Cerebrovascular Accident

Clients with Cerebrovascular Disease Cerebrovascular Accident (CVA)  Commonly known as stroke or brain attack  A condition in which neurologic deficits result from decreased blood flow to localized area of the brain  Neurologic deficits determined by the area of brain involved, size of affected area, length of time blood flow is decreased or stopped  Major loss of blood supply to brain can cause severe disability or death; if short or small area involved client may not be aware  Pathophysiology  Characterized by gradual, rapid onset of neurologic deficits due to compromised cerebral blood flow  Blood flow and oxygenation of cerebral neurons decreased or interrupted; changes occur in 4 – 5 minutes  Cells swell and cerebral blood vessels swell decreasing blood flow; vasospasm and increased blood viscosity further impede blood flow  Penumbra is a central core of dead or dying cells surrounded by band of minimally perfused cells  Cells of the penumbra receives marginal blood flow and their metabolic activities are impaired  These cells may survive if adequate circulation is reestablished  Neurologic deficits occur on opposite side where stroke occurred in brain: contralateral deficit  Causes  Ischemia  Occurs when the blood supply to a part of the brain is interrupted or totally occluded  Commonly due to thrombosis or embolism • Thrombotic (large vessel) stroke o The most common cause of ischemic stroke o Atherosclerosis is the primary cause o Fatty materials deposit on large vessel walls (especially at arterial bifurcations) and eventually these plaques causes stenosis of the artery o Blood swirls around the irregular surface of the plaques causing platelets to adhere and the vessel becomes obstructed o These causes infarcts usually affecting the cortex o Most common type of stroke in people with diabetes

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Lacunar (small vessel) stroke o Endothelium of smaller vessel is primarily affected due to hypertension o Leading to arteriosclerosis and stenosis o Infarcts are usually located in the deeper, noncortical parts of the brain or in the brainstem Embolic stroke o Occlusion of a cerebral artery by an embolus or blood clot o Embolus forms outside the brain, detaches and travels through the cerebral circulation where it lodges and causes an obstruction o Chronic atrial fibrillation is associated with a high incidence o Other sources of emboli include tumor, fat, bacteria and air o Usually has a sudden onset with immediate maximum deficit

Hemorrhage  Results from rupture of a cerebral vessel causing bleeding into the brain tissues  Bleeding results with edema, compression of the brain contents or spasm of the adjacent blood vessels  Often secondary to hypertension and most common after age 50  Other factors includes ruptured intracranial aneurysms, trauma, erosion of blood vessels by tumors, arteriovenous malformations, anticoagulant therapy, blood disorders  Usually produce extensive residual functional loss and slowest recovery  Risk factors  Hypertension  Diabetes mellitus  Atherosclerosis  Substance abuse including alcohol, nicotine, heroin, amphetamines, cocaine  Obesity, sedentary life-style, hyperlipidemia, atrial fibrillation, cardiac disease, cigarette smoking, previous transient ischemic attacks  Women: oral contraceptive use, pregnancy, menopause  Clinical manifestations  Stroke manifestations can be correlated with the cause and with the area of the brain in which perfusion is affected  Manifestations of thrombotic stroke develop over minutes to hours to days (slow onset is related to increasing size of the thrombus) 

Embolic strokes occur suddenly and without warning Hemorrhagic stroke occurs rapidly with manifestations developing over minutes to hours  General findings unrelated to specific vessel sites includes headache, vomiting, seizures and changes in mental status  Early warnings of impending ischemic stroke includes  Transient hemiparesis  Loss of speech  Hemisensory loss  Specific deficits after stroke  Motor deficits  Affects connections involving motor areas of cerebral cortex, basal ganglia, cerebellum, peripheral nerves  Produce effects in contralateral side ranging from mild weakness to severe limitation  Hemiplegia (paralysis of half of body)  Hemiparesis (weakness of half of body)  Apraxia (inability to perform a previously learned skilled task in the absence of paralysis) • Able to conceptualize the content of the message to send to muscles but motor patterns necessary to convey the impulse cannot be reconstructed • Instructions do not reach the limb from the brain and desired action cannot happen • E.g. dressing and bathing  Flaccidity (absence of muscle tone or hypotonia)  Spasticity (increased muscle tone usually with some degree of weakness)  Affected arm and leg are initially flaccid and become spastic in 6 – 8 weeks, causes characteristic body positioning • When voluntary muscle control is lost, strong flexor muscles overbalance the extensors • Imbalance can cause serious contractures o Adduction of shoulder o Pronation of forearm o Flexion of fingers o Extension of hip and knee o Foot drop, outward rotation of leg, with dependent edema  Muscles of the thorax and abdomen are usually not affected because they are innervated from both cerebral hemispheres  Communication disorders  

Usually result of stroke affecting dominant hemisphere (left hemisphere dominant in 95% right-handed persons; 70% lefthanded persons)  Aphasia (deficit in the ability to communicate or inability to use or understand language) • Involve any or all aspects of communication including speaking, reading, writing and understanding spoken language • Wernicke’s aphasia o Receptive, sensory or fluent aphasia o Sensory speech problem in which one cannot understand spoken or written word o Speech may be fluent but with inappropriate content o Result of infarction in the temporal lobe • Broca’s aphasia o Expressive, motor or nonfluent aphasia o Motor speech problem in which client understands what is said but can only respond verbally in short phases or inability to combine sounds into appropriate words and syllables o Ability to write, make signs or speak is lost o Result of infarction in the frontal lobe • Mixed or global aphasia o Affects both speech comprehension and speech production o Can be so extensive that neither expressive nor receptive language abilities are retained  Dysarthria (imperfect articulation that causes difficulty in speaking) • Client understands language but has difficulty pronouncing words • No disturbance is evident in grammar and sentence construction unlike in aphasia • Caused by cranial nerve dysfunction resulting with weakness or paralysis of the muscles of the lips, tongue and larynx • Often manifested with difficulty chewing and swallowing (dysphagia) because of poor muscle control  Sensory-perceptual deficits  Visual changes • Parietal and temporal lobe strokes may cause visual acuity impairment 

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Depth perception and visual perception of horizontal and vertical plane may also be impaired • Diplopia (double vision) and ptosis (drooping of eyelids) are also common  Homonymous hemianopia • Visual loss in the same half of the visual field of each eye • Client may see clearly on one side of the midline but see nothing on the other side  Agnosia (inability to recognize one or more subjects that were previously familiar through the senses) • May be visual, tactile or auditory • Client with visual agnosia sees objects but is unable to recognize or attach meaning to them • Disorientation is common due to inability to recognize environmental cues, familiar faces or symbols  Hemisensory loss (loss of sensation on one side of the body) • Paresthesia is common • Proprioception (ability to perceive the relationship of body parts to the external environment) is impaired  Unilateral neglect (inability to respond to stimulus on the contralateral side of the cerebral infarct) • Attention disorder in which client ignores affected part of body • Client cannot integrate or use perceptions from affected side of body or from environment on affected side  Elimination disorders  Partial loss of sensation that triggers bladder and bowel elimination • Urinary frequency, urgency and incontinence are common  Bowel elimination changes result from LOC changes, immobility, dehydration  May also relate to cognitive deficits  Cognitive and behavioral changes  Ranges from mild confusion to coma  May result from actual tissue damage from stroke, cerebral edema, or increased intracranial pressure  May exhibit • Emotional lability: laughing or crying inappropriately • Loss of self-control (i.e. swearing, refusing to cooperate) • Decreased tolerance for stress (anger, depression)

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Intellectual changes: memory loss, decreased attention span, poor judgment, inability to think abstractly

 Diagnostic tests  CT scan without contrast: determine hemorrhage, tumors, aneurysms, ischemia, edema, tissue necrosis, shifting in intracranial contents  Arteriography of cerebral vessels: reveals abnormal vessel structures, vasospasm, stenosis of arteries  MRI: detect shifting of brain tissues resulting from hemorrhage or edema  Positron emission tomography (PET), single-photon emission computed tomography (SPECT): examine cerebral blood flow distribution and metabolic activity of brain  Management and Nursing care  Medical management is directed at early diagnosis and early identification  Maintain cerebral oxygenation and cerebral blood flow  Maintain patent airway and turn patient to side if unconscious  Elevate head and neck should not be flexed  Hypertension may be reduced with vasodilators and calcium channel blockers  Thrombolytic agents are given to dissolve the clot • Intracerebral hemorrhage should be ruled out first • Must be given within 3 hours of onset of manifestations • E.g. streptokinase, urokinase and tissue plasminogen activator (alteplase)  Antiplatelet and anticoagulants are given to prevent clot formation • Heparin and warfarin • Aspirin, clopidogrel (Plavix), ticlodipine (Ticlid) or dipyridamole (Persantine)  Corticosteroids to treat cerebral edema, diuretics to reduce increased intracranial pressure and anticonvulsants to prevent seizures  Hyperthermia is treated immediately • Temperature elevations lead to increased cerebral metabolic needs which in turn cause cerebral edema which can lead to further ischemia • Antipyretics are used • Causing the client to shiver should be avoided  Aspiration precaution is done

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Oral food and fluids are generally withheld for 24-48 hours • Tube feeding is done  Prevent valsalva maneuver • Maneuver increases ICP • Straining stool, excessive coughing, vomiting, lifting and use of the arms to change position should be avoided • Mild laxatives and stool softeners are often prescribed  Compensate for perceptual difficulties  For clients with visual deficits • Approach the client from the unaffected side • Place articles on the unaffected side • Teach client to turn the head from side to side to see entire visual field • Eye patch over one eye in clients with diplopia is helpful  Assist and support client • Prevent injury and falls • Promote self-care and prevent skin breakdown  Prevent complications  Physical therapy to prevent contractures and to improve muscle strength and coordination • Encourage bed exercise • Facilitate ROM and isometric exercises o Do not force extremities beyond the point of initiating pain and spasm o Always support the joint and move the extremity smoothly • Allow client to work on balance and proprioception skills  Occupational therapy • Help client relearn ADLs and to use assistive devices that promote independence • Teach client how to use the wheelchair and promote walking with assitance  Speech therapy for clients with impaired verbal communication • Most aphasic clients regain some speech through spontaneous recovery or speech therapy • Speech therapy should be started early • For aphasic clients o Speak at a slower rate

o Give client time to respond o Do not shout and always put client at ease o Repeat simple directions until they are understood o Give client practice in repeating words after you o The family should not do all the talking for the client  Provide emotional support and health education to the client and family