What is the NIH Stroke Scale (NIHSS) and how is it performed?

Updated: May 27, 2020
  • Author: Edward C Jauch, MD, MS, FAHA, FACEP; Chief Editor: Helmi L Lutsep, MD  more...
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Answer

A useful tool in quantifying neurologic impairment is the National Institutes of Health Stroke Scale (NIHSS) (see Table 2, below). The NIHSS enables the healthcare provider to rapidly determine the severity and possible location of the stroke. NIHSS scores are strongly associated with outcome and can help to identify those patients who are likely to benefit from reperfusion therapies and those who are at higher risk of developing complications from the stroke itself and potential reperfusion strategies.

The NIHSS is easily performed; it focuses on the following 6 major areas of the neurologic examination:

  • Level of consciousness

  • Visual function

  • Motor function

  • Sensation and neglect

  • Cerebellar function

  • Language

The NIHSS is a 42-point scale. Patients with minor strokes usually have a score of less than 5. An NIHSS score of greater than 10 correlates with an 80% likelihood of proximal vessel occlusions (as identified on CT or standard angiograms). However, discretion must be used in assessing the magnitude of the clinical deficit and resulting disability; for instance, if a patient's only deficit is mutism or blindness, the NIHSS score will be 3. Additionally, the scale does not measure some deficits associated with posterior circulation strokes (ie, vertigo, ataxia). [58]

Table 2. National Institutes of Health Stroke Scale (Open Table in a new window)

 

Category

Description

Score

1a

level of consciousness (LOC)

Alert

Drowsy

Stuporous

Coma

0

1

2

3

1b

LOC questions (month, age)

Answers both correctly

Answers 1 correctly

Incorrect on both

0

1

2

1c

LOC commands (open and close eyes,

grip and release nonparetic hand)

Obeys both correctly

Obeys 1 correctly

Incorrect on both

0

1

2

2

Best gaze (follow finger)

Normal

Partial gaze palsy

Forced deviation

0

1

2

3

Best visual (visual fields)

No visual loss

Partial hemianopia

Complete hemianopia

Bilateral hemianopia

0

1

2

3

4

Facial palsy (show teeth, raise brows,

squeeze eyes shut)

Normal

Minor

Partial

Complete

0

1

2

3

5

Motor arm left* (raise 90°, hold 10 seconds)

(preferably with the palm facing up)

No drift

Drift

Cannot resist gravity

No effort against gravity

No movement

0

1

2

3

4

6

Motor arm right* (raise 90°, hold 10 seconds)

(preferably with the palm facing up)

No drift

Drift

Cannot resist gravity

No effort against gravity

No movement

0

1

2

3

4

7

Motor leg left* (raise 30°, hold 5 seconds)

No drift

Drift

Cannot resist gravity

No effort against gravity

No movement

0

1

2

3

4

8

Motor leg right* (raise 30°, hold 5 seconds)

No drift

Drift

Cannot resist gravity

No effort against gravity

No movement

0

1

2

3

4

9

Limb ataxia (finger-nose, heel-shin)

Absent

Present in 1 limb

Present in 2 limbs

0

1

2

10

Sensory (pinprick to face, arm, leg)

Normal

Partial loss

Severe loss

0

1

2

11

Extinction/neglect (double simultaneous testing)

No neglect

Partial neglect

Complete neglect

0

1

2

12

Dysarthria (speech clarity to "mama,

baseball, huckleberry, tip-top, fifty-fifty")

Normal articulation

Mild to moderate dysarthria

Near to unintelligible or worse

0

1

2

13

Best language** (name items,

describe pictures)

No aphasia

Mild to moderate aphasia

Severe aphasia

Mute

0

1

2

3

 

Total

-

0-42

* For limbs with amputation, joint fusion, etc, score 9 and explain

** For intubation or other physical barriers to speech, score 9 and explain. Do not add 9 to the total score. NIH Stroke Scale (PDF)


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