Is the NIHSS used for all types of strokes?

While the NIHSS is commonly used for ischemic strokes, it can also be applied to hemorrhagic strokes and other neurological conditions to assess neurological defic

What is the scoring range for the NIHSS?

The NIHSS scoring ranges from 0 to 42, with higher scores indicating more severe stroke symptoms.

ADDONS / SCALES

NIH Stroke Scale (NIHSS)

David Goldemund M.D.
Updated on 14/03/2024, published on 27/09/2022

→ NIHSS protocol

→ NIHSS online protocol (MDCALC)

NIHSS is a standardized neurological scale developed to help physicians objectively quantify stroke severity
scoring range: 0-42 (with higher scores indicating more severe stroke symptoms)
scoring rules must be strictly followed to ensure reproducibility
variants of the NIHSS have been introduced:
- modified NIHSS
  - some items are easier to score; data indicate higher reproducibility compared to the original NIHSS
  - however, it has not been widely adopted
- NIHSS-8

Classification of stroke severity based on NIHSS

Different classifications and tresholds have been reported

(Kimura, 2022)

NIHSS < 8 (mild stroke)
NIHSS 8-15 (moderate stroke)
NIHSS ≥ 16 (severe stroke)

(Kogan, 2020)

NIHSS ≤ 4 (minor stroke)
- even patients with NIHSS 0 may have stroke and not TIA
NIHSS 5-15 (moderate stroke)
NIHSS 16-20 (moderate to severe stroke)
NIHSS 21-42 (severe stroke)

(Koton, 2022)

NIHSS ≤ 5 (minor)
NIHSS 6–10 (mild)
NIHSS 11–15 (moderate)
NIHSS 16–20 (severe)
NIHSS > 20 (very severe)

Basic principles of NIHSS assessment

administer the items in the order listed, and do not go back to change scores
follow the instructions provided for each item
score based on what the patient actually does, not on what the clinician believes they could or should do
always assess the first response, not the best one (except for item 9 – Best Language)
- for example, if a patient initially gives an incorrect answer about their age and later corrects themself, the answer should be scored as incorrect
- this is crucial because otherwise, it is not possible to ensure reproducibility
never assist or coach the patient during the examination (unless the instructions explicitly allow this)
some items are scored only if present
- for example, ataxia is scored as absent in a plegic patient
older deficits are also scored, except for sensory impairments

Clinical implications

NIHSS is NOT a guide to select tPA-suitable patients – tPA should be used regardless of severity → see IVT contraindication
NIHSS indicates stroke severity and has been shown to correlate with infarct size and risk of hemorrhage
- NIHSS of >20 was associated with a 17% rate of intracranial hemorrhage when treated with tPA, compared to a 3% rate in patients with a score of <10 (The NINDS t-PA Stroke Study Group 1997).
NIHSS may also predict large vessel occlusion (LVO)
- higher NIHSS indicates a higher probability of LVO; although a low NIHSS score does not necessarily exclude it
- some cut-off values for predicting LVO have been reported
  - NIHSS scores ≥ 9 within 3 hours after symptom onset and NIHSS scores ≥ 7 within >3 to 6 hours (Heldner, 2013)
baseline NIHSS may predict clinical outcome
- a retrospective review of 1281 ischemic stroke patients found that each 1-point increase in NIHSS reduced the odds of an excellent outcome by 24% at 7 days and 17% at 3 months (Adams 1999).
- patients with moderate (6-13 points) or severe (>14 points) NIHSS scores were 3 times more likely to be placed in a nursing home after discharge and 8 times more likely to require rehabilitation therapy (Rundek 2000).
- patients with a score of ≤ 4 are highly likely to have favorable clinical outcome irrespective of treatment

National Institute of Health Stroke Scale (NIHSS)
1a. Level of Consciousness the investigator must choose a response if a complete evaluation is prevented by such obstacles as an endotracheal tube, language barrier, orotracheal trauma, or bandages a 3 is scored only if the patient does not move (other than reflexive posturing) in response to noxious stimulation	0 – alert; keenly responsive 1 – not alert; arousable verbally or by minor stimulation to obey, answer, or respond 2 – not alert; requires repeated or strong/painful stimulation to make at least escape movements 3 – coma, reflex postures (reflex), totally unresponsive and areflexic
1b. LOC – Answers the patient is asked about the current month and their age the answer must be correct – there is no partial credit for being close aphasic and stuporous patients who do not comprehend the questions will score 2 patients unable to speak because of endotracheal intubation, orotracheal trauma, severe dysarthria from any cause, language barrier, or any other problem not secondary to aphasia are given a 1 only the initial answer is scored; no verbal or nonverbal cues are allowed	0 – answers both questions correctly 1 – answers 1 question correctly or severe dysarthria/mechanical or language barrier 2 = answers neither question correctly, aphasia, coma
1c. LOC – Tasks the patient is asked to open and close the eyes and then to grip and release the non-paretic hand (or other tasks) credit is given if a clear attempt is made but not completed due to weakness if the patient does not respond to the command, the task should be demonstrated (pantomime), and the result scored (i.e., follows none, one, or two commands) patients with trauma, amputation, or other physical disabilities should be given appropriate one-step commands only the first attempt is scored	0 – performs both tasks correctly 1 – performs one task correctly 2 = performs neither task correctly, coma
2. Best gaze only horizontal eye movements are tested voluntary or reflexive (oculocephalic) eye movements are scored, not caloric testing patients with an isolated peripheral nerve paresis (CN III, IV, or VI) score 1 patients with ocular trauma, coma, bandages, pre-existing blindness, or other disorders of visual acuity or fields should be tested with reflexive movements	0 – normal 1 – isolated peripheral paresis or partial gaze palsy in one or both eyes; can be overcome by the oculocephalic maneuver, no forced deviation or total gaze paresis 2 – forced deviation or total gaze paresis, cannot be overcome by the oculocephalic maneuver
3. Visual fields test by side confrontation, use finger counting or visual threat (blink reflex) include double simultaneous stimulation; if there is extinction, the patient receives a 1, and the results are used for item 11 with unilateral blindness, visual fields in the fellow eye are scored score 1 only if there is a clear-cut asymmetry, including quadrantanopia if the patient is blind from any cause, score 3	0 – normal 1 – partial hemianopia or extinction 2 – complete hemianopia 3 – bilateral hemianopia or blindness (including cortical blindness)
4. Facial palsy ask or use pantomime to encourage the patient to show teeth or raise eyebrows and close eyes assess the symmetry of the grimace in response to noxious stimuli in the poorly responsive or noncomprehending patient if facial trauma/bandages, orotracheal tube, tape, or other physical barriers obscure the face, these should be removed to the extent possible	0 – normal 1 – minor paralysis (flattened nasolabial fold, asymmetry on smiling) 2 – partial paralysis (total or near-total paralysis of the lower face) 3 – complete uni- or bilateral paralysis (absence of facial movement in the upper and lower face), coma

5. Motor arm extend the arms (palms down) 90 degrees (if sitting) or 45 degrees (if supine) drift is scored if the arm falls before 10 seconds the aphasic patient is encouraged to use urgency in the voice and pantomime but not noxious stimulation start with the non-paretic arm in the case of amputation or shoulder fusion, the examiner should record the score as untestable (UN) and clearly write the explanation for this choice	0 – no drift; limb holds 90 (or 45) degrees for 10 seconds 1 – limb drifts down before 10 seconds; does not hit the bed or other support 2 – some effort against gravity; limb fails to reach or maintain (if cued) 90 (or 45) degrees, drifts down to bed 3 – no effort against gravity; arm falls to the bed 4 – no movement UN = amputation or joint fusion, explain
6. Motor leg hold the leg at 30 degrees (tested supine). Drift is scored if the leg falls before 5 seconds the aphasic patient is encouraged using urgency in the voice and pantomime but not noxious stimulation start with the non-paretic leg in the case of amputation or hip fusion, the examiner should record the score as untestable (UN) and write the explanation for this choice	0 – no drift; leg holds 30-degree position for whole 5 seconds 1 – drift by the end of 5 seconds, but the leg does not hit the bed 2 – some effort against gravity; leg falls to bed by 5 seconds but has some effort against gravity 3 – no effort against gravity; the leg falls to bed immediately, with some movement on the bed 4 – no movement UN = amputation or joint fusion, explain
7. Limb ataxia test with eyes open the finger-nose-finger and heel-shin tests are performed on both sides ataxia is scored only if present out of proportion to the weakness ataxia is scored as 0 in a patient who cannot understand, is paralyzed, or is in a coma ensure testing is done in an intact visual field in case of blindness, test by having the patient touch the nose from the extended arm position only in the case of amputation or joint fusion the examiner should record the score as untestable (UN) and clearly write the explanation for this choice	0 – absent or paralyzed/does not understand/coma 1 – present in one limb 2 – present in two limbs UN = Amputation or joint fusion, explain
8. Sensory a sensation or grimace to pinprick or withdrawal from the noxious stimulus in the obtunded or aphasic patient the examiner should test as many body areas (arms [not hands], legs, trunk, face) as needed to accurately check for hemisensory loss only sensory loss attributed to stroke is scored as abnormal a score of 2 should only be given when a severe or total loss of sensation can be clearly demonstrated; stuporous and aphasic patients will probably score 1 or 0 bilateral loss of sensation due to brainstem stroke is scored 2 if the patient is unresponsive, quadriplegic, or in a coma, give a 2 on this item	0 – normal 1 – mild-to-moderate sensory loss; pinprick is less sharp/duller, or there is a loss of superficial pain with a pinprick, but the patient is aware of being touched 2 – severe or total sensory loss; the patient is unaware of being touched; coma/unresponsive

9. Best Langauge a great deal of information about comprehension will be obtained during the preceding sections; understanding is judged from responses here, as well as to all of the commands in the preceding general neurological exam the patient is asked to name the items on the attached naming sheet and to read from the attached list of sentences the patient is asked to describe the attached picture if visual loss interferes with the tests, ask the patient to identify objects placed in the hand, repeat, and produce speech the intubated patient is asked to write the patient in a coma (item 1a=3) will automatically score 3 the examiner must choose a score for the patient with a stupor or limited cooperation, but a score of 3 should be used only if the patient is mute and follows no one-step commands	0 – no aphasia 1 – mild-to-moderate aphasia; loss of fluency or ability to understand without significant limitation 2 – severe aphasia with fragmentary expression; the great need for inference, questioning, and guessing by the listener; the listener carries the burden of communication 3 – mute, global aphasia – no usable speech or auditory comprehension, coma/unresponsive
10. Dysarthria an adequate speech sample must be obtained if the patient has severe aphasia, the clarity of articulation of spontaneous speech can be rated if the patient is intubated or has other physical barriers to speech, the examiner should record the score as untestable (UN) and write the explanation do not tell the patient why they are being tested	0 – normal 1 – mild-to-moderate dysarthria; patient slurs at least some words, can be understood with some difficulty 2 – severe dysarthria (unintelligible slurring out of proportion to dysphasia), anarthria, mutism, coma UN – intubated / other physical barriers – explain
11. Extinction and Inattention (formerly neglect) sufficient information to identify neglect may be obtained during the prior testing test simultaneous sensitivity and visual field, search for anosognosia if the patient has severe vision loss preventing visual double simultaneous stimulation, and the cutaneous stimuli are normal, the score is normal if the patient has aphasia but does appear to attend to both sides, the score is normal abnormality is scored only if present, so the item is never untestable	0 – no abnormality 1 – neglects 1 modality – visual, tactile, auditory, spatial, or personal inattention or extinction to simultaneous bilateral stimulation in one of the sensory modalities 2 – neglects >1 modality, profound hemi-inattention or extinction (fails to recognize own hand or orients to only one side of space), coma

Scoring patients in a coma (item 1a = 3)
1a Level of consciousness 1b LOQ questions (answers) 1c LOC questions (tasks) 2 Best gaze 3 Visual fields 4 Facial palsy 5-6 Arm and leg motor drift (left and right) 7 Limb Ataxia 8 Sensory 9 Best language (aphasia) 10 Dysarthria 11 Extinction and Inattention (neglect)	3 2 2 test oculocephalic maneuver test blink reflex 3 16 0 2 3 2 2