NIHSS score 42

This code indicates a National Institutes of Health Stroke Scale (NIHSS) score of 42, representing the most severe end of the scale. An NIHSS score of 42 signifies profound neurological deficits, typically observed in patients with extensive and devastating acute cerebral infarction or hemorrhage. This score reflects severe impairment across multiple neurological domains, including consciousness, motor function, sensation, and language.

Use this code when the medical record explicitly documents an NIHSS score of 42 for a patient experiencing an acute stroke. This score is typically assessed by trained medical professionals in the emergency department or acute care setting following a suspected or confirmed stroke event. Documentation must clearly state the NIHSS score as 42.

• Always ensure the medical record explicitly states "NIHSS score 42" or equivalent documentation.
• This code is a secondary diagnosis and should be sequenced after the primary diagnosis for the acute stroke (e.g., I63.x for ischemic stroke or I61.x for hemorrhagic stroke).
• Do not use this code if the NIHSS score is not explicitly documented as 42; use the appropriate code for the documented score.