Preoperative percutaneous cranial nerve mapping in head and neck surgery.

OBJECTIVE

To identify and map the course of the peripheral branches of the cranial nerve preoperatively and percutaneously.

DESIGN

Prospective study. Preoperative percutaneous nerve mapping performed prior to the operation under deep sedation or general anesthesia without muscle paralysis.

SETTING

Private office surgery suite, freestanding surgery center, and regional medical centers.

PATIENTS: A total of 142 patients undergoing head and neck surgery and facial plastic surgery between August 1994 and July 1999.

INTERVENTION: Monopolar probe was used for nerve stimulation. Electromyographic reading was done through intramuscular bipolar recording electrodes. The equipment used was a nerve monitor.

RESULTS

The mandibular divisions were tested in 142 cases, the frontal division in 60 cases, the accessory nerve in 12 cases, and the hypoglossal nerve in 3 cases. Satisfactory mappings were obtained in 115 cases of the mandibular division, 49 cases of the frontal division, 8 cases of the accessory division, and 1 case of the hypoglossal nerve.

CONCLUSIONS

Preoperative percutaneous nerve mapping is a new method of identifying the location of the peripheral branches of the cranial nerves. Identifying and mapping the course of peripheral branches of the cranial nerves safely assists the head and neck surgeon in the placement of incisions in a favorable location and in the dissection of the area involving the nerves. Mapping alerts the surgeon to an area containing a nerve and allows the surgeon to avoid just the specific area where a nerve is present, preventing large-scale abandonment of unmapped areas for fear of potential nerve damage.