The NIH Stroke Scale, or NIHSS, is a standardized tool used to measure stroke-related neurologic deficits. This cheat sheet helps students review the exam items, scoring ranges, and the meaning of the total score. It is useful for understanding how clinicians communicate stroke severity clearly and consistently.
It also supports safe medical science learning by showing that stroke assessment must be performed by trained professionals.
The NIHSS includes 11 scored categories that test consciousness, vision, movement, sensation, language, speech, and attention. Each item has a defined score, and higher numbers usually mean more severe neurologic impairment. The total score is calculated as NIHSS total score = sum of all 11 item scores, with a possible range of 0 to 42.
A quick reference should emphasize correct observation, clear instructions, and consistent documentation.
Key Facts
- The NIHSS total score is calculated as total score = 1a + 1b + 1c + 2 + 3 + 4 + 5a + 5b + 6a + 6b + 7 + 8 + 9 + 10 + 11.
- The full NIHSS score range is 0 to 42, where 0 means no measurable stroke deficit on the scale.
- Common severity categories are 0 = no stroke symptoms, 1 to 4 = minor stroke, 5 to 15 = moderate stroke, 16 to 20 = moderate to severe stroke, and 21 to 42 = severe stroke.
- Level of consciousness items include alertness, answering month and age, and following simple commands such as opening and closing the eyes.
- Motor arm and motor leg items are scored separately for right and left sides, with 0 meaning no drift and 4 meaning no movement.
- Language and dysarthria are different NIHSS items because aphasia measures language understanding or production, while dysarthria measures clarity of speech.
- Neglect, also called extinction and inattention, is scored by testing whether the patient notices stimuli on both sides at the same time.
- The NIHSS should be scored from what the patient actually does during the exam, not from what the examiner thinks the patient could do.
Vocabulary
- NIH Stroke Scale
- A standardized neurologic scoring system used to describe and track stroke-related deficits.
- Aphasia
- A language disorder that affects speaking, understanding, reading, or naming because of brain injury.
- Dysarthria
- Slurred or unclear speech caused by weakness or poor control of the muscles used for speaking.
- Hemianopia
- Loss of vision in half of the visual field, often affecting the same side in both eyes.
- Ataxia
- Poor coordination of voluntary movement that may appear as inaccurate finger-to-nose or heel-to-shin movement.
- Neglect
- Reduced awareness of one side of the body or space, even when strength and basic sensation may still be present.
Common Mistakes to Avoid
- Adding only one side for motor testing is wrong because right and left arm and leg scores are separate NIHSS items.
- Scoring based on the suspected diagnosis is wrong because NIHSS scoring must reflect the patient's observed performance during the exam.
- Confusing aphasia with dysarthria is wrong because aphasia is a language problem, while dysarthria is a speech muscle control problem.
- Giving extra coaching or repeated hints is wrong because it can change the measured deficit and make the score less reliable.
- Ignoring an untestable item is wrong because NIHSS documentation requires the correct item score or special notation according to the scoring instructions.
Practice Questions
- 1 A patient has item scores of 1, 0, 1, 0, 2, 1, 0, 2, 2, 1, and 1 across the NIHSS categories. What is the total NIHSS score?
- 2 A patient scores 0 for gaze, 2 for visual fields, 1 for facial palsy, 3 for right arm, 0 for left arm, 2 for right leg, 0 for left leg, 1 for sensory, 2 for language, 1 for dysarthria, and 1 for neglect. What is the total score for these listed items?
- 3 Using the common severity categories, how would you classify an NIHSS score of 18?
- 4 Why is it important to score what the patient actually does during the NIHSS exam instead of estimating what the patient might be able to do?
Understanding NIH Stroke Scale Quick Reference
A stroke can affect different brain networks, so two people with the same total score may need very different care. A person with weakness on one side may have trouble walking or holding objects. Another person may have a language problem that makes it hard to explain needs, even when arm strength is normal.
The pattern of item scores helps clinicians locate which functions are affected. Sudden face drooping, arm weakness, speech trouble, vision loss, severe imbalance, or confusion are warning signs that need emergency action. Students should remember that a scale score does not replace brain imaging, medical history, or a full examination.
Reliable scoring depends on a consistent exam method. The examiner gives the stated instruction once, uses the required stimulus, then records the observed response. Repeated hints can make a response look better than it truly is.
A patient may be unable to answer because of hearing loss, a language barrier, injury, sedation, or a preexisting disability. These factors must be identified in the record. Some items have special scoring rules for barriers such as amputation or severe visual loss.
The goal is not to make the number seem high or low. The goal is to create an accurate snapshot that another trained clinician can understand.
Several NIHSS items are easy to confuse. Aphasia is a problem with using or understanding language. A person may use the wrong words, fail to follow a spoken command, or be unable to name a familiar object.
Dysarthria is different. The person may know exactly what to say, but weak or poorly coordinated speech muscles make the words unclear. Neglect is different from blindness or weakness.
A person with neglect may fail to notice one side of the body or space, especially when information is presented on both sides together. These differences matter because they point to different brain functions and can affect safety during eating, walking, reading, or driving.
The score can change over minutes or hours. A rising score may signal worsening brain function, while improvement can show that a treatment or natural recovery is helping. For this reason, documentation should include the time of assessment, the item scores, notable barriers, and the patient responses that support the score.
A total alone can hide important changes. For example, a person could gain movement in an arm while developing more severe language difficulty, leaving a similar total. When learning this tool, focus on the exact definitions for each response level.
Practice noticing observable behavior rather than guessing intent. In real clinical settings, only trained professionals perform and interpret the NIHSS as part of urgent stroke care.