Ataxia in the Stroke Patient quiz 4
How does alcohol relate to Cerebellar Ataxia?
"Ethanol specifically affects cerebellar function, persons who are inebriated often walk with a staggering and unsteady gait"
Simple Movement
"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"
Stroke
"Syndrome of acute focal neurologic deficit from a vascular disorder that injures brain tissue"
Generalized Stress Response (GSR) Sympathetic Nervous System (SNS)
-"Fight or Flight Response" -Increased heart rate and strength of contraction -Increased metabolic rate, stored fat released into circulation -Bronchodilation in lungs -Pupils Dilate -Vasoconstriction of: skin, gut, and kidneys
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
Risk Factors for Stroke: Uncontrollable
-Age -Race -Gender -Family History -Previous Stroke or TIA -Fibromuscular Dysplasia -Patent Foramen Ovale
Heel-Shin Test for ataxia
-Ask patient to move right heel up and down the left shin -Repeat enough times fully assess for ataxia -Then repeat using other extremity
Finger-Nose-Finger Test for ataxia
-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 (pt with ataxia will miss nose most of the time)
NIHSS: Limb Ataxia assesses and tests:
-Assesses evidence of a unilateral cerebellar lesion -Assesses incoordination from weakness -Test with eyes open, in intact visual field -Test on bilateral extremities
hemorrhagic stroke
-Bleeding into the brain tissue, from blood vessel rupture -Much higher fatality rate 37-38% of occurrence results in death (American Heart Association, 2010)
During a stroke:
-Blood supply is interrupted or severely reduced -Deprivation of oxygen and nutrients to brain tissue -Brain cells begin to die
Uncontrollable Risk Factor FAMILY HISTORY A region on:
-Chromosome 13 in Caucasians -Chromosome 19 in African-Americans
Controllable Risk Factor & Inflammation Inflammatory markers associated:
-Coronary disease development -Disease severity -Occurrence of coronary events
Hormone Involvement in GSR:
-Corticotropin-releasing Factor (CRF) -Adrenocorticotropic hormone (ACTH) -Cortisol
Cerebellar Ataxia
-Decomposition of movement -Movements become slow and jerky, Such as pronation-supination-pronation of hands -Each component of the movement occurs separately instead of being blended into a smooth action
Renin-Angiotensin-Aldosterone Pathway
-Decreased blood flow to kidneys as response to SNS stimulation -Renin released -Activates angiotensinogen -Forms Angiotensin I -Converted into Angiotensin II a strong vasoconstrictor -Aldosterone released from adrenal cortex -turns on Na/K ATPase in kidneys -leads to increased blood volume and increased blood pressure, should increased blood flow to the kidneys
National Institute of Health Stroke Scale function:
-Document and communicate -Baseline deficits -Changes over time
Cell Ischemia effects:
-Effects occur quickly -No stored glucose in brain -Incapable of anaerobic metabolism
Intact cerebellum analyzes proprioceptive information to predict:
-Future position of moving parts -Speed of movement -Projected time course of movement
What is a hemorrhagic stroke caused by?
-HTN -Aneurysms -AVM (Arteriovenous malformation) -Head injury
Stress can impact controllable risk factors for stroke
-Hypertension -High cholesterol -Tobacco use -Alcohol use -Physical Inactivity -Obesity
Risk Factors for Stroke: Controllable
-Hypertension (HTN) -Atrial Fibrillation -High Cholesterol -Diabetes -Tobacco Use & Smoking -Alcohol Use -Physical Inactivity -Obesity
Neuronal Injury: Excitotoxicity Release of excitotoxic glutamate & aspartate open up calcium channels
-Influx of calcium, sodium and chloride -Out flux of potassium -Resulting in irreversible neuronal damage -Results in release of cytokines and other mediators
As movement approaches target, Cerebellum will:
-Inhibit agonist muscles -Excite antagonist muscles
ischemic stroke
-Interruption of blood flow in a cerebral vessel -Most common type -Account for 70-80% of strokes
People with ataxia experience Failure of muscle control in arms and legs Results in:
-Lack of balance & coordination -Disturbance in gait
Going challenges of ataxia
-Loss of independence -May feel alone -Lead to depression & anxiety
Uncontrollable Risk Factor: 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
Uncontrollable Risk Factor: GENDER: WOMEN 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
Treatment for ataxia
-Physical & Occupational Therapy -Strengthen muscles -Assistive devices -Assist in walking and other activities of daily living (ADLs)
Cerebellum Involvement Can continuously assess status of each body part?
-Position -Rate of movement -Forces, such as gravity, opposing it
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
Hormone Involvement in GSR: Corticotropin-releasing Factor (CRF)
-Released by the hypothalamus -Stimulates ACTH release
Hormone Involvement in GSR: Cortisol
-Released from adrenal cortex -Affects many systems and processing in the body
Hormone Involvement in GSR: Adrenocorticotropic hormone (ACTH)
-Released from the anterior pituitary gland -Stimulates synthesis and release of cortisol
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
Movement Motor cortex:
-Sends signals to cerebellum -Communicates movement to make
Cerebellum
-Stores learned sequences of movements -Fine tuning & coordination of movement produced elsewhere in brain -Integrates all information to produce fluid movements
Conditions that can cause acquired (non-genetic) ataxia
-Stroke -Multiple Sclerosis -Tumors -Alcoholism -Peripheral neuropathy -Metabolic disorders -Vitamin deficiencies
Uncontrollable Risk Factor FAMILY HISTORY 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
Effects of Cortisol on cardiovascular
-arterioles more responsive to sns -increased contractility
Effects of Cortisol on renal
-calcium lost in urine -Na+/K+ pump reabsorbs Na+ and H2O into blood, secretes K+ into urine
Controllable Risk Factor & Inflammation atherosclerosis causes
-endothelial dysfunction -One of the earliest manifestations of atherosclerosis
Effects of Cortisol on immune
-production of prostaglandins blocked -thymus atrophies -neutrophils can't leave blood -monocytes and macrophages less active
Limb Ataxia SCALE DEFINITION 0,1,2,UN
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 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?
1
****National Institute of Health Stroke Scale (NIHSS) 15 Item Clinical Deficit Scale Assess: (in order)
1.)Level of Consciousness 2.)Gaze 3.)Vision 4.)Facial Palsy 5.)Arm & Leg Strength 6.)Limb Ataxia 7.)Neglect 8.)Dysarthria 9.)Aphasia
_____% of all cerebral strokes involve the cerebellum
15%
When was the National Institute of Health Stroke Scale first used?
1989
***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. When tested for ataxia, it was present on the bilateral upper extremities. What score would be given according to the NIHSS?
2 Score 2 if present in bilateral upper or lower extremities, or an arm and leg on the same side of the body.
Uncontrollable Risk Factor: GENDER: WOMEN ________ more women than men experience stroke each year
55,000
About ______ Americans afflicted with stroke
700,000
National Institute of Health Stroke Scale (NIHSS) total score means?
> 16 high probability of death or severe disability <6 predicts a good recovery
***Select the controllable risk factors for stroke: A.) hypertension B.)previous stroke C.) Age D.) Hyperlipidemia
A.) hypertension D.) Hyperlipidemia
**Proprioreceptor input is:
Any sensory nerve ending responding to stimuli from within body related to movement & spatial position
*****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. What is the anticipated medical diagnosis of the patient?
Cerebellar Stroke
***What part of the brain was infarcted if the patient has ataxia?
Cerebellum
***Neural cell ischemia is caused from:
Energy dependent membrane ion pumps fail (No energy is getting to the cell.)
***T or F Men are at higher risk of stroke.
F Women are at higher risk of stroke & also have increased mortality.
People with ataxia experience
Failure of muscle control in arms and legs
***T or F Ataxia needs to be assessed prior to weakness in the NIH Stroke Scale.
False Ataxia is assessed after weakness!
***T or F Ataxia occurs because of muscle weakness after a stroke.
False Ataxia is incoordination, not weakness!
Cerebellum Involvement feedback?
Feedback from muscles, tendons, & joints
Uncontrollable Risk Factor FAMILY HISTORY Evidence suggests genes influence vulnerability to ______ and ______
HTN & stroke
***Identify the most appropriate nursing diagnosis in terms of special needs when ataxia is present.
Impaired physical mobility
As movement approaches a target, the cerebellum will:
Inhibit agonist muscles & Excite antagonist muscles (Movement is pendulous, so muscles have to be stopped.)
Neuronal Injury: Excitotoxicity Influx of calcium, sodium and chloride
Intracellular calcium responsible for activation of a series of destructive enzymes
***Ataxia is:
Lack of coordination
Movement Cerebellum:
Makes continuous adjustments
What does NIHSS stand for?
National Institute of Health Stroke Scale
***Yes or No If the patient has weakness in the right arm and is unable to lift the arm off the bed, would ataxia be present?
No Ataxia is not present because the patient is unable to perform the test. The score would be absent due to paralysis
***Treatment for ataxia in the stroke patient is:
No Treatment Available Currently no treatment available. PT & OT to help with function.
When nerve cells are lost or damaged: what happens?
Provide less control to muscles
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
Cerebellum Involvement receives ?
Receives proprioceptor input from vestibular system
Cell Ischemia
Reduced or absent blood flow deprives cell of needed nutrients
When nerve cells are lost or damaged: what does it result in?
Resulting in: loss of coordination
What side the body controls what with Ataxia after Stroke
Right side of cerebellum controls coordination on right side of body, left side controls left
***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. What appropriate nursing diagnosis would be given to this patient related to the presences of ataxia?
Risk for injury: falls Think safety with patients experiencing ataxia! This patient has left sided weakness, plus BUE ataxia. This could make using mobility devices harder.
Complex 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
Movement Final result:
Smooth movement, key with delicate maneuvers
What is the US leading cause of mortality & morbidity
Stroke
What does the National Institute of Health Stroke Scale predict?
Strongly predicts the likelihood of recovery after stroke
Effects of Cortisol on muscular
actin and myosin break down
______ lobe of cerebellum is involved in motor control
anterior lobe
proprioceptive information
any sensory nerve ending that responds to stimuli originating from within the body related to movement and spatial position
pendular
as movement begin, momentum develops and must be overcome before the movement can be stopped
Controllable Risk Factor & Inflammation Inflammation can influence the development of ______
atherosclerosis
Effects of Cortisol on skeletal
decreased bone deposition
Effects of Cortisol on pancreas
decreased insulin release
Ischemia depletes?
depletes neuronal energy stores causing energy dependent membrane ion pumps to fail
Release of excitotoxic ______ and _____ open up _______ ______
glutamate & aspartate calcium channels
Progression of atherosclerosis may be associated with?
high concentrations of inflammatory markers
Neuronal Injury: Excitotoxicity Results in?
increased extracellular glutamate concentration
What is the most common type of stroke?
ischemic stroke
Effects of Cortisol on adipose tissue
lipids released from periphery, redeposited in trunk
agonist muscles
muscles involved in starting muscle movement
antagonist muscles
muscles involved in stopping muscle movement
Is there a cure for ataxia following a cerebellar stroke?
no
DYSMETRIA
over or under reaching
All body movements are
pendular
Cerebellum Involvement Indirect signals from?
somesthetic, visual, & auditory systems to provide background info for ongoing movement
Effects of Cortisol on liver
stored glucose released into blood
****T or F Ataxia in stroke is acquired ataxia.
true Acquired ataxia is non-genetic
