To the best of our knowledge, this

To the best of our knowledge, this is the largest single-center study to have investigated the prognostic ability of intraoperative EMG monitoring during MVD for HFS. Patients who had less than 1 year of symptoms showed a significantly higher rate of LSR loss after decompression compared with patients who had more than 10 years of symptoms. EMG monitoring was helpful for identifying the offending vessel(s), especially when multiple offending vessels were involved, and was also useful for confirming facial nerve decompression after Teflon sheet insertion from neurovascular contact. Intraoperative monitoring of the LSR during MVD for HFS had some prognostic value over a short-term follow-up period; however, this was not true over long-term follow-up periods. When the LSR was not alleviated even after correct decompression, our data indicate that extending follow-up for longer than 1 year is a useful solution.