NIH Stroke Scale (NIHSS)

National Institutes of Health Stroke Scale

Total Score: 0 / 42

No symptoms

1a. Level of Consciousness

The examiner must choose a response, even if a full assessment is hindered by obstacles such as an endotracheal tube, language barrier, or orofacial trauma.

0 — Alert; keenly responsive

1 — Not alert; arousable by minor stimulation to obey, answer, or respond

2 — Not alert; requires repeated stimulation or painful stimulation to perform non-stereotyped movements

3 — Coma: responds only with motor or autonomic reflexes, or not at all

1b. LOC Questions

Ask the patient the current month and their age. The answer must be correct — no credit for being close. Aphasic and stuporous patients who do not comprehend the questions score 2.

0 — Answers both questions correctly

1 — Answers one question correctly

2 — Answers neither question correctly

1c. LOC Commands

Ask the patient to open and close their eyes, then to grip and release the non-paretic hand. If the hands cannot be used, substitute another one-step command.

0 — Performs both tasks correctly

1 — Performs one task correctly

2 — Performs neither task correctly

2. Best Gaze

Test only horizontal eye movements. Voluntary or reflexive (oculocephalic) eye movements are accepted. Caloric testing is not performed.

0 — Normal

1 — Partial gaze palsy: gaze is abnormal in one or both eyes but forced deviation or total paresis is absent

2 — Forced deviation or total gaze paresis not overcome by the oculocephalic maneuver

3. Visual Fields

Test upper and lower quadrants by confrontation, using finger counting or visual threat. If the patient looks towards the side of the visual stimulus, this may be scored as normal.

0 — No visual loss

1 — Partial hemianopia

2 — Complete hemianopia

3 — Bilateral blindness (including cortical blindness)

4. Facial Palsy

Ask or use pantomime for the patient to show their teeth or smile and close their eyes. In poorly responsive patients, score the symmetry of facial movement to painful stimulation.

0 — Normal symmetrical movement

1 — Minor palsy (flattened nasolabial fold, asymmetry on smiling)

2 — Partial palsy (total or near-total paralysis of the lower face)

3 — Complete palsy (absence of movement in upper and lower face)

5a. Motor — Left Arm

Position the limb: 90° (if sitting) or 45° (if supine), palms facing downward. Ask the patient to hold the position for 10 seconds.

0 — No drift; holds position for 10 seconds

1 — Drift before 10 seconds without hitting the bed

2 — Some effort against gravity but cannot sustain the position

3 — No effort against gravity; limb falls

4 — No movement

X — Not testable (amputation or joint fusion) — not scored

5b. Motor — Right Arm

Position the limb: 90° (if sitting) or 45° (if supine), palms facing downward. Ask the patient to hold the position for 10 seconds.

0 — No drift; holds position for 10 seconds

1 — Drift before 10 seconds without hitting the bed

2 — Some effort against gravity but cannot sustain the position

3 — No effort against gravity; limb falls

4 — No movement

X — Not testable (amputation or joint fusion) — not scored

6a. Motor — Left Leg

Patient always in supine position. Position the leg at 30°. Ask the patient to hold the position for 5 seconds.

0 — No drift; holds position for 5 seconds

1 — Drift before 5 seconds without hitting the bed

2 — Some effort against gravity; touches the bed within 5 seconds

3 — No effort against gravity; limb falls immediately

4 — No movement

X — Not testable (amputation or joint fusion) — not scored

6b. Motor — Right Leg

Patient always in supine position. Position the leg at 30°. Ask the patient to hold the position for 5 seconds.

0 — No drift; holds position for 5 seconds

1 — Drift before 5 seconds without hitting the bed

2 — Some effort against gravity; touches the bed within 5 seconds

3 — No effort against gravity; limb falls immediately

4 — No movement

X — Not testable (amputation or joint fusion) — not scored

7. Limb Ataxia

Assesses evidence of unilateral cerebellar lesion. Test with eyes open. In case of visual deficit, test in the intact visual field. Assess finger-nose-finger and heel-shin tests bilaterally.

0 — Absent

1 — Present in one limb

2 — Present in two limbs

X — Not testable (amputation or joint fusion) — not scored

8. Sensory

Test with pin-prick or withdrawal to painful stimulus in obtunded or aphasic patients. Only sensory loss attributed to stroke is scored. Test face, arms, trunk, and legs.

0 — Normal; no sensory loss

1 — Mild-to-moderate sensory loss: patient feels the pinprick is less sharp on the affected side but is aware of being touched

2 — Severe to total sensory loss: patient is not aware of being touched in the face, arm, and leg

9. Best Language

Ask the patient to describe a picture, name items on a naming sheet, and read from a list of sentences. Comprehension is judged from these responses and the commands assessed earlier.

0 — No aphasia; normal

1 — Mild-to-moderate aphasia: loss of fluency or comprehension, without significant limitation of ideas expressed

2 — Severe aphasia: fragmented communication; considerable reliance on inference and guessing by the examiner

3 — Mute or global aphasia: no usable speech or auditory comprehension

10. Dysarthria

Obtain a speech sample by asking the patient to read or repeat words from a standardized list. In patients with severe aphasia, assess the articulation of spontaneous speech.

0 — Normal

1 — Mild-to-moderate dysarthria: slurs words but can be understood with some difficulty

2 — Severe dysarthria: speech is unintelligible or mute/anarthric, out of proportion to any aphasia

X — Intubated or other physical barrier — not scored

11. Extinction and Inattention (Neglect)

Sufficient information may be obtained during the prior testing. If the patient has severe visual loss preventing double simultaneous visual stimulation and cutaneous stimulation is normal, the score is 0.

0 — No abnormality

1 — Inattention or extinction in one modality (visual, tactile, auditory, spatial, or personal)

2 — Profound hemi-inattention or extinction in more than one modality; does not recognize own hand or orients to only one side of space

Interpretation

Select the options above to calculate the NIHSS score.

Stroke Severity Classification

NIHSS Score	Severity
0	No stroke symptoms
1 – 4	Minor stroke
5 – 15	Moderate stroke
16 – 20	Moderate-to-severe stroke
21 – 42	Severe stroke

Note: The NIHSS is a validated tool for assessing the severity of acute ischemic stroke, with a score ranging from 0 to 42. It is used in initial triage, monitoring of neurological progression, and prognostic estimation. The decision regarding reperfusion therapy is multifactorial and cannot be based on the NIHSS score alone. This tool does not replace individualized clinical assessment.

References

1. Brott T, Adams HP Jr, Olinger CP, et al. Measurements of acute cerebral infarction: a clinical examination scale. Stroke. 1989;20(7):864–870. PubMed ↗
2. Powers WJ, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update. Stroke. 2019;50(12):e344–e418. PubMed ↗

Calculamedica

NIH Stroke Scale (NIHSS)

1a. Level of Consciousness

1b. LOC Questions

1c. LOC Commands

2. Best Gaze

3. Visual Fields

4. Facial Palsy

5a. Motor — Left Arm

5b. Motor — Right Arm

6a. Motor — Left Leg

6b. Motor — Right Leg

7. Limb Ataxia

8. Sensory

9. Best Language

10. Dysarthria

11. Extinction and Inattention (Neglect)

Interpretation

Stroke Severity Classification