Effect of High Altitude on Human Auditory Brainstem Responses

 

S. B. Singh*, L. Thakur, J. P. Anand, Deepak Yadav,

Amitabh, P. K. Banerjee and W. Selvamurthy

 

Defence Institute of Physiology and Allied Sciences (DIPAS),

Lucknow Road, Timarpur,

Delhi – 110 054

 

( Received on June 17, 2003 )

 

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Abstract : The effect of hypobaric hypoxia on Brain Stem Auditory evoked potentials (BAERs) were studied. BAERs were recorded in 30 volunteers at sea level (SL) and then at high altitude (HA) of 3200 m (HA I) and 4300 m (HA II) in Eastern Himalayas and on return to sea level (RSL). The BAERs were recorded using Nicolet Compact – 4 (USA) in response to monaural auditory stimuli consisting of clicks of 100 µs square pulse at a rate of 15/sec. The BAERs were recorded on day 4 of their stay at 3200 m and 4300 m respectively. Findings indicated an increase in absolute peak latencies of wave V at 3200 m, which was statistically significant. On further ascent to 4300 m there was an increase in absolute peak latencies of wave I and III indicating delay in sensory conduction at the medullo-pontine auditory pathways.

Key words : auditory evoked potential             high altitude

                     absolute peak latency                   interpeak latency