NIH Stroke Scale Calculator
Add up the fourteen items of the NIH stroke scale and get the total and the usual severity band for that score.
What it does
The National Institute of Neurological Disorders and Stroke publishes a form that starts with three lines of instructions and then fourteen numbered items, each with a description of how to test it and a row of scores to circle. It is the most used way of measuring how bad a stroke is, and it takes about five minutes at the bedside.
The instructions on the form are the reason it works. Administer the items in the order listed, record the performance in each category after each subscale exam, do not go back and change scores, and follow the directions for each technique. The scores should reflect what the patient does, and except where the form says otherwise the patient should not be coached into a better performance.
The scale runs from 0 to 42. The first three items look at level of consciousness, with one point for being alert, one for answering the month and the age, and one for following a command. Then come the findings that map onto the stroke itself: gaze, visual fields, facial palsy, motor power in each arm and leg, ataxia, sensation, language, dysarthria, inattention and swallowing.
This page adds the scores up and gives the band that the total is usually read against, 0 to 4 for a minor stroke, 5 to 15 for a moderate one, 16 to 20 for moderate to severe and 21 to 42 for severe. It also lists the items that scored above zero, which is the part of the examination that describes the stroke.
The limits are important. The scale is administered by trained clinicians, and the form says the examiner has to pick a score in situations where an item cannot be tested, such as an endotracheal tube or a language barrier. The total on its own is not a diagnosis and does not say what is wrong or what should be done, and this page is for information only.
How to use
- Score each item as the form describes, in order, and enter the number here.
- Start with items 1a, 1b and 1c, the three parts of the level of consciousness.
- Work through the motor items 5a and 5b with the arms and legs held out and count how long the patient can hold them up.
- For the language items use the picture, the naming sheet and the sentences on the form.
- Read the total and the band it falls in.
- Take the result to the treating team, and treat this page as a check on the arithmetic rather than as a clinical tool.
Formula
- Total
- Sum of the fourteen scored items, from 0 to 42 points.
- Item
- One of the fourteen items, scored from 0 up to the maximum that item allows.
The severity bands used here are the ones most often quoted for the scale: 0 to 4 minor, 5 to 15 moderate, 16 to 20 moderate to severe and 21 to 42 severe. The form itself does not set bands, it sets the items and their scoring rules, and the handling of untestable items is written into the individual items, with automatic scores for a patient in a coma.
Worked example
Example: a patient with gaze, visual field, facial and limb findings and mild aphasia
Defaults: level of consciousness 0 on all three items, best gaze 1, visual fields 2, facial palsy 1, motor arm 2, motor leg 2, ataxia 0, sensory 1, best language 1, dysarthria 1, extinction 0 and dysphagia 0.
- The three consciousness items score 0, 0 and 0, so the patient is alert, answers both questions and follows both commands.
- Best gaze 1 and visual fields 2 add 3 points.
- Facial palsy 1, motor arm 2 and motor leg 2 add another 5 points.
- Sensory 1, best language 1 and dysarthria 1 add 3 more points.
- Ataxia, extinction and dysphagia all score 0, so nothing comes from those three.
- The total is 3 + 5 + 3 = 11 points out of the possible 42.
- The tool shows 11 points, a moderate stroke band, and the items that scored above zero: Best gaze 1, Visual fields 2, Facial palsy 1, Motor arm 2, Motor leg 2, Sensory 1, Best language 1 and Dysarthria 1.
Reference table
| Item | What it tests | Scores |
|---|---|---|
| 1a, 1b, 1c | Level of consciousness, questions and commands | 0 to 3, 0 to 2, 0 to 2 |
| 2 and 3 | Best gaze and visual fields | 0 to 2 and 0 to 3 |
| 4 | Facial palsy | 0 to 2 |
| 5a and 5b | Motor power in the arm and the leg | 0 to 4 each |
| 6 and 7 | Ataxia and sensation | 0 to 2 each |
| 8, 9 and 10 | Best language, dysarthria and inattention | 0 to 3, 0 to 2, 0 to 2 |
| 11 | Dysphagia | 0 to 2 |
Limits
- The scale is administered by trained clinicians, and the form says the examiner has to choose a score when an item cannot be tested rather than leave it blank.
- The total on its own says how severe the deficit looks, and nothing about the cause, the blood vessels involved or the treatment.
- Several items, such as aphasia and dysarthria, depend on the language of the examination and on the examiner, which shifts the score a little.
- The band boundaries are conventions rather than rules, and the form itself does not define them.
Common mistakes
- Scoring what the patient could do rather than what they did. The form is explicit that the score reflects performance, not potential.
- Coaching the patient through an item, which the form says not to do except where it is indicated.
- Going back and changing an earlier score. The instructions say to record each item as it is done and not to revise.
- Leaving an item blank when it cannot be tested. The form gives automatic scores for a patient in a coma, and the examiner picks a score in other situations.
- Reading the band as a prognosis. The scale measures deficit severity at one moment, and it is repeated over hours and days to show the trend.
Try it yourself
Quick checks. Answers sit tucked under each question.
What does a score of 11 mean?
It reads as a moderate stroke, because 5 to 15 is the band usually quoted for moderate severity. The total of 11 comes from eight items: best gaze 1, visual fields 2, facial palsy 1, motor arm 2, motor leg 2, sensory 1, best language 1 and dysarthria 1.
A patient in a coma cannot answer questions or follow commands. How are those items scored?
The form gives automatic scores for a patient in a coma, who is given 2 for sensory and 3 for language, and the examiner still has to choose a score for the consciousness items. The point of the instruction is that no item is left blank, so the total always means the same thing.
The patient gets much better overnight. Does the scale change?
Yes, the scale is repeated, and the form records the intervals it is used at: at baseline, two hours after treatment, 24 hours after the onset of symptoms, 7 to 10 days, and 3 months. The change in the total over time is how improvement is measured.
Questions
What is the NIH stroke scale?
A standardised way of measuring the severity of a stroke, published by the National Institute of Neurological Disorders and Stroke as a form for the examiner to work through. It is the most widely used stroke severity scale in clinical practice.
How many items are there?
Fifteen numbered items, of which fourteen carry points, because the first is split into three parts for level of consciousness, the questions and the commands. The total runs from 0 to 42.
What do the scores mean?
The commonly used bands are 0 to 4 for a minor stroke, 5 to 15 for a moderate one, 16 to 20 for moderate to severe and 21 to 42 for severe. The form itself does not set bands, so these are conventions.
Why is it done in a fixed order?
The form says to administer the items in the order listed and to record the performance in each category after each subscale exam. The order matters because the later items test language and attention, and doing the easier ones first keeps the patient cooperative.
Can it be used for anything other than stroke?
It is built for stroke and the form is specific about which findings count as abnormal because of the stroke, for example saying that only sensory loss attributed to stroke is scored as abnormal. It is sometimes adapted for other conditions, but then the numbers are not the standard ones.
What should I do with the result?
Give it to the treating team with the rest of the examination. The score is one part of the assessment, alongside the imaging, the blood tests and the clinical picture, and it is repeated over time to show whether the patient is improving.
Sources
- National Institute of Neurological Disorders and Stroke: the NIH stroke scale form and instructions
- National Institute of Neurological Disorders and Stroke: the NIH stroke scale with the item descriptions