Retrospective study of the combined application of the blink reflex and lateral spread reflex in microvascular decompression of facial nerve surgery.

BACKGROUND

The blink reflex (BR) can be used as a routine monitoring method during facial nerve microvascular decompression. This study aimed to investigate whether the use of the BR in hemifacial spasm (HFS) surgery is comparable to that of the lateral spread reflex (LSR), and to explore its significance for guiding intraoperative neurophysiological monitoring (IONM).

METHODS

Patients undergoing facial nerve microvascular decompression from 2016 to 2018 were included in the study. According to the results of IONM, the intraoperative monitoring items of the BR and two conventional facial nerve microvascular decompression procedures, namely the marginal mandibular branch LSR (MAR-LSR) and zygomatic branch LSR (ZYG-LSR), were compared. We mainly compared whether there were differences in the occurrence rate, disappearance rate, waveform, occurrence current, and prognosis of the three monitoring methods.

RESULTS

The occurrence rate of the BR was lower than that of the MAR-LSR and ZYG-LSR, as well as the three combined detection groups. The disappearance rate of the BR was not different to that of the MAR-LSR, but higher than that of the ZYG-LSR group. In addition, the waveform of the BR showed differences from that of the MAR-LSR and ZYG-LSR. The incidence of postoperative residual symptoms in patients with any kind of reflex on the first day after surgery and the day of discharge was significantly higher than that of patients in which all three reflexes disappeared.

CONCLUSIONS

Combined BR and LSR monitoring can reduce the occurrence of postoperative residual symptoms. We suggest that by increasing the use of BR examination during surgery, the integrity of the trigeminal nerve can be protected.