NIHSS score 40

This code indicates a National Institutes of Health Stroke Scale (NIHSS) score of 40, representing the most severe end of the scale. An NIHSS score of 40 signifies profound neurological deficits, typically observed in patients with extensive and devastating acute ischemic stroke. This score reflects severe impairment across multiple neurological domains, including consciousness, motor function, sensation, and language.

Use this code when documentation explicitly states an NIHSS score of 40, indicating maximum neurological deficit following an acute stroke. This score is typically assessed by trained medical professionals in the acute phase of stroke management. Documentation should clearly support the calculation and reporting of this specific score.

• Always sequence the appropriate acute stroke diagnosis (e.g., I63.x) before this NIHSS code.
• Ensure the medical record clearly documents the NIHSS assessment and the resulting score of 40.
• Do not use this code if the NIHSS score is not explicitly documented as 40; use other R29.7xx codes for different scores.