Acute Brain Injury

LHS Stroke Center

Objectives

• Understand need for stroke protocol.• Review Brain Anatomy and function.• Understand cerebral perfusion.• Differentiate the different types of strokes.• Identify signs & symptoms of potential stroke

patients.• Will be able to understand neuro deficits

through an accurate neuro exam.• Treatment of Acute Brain injury.

Brain

• Body’s controlling organ

• Responsible for organizing functions of other body organ systems

Brain Anatomy Review

• Occupies 80% of intracranial space• Divisions

– Cerebrum– Cerebellum– Brain Stem

Brain Anatomy Review

• Cerebrum: largest and most advanced portion of brain. – Cortex– Frontal lobe– Parietal lobe– Temporal lobe– Occipital lobe

Cerebrum

• Frontal lobe: – controls planning, organizing, problem solving and

selective attention. – The prefrontal cortex controls personality and

higher cognitive functions such as behavior and emotions.

– The back of the frontal lobe consists of pre-motor and motor areas which control movements

– Damage – hemiparesis, facial droop, expressive aphasia, impulsive behavior

Cerebrum (cont):

• Parietal Lobes:– contain the primary sensory cortex, – controls sensation (touch and pressure) – fine sensation ( judgment of texture, weight, size, shape)

• Damage to the right parietal lobe can cause – visual-spacial deficits, making it hard for a patient to find

their way around new or familiar places.

• Neglect of affected side• Damage to the left parietal lobe may disrupt the

ability to understand spoken and/or written communication

Cerebrum (cont):

• Temporal Lobes:– Located around ear level– Allows differentiation of smells and sounds– Helps sort new information– Responsible for short-term memory– Right lobe is primarily involved in visual memory

(faces and pictures)– Left lobe is primarily involved in verbal memory

(names and words)– Damage - aphasia, memory loss, may be

temporary

Cerebrum (cont):

• Occipital Lobe:– Processes visual information– Visual reception– Visual recognition of shapes and colors– Damage to this lobe can cause visual deficits

The Cerebellum

• Second largest area of the brain

• Controls reflexes, balance and certain aspects of movement and coordination, equilibrium, fine motor skills

• Damage from a Stroke:– lack of coordination (ataxia), clumsiness, balance

problem– Inability to walk, talk, eat and perform other self-

care tasks

The Brain Stem

• Responsible for the Critical Functions of Life

• Breathing, digestion, heart beat, temperature

• Includes alertness and arousal or the state of being awake

• Damage from a stroke:– Most devastating and life threatening as they can disrupt

involuntary functions essential to life– People who survive a brain stem stroke will remain in a vegetative

state or left with severe impairments

Brain Anatomy Review

• Brain Stem– connects hemispheres, cerebellum and SC– responsible for vegetative functions & VS

Midbrain• relay point for visual and auditory impulses

Pons• conduction pathway between brain and other regions of

body Medulla oblongata

• cardiac, respiratory, and vasomotor control centers• control of vomiting and coughing

Brain Anatomy Review

• Brain Stem– Cranial Nerves– Reticular Activating System

• level of arousal (level of consciousness)– Primary control along with cerebral cortex

– Meninges• Dura mater: tough outer layer, separates cerebellum

from cerebral structures, landmark for lesions• Arachnoid: web-like, venous vessels that reabsorb CSF• Pia mater: directly attached to brain tissue

Meninges

Brain Metabolism

• High metabolic rate– consumes 20% of body’s oxygen– largest user of glucose– requires thiamine– can not store nutrients

Brain Perfusion

• Perfusion

– Cerebral Blood Flow (CBF)

• dependent upon CPP

• flow requires pressure gradient

– Cerebral Perfusion Pressure (CPP)

• pressure moving the blood through the cranium

• autoregulation allows BP change to maintain CPP

• CPP = Mean Arterial Pressure (MAP) - Intracranial Pressure (ICP)

• Blood Supply– vertebral arteries

• supply posterior brain (cerebellum and brain stem)– carotid arteries

• most of cerebrum

Brain Metabolism & Perfusion

• Perfusion– Mean Arterial Pressure (MAP)

• largely dependent on cerebral vascular resistance (CVR) since diastolic is main component

• blood volume and myocardial contractility• MAP = Diastolic + 1/3 Pulse Pressure• usually require MAP of at least 60 mm Hg to perfuse

brain– Intracranial Pressure (ICP)

• edema, hemorrhage• ICP usually 10-15 mm Hg

Blood Flow of the Brain

• Cerebral circulation – The movement of blood through the network of blood

vessels supplying the brain. – The arteries deliver oxygenated blood, glucose and other

nutrients to the brain – the veins carry deoxygenated blood back to the heart,

removing carbon dioxide, lactic acid, and other metabolic products.

– The cerebral circulatory system has many safeguards.– Failure of these safeguards results in cerebral vascular

accidents, commonly known as strokes

Blood Flow of Brain

There are two main pairs of arteries that supply the cerebral arteries and the cerebellum.

• Internal Carotid Arteries: These large arteries are the left and right branches of the common carotid arteries in the neck which enter the skull. – The external carotid branches supply the facial tissues.

– The internal carotid artery branches into the anterior cerebral artery and continues to form the middle cerebral artery.

• Both internal carotid arteries, within and along the floor of the cerebral vault, are interconnected via the anterior communicating artery.

• Both internal carotid arteries are interconnected with the basilar artery via bilateral posterior communicating arteries.

Blood flow of the Brain

• The Circle of Willis, long considered to be an important anatomic vascular formation, provides backup circulation to the brain.

– If one of the supply arteries is occluded, the Circle of Willis provides interconnections between the internal carotid arteries and basilar artery along the floor of the cerebral vault, providing blood to tissues that would otherwise become ischemic

Cushing’s Triad

• Increasing Intracranial Pressure• Increasing systolic blood pressure• Widening pulse pressure• Bradycardia• Bradypnea

These are late signs and probable irreversible. Brain Stem herniation is in progress

Cerebrospinal Fluid (CSF

• Surrounds brain, spinal cord in space between arachnoids and pia mater (subarachnoid space)

• Acts as a shock absorber• Protects brain from jolts, shocks

Brain Attack Facts

• Stroke is also known as a cerebrovascular accident or "brain attack.“

• A stroke is a life-threatening event in which part of the brain is deprived of adequate oxygen.

• Strokes are extremely dangerous, accounting for more than 160,000 deaths each year, according to the Centers for Disease Control and Prevention.

Brain Attack Facts

• Stroke is the third leading cause of death in the United States, behind heart disease and cancer.

• It is also a leading cause of adult disability and institutionalization.

• Each year, about 700,000 people suffer strokes. Of those, 500,000 are first-time strokes, and 200,000 are recurrent.

Symptoms

• Symptoms may be sudden and include:– weakness or numbness of the face, arm, or leg, especially

on one side of the body – confusion or difficulty speaking or understanding

– problems with vision such as dimness or loss of vision in one or both eyes

– dizziness or problems with balance or coordination

– problems with movement or walking

– severe headaches with no other known cause

Symptoms

• Other, less common, symptoms of stroke may include the following:

– sudden nausea, vomiting, or fever not caused by a viral illness

– brief loss or change of consciousness such as fainting, confusion, seizures, or coma

– transient ischemic attack (TIA), or "mini-stroke"

Risk factors for stroke that can be changed, treated, or medically managed

• high blood pressure • diabetes mellitus • heart disease• cigarette smoking• history of transient

ischemic attacks (TIAs) • high red blood cell

count

• high blood cholesterol and lipids

• lack of exercise, physical inactivity

• Obesity• excessive alcohol use • drug abuse• abnormal heart rhythm

• cardiac structural abnormalities

Risk factors for stroke that cannot be changed:

• age

• gender

• race

• history of prior stroke• heredity/genetics

Types of Brain Attacks

• Ischemic—”deprived of blood”– Sometimes called “occlusive”– Accounts for 83% stroke cases

• Hemorrhagic—”caused by bleeding”– Hypertension primary cause– Loss of blood flow for 3-5 minutes causes necrosis

of the CNS– Accounts for 17% of stroke cases

Ischemic Stroke

Thrombotic– Artery is gradually

occluded by a plug of material the collects in a given site

• Uncommon in smaller arteries

• Usually in areas of disturbance like twists and bends in an artery

– Atherosclerosis: Greek “hard paste”

Embolic – Artery is suddenly

occluded by material that moves through the vascular system to occlude an artery

– Often a fragment from a thrombosis

– Atrial fibrillation is a common cause

Ischemic Strokes Source

• The most common source of an embolic stroke is the left atrium of the heart:– Atrial Fibrillation

• Another source is from the carotid artery, – atherosclerotic plaque and clots detach and are

carried through the blood stream into cerebral vasculature.

Embolism

Ischemic Stroke

Hemorrhagic stroke(cerebral hemorrhage)

• Caused by disruption of a cerebral blood vessel, bleeds into surrounding tissue– Due to weakness of the vessel wall.

– Aneurysm

– AV Malformation

– Traumatic injury to the vessel

– pressure on arterial walls or chronic hypertension—causing “microaneurysms”

• DO NOT TREAT WITH THROMBOLYTICS

Hemorrhages

• Extracerebral hemorrhages—bleeding outside of the brain– Subarachnoid– subdural – extradural

• Intracerebral hemorrhages– Within brain

substance bleed

Aneurysm

• “Pouches” formed in arterial walls– berry or saccular, term depends upon the shape– Nearly 50% of extracerebral aneurysms occur in

the arteries at the base of the brain (vertebrals, basilar, internal carotid and Circle of Willis)

• Most are due to injury to:– MCA Middle Cerebral Artery– ACA Anterior Communicating Artery– 2-3% occur in the posterior cerebral artery

Lacunar Stroke

• Small blood vessels in brain

• The word lacunar comes from the Latin word meaning "hole" or "cavity." these are small vessels.

• Lacunar infarctions are often found in people who have diabetes or hypertension (high blood pressure).

Right & Left Hemisphere CVA

Feature Left Right

Language Aphasia Impaired sense of humor

Memory Deficit Disoriented

Vision Right visual field deficit

Problem Reading

Spatial deficits

Loss of depth perception

Behavioral Slow

cautious

Impulsive

Euphoric

Stroke Assessment

Single most important assessment is Level of consciousness

• Sternal Rub – cautious, can be easily bruised

• Trapezius Squeeze– Muscle at top of shoulder

• Supraorbital Pressure– Avoid if facial fractures

Central stimulation preferred, Peripheral stimulation such as nail bed pressure may only elicit reflexive movement

*Consider patients past medical history and baseline

In stuporous or comatose patients

• Assess gag, corneal, and swallow reflex• Assess Babinski

– Positive - Toes flare– Negative - Toes curl downward

• Assess Doll’s eyes (If no neck injury)– Open eyes and turn head left then right

• Positive or normal – the eyes automatically move in the direction opposite the rotation

• Negative - the eyes move in the same direction as the head rotation. This could indicate brain death

Cranial Nerve Assessment

I Olfactory Sense of smell

II OpticCan the patient read? Have patient focus forward and test peripheral vision by counting your fingers

III Oculomotor Pupils equal, reactive, and accommodation

IV Trochlear Have patient look down and in

V Trigeminal Lateral jaw movement and face sensation. In a comatose patient, check corneal reflex

VI Abducens Move eyes side to side

VII Facial Have patient smile and raise eyebrows

VII Acoustic Any change in hearing ?

IXGlossopharyngeal Can the patient swallow ?

X Vagus Does the patient have a gag ? Is speech affected ?

XISpinal Accessory Have patient shrug shoulders and turn head side to side.

XII Hypoglossal Have patient extend tongue. Can patient articulate a certain phrase

Level of Consciousness

Alert & Oriented Alert, attentive, following commands. If asleep,

awakens and remains attentive.

Lethargic Drowsy but will awaken to stimulation. Slow to answer questions or inattentive.

Obtunded Difficult to arouse, needs constant stimulation to follow commands. Will fall back to sleep without stimulation

Stupor Patient needs vigorous and continuous stimulation. Often requires painful stimuli. Will NOT follow commands. May moan and withdrawal from pain

Coma No response to painful stimuli, no verbal sound, reflexive movement only.

Glasgow Coma Scale

• The Glasgow Coma Scale– Most widely used scoring system for use in

quantifying level of consciousness following traumatic brain injury.

– Simple – Relatively high degree of interobserver reliability – Correlates well with outcome following severe

brain injury.

Glasgow Coma Scale

• Eye Opening (E) Verbal Response (V)

4. Spontaneous 5. Normal Conversation

3. to Voice 4. Disoriented Conversation

2. To Pain 3. Incoherent words

1. None 2. No words, only sounds

1. None• Motor response (M)

6. Normal

5. Localized to Pain Total = E+V+M

4. Withdraws to Pain Score 3-15

3. Decorticate Posturing

2. Decerebrate Posturing

1. None

• USE THE FACE, ARM AND SPEECH TEST

Facial Weakness – Ask the person to smile. Look for drooping at the mouth or eye

Arm Weakness – Ask the person to raise both arms. Look for unilateral drift or weakness

Speech – Ask the person to talk noting if the speech is clear and they understand what you are saying

Test all 3 symptoms and if one fails, initiate the ITeam.

Arm Drift

Speech

• Normal: Patient uses correct words with no slurring

• Abnormal: Slurred or inappropriate words or mute

• Aphasia – Inability to articulate speech • Dysphasia - impairment of speech

– Receptive Dysphasia - Inability to comprehend– Expressive Aphasia – Inability to communicate

Fast Stroke Screening Tool

1. Patient Name: ____________________________________2. Information/History from : Caregiver ________

PatientFamilyOther__________

3. Time last seen normal/baseline and awake ___:___ __/___/____4. Patient is having new:

Facial Droop YES NO UNABLE TO ASSESSArm drift YES NO UNABLE TO ASSESSSpeech Difficulty YES NO UNABLE TO ASSESS

5. History of seizures or epilepsy absent YES NO UNKNOWN

6. Symptom duration < 24 hours YES NO UNKNOWN7. Patient not wheelchair bound

or bedridden at baseline YES NO UNKNOWN8. Glucose between 60 and 400 YES NO UNKNOWN9. GCS ___________

ALL YES ? INITIATE CODE BRAIN ATTACK PROTOCOL*Not a permanent part of patient record

Decorticate & Decerebrate Posturing

Cincinnati Stroke Scale

• Facial Droop (ask patient to smile or show their teeth)

• Arm Drift (Ask patient to close eyes and hold both arms out with palms up)

• Speech (Ask patient to say “The sky is blue in Cincinnati”)

• Time is crucial!

• Both sides should move equal

• Both arms move the same

• Patient uses correct words no slurring

• About 3 hours before treatment won’t help

Ischemic Brain Attack Management

• Maintain airway--oxygenate• Neuro assessment Glasgow Coma Scale• Treat with tPA (tissue plasminogen

activator) within 3 hours• Correct hypoglycemia, watch for

hyperglycemia• No free water IV fluids• Raise serum osmolality to 310 mOs/L• Blood pressure management

Blood Pressure Management

• Optimal blood pressure targets remain to be determined. Many patients are hypertensive on arrival. Recent American Stroke Association guidelines have reinforced the need for caution in lowering blood pressures acutely.

• In the small proportion of patients with stroke who are relatively hypotensive, pharmacologically increasing blood pressure may improve flow through critical stenoses

LHS Stroke Protocol Orders Blood Pressure guidelines

• During Alteplase– For SBP 200 mmHg or greater or DBP 110 mmHg

or greater give Labetalol 20 mg IVP over 1-2 minutes. May repeat Labetalol 20mg IVP q10min to total dose of 150 mg.

• Post Alteplase– Labetalol HCL 20mg IVP q10min x 3 doses for

SBP greater than 180 mmHg or DBP greater than 105 mmHg.

Blood Pressure Guidelines for those not receiving tPA

• Notify physician if– SBP greater than or equal to 180 mmHg – DBP greater than or equal to 105 mmHg, – if there are changes in neuro status

Treatment with tPA for Ischemic Brain Attack

• Administer tissue plasminogen activator (tPA) within 3 hours.

• Must do diagnostic CT first

• Determine eligibility

tPA dosaging

• Total recommended dose is 0.9mg/kg; maximum total dose is 90mg

• Patients < 100kg infuse as follows:– Load with 0.09mg/kg bolus (10% of 0.9mg/kg dose) over 1

minute– Then administer 0.81mg/kg infusion (90% of 0.9mg/kg dose) over

1 hour• Patients ≥ 100kg infuse as follows:

– Load with 9mg bolus (10% of 90mg)over 1 minute– Then administer 81mg infusion (90% of 90mg dose) over 1 hour

**Doses should be given within 3 hours of symptom onset**Administering anticoagulants or aspirin within 24 hours of alteplase is

not recommended

Questions

Bibliography

• www.stroke.org• www.strokeassociation.org• www.kuakini.org• www.americanheart.org• http://rn.modernmedicine.com