and basilar arteries
Two types of hemorrhagic stroke's
Intracerebral hemorrhage and subarachnoid hemorrhage
TPA will also increase the risk of
Intracranial hemorrhage
Penumbra
Is central core of dead or dying sells surrounded by a band of minimally perfused swells
Risk of strokes
Occur more frequently in man and risk of stroke is greater in women during pregnancy and for six weeks following birth
Manifestations of a hemorrhagic stroke
Occur suddenly and when the affected individual is engaged in some activity
Thrombotic stroke
Occurs rapidly but progresses slowly
Embolic ischemic stroke
Occurs when a blood clot or clump of matter traveling through the cerebral blood vessels become lodged in a vessel that is too narrow to permit further movement
Hemorrhagic stroke
Occurs when a blood vessel breaks open spilling blood into spaces surrounding neurons
Hemorrhagic stroke or intracranial hemorrhage
Occurs when a cerebral blood vessel ruptures
Ischemic strokes
Occurs when the blood supply to a part of the brain is interrupted by a thrombus which is a blood clot or an embolus which is foreign matter traveling through the circulation or stenosis which is narrowing
Thrombotic stroke's most often occur in this population
Older individuals who are resting or sleeping because blood pressure is lower during sleep
Hemiplegia
Paralysis of the left or right half of the body
Surgery such as carotid endarterectomy
Performed at the carotid artery by furcation to remove atherosclerotic plaque
Extracranial-intracranial bypass of the internal carotid, middle cerebral or vertebral arteries
Performed when included or stenotic vessel is not directly accessible. The process reestablish his blood flow to the affected area of the brain
Ischemic strokes
Result from blockage or stenosis of a cerebral artery decreasing blood flow and causing brain infarction
Other factors that cause a hemorrhagic stroke
Rupture of plaque encrusted artery wall, ruptured aneurysm, trauma, erosion of blood vessels by tumors, arteriovenous malformations, anticoagulant therapy and blood disorders
PLAC test
Scans the blood for high levels of lipoprotein associated with phospholipase A2
Stroke may cause partial loss of the
Sensations that trigger bladder illuminations resulting in urinary frequency, urgency or incontinence
One of the main symptoms patients suffer from a hemorrhagic stroke
Severe headache
Characteristics of an EKG and individuals with a stroke
Shortened PR interval, Pete T waves and a D pressed ST segment
Risk factors for stroke
Sleep apnea because it increases blood pressure smoking sickle cell disease and substance abuse
A woman's symptoms when having a stroke
Sudden face and limb pain, sudden nausea and sudden hick ups and sudden shortness of breath, palpitations and generalized weakness
Manifestations of an embolic stroke
Sudden onset and causes immediate deficits
Manifestations of TIA
Sudden onset and often disappear within minutes or hours
When cellular metabolism ceases cells will
Swell as sodium draws water into the cell
Clients may be deemed medically inappropriate for treatment with TPA if
Symptoms are greater than three hours
Thrombotic stroke begins with
TIAA and continues to worsen over 1 to 2 days this condition is called a stroke in evolution
Neglect syndrome
The individual cannot integrate and use perceptions from the affected side of the body and therefore ignores that side
Embolic strokes originate from this
The thrombus in the left chambers of the heart formed during atrial fib relation
Even if embolus is absorbed
The vessel wall where the embolus lodges maybe weekend increasing the potential for cerebral hemorrhage
In a lumbar puncture test the CSF pressure maybe elevated if patient had this type of stroke
Thrombotic stroke
Warning signs of an ischemic thrombotic stroke
Tia
A platelet aggregation inhibitor that reduces thrombotic stroke risk
Ticlopidine
Large vessel disease caused by plaque
Usually a result of thrombi
Manifestation of hemorrhagic stroke depend on the location but include
Vomiting headache seizures, hemiplegia and loss of consciousness
Most commonly use anticoagulant drugs therapy for ischemic stroke
Warfarin sodium, heparin and enoxaparin
Hemiparesis
Weakness of the left or right half of the body
Hypertension
When increased systemic pressure causes an increase in cerebral blood flow which results in over distention of cerebral vessels
Cellular metabolism
Will cease when blood flow to cerebral neurons is interrupted and glucose glycogen and ATP are depleted and sodium potassium pump fails
Typical clients of an embolic ischemic stroke
Younger clients and it occurs when the client is awake and active
Small vessel disease caused by plaque also called lacunar infarct's
very small infarcts in the deep non-cortical areas of the brain or brain stem