Study of brainstem auditory evoked potentials in early (grade I) essential hypertensive patients

Abstract

Background: Essential hypertension is one of the most common world’s health diseases. It frequently affects central nervous system (CNS) by producing micro-infarctions which results into altered evoked potentials. Previous studies have shown correlation between hypertension and brain stem auditory evoked potentials. But very scarce data is available on all the parameters of BAEP and essential hypertension especially “amplitude ratio” which distinguishes between central and peripheral impairment. This study was undertaken to evaluate the brain stem auditory evoked potentials (BAEPs) as early marker of cognitive damage in essential hypertension.Methods: BAEPs were recorded in 50 hypertensive subjects and in 50 normotensive controls. Absolute peak latencies, interpeak latencies of different waves and amplitude ratio were compared in both the groups by using unpaired student’s T test.Results: Significant changes in absolute latencies of wave I and V, Interpeak latency I-III, III-V and I-V and amplitude ratio V/I was observed in hypertensive group as compared to control group.Conclusions: Findings of the current study suggests that hypertension does affect the neuronal excitation in the auditory pathways, thereby suggesting that BAEP may provide the early evidence for the presence of CNS dysfunction in the patients of essential hypertension.

Electrocochleography and Auditory Brainstem Responses in Persons with Non-Optimal Blood Pressure

“…Tandon et al 10 also failed to find significant differences in IWIs between hypertensives and controls. In contrast, Gawali et al 12 reported significantly shorter IWI I–III in hypertensives than controls. In our study, the only significant difference in IWIs between optimal and nonoptimal BP subjects was IWI III–V at the highest stimulus level, which was 0.14 milliseconds longer in the nonoptimal BP group.…”

“…In our study, the only significant difference in IWIs between optimal and nonoptimal BP subjects was IWI III–V at the highest stimulus level, which was 0.14 milliseconds longer in the nonoptimal BP group. Prolonged IWI III–V has been identified in some, 11 12 but not all 10 other related ABR studies in HTN. To evaluate the potential contribution of hearing sensitivity to absolute wave latencies and IWIs, we included PTA 1,2,3,4 as a covariate in the linear mixed effects model.…”

“…Tandon et al 10 also reported this correlation and others have demonstrated ABR wave V latency delays in hypertensives. 11 12 There is a clear visual pattern in Fig. 4 that would suggest the HTN group has higher wave V latencies than those of the optimal group.…”

“…Goyal et al 11 identified significantly prolonged ABR wave V latencies and waves III to V interwave intervals (IWIs) in patients (40–60 years) with HTN compared with age- and sex-matched controls. Similarly, Gawali et al 12 reported delayed ABR waves I and V latencies and prolonged IWIs in hypertensive patients compared with controls. However, the effect of slight BP elevation (i.e., prior to diagnosable HTN) on early auditory evoked potentials (AEPs) has not been studied.…”

“…Wave I latency delays in HTN have been recognized in previous studies. 10 11 12 Goyal et al 11 identified significant ABR wave I latency delay (∼0.16 milliseconds) in hypertensives versus controls but only for subjects with the severest HTN. Similarly, Tandon et al 10 found wave I latency prolongation only in Stage 3 HTN.…”