Application of ocular vestibular evoked myogenic potentials in acute brainstem infarctions / 中华物理医学与康复杂志

ABSTRACT

Objective To explore the value of ocular vestibular evoked myogenic potential in treating brainstem infarctions through comparing the characteristics ocular vestibular evoked myogenic potential (oVEMP) and brainstem auditory evoked potential (BAEP) in patients with brainstem infarctions.Methods A total of 60 patients with brainstem infarctions were enrolled in a brainstem infarction (BI) group, while another sixty healthy volunteers were selected as the control group.All patients underwent oVEMP and BAEP tests via air-conducted stimuli.Results The oVEMPs were elicited reliably and stably in 58 of the control group, and 42 of the BI group, with the bilateral N1 and P1 latencies of oVEMP significantly prolonged [N1 (left) : 11.85 ± 0.82 ms, N1 (right) : 11.91 ± 0.86 ms, P1 (left) : 15.52 ± 1.61 ms, P1 (right) : 15.63 ± 1.64 ms respectively] and the bilateral N1-P1 amplitudes of oVEMP significantly reduced [1.23 ±0.42 μV (left) and 1.58 ± 0.70 μV (right) respectively].Moreover, no recordable oVEMPs was elicited in the other 18 patients, among which found 13 prolonged N1 latencies, 10 prolonged P1 latencies, 6 prolonged N1 and P1 latencies and 8 reduced N1-P1 amplitudes of oVEMP.Altogether, 45 abnormal oVEMPs were found, with an abnormal rate of 75％.The average peak latencies of Ⅴ waves [(5.98 ± 0.37) ms] and interpeak latencies of Ⅲ-Ⅴ and Ⅰ-Ⅴ waves [2.93 ± 0.34 ms and 4.96 ± 0.39 ms respectively] in the BI group were significantly prolonged compared to the controls (P＜ 0.01).The amplitude ratio of Ⅴ/Ⅰ (0.48 ± 0.10) in the BI group was significantly reduced compared to the controls (P ＜ 0.05).Forty-two abnormal BAEPs were found, with an abnormal rate of 75％ , including 17 prolonged latency of Ⅴ waves, 6 prolonged latency of Ⅲ waves, 15 prolonged interpeak latencies of Ⅲ-Ⅴ waves, 9 prolonged interpeak latencies of Ⅰ-Ⅴ waves, 11 cases of Ⅲ-Ⅴ interpeak latency larger than Ⅰ-Ⅲ interpeak latencies, 13 cases of the amplitude ratio of Ⅴ / Ⅰ smaller than 0.5 and 3 case of unclear waves.There were no significant differences in abnormal rate when using the oVEMP (42/60 and 75％) and BAEP (45/60 and 70％) testing However, the abnormal rate was 91.7％ when combining oVEMP with BAEP testing, significantly higher than that when only conducting BAEP testing.Conclusion Patients with brainstem infarctions have abnormalities in oVEMP.Combined with MRI and other electrophysiological testing, oVEMP may contribute to the diagnosis of brainstem infarctions.