Stroke

Symptoms of stroke vary widely depending on what 3 things?

- the type of infarct - the location - the amount of brain involved

What percent of strokes are ischemic due to the blockage of a blood vessel secondary to thrombosis or embolism?

80%

What may help restore tissue perfusion in ischemic stroke and is the only FDA-approved thrombolytic for stroke?

Alteplase (intravenous rtPA)

What signs typically indicate brainstem involvement?

Crossed signs (eg, right-sided facial droop with left-sided extremity weakness) typically indicate brainstem involvement.

The evaluation should include the use of what scale, (a standardized system that measures the level of impairment caused by stroke)?

NIH Stroke Scale (NIHSS)

What are symptoms of a hemorrhagic stroke that involves cerebellar hemorrhage?

Sudden onset of: - dizziness - vomiting - truncal instability - gaze palsies - stupor

True or false: Endovascular therapies such as intra-arterial and mechanical thrombolysis are being used for a subset of patients with acute ischemic stroke. Consideration or the use of mechanical thrombolysis should not prevent or delay administration of rtPA.

True

It is critical to find out the exact onset of stroke symptoms, as thrombolytics can only be given within what time window?

within a 4.5-hour window from the onset of symptoms in ischemic strokes

What is the inclusion criteria for IV thrombolysis administration in ischemic stroke?

• Age 18 years or older • Clinical criteria of ischemic stroke • Time of onset well established, <3 hours

We must be cognizant that...

"Time is Brain Tissue."

The National Institute of Neurological Disorders and Stroke (NINDS) has established door-to-treatment time frames in responding to acute stroke. These include which 4 timeframes?

- A physician evaluation within 10 minutes of arrival - Specialist/neurologist notification within 15 minutes - CT of head within 25 minutes - CT interpretation within 45 minutes - For ischemic strokes, the guideline for the administration of rtPA (recombinant tissue-type plasminogen activator) in eligible patients is within 60 minutes of arrival to the facility, within the "golden hour" of stroke care

Name categories of the NIH stroke scale.

- Level of consciousness questions (know month and age?) - Level of consciousness commands (patient instructed to open and close eyes and then to grip and release nonparetic hand) - Best gaze (horizontal gaze tested) - Best visual (visual fields tested by confrontation) - Facial palsy (pt instructed to show teeth or raise eyebrows or close eyes) - Best motor arm - Best motor leg - Limb ataxia (finger-nose-finger and heel-toe bilaterally) - Sensory (sensation or grimace to pinprick) - Best language (describe picture, name items on sheet) - Dysarthria (read or repeat words from a sheet) - Extinction and Inattention

What are symptoms of a dominant hemisphere ischemic stroke?

- contralateral numbness and weakness - contralateral visual field cut - gaze preference (steering the eyes towards the respective lesion side) - dysarthria (slurred or slow speech) - aphasia (loss of ability to understand or express speech)

What are symptoms of a nondominant hemisphere ischemic stroke?

- contralateral numbness and weakness - visual field cut - contralateral neglect - dysarthria (slurred or slow speech)

What are symptoms of a middle cerebral artery ischemic stroke?

- contralateral numbness and weakness (face, arm > leg) - aphasia (if dominant hemisphere)

What are symptoms of an anterior cerebral artery ischemic stroke?

- contralateral weakness (leg > arm) - mild sensory deficits - dyspraxia (clumsiness)

What are symptoms of an ischemic stroke involving vertebrobasilar syndrome?

- dizziness - vertigo - diplopia - dysphagia (difficulty swallowing) - ataxia (gait abnormality) - ipsilateral cranial nerve palsies - contralateral weakness (crossed deficits)

Most of the diagnostic studies in acute stroke patients are used to do what?

- exclude other etiologies of neurologic impairments, and - identify possible contraindications to tPA administration

Some of the major contraindications to thrombolytic therapy include what 4 things?

- hemorrhagic stroke, - severe hypo- or hyperglycemia, - uncontrolled severe hypertension, - significant bleeding conditions

What are symptoms of a posterior cerebral artery ischemic stroke?

- lack of visual recognition - altered mental status with impaired memory - cortical blindness (total or partial loss of vision in a normal-appearing eye caused by damage to the brain's occipital cortex)

What are symptoms of a hemorrhagic stroke that involves intracerebral hemorrhage?

- may be clinically indistinguishable from infarction - contralateral numbness and weakness - aphasia - neglect (depending on hemisphere) - headache - vomiting - lethargy - marked hypertension more common

What are symptoms of a transient ischemic attack (TIA)?

- neurological deficit resolving within 24 hours - highly correlated with future thrombotic stroke

What are symptoms of an ischemic stroke that involves a lacunar infarct?

- pure motor or sensory deficit

What are symptoms of an ischemic stroke that involves basilar artery occlusion?

- quadriplegia - coma - locked-in syndrome (paralysis except upward gaze)

Treatment of stroke is aimed at what 3 things?

- stabilizing the ABCs, - evaluating for possible thrombolytic administration, - addressing comorbid conditions such as hypertension

Elevated blood pressures are generally left untreated to maintain cerebral perfusion pressure. However...

- systolic blood pressures >220 mm Hg and diastolic blood pressures >120 mm Hg are best treated with easily titratable agents, such as IV labetalol and nitrates. The blood pressure should not be lowered more than 25% of the presenting mean arterial blood pressure.

The history and physical examination remains the cornerstone of evaluating stroke patients. The symptoms may include what things?

- weakness - numbness - discoordination of the limbs or face - cranial nerve palsies - dysarthria (speech disorder caused by muscle weakness) - cognitive impairments, such as aphasia or neglect.

Question 1: A 58-year-old man experienced a neurologic deficit and is diagnosed as having a stroke. Which of the following is the most likely etiology? A Ischemic B Hemorrhagic C Drug-induced D Trauma-induced E Metabolic-related

A Ischemic Ischemia is the most common etiology of stroke (due to thrombosis, embolism, or hypoperfusion) and is responsible for up to 80% of strokes.

What is the National Institutes of Health (NIH) stroke scale?

A bedside assessment tool that provides a reproducible, quantitative measurement of the stroke-related neurologic deficit.

What are are the 2 most urgent diagnostic studies in suspected stroke?

A bedside glucose measurement and a CT scan of the head.

What score on the NIH stroke scale represents a "severe stroke"?

A score above 20 to the maximal score of 42 represents a severe stroke.

Because cardiac abnormalities are common among stroke patients, what should be obtained?

An EKG Although further cardiovascular studies will ultimately be performed, they should be done as an inpatient so that the acute care of the patient is not delayed.

What is an early CT finding in ischemic stroke?

An early CT finding in ischemic stroke is loss of the gray-white differentiation, due to increased water concentration in ischemic tissues, leading to a loss of distinction among the basal ganglia nuclei, gyri swelling, and sulcal effacement. Another early CT finding is increased density within the occluded vessel, which represents the thrombus.

Question 2: An 80-year-old man is being evaluated for possible thrombolytic therapy after presenting with 2 hours of right arm weakness and aphasia. Which of the following is a contraindication for thrombolytic therapy? A Bilateral cerebral infarct B Hemorrhagic stroke C Hypertension-related stroke D Age of 80 years

B Hemorrhagic stroke Indications for tPA administration include an ischemic stroke with a clearly defined time of onset, measurable neurologic deficit, and a baseline CT with no evidence of intracranial hemorrhage. Contraindications for tPA therapy vary and include, but are not limited to: seizure at the time of stroke, history of intracranial hemorrhage, persistent blood pressure greater than 185/110 mm Hg despite antihypertensive therapy, recent surgery or GI bleed, recent MI, pregnancy, elevated aPTT or INR due to heparin or warfarin use, or platelet count less than 100,000.

Question 3: An otherwise healthy 65-year-old woman is taken to the ED with probable stroke. Which of the following are the most urgent diagnostic studies? A Coagulation studies B ECG and cardiac enzymes C Bedside blood glucose and CT scan of the head D MRI of the head with and without contrast

C Bedside blood glucose and CT scan of the head Bedside blood glucose and CT scan of the head are the most urgent diagnostic studies in evaluating possible stroke patients. Coagulation studies, a complete blood count or platelet count should NOT delay tPA administration, unless the patient is taking anticoagulation or has suspected thrombocytopenia. Non-contrast head CT is generally the initial imaging study, not MRI, to exclude hemorrhage or tumor as a cause of neurologic deficits. Though MRI provides more information, its cost, limited availability, restricted patient access, and other contraindications such as patient claustrophobia or metal implants limit its use.

Question 4: A 67-year-old woman is seen in the emergency room with left arm weakness and right facial droop. Her blood pressure is 180/105 mm Hg. Which of the following is the best management for the hypertension? A Lower the blood pressure to less than 160/80 mm Hg by giving a small dose of labetalol. B Lower the blood pressure to less than 120/80 mm Hg. C No intervention for her blood pressure, but continue to monitor. D Lower the blood pressure to below 160/80 mm Hg if she is eligible for tPA.

C No intervention for her blood pressure, but continue to monitor. Emergency administration of antihypertensive agents should be withheld in acute stroke to maintain cerebral perfusion pressure, unless the blood pressure is greater than 220/120 mm Hg. In patients who are eligible for tPA, the goal BP is less than 185/110 mm Hg. If patients have concurrent conditions (eg, aortic dissection, hypertensive encephalopathy, acute renal failure, or congestive heart failure) that require acute lowering of blood pressure, a reasonable goal is to lower their mean arterial pressure 15% to 25% within the first 24 hours.

Acute onset of focal neurologic deficits is typical for what?

CVA (cerebrovascular accident), aka stroke

Current guidelines allow strokes with scores above what number to be treated with tPA?

Current guidelines allow strokes with scores above 4 to be treated with tissue-type plasminogen activator (tPA).

Hemorrhagic strokes are usually seen in which age group, and are due to what processes?

Hemorrhagic strokes are typically seen in younger patients and are due to intraparenchymal or subarachnoid cerebral vessel bleeding.

The NIH stroke scale measures what factors?

It measures several aspects of brain function such as: - consciousness - vision - sensation - movement - speech - language

What is the mean arterial blood pressure (MAP)? How do you calculate it?

MAP, or mean arterial pressure, is defined as the average pressure in a patient's arteries during one cardiac cycle. It is considered a better indicator of perfusion to vital organs than systolic blood pressure (SBP). To calculate a mean arterial pressure, double the diastolic blood pressure and add the sum to the systolic blood pressure. Then divide by 3.

How is MRI superior to CT? What is the drawback of MRI?

MRI is superior to CT for the demonstration of subacute and chronic hemorrhage. Gradient-echo MR can also detect other vascular lesions, such as malformations and amyloid angiopathy. However, the time required to obtain these studies may delay the time-sensitive administration of tPA.

Stroke patients are managed as critically ill patients. Management imperatives include what things?

Management imperatives include: - assessment and stabilization of the ABCs - formal evaluation for possible thrombolytic administration - addressing comorbid conditions such as hypertension.

What are management priorities in the case of a suspected CVA?

Management priorities include: - ABCs (airway, breathing, and circulation) - stabilization of vitals - a careful history and physical to distinguish CVA from other etiologies which may present similarly, such as hypoglycemia.

What are thrombolytics?

Medications that act to degrade clots and are used in the treatment of myocardial infarctions, pulmonary embolisms, and strokes.

In the case of a suspected stroke, what is the most appropriate next diagnostic step, and best therapy?

Most appropriate next step: CT scan of the head (no contrast) Best therapy: thrombolytics

What is used to quickly determine whether the CVA is ischemic or hemorrhagic?

Non-contrast CT scan

Define transient ischemic attack (TIA).

Occurs when the blood supply to a particular area of the brain is interrupted. It is often referred to as a "mini stroke," and the symptoms typically last minutes to hours, but resolve within 24 hours.

What are other risk factors for stroke, aside from old age, being male, or African American?

Other risk factors for stroke include: - a history of TIA or previous stroke - hypertension - atherosclerosis - cardiac disease (eg, atrial fibrillation, myocardial infarction, and valvular disease) - diabetes - carotid stenosis - dyslipidemia - hypercoagulable states - tobacco - alcohol use

Strokes are more common in what age group, sex, and race?

Strokes are more common in the elderly (75% occur in patients older than 75 years), males, and African Americans.

Blood pressure should be below what in order to give rtPA?

The blood pressure should be below 185/110 mmHg for rtPA administration.

The differential diagnoses for stroke is broad. Name some.

The differential for stroke is broad and may include: neurologic entities such as seizure/Todd's paralysis; complicated migraine headaches; nonconvulsive status epilepticus; flares of demyelinating disorders such as multiple sclerosis, and spinal cord lesions. Toxic/metabolic abnormalities such as hypo- and hyperglycemia, hypo- or hypernatremia, drug overdose, and botulism are possibilities. It is also important to consider infectious etiologies, such as systemic infection, Bell's palsy, meningitis/encephalitis, Rocky Mountain spotted fever, and brain abscess. Cardiac or vascular causes should also be ruled out, including hypertensive encephalopathy, carotid/aortic/vertebral artery dissection, subarachnoid hemorrhage, or cerebral vasculitis. Other etiologies such as tumor, sickle cell cerebral crisis, vitamin deficiencies, depression or psychosis, and heat stroke are some of the other considerations.

What is the goal when a pt presents with a suspected CVA?

The goal is to complete an evaluation and, if the patient is eligible, initiate treatment within 60 minutes of the patient's arrival to the ED.

What is the most common dysrhythmia?

The most common dysrhythmia is atrial fibrillation.

Define stroke.

The rapid development of the loss of brain function due to a disturbance in the blood vessels supplying the brain. It is also referred to as a CVA.

Ischemic strokes are generally seen in which age group, and present with what symptoms?

They are generally seen in patients older than the age of 50, and present with the sudden onset of focal neurologic deficits.

If the event is ischemic, the patient may be a candidate for what?

Thrombolytic administration

How is the treatment of hemorrhagic stroke different than ischemic stroke?

Treatment of hemorrhagic stroke is different, and includes: - blood pressure control with antihypertensives such as nimodipine, - possibly reversing any anticoagulation with cryoprecipitate or platelets, - consultation with a hematologist and neurosurgeon. (Note: Cryoprecipitate is prepared from plasma and contains fibrinogen, von Willebrand factor, factor VIII, factor XIII and fibronectin. Cryoprecipitate is the only adequate fibrinogen concentrate available for intravenous use.)

True or false When rtPA is adminstered, neither heparin nor aspirin is used during the initial 24 hours. However, thrombolytics should not be withheld from a patient who has recently taken aspirin.

True

True or false: Clinicians must take a careful history, including the time of onset of symptoms.

True

True or false: If the patient awoke with symptoms or is unable to communicate, the physician must determine when the patient was last awake and "normal."

True

True or false: In May 2009, the American Heart Association/American Stroke Association (AHA/ASA) guidelines for the administration of rtPA following acute stroke were revised to expand the window of treatment from 3 to 4.5 hours to provide more patients with an opportunity to receive benefit from this effective therapy.

True

True or false: It is possible, although challenging, to clinically infer the location of the anatomic insult to the clinical presentation by correlating symptoms with circulatory region.

True

True or false: Many hospitals have a "Stroke Team" or a "Code Stroke" protocol that facilitates the prompt diagnosis and treatment of stroke patients, as the treatment of stroke is highly time sensitive.

True

True or false: Other imaging modalities, such as contrast-enhanced CT and MRI, may equal CT's efficiency in detecting intracerebral hemorrhage.

True

True or false: Recombinant tissue plasminogen activator (rtPA) should be used with caution in individuals with severe stroke symptoms, NIHSS >22.

True

True or false: Stroke is a serious and common disorder that affects over 795,000 persons in the United States each year.

True

True or false: Strokes may present in a variety of ways, and the differential diagnosis of stroke is broad.

True

True or false: The NIH/NINDS study in 1995 found that alteplase improved functional outcomes at 3 months compared to placebo, if given within 3 hours of symptom onset.

True

True or false: The NIHSS measures the impairment due to stroke.

True

True or false: Thrombolytic therapy should be initiated in patient with an ischemic stroke as soon as possible since "time is brain."

True

True or false: Stroke remains the fourth leading cause of death in the United States, and the number one cause for disability.

True 20% of affected persons will die within 1 year. Many surviving victims are left with neurologic deficits and may be unable to care for themselves.

True or false: Patients with suspected strokes should undergo diagnostic imaging, commonly a non-contrast head CT scan.

True Because of the difficulty in clinically differentiating a hemorrhagic from an ischemic stroke, the CT is vital for ruling out an intracerebral bleed, which is an absolute contraindication to thrombolytic therapy and often requires neurosurgery consultation.

Ture or false: Other blood tests usually include a complete blood count including platelets (platelets should also be above 100,000 per mm3 to administer thrombolytics), coagulation studies, and cardiac markers.

True Coagulation studies are important on patients with anticoagulation who are supratherapeutic and at higher risk for an intracerebral bleed.

True or false: Recent studies have suggested that there may be a longer therapeutic window for the administration of thrombolytics.

True However, earlier administration is always better since "time is brain;" nervous tissue is lost as the stroke progresses.

True or false: Another critical bedside test that should be performed is a capillary blood glucose (CBG).

True Severe hypoglycemia and occasionally hyperglycemia can mimic acute stroke, and these conditions can be rapidly ruled out with a normal glucose level.

Aphasia usually corresponds to what type of stroke?

aphasia usually corresponds to a left hemispheric stroke

Oxygen saturation is needed to exclude what?

hypoxia as etiology of neurologic impairments

Strokes are classified as either...

ischemic or hemorrhagic

Neglect usually indicates what type of stroke?

neglect generally indicates a right hemispheric stroke

How is alteplase (rtPA) given? Include dosage.

rtPA is usually administered 0.9 mg/kg with a maximum dose of 90 mg, with 10% of the dose administered as an IV bolus, and the remainder infused over 60 minutes.

What is exclusion criteria for IV thrombolysis administration in ischemic stroke?

• Minor stroke symptoms • Rapidly improving neurological signs • Prior intracranial hemorrhage or intracranial neoplasm • Arteriovenous malformation or aneurysm • Blood glucose <50 mg/dL or >400 mg/dL • Seizure at onset of stroke • Gastrointestinal or genitourinary bleeding within preceding 21 days • Arterial puncture at a noncompressible site or lumbar puncture within 1 week • Recent myocardial infarction • Major surgery within preceding 14 days • Sustained pretreatment severe hypertension (systolic blood pressure >185 mm Hg, diastolic blood pressure >110 mm Hg) • Previous stroke within past 90 days • Previous head injury within past 90 days • Current use of oral anticoagulant or prothrombin time >15 seconds or INR >1.7 • Use of heparin within preceding 48 hours or prolonged partial thromboplastin time • Platelet count <100,000/mm3