NIHSS score 13

This code indicates a specific severity of neurological deficit as measured by the National Institutes of Health Stroke Scale (NIHSS). An NIHSS score of 13 signifies a moderate to severe stroke, reflecting significant impairment in multiple neurological domains. This score is a critical indicator of stroke impact and guides treatment decisions and prognosis.

This code is used when a patient has been assessed using the NIHSS, and the documented score is precisely 13. It is typically applied in acute stroke settings, emergency departments, and inpatient neurology units. Documentation must clearly state the NIHSS score as 13, usually within a physician's note or neurological assessment.

• Ensure the documented NIHSS score is exactly 13; do not round or approximate.
• This code is for the score itself, not the underlying stroke diagnosis, which should be coded separately.
• Always sequence this code after the primary diagnosis for the stroke (e.g., I63.x).