Concussion with prolonged loss of consciousness and return to pre-existing conscious level

This code signifies a concussion characterized by a sustained period of unconsciousness, from which the patient eventually recovers to their baseline cognitive state. It indicates a more severe initial impact than concussions without prolonged loss of consciousness, but with a favorable neurological outcome regarding the level of consciousness.

Apply this code when documentation clearly states a diagnosis of concussion accompanied by a prolonged loss of consciousness (e.g., several hours to days) and subsequent return to the patient's pre-injury conscious level. Supporting documentation would include physician notes detailing the duration of unconsciousness, neurological assessments, and confirmation of recovery to baseline consciousness.

• Ensure "prolonged" loss of consciousness is explicitly documented; differentiate from brief or transient loss.
• Do not use if the patient has not returned to their pre-existing conscious level, as this indicates a different severity or type of brain injury.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter.