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?