Chapter 21 Stroke

Risk factors of Stroke

Leukemia DM Cholesterol High Plasma Homocysteine Overweight/Obesity

High Plasma Homocysteine (in respect to stroke)

Levels and low folate and vitamin B6 are associated with increased risk of carotid disease and heart attack -> increased stroke risk. Getting tested for homocystinurina which is a rare inherited disorder. This disorder can determine if you are at increased risk of heart attack or stroke.

What is a Subdural Hemorrhage?

(Most often) the result of tearing of the bridging veins between the brain surface and the dural sinus. Results in blood accumulation in the dural space. Small amounts can be reabsorbed by the body; larger amounts of bleeding become a space occupying lesion Compression of the brain can result.

Statistics (leading causes of death)

1) Heart disease: 597,689; 2) Cancer: 574,743; 3) Chronic lower respiratory diseases: 138,080; 4) Stroke (cerebrovascular diseases): 129,476

Where do most strokes occur (demographic/regionally speaking)?

2/3 of strokes occur in low-> middle income countries.

What is the second most common cause of ICH?

A ruptured vascular malformation

What is a stroke?

A vascular event resulting in damage to brain tissue that surrounds the affected vessel(s).

What are signs of Posterior Cerebral Artery Syndrome?

Abnormal sensation of pain, temp, proprioception, touch. Sensations may be exaggerated

What are the ABC's of predicting a stroke's progression?

Age (1 point for being over 60 y.o.) Blood pressure (1 point for systolic blood pressure above 140 mmHg or diastolic pressure above 90 mmHg) Clinical Factors- (2 points for symptoms lasting longer than 60 minutes and 1 point for symptoms lasting less than 60 minutes) Duration- 2 points for symptoms lasting longer than 60 minutes and 1 point for symptoms lasting less than 60 minutes.

Non-Modifiable factors of stroke:

Age, Race, Genetics and Sex Stroke incidences double with every decade after 55 y.o. Women are 20% less chance than men. Family history increases risk.

What are common causes for subarachnoid hemorrhage?

Aneurysm and vascular malformations are primary causes Many underlying causes including trauma, neoplasms, HTN, and vascular malformations

What increases the likelihood of stroke by 6x?

Atrial fibrillation.

What is an Intracranial Hemorrhage (ICH)?

Bleeding from an arterial source into brain parenchyma; regarded as the most deadly of stroke subtypes

What is a Subarachnoid Hemorhage?

Can begin with sudden onset of a "thunderclap" with searing pain (headache); sometimes associated with exertion; Results in frank blood between the arachnoid and the pia

This is a key contributing factor to occurrence of CVA.

Cardiac dysfunction

What is the primary cause of stroke?

Cerebrovascular disease.

What is Internal Carotid Artery Syndrome?

Clinical pictures vary with cause. May present with combination of middle/anterior cerebral artery syndromes.

What is Middle Cerebral Artery Syndrome?

Contralateral hemiplegia and hemianesthesia with global aphasia if the dominant hemisphere is affected

What is a Transient Ischemic Attack (TIA)?

Decreased blood flow leading to focal neurologic symptoms that completely resolve within 24 hours.

Incidence of Stroke

First strokes in the US ~ 750,000 annually. These account for 75% of acute events 25% are recurrent strokes

What are clinical manifestations for stroke?

Generally related to the type (and location) of the stroke TIA may be the first indication of CVA

What are the clinical manifestation of ICH?

Gradual onset of neurological symptoms as greater areas of brain tissue are affected by the bleed Functional loss may appear first, f/b (followed by), headache, vomiting, decreased alertness

Modifiable risk factors

HTN Various cardiac disease increase stroke risk: CHS, Left Ventricular hypertrophy and cardiac failure.

Cholesterol (in respect to stroke)

High total cholesterol increases the risk of ischemic stroke

When are peak incidence for subdural hemorrhage?

In the 60s and 70s; men> women; Often caused by minor trauma, especially falls. Patients may present with headache and/or alterations in mental status

Diabetes Mellitus (in respect to stroke)

Increased risk secondary large artery atherosclerosis, increased cholesterol levels, and plaque formation; reduced small vessel ability to vasodilate

What is the incidence rate of ICH?

Increases with age; Men>women; Higher in African-American than Caucasian in US, but higher in Asian populations worldwide

What are secondary causes of stroke?

Intrinsic vascular damage or effects of an embolus that develops remotely and eventually blocks intracranial blood flow.

What are signs of Anterior Infeiror Cerebellar Artery Sydrome?

Ipsilateral deafness, facial weakness, vertigo, nausea/vomiting, nystagmus and ataxia

What is the most common type of stroke?

Ischemic Stroke

What ethnic group(s) are at the highest risk for stroke?

Mexican- America and African American men have a 50% higher risk for stroke compared to Caucasian men.

What is the most common site for emboli?

Middle Cerebral Artery

What is an ischemic stroke?

Most common type of stroke (85%); Occlusion of a major vessel by thrombus or embolus which is the most common cause of this type of stroke.

How are subdural hemorrhages diagnosed?

Non-contrast enhanced CT scan. Confirmed diagnosis should be treated as medical emergency

What are signs of Superior Cerebellar Artery Syndrome?

Occlusion results in severe ipsilateral cerebellar ataxia, n/v, dysarthria (slurred speech) and dysmetria to ipsilateral UE

How well do predictive values estimate the likelihood of stroke?

Predictive values for a stroke within 7 days: 0-4, 4% chance. 5, 12% chance.6, 32% chance.

What is the difference between primary and secondary ICH

Primary ICH: spontaneous bleeding without a readily identifiable precipitant Secondary ICH: occurs most often in association with trauma, impaired coagulation, toxin exposure, or an anatomic lesion

What leads to a higher incidence of stroke in African Americans?

Sickle Cell

What are risk factors for subarachnoid hemorrhage?

Smoking Excessive alcohol consumption HTN. Familial risk has been shown - increased risk for 1st degree relatives of SAH victim

What region of America has the death rate related to strokes?

Southeast ,US African-American, American Indian/Alaska Natives, Asian/Pacific Islanders, and Hispanics die from stroke at younger ages than Caucasians.

What is the leading cause of long-term disability?

Stroke

Overweight/ Obesity/Smoking/Drug(cocaine)/Alcohol abuse (in respect to stroke)

Tend to be associated with hemorrhagic strokes

What is the most common source of embolus?

The heart

Atherosclerosis

build up of plaque inside your arteries. [Arteries are blood vessels that carry oxygen-rich blood to your heart and other parts of your body.] Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body

True/False: Individuals who have an ischemic stroke are at risk for a second stroke?

True

Anterior Cerebra Artery Syndrome

Uncommon with minimal dysfunction 20 collateral circulation. If present, there would be contralateral hemiparesis and sensory loss with greater LE involvement

What are signs Basilar artery syndrome?

Unilateral symptoms involving the sensory and motor aspect of the Cranial nerves

Prognosis of stroke

University of Oxford ABCD scale can be used to determine the chance of progression to CVA diagnosis with more severe impact Age, Blood pressure, Clinical features, Duration

Leukemia (in respect to stroke)

Very high WBC count increases chance of microinfarcts and vascular rupture.

What are signs of Vertebral and Posterior Inferior Cerebellar Artery Syndrome

Wallenberg syndrome: vertigo, nausea, hoarseness, dysphagia; also, ipsilateral ataxia, ptosis, impaired ipsilateral sensation - face and contralateral portion of torso and limbs

When does neural death (infarcction) occur?

When the brain receives less than 8-10 mL/100 mg/min.

What is Posterior Cerebral Artery Syndrome?

a condition whereby the blood supply from the posterior cerebral artery (PCA) is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel

What is an embolus?

anything (a blood clot, air bubble, piece of fatty deposit, or other object )that travels through the blood vessels until it reaches a vessel that is too small to let it pass (resulting in an embolism)

What is chronic HTN?

fibrinoid necrosis in the penetrating and subcortical arteries weakened arterial walls and microaneurysms that predispose to spontaneous ICH; acute rises in BP can have the same impact

What are associated symptoms to subarachnoid hemorrhage?

n/v (nausea and vomiting), syncope, neck pain, coma, confusion, lethargy, and seizures; drowsiness, restlessness, and agitation are especially common Hemiplegia or hemianopsia are absent unless bleeding into the brain occurs

n/v means?

nausea and vomiting

What are signs of Lacunar Syndrome?

the most common type of stroke, and results from occlusion of small penetrating arteries that provide blood to the brain's deep structures. Most common in people with HTN and DM (same as ischemic necrosis)

Subarachnoid Hemorrhage is also known as a

thunder clap headache