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Download Courtney Wilson, 2012. Transient Ischemic Attack.
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Microsoft clip art Transient Ischemic Attack Courtney Wilson, BSN, RN-C MSN 621 - 2012 AT THE COMPLETION OF THIS TUTORIAL THE LEARNER WILL: 1. Identify the pathophysiology of a transient ischemic attack (TIA). 2. Identify the clinical implications of a TIA. 3. Identify TIA diagnostic tools. 4. Identify medical treatments for a TIA. 5. Identify the risk factors for a TIA. 6. Identify measures to prevent a TIA. Microsoft clip art WHAT TO EXPECT You will be presented material about TIAs and given an interactive quiz at the end of each section. Rationales for answers will be provided. At the end of the tutorial a case study is presented, allowing you to apply your knowledge of TIAs to clinical practice. “HOVER AND DISCOVER.” When you see words underlined in TEAL, hover over them to receive additional information on the subject. Please utilize the provided hyperlinks. Double click on the underlined websites in TEAL to access them directly. ENJOY AND HAVE FUN! A TIA IS A transient cerebral blood flow disruption which affects a focal portion of the brain, causing temporary ischemia without acute infarction. A transient ischemia attack of the brain causing neurological deficits which last for less than 24 hours; most often less than 1 to 2 hours. TIA symptoms are RAPID in onset! Caused by atherosclerotic disease of the cerebral vessels and emboli that temporarily disturb blood flow to a portion of the brain. This blockage resolves on its own before permanent neurological damage occurs. Clot formation may result from… (Porth & Matfin, 2009) Hypercoagulability Vessel spasm Disturbed blood flow A TIA IS WARNING STROKE Microsoft clip art Known as a “warning” or “mini” stroke. 4 to 8% of patients are at risk of having a stroke within 1 month of having a TIA! (American Stroke Association, 2012) Also described as a “zone of penumbra without central infarction.” (Porth, 2009) Penumbra means “halo.” During the stroke process there is usually a central core or “zone” of ischemic cells. This area is surrounded by an ischemic band or area of poorly perfused cells called the PENUMBRA. There is NO cell infarction that occurs during a TIA! Clot or plaque in the cerebral vessel Focal ischemic area in the brain “Zone” of ischemic cells Penumbra surrounds this area A TIA IS Brain cells of the Penumbra receive collateral blood supply from nearby vessels. The “support” vessels anastomose with branches of the occluded vessel to provide supplemental perfusion. The ischemic area of the brain experiences temporary ‘electrical failure’ during the TIA, causing neurological deficits. Because perfusion is quickly restored, the structure of the brain cell is maintained and permanent sequelle do not occur. Ischemic area Note the dark grey area surrounding the light grey ischemic cells. This is the PENUMBRA. Stroke Center (n.d.) Used by permission. A TIA IS A type of “brain attack” where the penumbra cells SURVIVE! Cerebral vessel survival depends on successful TIMELY return of adequate circulation to the ischemic area. Remember: TIA = ZONE OF PENUMBRA WITHOUT CENTRAL INFARCTION. Microsoft clip art REVIEW QUESTION Microsoft clip art A TIA is a ___________blockage (clot) that occurs in a focal part of the brain. permanent partial transient FALSE FALSE TRUE TIA symptoms resolve once the blood flow returns to the cerebral artery that is affected. The blockage is complete, but does not remain long enough to cause permanent brain damage. TIA symptoms “come and go”. They resolve once blood flow is restored to the area of the brain affected. REVIEW QUESTION Microsoft clip art Focal ischemic cerebral neurological deficits (TIAs) usually last less than ______. 24 – 48 hrs FALSE Not quite, this is a little too long. Symptoms last less than 24 hrs. 1 week FALSE This is too long for TIA symptoms. Stroke symptoms may last this long. 1 – 2hrs TRUE TIA symptoms last less than 24hrs, usually less than 1 to 2 hrs. CLINICAL IMPLICATIONS OF A TIA Symptoms of a TIA are EXACTLY the same as for a STROKE! Is considered a critical situation! The specific manifestations of a TIA are determined by… The affected cerebral artery. The area of brain tissue supplied by that vessel. The adequacy of the collateral circulation. (Porth, 2009) TIA SYMPTOMS = AN EMERGENCY! = Microsoft clip art Microsoft clip art CLINICAL IMPLICATIONS OF A TIA Symptoms of a TIA are always sudden in onset, focal and usually unilateral (one-sided). (Porth, 2009) TIA symptoms (Porth, 2009) Weakness to the face, arm, leg. (Most common) Microsoft clip art Unilateral Numbness. Parasthesia Confusion, trouble speaking or understanding. Aphasia ??? Dysarthria Microsoft clip art CLINICAL IMPLICATIONS OF A TIA TIA Symptoms… (Porth, 2009) Trouble seeing in one or both eyes. Amaurosis fugax Hemianopia Microsoft clip art Trouble walking, dizziness, loss of balance or coordination. Ataxia Severe headache with no known cause. Cephalgia Microsoft clip art REVIEW QUESTION Microsoft clip art The most common manifestation of a TIA is______. This symptoms usually presents unilaterally. Dysarthria Weakness Hemanopia FALSE TRUE FALSE Sorry, this is not the most common TIA symptom. It means to have slurred speech. Unilateral weakness to the face & arm, and sometimes leg is the most common TIA symptom. Good try, but this is not the most common symptom of a TIA. It means to have lost ½ of your visual field. REVIEW QUESTION Microsoft clip art The manifestations of a TIA are _________ in onset and usually ___________ in presentation. Progressive/ Bilateral FALSE Sorry, TIA symptoms are rapid in onset and usually affect only one side of the body. This symptom would require additional testing. Sudden/ Unilateral TRUE This is correct! TIA symptoms due occur suddenly and usually affect one side if the body. Slow/ generalized FALSE Not quite, remember that TIA symptoms occur rapidly and are unilateral in nature. DIAGNOSING A TIA The diagnostic evaluation should aim to… Determine the presence of hemorrhage or ischemia Identify the stroke or TIA mechanism (cause) Characterize the severity of the clinical deficits Unmask the presence of risk factors. Microsoft clip art (Porth, 2009) DIAGNOSING A TIA 1. Complete History Documentation of previous TIAs or strokes. The time of onset, pattern and rapidity of system progression. Specific focal systems. (Porth, 2009) Microsoft clip art 2. Physical and neurological exam. National Institute of Health neurological exam NIH Stroke Scale (NIH) (Double click above to check it out!) http://www.ninds.nih.gov/doctors/NIH_Stroke_Scale.pdf DIAGNOSING A TIA 3. Imaging Studies. BRAIN IMAGING – document the brain infarction. Microsoft clip art CT Scan of the brain – Preferred imaging in an emergent/acute setting to rapidly rule out a cerebral hemorrhage diagnosis. CAUTION: THE TIA PATIENT WILL HAVE A NEGATIVE CT SCAN OF THE HEAD! Magnetic Resonance Imaging (MRI) of the brain – Preferred imaging for ischemic lesions of the brain. DIAGNOSING A TIA VASCULAR IMAGING – identifies the anatomy and pathologic processes of the related blood vessels. (Porth 2009) CT Angiography (CTA): Magnetic Resonance Angiography (MRA): Catheter based “conventional” angiography : Microsoft clip art Ultrasonography : Duplex Ultrasonography: assessment of the carotid bifurcation. Transcranial Doppler: assessment of the flow velocities in the cerebral circulation. ???? ???? CASE STUDY Microsoft clip art Patient: 68 yr old African American male, Mr. G, presents to the ED with reports of numbness and tingling to his right face, right arm, and slight difficulty with word choice for the past 35 minutes. No facial asymmetry noted. He also reports a moderate to severe headache since yesterday. Patient ran out of his BP meds 1 week ago and states he forgot to refill them. He tells the RN that his BP was “normal” when he checked it a month ago. MEDS: Lisinopril 40mg/day & Metformin 1000mg/BID. Patient states he isn’t the best at taking his medications daily. VITALS: 178/98, 96, 18, 98.6, Pox 96% at room air. Glucose /capillary : 120mg/dL NIH score = 2 PAST MEDICAL HISTORY: - NKDA - Diabetes Mellitus/Type II - HTN, Hyperlipidemia, recent cholesterol of 190. - No surgeries or previous hospitalizations. REVIEW QUESTION Microsoft clip art What is the INITIAL diagnostic imaging test that would be completed when Mr. G arrives to the ER with his symptoms to provide a differential diagnosis? MRI of the brain CT of the head without contrast FALSE FALSE MRI is a superior test for diagnosing ischemic lesions in the brain, but it is not a fast test. The CT scan of the head will quickly provide a differential diagnosis (stroke vs TIA). Time is brain function! Duplex ultrasonography TRUE The CT of the head will quickly differentiate between a stroke and a TIA. This will help direct the patient’s plan of care. This is a fast noninvasive test that will provide information to the patency of the carotid arteries and the blood flow to the brain. This will assist in possible surgical options if a large blockage presents. This is not the initial imaging that would be completed. TIA TREATMENT TIA treatment is focused on preventing recurrent TIAs, strokes and medical complications. “The risk of stroke is highest in the first week after stroke or TIA.” (Porth, 2009, p. 1324) Early implementation of antiplatelet agents in most cases is the standard of care. Current treatment options for TIA include ASPIRIN - first line of medical treatment. TICLOPIDINE CLOPIDOGREL CAROTID ENDARDECTOMY (Porth, 2009) TIA TREATMENT According to the American Heart Association’s journal Microsoft clip art Stroke. Depression is more prevalent among stroke and transient ischemic attack survivors than in the general population. It is underdiagnosed and undertreated. Researchers, analyzing 1,450 adults with ischemic stroke (blockage of a blood vessel in the brain) and 397 with TIA, found: Three months after hospitalization, depression affected 17.9 percent of stroke patients and 14.4 percent of TIA patients. At 12 months, depression affected 16.4 percent of stroke patients and 12.8 percent of TIA patients. Nearly 70 percent of stroke and TIA patients with persistent depression still weren’t treated with antidepressant therapy at either the 3 or 12 month intervals. OUTCOME: It is important for providers to screen for depression on follow-up after both stroke and TIA. http://newsroom.heart.org/pr/aha/depression-has-big-impact-on-stroke-231095.aspx REVIEW QUESTION Microsoft clip art Mr. G’s CT of his head was NEGATIVE. It has now been 35 minutes since he has arrived to the ED. His stroke symptoms have resolved. His BP is lower at 145/76, rate 78 after taking his Lisinopril 40mg which he is prescribed daily. DIFFERENTIAL DIAGNOSIS = TIA. What other medication will they most likely add to his daily medication regime? He reports no adverse reactions to any medications. Clopidogrel FALSE True, this medication can be used to treat recurrent TIAs, but this is not a first line medication for TIA prevention. Aspirin TRUE One adult Aspirin/day is the most common first line medication for preventing future TIAs. Ticlopidine FALSE This medication is a first line drug for TIA prevention, but it is usually reserved for those who are unable to tolerate aspirin. TIA RISK FACTORS Unmodifiable factors Age, Sex, Race, Heredity The incidence of stroke INCREASES with age. Stroke incident is greater among men than women’s at younger ages, but not at older ages. African Americans have almost 2x the risk of initial stroke than caucasians. Familial history of strokes/ TIAs. (Porth, 2009) TIA RISK FACTORS Modifiable Factors Hypertension –powerful determinant of stroke risk! Hyperlipidemia Smoking Diabetes Heart Disease (Atrial Fibrillation, Wall motion defects) Carotid disease Coagulation disorders Obesity/Inactivity Heavy alcohol use Cocaine use Microsoft clip art Microsoft clip art (Porth, 2009) REVIEW QUESTION Microsoft clip art What is Mr. G’s most predominant modifiable stroke/TIA risk factor? Hyperlipidemia African American Hypertension TRUE FALSE True, this a modifiable stroke risk factor, but not the most predominant for Mr. G. FALSE African Americans do have higher incidence of stroke vs. Caucasians, but this is not a modifiable risk factor. HTN is a powerful determinant of stroke/TIA risk. Mr. G’s BP is elevated and he hasn’t taken his HTN meds for 1 week. You must discuss with him the importance of medication compliance in preventing future TIAs or strokes! TIA PREVENTION Prevention is key! Microsoft clip art Treatment and management of modifiable risk factors offers the best opportunity to prevent cerebral ischemic events. (Porth 2009) Primary prevention of stroke by early detection. IMMEDIATE TREATMENT IS NEEDED AT THE FIRST SIGN OF STROKE! Be proactive with your patients regarding managing their modifiable risk factors, don’t wait until an ischemic event occurs! Promote the importance of… Medication compliance. Daily exercise, goal of 30 minutes/day. Smoking cessation. Refraining from illegal drug or ETOH use. Chronic disease management - (HTN/CAD/DM/A-fib) REVIEW QUESTION Microsoft clip art What will be the most effective PREVENTATIVE measure Mr. G can do to prevent future TIAs or strokes. Exercise Take his BP everyday Medication compliance FALSE FALSE TRUE True, this is a great preventative measure, but not the most effective for Mr. G at this time. Although this action will allow for better HTN monitoring, it unfortunately will not prevent future TIAs/ strokes. Mr. G’s BP was elevated and he hadn’t taken his HTN meds for 1 week. He may have prevented his TIA had he been taking his meds. Let’s review what you’ve learned in this tutorial. The pathophysiology of a TIA. The clinical implications of a TIA. How a TIA is diagnosed. Common treatments for a TIA. The risk factors of a TIA. TIA prevention. Microsoft clip art LITERATURE CITED American Stroke Association (January/February 2009) Why Rush? Stroke Connection. Retrieved March 15, 2012 from http://www.strokeassociation.org/STROKEORG/AboutStroke/TypesofStroke/TIA/Transient -Ischemic-Attack_UCM_310942_Article.jsp American Stroke Association (March 2012) Depression has big impact on stroke, TIA Survivors. Stroke. Retrieved March 15, 2012 from http://newsroom.heart.org/pr/aha/depression-has-big-impact-on-stroke-231095.aspx Microsoft Office 2003 Clip Art National Institute of Health (October 2003) National Institute of Health Stroke Scale for doctors. Retrieved March 1, 2012 from http://www.ninds.nih.gov/doctors/NIH_Stroke_Scale.pdf Porth, C. M., & Matfin, G. (2009). Pathophysiology Concepts of Altered Health States (8th ed.). Philadelphia, PA: Lippincott Williams& Wilkins. Stroke Center (n.d.). The Ischemic Penumbra. Permission received to use image. Retrieved March 15, 2012. http://www.strokecenter.org/professionals/brain-anatomy/cellular-injury-duringischemia/the-ischemic-penumbra/
