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

• 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

Drowsy but arousable to verbal stimuli

Stuporous or requires repeated or painful stimulation to attend

Coma or responds only with reflexive motor activity, is unresponsive or flaccid.

0

1

2

3

NIHSS Category 1b – Level of Consciousness – orientation

Category Description Score

1b. LOC Orientation and ability to answer standard questionsWhat month is it?How old are you?

Answers both correctly

Answers one correctly or is unable to speak due to intubation or severe dysarthria (slurred speech)

Both Incorrect – patients who do not understand the questions due to aphasia, stupor or coma are scored 2

0

1

2

NIHSS Category 1c – Level of Consciousness - Command

Category Description Score

1c. LOCPatient’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

Obeys 1 correctly

Both Incorrectly or not at all despite pantomime or demonstration cues, or patient is comatose

0

1

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 GazeEvaluates the patient’s ability to move eyes from side to side. •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)

Normal – able to move both eyes from left to right across the midline

Partial Gaze Palsy – able to move one or both eyes, may not be able to cross midline

Forced Deviation – total gaze paresis, forces eye deviation (looking at the lesion) or cannot be overcome with doll’s eye maneuver

0

1

2

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 Score3. Visual fieldsThe 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.

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.

No Visual Loss

HemianopiaPartial –include visual loss in a quadrant of total visual field

Complete - loss in both top and bottom of one side - left or right fields

Bilateral - loss in both left and right side of field or total blindness

0

1

2

3

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 Score4. 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 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

0

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 Score5a, 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 ArmNo Drift – no downward movement for the full 10 seconds

Drift before full count but does not touch support surface

Can’t Resist Gravity – successful movement but limb hits surface before full count

No effort against gravity– no effort to lift limb off surface or resist gravity, but some movement is seen

No Movement – flaccid extremity with no effort or movement

Amputation, joint fusion (explain)

0

1

2

3

4

9

5b. Right Arm - As above 0 - 9

NIHSS Category 6 – Motor Leg

Category Description Score6a,b. Motor Leg – Left, right

Each leg is scored one at a time.

Elevate extremity to 30o and held for a count of 5 seconds. Score drift / movement

No Drift – no downward drift or movement for the full count

Drift – some downward movement or drift noted but leg does not hit bed

Can’t Resist Gravity – able to lift leg off bed but cannot hold for full 5 seconds without hitting bedNo Effort Against Gravity – unable to lift leg off bed but some movement is seen

No Movement – no voluntary movement or flaccid extremity, patient comatoseAmputation, joint fusion (explain)

0

1

2

3

4

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 fingerFor 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

Present in one limb

Present in two limbs

0

1

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 Score8. SensoryPin-prick testingTest the face, arms (not the hands), trunk and leg (not the feet).

Compare side-to-sideEvaluate 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.

Normal – no sensory loss reported

Partial Loss – mild to 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.

0

1

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 LanguageHave the patient •Name the items•Describe the picture•Read the sentencesAccommodations 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

Mild to Moderate Aphasia–(loss of fluency ability to comprehend, but is able to get the general idea)

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.

0

1

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/dysarthria.htm

NIHSS Category 10 – Dysarthria

Category Description Score10. Dysarthria

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.

Normal articulation – clear speech

Mild to Moderate dysarthria –Some slurring of words noted but can be understood with some difficulty.

Near to unintelligible or worse – 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

0

1

2

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 InattentionUse information from prior testing.

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 a consistent response is produced, touch both sides at 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.

No Neglect

Partial Neglect

Complete Neglect

0

1

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.

NIHSS Clinical Performance and Utility

The NIHSS is used to ◦Clearly document neurologic outcomes◦Plan safe nursing care◦Provide consistency of communication

between nurses and other health care professionals.

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.

1. LOCa-0,LOCb-0,LOCc-02. Best Gaze = 13. Visual fields = 24. Facial Palsy = 25. Motor Arm L=2, R=16. Motor Leg L=1, R=07. Limb Ataxia =08. Sensory =29. Best Language =010. Dysarthria = 111. 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 overtime 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.Patients with low scores may still have a

disabling or life-threatening 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

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 Drawbacks

Can be used by a range of health-care 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

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).

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 Validity of NIHSSThe 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.

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.

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.NIHSS

0

5

104 4

8 7 8 9

NIHSS, Nursing Care and Patient Outcomes

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, 603-12.

NIHSS_update

PROPERTIESOn passing, 'Finish' button: Goes to Next SlideOn failing, 'Finish' button: Goes to Next SlideAllow user to leave quiz: At any timeUser may view slides after quiz: At any timeUser may attempt quiz: 10 times