Injury of trochlear nerve, right side, sequela

This code signifies a long-term or late effect resulting from a previous injury to the trochlear nerve on the right side. The trochlear nerve (cranial nerve IV) innervates the superior oblique muscle, responsible for eye movement, and its injury can lead to diplopia (double vision) and impaired downward and outward gaze. "Sequela" indicates that the acute injury has resolved, but its lasting effects persist.

Use this code when documenting a chronic or residual condition directly attributable to a past injury of the right trochlear nerve. This typically applies when the patient presents with persistent symptoms such as vertical diplopia or compensatory head tilt, and the medical record clearly indicates a history of a specific traumatic event or condition that damaged the nerve. Documentation should specify the right side and confirm the sequela nature of the presentation.

• Ensure documentation explicitly states "sequela" or clearly indicates a chronic, residual condition from a past injury, not an acute injury.
• Verify the laterality is precisely documented as "right side" to avoid miscoding.
• Consider an external cause code (V00-Y99) if the original cause of the injury is known and relevant for reporting.