Cerebrovascular Accidents

1
Cerebrovascular Accidents

• Sharon Best, PA-C, MHS

2
The Brain

• Three main components of the brain
• The cerebrum
• The cerebellum
• The brain stem

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The Cerebrum
The Cerebellum Coordinates information from
the visual, motor, and auditory. Responsible
for balance- equilibrium and coordination of
movement

• Primary motor cortex frontal lobe
• Primary sensory cortex parietal lob
• Auditory area temporal lobe
• Brocas area motor/ speech
• Wernickess area sensory speech

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Meninges

• Meninges are connective tissue
• membranes covering the brain
• and spinal cord
• Three layers
• Pia mater P
• (delicate mother)
• deepest/ inside layer closest to brain
• Arachnoid membrane A
• (arachnoidspider)
• middle layer, has weblike strands
• Dura mater D
• (tough mother)
• superficial/outside layer

Pia
Arachnoid
Dura
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The Brain Stem

• The uppermost portion of the spinal cord
• Divided into the midbrain, medulla, and pons
• Responsible for a variety of automatic functions
• respiration
• heart rate
• blood pressure
• consciousness
• sexual arousal

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Nerve Tissue

• Consists of 2 types
• 1. Neurons a nerve cell,
• consisting of a cell body
• w/ dendrites and an axon
• 2. Neuroglial cells supporting
• tissue, includes astrocytes,
• oligodendroglial cells, and
• microglial cells (gliaglue)

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The Myelin Sheath

• Axons of the neurons are wrapped in a myelin
  sheath
• The myelin sheath of the Peripheral Nervous
  System is made
• up of Schwann cells
• The myelin sheath of the Central Nervous System
  (ie brain spinal cord is made of
  oligodendrocytes
• Functions of the myelin sheath
• 1) protects and insulates
• 2) increases speed of impulses
• The spaces between the
• Schwann cells are
• called Nodes of Ranvier.

Where are we here? CNS or PNS?
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Nerves

• A nerve is a group of neurons
• (ie group of nerve cells)
• Types of nerves
• 1. Sensory nerves sends impulses towards CNS
• Eg optic (eye) acoustic (ear) nerves in
  skin for
• PPTT (Pain, Pressure, Temperature,
  Touch)
• 2. Motor nerves sends impulses away from
  CNS
• supply muscles effector neurons
• 3. Mixed nerves will send both sensory and
  motor
• impulses in both directions, since this type of
  nerve
• will enclose sensory neurons and motor neurons.
  

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Nerves and Nerve Tracks

• Recall motor and sensory nerves will cross over
  in the medulla and the spinal cord respectively.
• Therefore, each hemisphere will control the
  opposite side of the body
• For most persons, the left hemisphere is
  dominant.
• Nerves are groups of neurons that run through
  the spinal cord in groups called tracks
• Two important tracks
• 1. Ascending Track carries sensory neurons,
  which are transmitting impulses towards the brain
• 2. Descending Track carries motor neurons,
  which are transmitting impulses away from the
  brain

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Nerves and Nerve Tracks
Descending Track
Ascending Track
motor neurons
sensory neurons
Impulse towards the brain cross over in the
spinal cord
Impulse away from the brain cross over in the
medulla
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Circulation
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Cerebral Circulation

• Two sets of circulation will feed the brain
• 1. The Anterior Circulation
• The common carotid arteries divide to form
• the external and internal carotid
  arteries
• The internal carotids give rise to
• The middle cerebral arteries MCAs,
• which supply much of the lateral brain
• The anterior cerebral arteries ACAs,
• which supply much of the medial brain
• 2. The Posterior Circulation
• The vertebral arteries arise from the subclavian
  arteries
• Then they fuse over the medulla and form a single
  basilar artery
• The basilar artery gives rise to branches the
  feed the medulla, pons, cerebellum and the
  occipital lobes
• The posterior communicating arteries connect the
  anterior circulation with the posterior
  circulation forming the Circle of Willis

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Posterior Circulation

• The vertebral arteries arise from the subclavian
  arteries
• They fuse over the medulla and form a single
  basilar artery
• Branches of the basilar a. will feed

• Medulla, Pons (Cranial Nerves)
• Cerebellum
• Occipital lobes

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Anterior Circulation

• The common carotid arteries divide to form the
• external and internal carotid arteries.
• The internal carotids divide
• into the ACAs and the MCAs

The middle cerebral arteries MCAs supply much of
the lateral surfaces of the hemispheres
The anterior cerebral arteries ACAs supply
much of the medial surfaces of the hemispheres
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The Circle of Willis

• Small branches of arteries will connect the
  anterior circulation
• with the posterior circulation, forming the
  Circle of Willis

If posterior circulation is compromised, the
brain will draw from its anterior circulation.
If anterior circulation is compromised, the brain
will draw from its posterior circulation.
Thus, the brain will also provide collateral
circulation if and when it is needed .
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Thrombosis

• Formation of clot (thrombus) on the inner lumen
  of a vessel wall
• A thrombus is formed when the body perceives
  injury to the vessel wall
• Remember hemostasis?
• Vascular spasm
• Platelet plugging
• Chemical clotting cascade of reactions ? clot
  formation
• A thrombus may be very long in length
• It may be thick enough to occlude blood flow
  through vessel

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Cerebrovascular Accident CVA

• US stats
• Approx 700,000 people of all ages each year have
  a stroke
• Every 45 seconds someone in the US has a stroke
• Every 3 minutes someone dies of a stroke
• The 3 cause of death, and the leading cause of
  long-term disability
• Populations at risk
• African Americans
• American Indians
• Alaskan natives
• Mexican Americans
• Age gt 75 years old
• Pregnant woman and 6 weeks following childbirth
  at high risk
• Asian Americans are NOT at risk for a stroke

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Risk Factors for for CVA

• Modifiable Risk Factors we can change them
• HTN (high blood pressure)
• Artherosclerosis
• Hyperlipidemia
• Diabetes
• Life Style changes
• Dont SMOKE
• Limit alcohol
• Weight control
• Healthy diet, limit salt
• Dont use drugs of abuse
• exercise
• Non-modifiable we cannot change them
• Age most strokes gt age 75
• Race African Americans higher risk
• Gender men at higher risk
• Heredity genetic predisposition
• Prior stroke history

Rx compliance
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Cerebrovascular Accident CVA

• CVAs are disorders of the vascular system in the
  brain.
• Blood vessels are unable to supply blood and
  oxygen
• to the brain tissue (ie brain parenchyma)
• The most common CVAs are
• Stroke hemorrhagic or infarction CELL DEATH
  PERMANENT
• Transient Ischemic Attack TIA SYMPTOMS LAST lt
  24 HRS
• Subarachnoid Hemorrhage SAH A BLEED BELOW THE
  ARACHNOID MEMBRANE
• An interruption of blood flow to the brain will
  result in a neurological deficit
• Auditory deafness, ringing, vertigo (room
  spinning)
• Intellectual deficits confusion, memory,
  recognition problems
• Motor deficits weakness, paralysis hemiplegia
  unilateral, tremors, flaccidity, ataxia
• Sensory deficits numbness, burning, tingling,
  lack of sensation
• Visual blindness either total or in visual
  field(s) (eg homonymous hemianopsia)
• Speech (aphasias)
• Motor can not use muscles to speak (Brocas
  area) EXPRESSIVE APHASIA think! the pt cant
  express themselves
• Sensory can not perceive (receive) understand
  speech (Wernickes area) RECEPTIVE APHASIA
  think! Pt cant receive the information

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Transient Ischemic Attack TIA
Confused?

• Definition An interruption of blood flow to
  part of the 111111111111111
• brain, resulting in a neurological deficit.
  
• A WARNING SIGN of an impending stroke !!!!!
• Highest probability of stroke within first few
  days to weeks after TIA
• 25-30 of patients with a TIA will have a stroke
  within 5 years.
• Confused about the difference b/t a stroke and a
  TIA?
• If the neuro deficit persists gt 24 hrs, the
  patient is given the dx of a stroke
• If the neuro deficit persists lt 24 hrs, the
  patient is given the dx of a TIA
• Symptoms same as stroke any of the various
  types of neurological deficits
• Intellectual deficits confusion, memory loss,
  recognition problems
• Motor deficits weakness, paralysis, tremors,
  flaccidity, ptosis (eyelid drooping), ataxia
• Sensory deficits burning, numbness, tingling,
  lack of sensation, visual, auditory, speech
• Visual blindness either total or in specific
  visual fields (homonymous hemianopsia)
• Auditory deafness, ringing, buzzing, vertigo
  (room spinning)
• Aphasias EXPRESSIVE APHASIA motor pt cant
  express themselves with word

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Anopsia- Hemianopsia

• Anopsia total blindness
• Right homonymous hemianopsia pt lost vision in
  right fields bilaterally
• Left homonymous hemianopsia pt lost vision in
  left fields bilaterally

• Total Blindness, right eye
• B. Nasal hemianopsia of right eye
• C. Left homonymous hemianopsia huh-MON-uh-muhs
  hemE-an-OP-sEa
• D. Bitemporal hemianopsia .

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Anopsia- Hemianopsia
Can you bring it all together?
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Stroke Two general types

• 1. Ischemic Stroke 80 of all strokes
• Risk atherosclerosis
• Decrease in blood flow to the brain due to
  either
• 1. A thrombus clot formation on the inner
  wall of a blood vessel
• 2. An emboli moving debris of a thrombus or
  a piece of plaque
• Causes of emboli stagnant (pooling) blood
  will clot!
• Heart muscle dz MI, dilated cardiomyopathy,
  congestive heart failure
• valvular dz mitral stenosis, aortic stenosis,
  MVP, prosthetic valves
• Arrhythmias atrial fibrillation (very common!)
• Hemorrhagic Stroke 20 of all strokes
• a vessel bursts (ie aneurysm/ A-V malformation
• Pt will have the slowest rate of recovery and the
  
• highest probability of extensive
  neurological damage.
• Aneurysm a weakened area of a vessel wall,
• prone to rupture (ballooning of a vessel
  wall) berry aneurysms
• A-V malformation AVM anomalous arterial-venous
  connection
• patients are born with these, most go
  undetected

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Brain Hemorrhages
Intracerebral

• Intracerebral within the brain parenchyma
• Risk AVM or aneurysm HYPERTENSION
• Subarachnoid SAH beneath the
• arachnoid membrane, above the pia
• Risk AVM or aneurysm HYPERTENSION
• Subdural beneath the dura membrane,
• above the arachnoid
• Usually due to head trauma
• Epidural beneath the skull, above the dura
  membrane
• Usually due to head trauma
• Symptoms of SAH
• Occurs suddenly
• Severe headache Worst HA of my life
• Stiff neck
• Loss of consciousness
• Vomiting
• seizures

Stroke

hemorrhage
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Ischemic Stroke

• Ischemic (lack of blood flow), may be due to
• A thrombus (clot formation on the inner wall of a
  blood vessel)
• An emboli (moving debris of a thrombus or a piece
  of plaque)
• Artherosclerosis is a major risk factor for
  ischemic stroke
• Recall ischemia means hypoxia. Thus, brain
  tissue is not being adequately perfused.
• Ischemic stroke is the most common type of
  stroke
• 80 includes thrombotic and embolic stroke
• Treatment
• Tissue-Plasminogen-Activator t-PA
• Must be given within first 3 hrs of onset of
  symptoms
• t-PA will dissolve the formed/forming clot.
• TPA will activate plasminogen which will
  degrade the clot
• Remember hemostasis?

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Save the Penumbra!

• Cerebral function is dependent on oxygen and
  glucose
• No insulin receptors are needed to bring glucose
  into nerve cells
• If supply of oxygen or glucose is stopped, the
  brain tissue will die (ie infarction)
• For a brief period of time following a stroke,
  there is an area of HYPOXIC brain tissue
  surrounding the DEAD CORE called the PENUMBRA
• The prenumbra is an ischemic area (ie hypoxic)
• The prenumbra is NOT infarcted (IT IS NOT DEAD)
• It is the return of function to this hypoxic
• area which represents the patients
• ability to regain some neurological
• function after a stroke
• (ie when a patients stroke symptoms
• 
  partially resolve).

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CT versus MRI
What type of stroke is this?

• CT scan Computed Tomography
• Computerized analysis of multiple x-rays
• A head CT will be the first test done in the ER
  if a
• stroke is suspected it is a relatively
  quick procedure
• The purpose is to determine if stroke is
  hemorrhagic or ischemic
• Time is of an essence in a stroke pt! If the CT
  does NOT show a bleed, the stroke is considered
  ischemic
• If the pts symptoms are reported to be lt 3 hrs
  in duration, t-PA will be initiated. SAVE THE
  PENUMBRA!
• Why would you NOT want to give t-PA to a pt with
  a hemorrhage stroke?
• MRI Magnetic Resonance imaging
• No exposure to ionizing radiation (like x-rays)
• Based on the behavior of H ions in a magnetic
  field
• will often be done within the next few days to
  weeks
• Provides better contrast between normal and
  pathological
• tissues. Thus, it can pick up small areas
  of necrosis (dead nerve tissue) from a stroke
• Hmmm?? Beware, the ER may tell you the CT was
  negative, but the pt actually had a small
  ischemic stroke! The MRI next week will confirm so

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Lumbar puncture

• CSF exists b/t the pia mater and the arachnoid
  mater
• Functions of an LP
• to measure pressure in the subarachnoid space
  (ICP)
• ICP intracranial pressure
• to obtain CSF for examination and diagnosis
• - blood
• - bacteria gram stain/ CS
• - malignant cells
• - amount of glucose
• amount of protein
• used to inject therapeutic or diagnostic
  agents
• administration of spinal anesthetics

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Nursing Interventions before after an LP

• Prior to LP procedure
• Ensure the patient signed an informed consent
• Position the patient in the side-lying position
  with the
• vertebrae flexed to open up the space
  between L3-L4 or L4-L5
• Provide adequate education to patient and family
  to minimize fear
• Post LP procedure
• Keep the patient on bed rest with head
• of the bed flat for 6 hrs
• Assess vital signs frequently
• BP, HR, Temp
• Assess movement and sensation of
• lower extremities frequently for several
  hrs
• Check the puncture site for redness,
• swelling or drainage

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Cerebral Angiogram
Anterior circulation Common carotid
artery Internal/external carotid Where is the
stenosis?

• Radioactive dye is sent into cerebral circulation
• Indicated for Ischemic stroke patients, TIA
  patients
• Why not with a hemorrhagic stroke?
• No allergies to iodine !!!!! or shellfish!!!!
• No history of kidney dz dye is nephrotoxic!

Posterior circulation Vertebral artery Post
cerebral a. / Cerebellar a.
Anterior circulation Anterior cerebral artery
ACA
Anterior circulation Internal carotid
artery Middle cerebral artery MCA
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Motor Deficits of CVA

• The primary motor cortex is in the frontal lobe
• Ptosis drooping of an organ, usually referring
  to eyelid with stroke pt (ptosis dropping)
• Dysarthria difficulty speaking (arthrounto
  udder distinctly)
• Dysphagia difficulty swallowing (dys bad
  difficult) (phagia to eat)
• Ataxia poor balance, stumbling gait, staggering
  (a not taxis order)
• Hemiplegia hemiparesis paralysis in ½ of the
  body unilateral (hemi half) (plegia stroke)

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Sensory Deficits of CVA

• Sensory Cortexes
• Think! Deficits in PPTT from sensory neurons,
  and add numbness, tingling
• Some hemiplegic pts will perceive the weak or
  paralyzed side of the body to be very painful
• Unilateral neglect, pt does not recognize ½ of
  their body, eg pt will shave only ½ of face
• Proprioception problems pt has difficulty
  discerning position of his/her body in space
• Cranial Nerves
• Remember CN I through CN XII?
• Some sensory, some motor, some mixed
• Vision, smell, taste, hear, facial m., swallowing
  m.
• CNs are often affected in a stroke pt, Why?

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Glasgow Coma Scale

• Coma classification
• Severe GCS 8 Moderate GCS 9 -
  12 Minor GCS 13

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Nursing Intervention Acute Phase

• Acute Phase first 24-48 hrs
• 1. First and foremost Airway must be
  maintained!!
• Stroke pts are at risk for airway obstruction for
  many reasons
• Tongue may fall back if pt is in impaired state
  of consciousness
  to nurse can prevent this by putting the pt in
  side-lying position
• Stroke may have occurred in respiratory area of
  brain stem
• 2. Document vital signs
• BP is often very high initially. Rapid lowering
  will produce worse outcome for pt, due to risk of
  hypoperfusion of brain parenchyma, worsening
  infarction
• Increased pulse pressure is a sign of ICP
• pulse pressure systolic pressure diastolic
  pressure
• 3. Watch for signs/symptoms of ICP
• Sx Headache (worst HA in life), decreased LOC,
  vomiting, seizures, unequal pupils
• Risk of ICP can be decreased by quiet room,
  elevate head of bed 30-45 degrees, give stool
  softeners to prevent pt from straining with bowel
  movement
• Exercises, moving the pt and excessive suctioning
  can also raise ICP
• Expectorants can promote coughing which can raise
  ICP

blown pupil
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Nursing Intervention Acute Phase

• Acute Phase first 24-48 hrs
• 4. Perform Neuro checks to assess LOC Glasgow
  
• Normal pupilary rxn pupil constricts in response
  to light,
  then slowly returns to size
• Consensual response is when a light is shined in
  one pupil and both pupils will constrict
  simultaneously- this is a normal-healthy response
• Anisocoria a term used for unequal pupils
• Morphine and tranquilizers are NOT usually used
• b/c they make the neurological assessment
  difficult.
• 5. Oxygen therapy
• Brain parenchyma is hypoxic intubation, O2 via
  face mask
• or nasal cannula may be ordered. Pulse
  oximetry is important
• 6. Mealtimes
• Stroke pts are at risk for aspiration food in
  trachea
• Place pt in the Fowlers position or in a chair
  for meals
• Stay with the patient during meals
• Have suction equipment available in case
  aspiration

Fowlers position
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Nursing Intervention Post Acute-Phase

• Skin Integrity
• Hemiplegic pts at risk of decubitus (pressure
  )ulcers nurse should re-position pt q 2 hrs,
  elevate heels off bed, keep bedding dry and
  wrinkle free, offer protective boots
• Altered sensations put pt at risk of injury from
  
  pressure or excess heat or cold
• Move to chair out of bed chair,
  
  if able
• Aphasias adapt communication methods according
  type of aphasia
• nurse should speak slowly and clearly while
  facing patient,
• use gestures, pictures, facial expressions
• For which type of aphasia would you need this
  pain
• intensity scale? receptive or expressive?
• Constipation assess bowel movements due to
  compromised GI motility
• pt may b/c constipated. Give high fiber
  foods oatmeal, prunes,
  fresh fruits, whole
  grain breads/ cereals (bran)

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Nursing Intervention Post Acute-Phase

• Dysphagia/ Dysarthria warrants aspiration
  precautions
• pt to aspirate foods or fluids at mealtimes
  
  prevent, have pt sit at a 90-degree angle,
  chin tucked to chest
• Due to dehydration and immobility, pt may form
  
  thick bronchial secretions, if aspirated may
  cause pneumonia.
• Pneumonia is the 1 cause of death post-stroke
• Monitor IOs
• Pt may be given osmotic diuretics if increased
  ICP is expected
• If pt becomes dehydrated, increased risk of
  aspiration
  (Think! fluids thin bronchial mucus
  secretions)
• UTIs can develop due to stagnant flow of urine
• Watch for these additional complications
• Muscle contractures affected muscles will
  initially be
  flaccid, then possibly become spastic
• Thrombophlebitis stagnant blood? clotting
  factors
  aggregate? thrombus formation (remember
  hemostasis?)

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Prognosis

• Prognosis is becoming increasingly hopeful!
• Critical variables
• Pt condition before stroke comorbid conditions?
• DM, CAD, HTN, RA (rheumatoid arthritis), GI
  problems
• Timely medical treatment did pt present in the
  acute phase?
• Timing of onset of symptoms the sooner pt is
  treated, the better!
• Severity of neurological deficits sustained
• Pt who is comotase gt 36 hrs has poor chance of
  recovery
• Timely rehabilitative treatment
• Stabilization of VS, with no further neurological
  deficits, indicates pt is ready
• Goal maximize functional abilities and to teach
  new ways to compensate for losses to re-train pt
  in ADLs (activities of daily living)
• Instruct family members to perform passive range
  of motion on affected limb if plan is for pt to
  return home w/ outpatient rehabilitation
• Prognosis for hemorrhagic stroke victims is
  significantly worse than for patients with
  ischemic strokes

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Pharmacotherapy of special interest in Stroke

• Anti-thrombolytic Agents
• Will dissolve a formed/forming clot
• Must be given within first 3 hrs of onset of
  symptoms
• Tissue-Plasminogen-Activator tPA
• Streptokinase
• 2. Anticoagulant Therapy
• Should be initiated in the event of an ischemic
  stroke
• Contraindicated in hemorrhagic stroke! Pt will
  bleed more!
• Heparin prevents formation of new clots,
  monitored via PTT
• Coumadin (Warfarin) prevents formation of new
  clots, monitored via PT/INR this works much more
  slowly than heparin, since it inhibits Vit K,
  which is used by the liver to make a number of
  different clotting factors.
• INR (international normalized ratio) INR should
  be between 2.0-3.0 assess pt for bruising,
  bleeding from gums/nose/mouth and ck urine for
  hematuria
• 3. Osmotic diuretics
• Mannitol is first line treatment for increased
  ICP
• Not absorbed via the GI tract, must be given IV
• Nursing must be vigilant in monitoring pt IOs

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Pharmacotherapy general for nervous system

• Anticonvulsants
• Phenytoin (Dilantin)
• Carbamazepine (Tegretol)
• Phenobarbital (Luminal)
• Primidone (Mysoline)
• Ethosuximide (Zarontin)
• Mephenytoin (Mesantoin)
• Valproic acid (Depakote, Depakene)
• Gabapentin (Neurontin)
• Clonazepam (Klonopin)
• Diazepam (Valium)
• Lorazepam (Ativan)
• Clonazepam (Klonopin) 
• Barbiturates
• Phenobarbital (Luminal)
• Primidone (Myidone)
• Secobarbital (Seconal)

Anti-Parkinsons Trihexyphenidyl
(Artane) Trihexyphenidyl HCl (Artane) Benztropine
mesylate (Cogentin) Amantadine HCl
(Symmetrel) Bromocriptine mesylate
(Parlodel) Levodopa (Dopar)
Corticosteroids DECREASE INFLAMMATION Dexamethaso
ne (Decadron)   Osmotic diuretic agents DECREASE
ICP Mannitol (Osmitrol) Urea (Ureaphil)   Anticoag
ulants Heparin Sodium monitor w/ PTT Warfarin
sodium (Coumadin) monitor w/ PT/INR   Thrombolyti
c agents DISSOLVE CLOTS Streptokinase Tissue
plasminogen activator (tPA)
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Pharmacotherapy general for nervous system

• Anti-Vertigo/ Motion Sickness/ Anti-Emetic
• Dimenhydrinate (Dramamine)
• Diphenhydramine HCl (Benadryl)
• Meclizine HCl (Antivert)
• Promethazine HCl (Phenergan)
• Scopolamine (Transderm-scop)
• Trimethobenzamide (Tigan)
• Trimethobenzamide HCl (Tigan)
• Prochlorperazine (Compazine)
• Thiethylperazine (Torecan)
• Metoclopramide (Reglan)
• Ondansetron (Zofran)
•  
• Anti-inflammatory
• Dexamethasone Decadron

Platelet Aggregation Inhibitors Aspirin Dipyridamo
le (Persantine) Ticlopidine (Ticlid) Clopidogrel
(Plavix) Calcium Channel Blockers Nimodipine
(Nimotop) Nifidipine (Procardia) Vascular
Headache Suppressents Dihydroergotamine
(Ergostat) Sumatriptan (Imitrex) Cholesterol
reducing Pravastatin (Pravachol) Atorvastatin
(Lipitor) Simvastatin (Zocor) Lovastatin
(Mevacor) Rosuvastatin (Crestor)
Vasodilator Papaverine
ALERT statin drugs can cause adverse reactions
muscle aches, diarrhea, nausea, bloating
serious ADRs rhabdomyolysis muscle aches and
liver toxicity ie chemical hepatitis
confusion
42
The End

• Questions?
• Feel free to email me..
• bests_at_pbcc.edu