ataxia in the stroke patient kelli kulpa bsn, rn alverno college msn student neurosciences...
TRANSCRIPT
Ataxiain the Stroke Patient
Kelli Kulpa BSN, RNAlverno College MSN StudentNeurosciences Department
Froedtert Hospital
Objectives
• Describe pathophysiology of cerebellum as it relates to smooth muscle movements
• Describe how ischemia to cerebellum causes ataxia in stroke patient
• Identify presence of ataxia in stroke patient
• Identify appropriate nursing interventions and outcomes
TOPICS TO REVIEW
STROKE
CEREBELLUM
ATAXIA
NIH STROKE SCALE
CARE OF THE PATIENT WITH ATAXIA
Stroke• “Syndrome of acute focal
neurologic deficit from a vascular disorder that injures brain tissue” Porth (2005, p. 1245)
• US leading cause of mortality & morbidity
• About 700,000 Americans afflicted with stroke
• Many survivors left with some degree of deficit
Image from Microsoft Clipart
(Porth, 2005)
Risk Factors for Stroke
• Controllable• Hypertension (HTN)• Atrial Fibrillation• High Cholesterol• Diabetes• Tobacco Use & Smoking• Alcohol Use• Physical Inactivity• Obesity
• Uncontrollable• Age• Race• Gender• Family History• Previous Stroke or TIA• Fibromuscular Dysplasia• Patent Foramen Ovale
(National Stoke Association, 2009)
Image from Microsoft Clipart
Uncontrollable Risk Factor• AGE:
• Risk of stroke increases with age
• After age 55, risk doubles for every decade that passes
• Increased prevalence of controllable risk factors as age increases
• Hypertension• High Cholesterol• Diabetes
• RACE: AFRICAN-AMERICAN• Most impacted race in US• Twice as likely to die from
stroke than Caucasians• Occur earlier in life
• Reasons not fully understood, but have a higher rate of risk factors
• ex: 41% have HTN
(National Stoke Association, 2009)
Image from Microsoft Clipart
Uncontrollable Risk Factor
• GENDER: WOMEN• 55,000 more women than men experience stroke each
year
• Unique risk factors:• Oral Contraceptives• Pregnancy• Hormone replacement therapy• Post-menopausal with thick waist and high triglyceride
levels• Suffer more migraines, increase risk 3-6 times
(National Stoke Association, 2009)
Image from Microsoft Clipart
Uncontrollable Risk Factor• FAMILY HISTORY
• Evidence suggests genes influence vulnerability to HTN & stroke
• A region on:• Chromosome 13 in Caucasians• Chromosome 19 in African-Americans
• Carotid intimalmedial wall thickness (IMT)• Surrogate measure of subclinical atherosclerosis• Strong predictor of future ischemic strokes• Homozygous for 6A genotype
• Genetically predisposed to produce less stromelysin 1• High carotid artery wall thickness & greater risk of stroke
Image from Microsoft Clipart
(Morrison, Brown, Kardia, Turner, & Boerwinkle, 2003)
(Humphries & Morgan, 2004)
Controllable Risk Factor & Inflammation
• Inflammation can influence the development of atherosclerosis• Causes endothelial dysfunction
• One of the earliest manifestations of atherosclerosis
• Inflammatory markers associated: • Coronary disease development• Disease severity• Occurrence of coronary events
• Progression of atherosclerosis may be associated with high concentrations of inflammatory markers
(Humphries & Morgan, 2004)
GREAT!
SORRY!Cannot control if you
have a history of stroke
OPPS!Cannot control age
GOOD JOB!
TEST YOUR KNOWLEDGE• Select the controllable risk factors for stroke
(Multiple answers)
Hypertension
Age
Previous Stroke
Hyperlipidemia
Yes!Women are at higher risk of stroke & also have
increased mortality.
Sorry!Women are at higher risk of stroke & also have
increased mortality.
TEST YOUR KNOWLEDGE
• Men are at higher risk of stroke
TRUE
FALSE
Types of Stroke
• ISCHEMIC• Interruption of blood flow in
a cerebral vessel• Most common type• Account for 70-80% of strokes
• HEMORRHAGIC• Bleeding into the brain tissue,
from blood vessel rupture
• Caused by: • HTN• Aneurysms• AVM• Head injury
• Much higher fatality rate• 37-38% of occurrence results in death
(American Heart Association, 2010)
(Porth, 2005)Image from Microsoft Clipart
Cell Ischemia
• Reduced or absent blood flow deprives cell of needed nutrients
• Effects occur quickly• No stored glucose in brain• Incapable of anaerobic metabolism
(Porth, 2005)
Neuronal Injury: Excitotoxicity
• Ischemia depletes neuronal energy stores causing energy dependent membrane ion pumps to fail
• Results in increased extracellular glutamate concentration
• Release of excitotoxic glutamate & aspartate open up calcium channels• Influx of calcium, sodium and chloride
• Intracellular calcium responsible for activation of a series of destructive enzymes
• Out flux of potassium • Resulting in irreversible neuronal damage
• Results in release of cytokines and other mediators(Porth, 2005)
Inflammation Following Ischemia• Rapid production of inflammatory mediators
• White blood cell (WBC) recruitment to ischemic area as early as 30 minutes
• Capillary endothelium produces adhesive proteins causing WBCs to adhere to capillary lining
• WBCs move into injured tissue
• Phagocytize injured cells
• Extent of inflammation can be determined by C-reactive protein levels
Image used with permission from http://images.wellcome.ac.uk/
(Porth, 2005)
Try againThere are increased levels
of glutamate.
GOOD JOB!No energy is getting to the
cell.
Try againPhosphorus is not directly
related to this process
Try againIf the cell is not getting
adequate blood flow, there is not enough energy
available.
TEST YOUR KNOWLEDGE• Neural cell ischemia is caused from:
Too much energy available to the cell
Lack of phosphorus available
Energy dependent membrane ion
pumps fail
Decreased levelsof glutamate
Cerebellum• Stores learned sequences of
movements
• Fine tuning & coordination of movement produced elsewhere in brain
• Integrates all information to produce fluid movements
(Dubuc, 2002)
Image used with permission from http://thebrain.mcgill.ca/flash/i/i_06/i_06_cr/i_06_cr_mou/i_06_cr_mou.html#3
Movement• Motor cortex:
• Sends signals to cerebellum• Communicates movement to
make
• Cerebellum:• Makes continuous
adjustments
• Final result:• Smooth movement, key with
delicate maneuvers(Porth, 2005)
Image used with permission from http://thebrain.mcgill.ca/flash/i/i_06/i_06_cr/i_06_cr_mou/i_06_cr_mou.html
CerebellumHover over the highlighted words for definition
Cerebellum Involvement
• Receives proprioceptor input from vestibular system
• Feedback from muscles, tendons, & joints
• Indirect signals from somesthetic, visual, & auditory systems to provide background info for ongoing movement
(Porth, 2005)
• Can continuously assess status of each body part• Position• Rate of movement• Forces, such as gravity,
opposing it
(McGill University, 2002)
Dampening Muscle Movement• All body movements are pendular
• Intact cerebellum analyzes proprioceptive information to predict:• Future position of moving parts• Speed of movement• Projected time course of movement
• As movement approaches target, Cerebellum will:• Inhibit agonist muscles• Excite antagonist muscles
(Porth, 2005)
Image from Microsoft Clipart
(Porth, 2005)
“Require a burst of energy from an agonist muscle group; the movement is programmed from the start, so the movement proceeds from start to finish without modification”
Type of Movement
Simple Movement
Self-terminating Movement: require smooth muscle sequence of coordinated agonist & antagonist movements programmed by higher brain centers to start, then are modified as the movement proceeds
Complex MovementClick for Explanation Click for Explanation
Porth (2005, p. 1194)
Image from Microsoft Clipart
Try again;This is part of the
somesthetic system.
GOOD JOB!
OPPS!Vestibular apparatus, try
again.
Try again;This is part of the
somesthetic system.
TEST YOUR KNOWLEDGE• Proprioreceptor input is:
Meaningfulness of integrated sensory
information from various sensory systems
The inner ear structures that are associated with balance
and position sense
Any sensory nerve ending responding to stimuli from
within body related to movement & spatial position
Concerning perceptions of ‘where’ the stimulus is in space and in relation to
body parts
Opps!Think this through again. Movement is pendulous.
Yes!Movement is pendulous, so muscles have
to be stopped.
TEST YOUR KNOWLEDGE
• As movement approaches a target, the cerebellum will:
Inhibit agonist muscles & Excite antagonist muscles
Excite agonist muscles & Inhibit antagonist muscles
Ataxia• People with ataxia experience
• Failure of muscle control in arms and legs• Results in:
• Lack of balance & coordination• Disturbance in gait
Image from Microsoft Clipart
(National Institute Of Neurological Disorders And Stroke, 2010)
Acquired (non-genetic) Ataxia
• Conditions that can cause acquired ataxia• Stroke• Multiple Sclerosis• Tumors• Alcoholism• Peripheral neuropathy• Metabolic disorders• Vitamin deficiencies
(National Institute Of Neurological Disorders And Stroke, 2010)
Image from Microsoft Clipart
Ataxia after Stroke
• Right side of cerebellum controls coordination on right side of body, left side controls left
• When nerve cells are lost or damaged:• Provide less control to muscles• Resulting in: loss of coordination
• During a stroke:• Blood supply is interrupted or severely reduced• Deprivation of oxygen and nutrients to brain tissue• Brain cells begin to die
(Mayo Clinic Staff, 2009)
Image from Microsoft Clipart
Recent Findings
• 15% of all cerebral strokes involve the cerebellum
(Timmann et al., 2009)
• Anterior lobe of cerebellum is involved in motor control• Concluded from a study containing 34
patients with cerebellar infarcts(Schmahmann, Macmore, & Vangel, 2009)
Image from Microsoft Clipart
Cerebellar Ataxia
How does alcohol relate?Select the beer for the answer!
• Decomposition of movement
• Each component of the movement occurs separately instead of being blended into a smooth action
(Porth, 2005)
“Ethanol specifically affects cerebellar function, persons who are inebriated often walk with a staggering and unsteady gait” Porth (2005, p. 1213)
Image from Microsoft Clipart
(Porth, 2005)
Ataxia
• Rapid alternating movements are performed slowly and jerky• Such as pronation-supination-
pronation of hands
• Touching a target:• Movements broken down
into small steps• Each movement goes too far,
then overcompensated• DYSMETRIA
SELECT THE TARGET TO SEE AN ANIMATION OF DYSMETRIA
Image from Microsoft Clipart
(Porth, 2005)
Clinical Pearl
• Read the CT or MRI reports to identify where the infarct is located in the brain. If the cerebellum is involved, chances are ATAXIA will be exhibited in the patient
Image from Microsoft Clipart
Try again
GOOD JOB!
OPPS!
Try again
TEST YOUR KNOWLEDGE• Ataxia is:
Weakness
Impaired speech
Lack of coordination
No need to pay taxes
Almost there…look closer at the options.
Think again,motor cortex is involved in movement, but not directly
related to ataxia.
Try again;not related to movement
AWESOME!
TEST YOUR KNOWLEDGE• What part of the brain was infarcted if the
patient has ataxia?
Cerebellum
Parietal Lobe
Motor Cortex
Cerebrum
Opps!Ataxia after a stroke is not a genetic cause of ataxia.
Genetic ataxia is caused from mutations in genes.
Yes!Acquired ataxia is non-genetic.
TEST YOUR KNOWLEDGE
• Ataxia in stroke is acquired ataxia.
True
False
National Institute of Health Stroke Scale (NIHSS)
• Stroke scale functions:• Document and communicate
• Baseline deficits• Changes over time
• First used in 1989• Administered in mean time of 6.6 minutes• Interrater and intrarater agreement is good
Image from Microsoft Clipart
(Jensen & Lyden, 2006)
National Institute of Health Stroke Scale (NIHSS)
• Strongly predicts the likelihood of recovery after stroke
• Total score • > 16 high probability of death or severe disability• <6 predicts a good recovery
Image from Microsoft Clipart
(Duncan et al., 2005)
National Institute of Health Stroke Scale (NIHSS)
• 15 Item Clinical Deficit Scale• Assess:
• Level of Consciousness• Gaze• Vision• Facial Palsy• Arm & Leg Strength• Limb Ataxia• Neglect• Dysarthria• Aphasia
REMEMBER:MUST BE ASSESSED
IN ORDER LISTED
Image from Microsoft Clipart
(Jensen & Lyden, 2006)
NIHSSLimb Ataxia
“A few items consistently show poor agreement, notably ataxia,
dysarthria, and facial weakness” Jensen & Lyden (2006, p. 2)
YOU’RE NOT THE ONLY ONE WHO MAY MAKE AN ERROR
SCORING ATAXIA!!!
NIHSSLimb Ataxia
• Assesses evidence of a unilateral cerebellar lesion
• Assesses incoordination from weakness
• Test with eyes open, in intact visual field
• Test on bilateral extremities
(NIH Stroke Scale International, 2001)(National Institute Of Neurological Disorders And Stroke, 2001)
Evaluating Limb Ataxia
• Scored if present out of proportion to weakness
• Two instances when ataxia would not be assessed• Absent in patients who do not understand or are
paralyzed• Untestable (UN) if amputation or joint fusion
present
(NIH Stroke Scale International, 2001)(National Institute Of Neurological Disorders And Stroke, 2001)
Click on picture of face to view
example of finger-nose-finger test
with ataxia present
Finger-Nose-Finger Test• Ask patient to touch your
index finger with his index finger and then back to his nose
• Repeat enough times to fully assess for ataxia, moving your index finger each time to make a new target
• Then repeat using other extremity
(NIH Stroke Scale International, 2001)
Image from Microsoft Clipart
Heel-Shin Test
• Ask patient to move right heel up and down the left shin
• Repeat enough times fully assess for ataxia
• Then repeat using other extremity
(NIH Stroke Scale International, 2001)
Image from Microsoft Clipart
Click on picture to view example of
heel-shin test with ataxia present
Limb Ataxia• SCALE DEFINITION
• 0 Absent (Not present or paralyzed)• 1 Present in 1 limb (an arm or a leg)• 2 Present in 2 limbs (both arms, both legs,
or arm and leg on same side of body)
• UN Amputation or joint fusion (explain)
• The link below will take you to the National Institute of Health Stroke Scale Training Video• Assessment #7 Limb Ataxia http://www.youtube.com/watch?
v=8AXtl3QPH7Y&feature=related
(NIH Stroke Scale International, 2001)Video used with permission from NIHSS English Training Campus
Great job!Ataxia is incoordination, not weakness!
False:Ataxia is incoordination, not weakness!
TEST YOUR KNOWLEDGE
• Ataxia occurs because of muscle weakness after a stroke.
True
False
Great job!Ataxia is assessed after weakness!
Think about the order of the exam.Ataxia is assessed after weakness!
TEST YOUR KNOWLEDGE• Ataxia needs to be assessed prior to weakness in the NIH Stroke
Scale.
True
False
Great job!Ataxia is not present because the patient is
unable to perform the test.The score would be absent due to paralysis.
No, ataxia is not present because the patient isunable to perform the test.
The score would be absent or 0 due to paralysis.
TEST YOUR KNOWLEDGE• If the patient has weakness in the right arm and is unable to lift the
arm off the bed, would ataxia be present?
Yes
No
Try again!Only score UN if amputation
or joint fusion present.
GREAT JOB!
Try again!Ataxia is only present in the
R arm.
Try again!Ataxia is present in R arm.
TEST YOUR KNOWLEDGE• The patient exhibits some weakness in the right arm and is able to perform the finger-nose-
finger test. The patient misses the assessors finger. The patient completes test on left arm without difficulty. What score would be given for the upper extremity test?
0
2
1
UN
Treatment
• There is no current cure of ataxia following a cerebellar stroke
• Physical & Occupational Therapy• Strengthen muscles• Assistive devices
• Assist in walking and other activities of daily living (ADLs)
(National Institute Of Neurological Disorders And Stroke, 2010)
Image from Microsoft Clipart
Nurse Sensitive Outcomes
• Impaired Mobility• Mobilize early to prevent complications
• Active & Passive range of motion (ROM)• Participate in self-care & activities frequently
• Teach safe use of assistive devices• Educate & Facilitate adaptation of home/work
environment for maximal independence• Teach safety precautions• Expected outcomes:
• Optimal independence with ADLs & mobility• Maintain safety precautions
(Bader & Littlejohns, 2004)
Nurse Sensitive Outcomes
Self-Care Deficit• Evaluate ability to perform ADLs• Consult occupational therapy (OT)• Assess for risk of falls• Expected outcomes:
• Functional abilities recognized & advanced
(Bader & Littlejohns, 2004)
Nurse Sensitive Outcomes
Safety• Identify Fall Risk
• Implement fall prevention strategies• Universal Fall Risk Interventions• Fall Precautions due to activity impairment
• Expected outcome:• Effective in decreasing vulnerability to falls and
related injury(Summers et al., 2009)
Nurse Sensitive Outcomes
Anticipatory grieving related to loss of functional abilities• Facilitate discussions to allow patient/family to
voice concerns• Neuropsychiatry consult to evaluate cognitive vs.
depressive issues• Rehabilitation consult to evaluate needs• Support Groups• Expected outcomes:
• Supported & given resources to assist with coping(Bader & Littlejohns, 2004)
Coping• Challenges:
• Loss of independence• May feel alone• Lead to depression & anxiety
• Therapy or counseling may lessen sense of isolation and help cope
• Can lead to increased stress on the patient• Habitual Stress
• The physiologic & behavioral changes induced by generalized stress response can threaten homeostasis
(Porth, 2005)(Mayo Clinic Staff, 2009)
Generalized Stress Response
• Stroke is a life changing event people do not have time to prepare for
• Stress can impact controllable risk factors for stroke• Hypertension• High cholesterol• Tobacco use• Alcohol use• Physical Inactivity• Obesity
Generalized Stress Response (GSR)
(Porth, 2005)
Renin-Angiotensin-Aldosterone Pathway
(Porth, 2005)
Hormone Involvement in GSR• Corticotropin-releasing Factor (CRF)
• Released by the hypothalamus• Stimulates ACTH release
• Adrenocorticotropic hormone (ACTH)• Released from the anterior pituitary gland• Stimulates synthesis and release of cortisol
• Cortisol• Released from adrenal cortex• Affects many systems and processing in the body
(Porth, 2005)
Effects of Cortisol• Cardiovascular
• arterioles more responsive to sns• increased contractility
• Liver • stored glucose released into blood
• Pancreas• decreased insulin release
• Adipose tissue • lipids released from periphery,
redeposited in trunk
• Skeletal • decreased bone deposition
• Renal• calcium lost in urine• Na+/K+ pump reabsorbs Na+ and
H2O into blood, secretes K+ into urine
• Muscular• actin and myosin break down
• Immune • production of prostaglandins
blocked• thymus atrophies• neutrophils can't leave blood• monocytes and macrophages less
active
(Porth, 2005)
Try again!Ataxia affects movement,
not tissue perfusion.
Try again;Ataxia does not affect breathing in the stroke
patient.
Great job!Very important to also
consider fall risk!
Try again;Ataxia does not affect breathing in the stroke
patient.
TEST YOUR KNOWLEDGE• Identify the most appropriate nursing diagnosis in terms of special
needs when ataxia is present.
Impaired gas exchange
Impaired physical mobility
Ineffective breathing pattern
Impaired tissue perfusion
GREAT!Currently no treatment
available. PT & OT to help with function.
Try again;Not used for treating ataxia.
Try again;Movements are impaired
because of communication error in the brain.
Try again;Used for stroke treatment, but not for treating ataxia.
TEST YOUR KNOWLEDGE• Treatment for ataxia in the stroke patient is:
TPA
Muscle Relaxers
Heparin
No Treatment Available
Case Study
• A 67 year old male with a history of afib and prior stroke (with no deficits) was admitted from home with acute onset of nausea, generalized weakness, ataxia, and left sided weakness. Initial MRI noted a large acute ischemic infarct within the left cerebellum and smaller infarcted areas within the cerebellar vermis and right cerebellum with occlusion of the right internal carotid artery.
Try again;Be more specific
Try again;Be more specific.
GREAT!!!
Case Study• What is the anticipated medical diagnosis of the
patient?
Cerebellar Stroke
Weakness
Stroke
Try again;Ataxia is present in both
upper extremities.
GREAT!Score 2 if present in bilateral upper or lower extremities,
or an arm and leg on the same side of the body.
Opps!Ataxia is present, therefore,
0 cannot be the score.
Case Study• When tested for ataxia, it was present on the bilateral upper
extremities. What score would be given according to the NIHSS?
0
2
1
Great!Think safety with patients
experiencing ataxia!This patient has left sided
weakness, plus BUE ataxia. This could make using mobility
devices harder.
Try again,This could be present in the
patient, but does not relate to ataxia.
Sorry,This would be appropriate, but not specific to the symptom of
ataxia.
Case Study• What appropriate nursing diagnosis would be given
to this patient related to the presences of ataxia?
Impair tissue perfusion
Impaired memory
Risk for injury: falls
The End
• With the completion of the tutorial, you are now able to:• Describe pathophysiology of cerebellum as it
relates to smooth muscle movements• Describe how ischemia to cerebellum causes
ataxia in stroke patient• Identify presence of ataxia in stroke patient• Identify appropriate nursing interventions and
outcomes
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