Clinical Neurophysiology 131 (2020) 809–815

Significance of wave I loss of brainstem auditory evoked potentials during microvascular

decompression surgery for hemifacial spasm

Byung-Euk Joo, Sang-Ku Park, Min Ho Lee, Seunghoon Lee, Jeong-A Lee, Kwan Park

 

a b s t r a c t

Objective: We sought to define the significance of wave I loss of brainstem auditory evoked potentials
(BAEPs) during microvascular decompression (MVD) surgery for hemifacial spasm.
Methods: Out of 670 patients, 36 showed wave V loss during MVD surgery. These patients were classified
into the following two groups based on wave I loss: Total wave loss, including wave I loss, and wave V
loss with persistent wave I. We analyzed the differences in postoperative complications between the
groups. We also investigated when wave I loss occurred during MVD surgery.
Results: Of the 36 patients, 24 (66.7%) exhibited wave I persistence and 12 (33.3%) exhibited total wave
loss. The patients who showed total wave loss were significantly more likely to exhibit postoperative
hearing loss (p = 0.009). In addition, these patients exhibited a significantly higher frequency of postoperative
complications such as dizziness and tinnitus (p = 0.002 and p = 0.031, respectively). Total wave
loss occurred more frequently after the decompressive procedure of MVD surgery.
Conclusions: Total wave loss, including wave I loss, was more closely associated with severe postoperative
complications. Total wave loss occurred more frequently after the decompressive procedure of MVD
surgery.
Significance: These findings suggest the significance of wave I loss of BAEPs.