Transcript NIHSS

NIH Stroke Scale Assessment of
the Acute Stroke Patient
NIHSS Assessment of the Acute Stroke Patient
Objectives:
 The learner will be able to explain

◦ Why the NIHSS is performed
◦ How the NIHSS is performed
◦ Relate each section to the pathophysiology of
various types of stroke.
◦ State benefits and drawbacks to the NIHSS
◦ Relate the NIHSS to patient acute changes and
long-term outcomes
NIHSS
Abstract (Spilker, et. al)
“The stroke patient is acutely ill within minutes of
symptom onset. Typically, he or she is awake and
thus requires a focal neurologic exam to evaluate
vision, movement, sensation, and language. With the
advent of acute stroke treatments that need to be
rapidly implemented, it is critical that the nurse be
able to assess patients and relay the information
accurately and efficiently to other members of the
health team. ….
The National Institutes of Health Stroke Scale (NIHSS)
is a systematic assessment tool designed to measure
the neurologic deficits most often seen with acute
stroke patients. “
Case
A 43-year old woman is transported by EMS to the ED.
Paramedics noted her inability to move the left side of her
body.Vital signs on arrival are blood pressure 152/106,
temperature 99.2o, heart rate 76, respiratory rate 18. She is
awake, oriented to person, place, time and situation. Her
husband states she was in another room studying when, at
about 8:00pm she called to him complaining of dizziness, a
feeling of passing out and left-sided weakness and numbness.
The patient is able to provide a partial history of surgery
for tetralogy of Falot as a child and recent pacemaker
placement (3 years ago).
ED staff members made the diagnosis of stroke
and implemented the acute stroke protocol.
After ED review of all diagnostic data for
contraindications. it was determined she was
a candidate for thrombolytic therapy.
Arousal Exam versus Focal Neurologic Assessment
The patient described above is acutely ill. She has
suffered an ischemic stroke in her right middle
cerebral artery (MCA) circulation probably secondary
to an embolic event from the heart. She is awake and
her Glasgow Coma Scale is 15 or normal, her pupils
are equal round and reactive to light but despite these
‘normal’ general neurologic findings, she has
profoundly abnormal focal neurological signs.
However, the GCS and similar tools provide little
information about the nature or degree of focal
neurological deficits seen in ischemic stroke patients.
The neurological exam needed to assess this patient
should evaluate the function of this woman’s right
cerebral cortex where her neurologic pathology
originates.
NIHSS - Background
The NIHSS is a systematic assessment tool
designed to measure the neurologic deficits
more often seen with acute stroke. It was
developed in 1983 by NIH-sponsored stroke
research neurologists.
It was designed to standardize and document
an easy to perform, reliable and valid
neurologic assessment for use in stroke
treatment research trials.
Each assessment item was
considered for its value during
the first hours and days after
symptom onset.
General Directions for Performing the NIHSS
•
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Administer scale in numerical order
– don’t go back and change scores.
Score what you see,
not what you think you should see.
Examiners experience may vary and
this helps keep assessment objective and consistent.
Minimize cuing or coaching – score first attempt.
(Some patients may later correct an error, but do not
change the score).
Special considerations – Patients who have difficulty
staying awake are more difficult to evaluate due to
minimized cooperation. Alternative assessment
techniques may be utilized (see further description by
item).
Directions for Performing the NIHSS – Aphasic Patients
The NIHSS does encourage the use of
pantomime and gestures when assessing
the aphasic or confused stroke patient.
Specific pantomime or gesture clues have
been developed with the tool to
standardize the cueing that may be
necessary to successfully examine and
score these patients.
NIHSS Category 1 – Level of Consciousness
In acute stroke patients, decreased wakefulness
can indicate clinical deterioration.
Metabolic causes, due to a generalized or local
depression of cerebral cortex cellular
function, include hypoxia, systemic organ
failure, toxins, infections or ischemia.
Structural causes include injury or compression
of the brainstem or reticular activating
system, either from mass lesions,
hematomas, or cerebral edema.
NIHSS Category 1a – Level of Consciousness
Category
Description
Score
1a. Level of
Consciousness –
responses to
random verbal
stimuli
Alert – keenly responsive
0
Drowsy but arousable to
verbal stimuli
1
Stuporous or requires
2
repeated or painful stimulation
to attend
Coma or responds only with
reflexive motor activity, is
unresponsive or flaccid.
3
NIHSS Category 1b – Level of Consciousness – orientation
Category
Description
Score
1b. LOC
Orientation and
ability to answer
standard questions
What month is it?
How old are you?
Answers both correctly
0
Answers one correctly or is
unable to speak due to
intubation or severe
dysarthria (slurred speech)
1
Both Incorrect – patients
who do not understand the
questions due to aphasia,
stupor or coma are scored 2
2
NIHSS Category 1c – Level of Consciousness - Command
Category
Description
Score
1c. LOC
Patient’s ability to
follow one-step
commands
-Open / close eyes
“Blink” your eyes
-Squeeze and release
the unaffected hand
(Make fist/ Let go)
-Examiner may
pantomime or
demonstrate the
actions
Obeys both correctly
0
Obeys 1 correctly
1
Both Incorrectly or not at
all despite pantomime or
demonstration cues, or
patient is comatose
2
NIHSS Category 2 – Best Gaze
“Best Gaze” evaluates selected extraocular
movements. Abnormal findings can
indicate pathophysiology involving frontal
lobe, cerebellar, or vestibular dysfunction,
or generalized dysfunction of cerebral
cortex.
NIHSS Category 2 – Best Gaze
Category
Description
Score
2. Best Gaze
Evaluates the patient’s ability to
move eyes from side to side.
Normal – able to move
both eyes from left to
right across the midline
0
•If alert and can follow commands, have
the patient follow your finger with eyes
from left of midline to right of midline
without moving the head.
•A patient with preexisting blindness
can be told to look to the right, left, up
and down.
•If the patient does not understand or
cannot attend, establish eye contact
and move your face from left to right.
•If patient is unresponsive, score using
the “doll’s eyes” maneuver –
oculocephalic reflex)
Partial Gaze Palsy –
able to move one or
both eyes, may not be
able to cross midline
1
Forced Deviation –
total gaze paresis,
forces eye deviation
2
(looking at the lesion)
or cannot be overcome
with doll’s eye
maneuver
NIHSS Category 3 – Visual – Visual field assessment
Pathologic findings of
this item in stroke
patients usually arise
from lesions of the
optic radiations or
occipital lobes.
NIHSS Category 3 – Visual
Category
Description
Score
3.Visual fields
The upper and lower quadrants of vision are
tested by confrontation exam. The examiner
stands opposite the patient’s face. Ask the
patient to look straight ahead at the
examiners nose and count the fingers of the
examiner as they are introduced into the
patient’s and examiner’s visual field
quadrants.
No Visual Loss
0
Patients who are unable to understand or
follow instructions can still be assessed by
response to fingers displayed by
confrontation as they will often look in the
direction of the moving fingers even if not
comprehending the questions.
Hemianopia
Partial –include
visual loss in a
quadrant of total
visual field
Complete - loss
in both top and
bottom of one
side - left or
right fields
1
2
Bilateral - loss in
both left and
right side of field 3
or total
blindness
NIHSS Category 4 – Facial Palsy
Pathologic findings in item 4 indicate a lower motor neuron
lesion of ipsilateral cranial nerve VII or a lesions of the
contralateral corticobulbar tract or motor cortex. Bilateral
findings can indicate brainstem lesions.
This item evaluates symmetry or equality of facial movement.
Facial asymmetry can often be seen in even minor stroke. It
can be the first clue to the presence of swallowing
difficulties or dysphagia.
NIHSS Category 4 – Facial Palsy
Category
Description
4. Facial Palsy
(Show teeth, raise eyebrows,
squeeze eyes shut)
Ask the patient verbally or by
demonstration patient to
•show teeth
•Raise eyebrows
•Squeeze eyes shut
•In poorly responsive patients or
patients who cannot follow
commands, painful stimuli can be
introduced by sternal rub and the
grimace can be evaluated.
Normal – equal movement 0
on both sides of the face
Minor paralysis – limited
movement such as a
crooked smile, or loss of
nasal labial fold.
Partial paralysis - total or
near total loss of
movement in lower face
Complete paralysis or loss
of movement in one or
both sides of the face, or
patient is comatose
Score
1
2
3
NIHSS Category 5 – Motor Arm and 6 – Motor Leg
Dysfunctions found on
items 5 or 6 in stroke
patients most often are
related to lesions of
the motor cortex or
corticospinal tract
contralateral to the
affected side.
NIHSS Category 5 – Motor Arm
Category
Description
Score
5a, b. Motor Arm – Left ,
Right
•Each arm is evaluated
one at a time. Have
patient lift extremity palm
up at 90o (45o if lying
down) and hold up for a
count of 10. Score drift /
movement
•If patient is confused or
aphasic, pantomime and
gestures can be used. The
score is based on patient’s
ability to resist gravity.
5a. Left Arm
No Drift – no downward movement for
the full 10 seconds
0
Drift before full count but does not touch
support surface
1
Can’t Resist Gravity – successful
movement but limb hits surface before full
count
2
No effort against gravity– no effort to lift
limb off surface or resist gravity, but some
movement is seen
3
No Movement – flaccid extremity with no
effort or movement
4
Amputation, joint fusion (explain)
9
5b. Right Arm - As above
0-9
NIHSS Category 6 – Motor Leg
Category
Description
Score
6a,b. Motor Leg –
Left, right
No Drift – no downward drift or
movement for the full count
0
Each leg is scored
one at a time.
Drift – some downward movement or drift 1
noted but leg does not hit bed
Elevate extremity to
30o and held for a
count of 5 seconds.
Score drift /
movement
Can’t Resist Gravity – able to lift leg off
bed but cannot hold for full 5 seconds
without hitting bed
No Effort Against Gravity – unable to lift
leg off bed but some movement is seen
2
No Movement – no voluntary movement
or flaccid extremity, patient comatose
Amputation, joint fusion (explain)
4
3
9
6b. Right Leg – As Above
0-9
NIHSS Category 7 – Limb Ataxia
Examines the stroke patient’s ability to
coordinate movements. A weakened
extremity can appear poorly coordinated
but item 7 is scored as present only if
the ataxia or poorly controlled
movements are out of proportion to the
extremity weakness noted in item
5 or 6.
Abnormal findings on item 7 often indicate
posterior circulation lesions, specifically
lesions involving the cerebellum or its
connections with the posterior column
or brainstem.
NIHSS Category 7 – Limb Ataxia
Category
Description
Score
7. Limb Ataxia
(Finger-nose, heel down shin)
For each upper extremity:
Instruct the patient to touch the examiners
finger then to repeatedly touch their nose and
then re-touch the examiners finger
For each lower extremity:
Have the patient lift one leg and slide the heel of
his foot down the opposite shin and repeat the
motion at least twice.
Repeat for the other side.
Absent
0
Present in
one limb
1
Present in
two limbs
2
The score is “0” for a paralyzed who cannot move or confused patient who
cannot move their extremities or a confused patient who cannot follow
directions. This approach increases the tool’s reproducibility,
NIHSS Category 8 – Sensory
Sensory deficits and perceptual deficits are
common in stroke patients and need to be
carefully evaluated to assure patient safety.
Abnormal findings or sensory loss usually indicate
lesions or dysfunction involving the
contralateral thalamus or parietal lobe cortex.
NIHSS Category 8 – Sensory
Category
Description
Score
8. Sensory
Pin-prick testing
Test the face, arms (not the hands),
trunk and leg (not the feet).
Normal – no sensory
loss reported
0
Compare side-to-side
Evaluate for normal or abnormal
feelings, whether it “feels different”
from the opposite side.
Ask “do you feel the pin” “Does it feel
the same on both sides?”
In stuporous or aphasic patients,
painful stimulus can be used and
grimace can indicate intact sensation.
Partial Loss – mild to
1
moderate sensory loss.
Difference in perception
from side to side but
patient is aware of being
touched.
Severe or Total Loss –
patient is not aware of
being touched or pain.
Patients in a coma.
2
NIHSS Category 9 – Best Language
Language deficits are known to be common in
stroke patients.
Disturbances in speech and communication most
commonly indicate lesions in the Broca’s area,
Wernicke’s area or the frontal, parietal, or
parieto-occipital areas of the left hemisphere.
A small number of patients will
have language function located in
the right hemisphere.
NIHSS Category 9 – Best Language
The NIHSS uses a
standardized set of
visual stimuli.
NIHSS Category 9 – Best Language
Category
Description
Score
9. Best Language
Have the patient
•Name the items
•Describe the picture
•Read the sentences
Accommodations for
patients with limited
vision or education can
be made by eliciting
enough verbal feedback
to enable scoring as
shown.
Intubated patients who
can comprehend can be
evaluated if able to
write.
No aphasia – normal fluent speech
0
Mild to Moderate Aphasia–(loss of
fluency ability to comprehend, but is
able to get the general idea)
1
Severe Aphasia–speech if present is
fragmentary, often limited to one
word answers, the burden of
communication is on the listener
Mute or global aphasia – no usable
speech or apparent auditory
comprehension. A patient in a coma
is give n a 3.
2
3
NIHSS Category 10 – Dysarthria
Evaluates quality of the patient’s
speech. Pathophysiology is much
the same as for facial weakness
and can involve either the
ipsilateral lower motor neuron
cranial nerve deficits or lesions
of the contralateral motor
cortex.
“Dysarthria is a motor speech disorder.
The muscles of the mouth, face, and
respiratory system may become
weak, move slowly, or not move at
all after a stroke or other brain
injury. The type and severity of
dysarthria depend on which area of
the nervous system is affected.”
http://www.asha.org/public/speech/disorders/dysarthri
a.htm
NIHSS Category 10 – Dysarthria
Category
Description
Score
10. Dysarthria
Normal articulation – clear
speech
0
Mild to Moderate dysarthria –
Some slurring of words noted
but can be understood with
some difficulty.
1
Have patient read the list of
words or having the patient
repeat the words after you.
Evaluate speech clarity.
•Intubated patients cannot
be evaluated on this item.
Near to unintelligible or worse – 2
speech is so slurred that it is
unintelligible, or patient is mute,
or has severely limited speech, or
is comatose.
Intubated or Other physical
Barrier
9
NIHSS Category 11 – Extinction and Inattention
This item primarily evaluates the contralateral parietal lobe
cortex. The ability to perceive needs to be evaluated,
documented and considered in the plan of care as early
as possible, in ED, ICU or unit.
Recognition of visual, tactile, spatial, or
personal inattention can prevent falls,
one common complications after stroke.
Extinction To test extinction, have the patient sit on the edge of the examining table
and close their eyes. Touch the patient on the trunk or legs in one place and then tell the
patient to open their eyes and point to the location where they noted sensation. Repeat
this maneuver a second time, touching the patient in two places on opposite sides of
their body, simultaneously. Then ask the patient to point to where they felt sensation.
Normally they will point to both areas. If not, extinction is present. With lesions of the
sensory cortex in the parietal lobe, the patient may only report feeling one finger touch
their body, when in fact they were touched twice on opposite sides of their body,
simultaneously. With extinction, the stimulus not felt is on the side opposite of the
damaged cortex.The sensation not felt is considered "extinguished".
NIHSS Category 11 – Extinction and Inattention
Category
Description Score
11. Extinction and Inattention
Use information from prior testing.
No Neglect
0
Partial
Neglect
1
To perform DSS testing, ask patient to close his eyes.
Introduce touch stimuli alternately on left to right side.
Ask patient to state which side is being touched. After Complete
a consistent response is produced, touch both sides at Neglect
once.
•The normal individual will identify stimulation on
both sides simultaneously.
• A patient without sensory impairment on individual
limb testing may have difficulty with DSS and
extinguish or neglect weaker sensory information on
affected side.
•DSS applies also to visual fields.
•Visual neglect may be identified in item 9 if they
describe only one half of the picture.
2
NIHSS Clinical Performance and Utility
Performing the NIHSS has been timed to take
5 – 8 minutes.
 Experience or familiarity increases efficiency.
 Patients with impaired attention or language
deficits require more exam time even with an
experienced examiner.
 The complete scale should be done as a
baseline and the beginning of each nursing
shift.
 LOC and extremity motor assessments or
specific items designated by the neurologist
can be used for more frequent assessments.
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NIHSS Clinical Performance and Utility
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The NIHSS is used to
◦ Clearly document neurologic outcomes
◦ Plan safe nursing care
◦ Provide consistency of communication between
nurses and other health care professionals.
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Laminated cards of the visual cues should be
readily available
A reference copy of the expanded directions
should be stored on every unit that cares for
stroke patients.
The general directions should be printed on
every version used at the bedside.
Case Study - Revisited
It took 6.5 minutes to perform the NIHSS on our patient.
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1. LOCa-0,LOCb-0,LOCc-0
2. Best Gaze = 1
3.Visual fields = 2
4. Facial Palsy = 2
5. Motor Arm L=2, R=1
6. Motor Leg L=1, R=0
7. Limb Ataxia =0
8. Sensory =2
9. Best Language =0
10. Dysarthria = 1
11. Extinction/Inattention = 2
TOTAL Score = 14
Meaning of the NIHSS score
The absolute score (0 to 42) has
limited meaning.
 Think of the score as a way to
quantify findings so that changes over
time can be measured relative to the
individual patient’s baseline.
 Findings for sensory, visual, and perception (neglect/
inattention) mean the patient cannot perceive there own
deficits or surroundings, thus presents a patient safety risk.
 Predictive value for planning rehab or long-term needs

◦ More than 80% of patients with score of 5 or less are discharged home
◦ Those with scores between 6 and 13 usually require acute rehab
◦ Patients with scores of 14 or higher frequently need long-term care.
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Patients with low scores may still have a disabling or lifethreatening infarction in the cerebellum or brainstem,.
The value of the score does not identify the cause of the
stroke. It does not replace a complete neurological exam.
Zero on the NIHSS Does Not Equal the Absence of Stroke
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Martin-Schild, et. Al (2011) identified 20 patients
with NIHSS = 0 in a population of 2618 patients
with acute ischemic stroke admitted to the
hospital.
Despite a zero score, these patients had an acute
infarction identified by MRI.
The most common presenting symptoms were
headache, vertigo, nausea and ataxia.
Neurologic signs on the comprehensive neuro
exam included truncal ataxia (45%), agitated
confusion (10%), normal exam result (no s/s), and
individuals s/s such as nystagmus, limb weakness,
memory impairment, Horner's syndrome, reduced
visual acuity without field cut.
57.9% had posterior circulation infarcts, while
42.1% had anterior circulation infarct locations.
Benefits
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Can be used by a range of healthcare providers
Reliable in diverse groups,
settings, and languages
Simple and quick to perform
Can be reliably abstracted from
medical records even when a
baseline NIHSS was not
performed in real-time on
admission.
Is used to establish threshold
values for certain treatments.
Provides a sensitive tool for serial
monitoring in hospitals
Can be used to predict discharge
status
Drawbacks
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Emphasis on language and
following commands may result in
a higher score for dominant
hemisphere strokes.
There is less emphasis on signs of
posterior circulation strokes.
Although some items may be related to the
vertebro-basilar system, some elements are
not included (diplopia, dysphagia, gait
instability, hearing and nystagmus).
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A low score may result in
failure to treat with tPA.
In one study, 1/3 of patients
deemed “too mild to treat” were
dead or disabled at discharge.
Reliability of NIHSS
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The overall reliability of the
NIHSS has been thoroughly
reviewed since 1989.
Yet, some items have shown low
interrater reliability. These
include LOC, Gaze, Facial Palsy,
Ataxia and Dysarthria.
One study found inter-rater
reliability was higher if the
examiner had previously done
an NIHSS certification exam.
Facial Palsy and Ataxia still
showed poor interrater
reliability.
Validity of NIHSS
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One measure of validity of the
NIHSS is it correlation with
infarct volumes (concurrent
validity) which has been
compared using CT and MRI
scans, and ranges, with correlation
coefficients of 0.4 -0.8

The clinical predictive validity of
NIHSS has also been shown in
several investigations.
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In one study, for patients with NIHSS<=3,
2/3rd had an excellent outcomes. Very few
with NIHSS>15 had excellent outcomes at
3 months
What change in NIHSS defines Neurologic Deterioration?
Neurologic deterioration (ND) occurs in 1/3 of all acute
ischemic stroke (AIS) patients. Recognizing acute changes
is crucial in order to address reversible causes of ND
Siegler, et. Al (2012) studied 347 patients presenting to one
center within 48 hours of onset of AIS.
An increase of greater or equal to 2 points in NIHSS was a
highly sensitive predictor for poor functional outcome,
unfavorable discharge, and mortality.
One caveat: an increasing score in a single item (new
onset hemiplegia) may call for an emergent workup, even
if other improving items (language) offset the change
yielding low or zero net effect in NIHSS.
10
8
5
4
0
800
9
8
7
4
1200
1600
NIHSS
2000
0
400
NIHSS, Nursing Care and Patient Outcomes
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It is the nurse’s ability to assess the neurologic status of the
acute stroke patient and detect changes that will be key to
identifying and affecting patient outcomes.
One strategy to build confidence is for the on-coming shift
nurse to perform the independent NIHSS and then compare
their results to those of the off-going shift. This gives both
care providers a chance to compare notes, as well as ensuring
a safe handoff.
The nurse should consider the limitations to the NIHSS when
identifying a possible stroke patient and in evaluating
neurological deteriorization.
Using the NIHSS provides
consistent practice throughout the
organization and facilitates
interdisciplinary coordination.
References
Spiller, J., Kongable, G., Barch, C., Braimah, J., Brattina, P., Daley, S., Donmarumma,
R., Rapp, K. Sailor, S., and the NINDS rt-PA Stroke Study Group (1997).
Using the NIH Stroke Scale to Assess Stroke Patients. Journal of Neuroscience
Nursing, 29(6),,394-92.
Meyer, B. & Lyden, P. (2009). The Modified National Institutes of Health Stroke
Scale (mNIHSS): Its Time Has Come. International Journal of Stroke 4(4).
Doi.10.1111/j.1747-4949.2009.00294.x
Seigler, J., Boehme, A., Kumar, A., Gillette, M., Albright, K. and Martin-Schild, S.
(2012). What Change in the National Institutes of Health Stroke Scale
should define neurological deterioration in acute ischemic stroke? Journal of
Stroke and Cerebrovascular Disease.
Doi:10.1016/j.strokecerebrovasdis.2012.04.012
Martin-Schild, s., Albright, K., Tanksley, J., Panday,V., Jones, E., Grotta, J.m & Savitz,
S. (2011). Zero on the NIHSS does not equal the absence of stroke. Annals
of Emergency Medicine, 57(1). doi:10.1016/j.annemergmed.2010.o06.564
Kasner, S. (2006). Clinical interpretation and use of stroke scales. Lancet, 5, 60312.
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