Effects of hypothermia on the human brainstem auditory response

Abstract

Latency measurements between three potentials (waves I, III, and IV/V) of the human brainstem auditory response can allow early detection of certain posterior fossa lesions. The diagnostic use of these interwave latencies requires knowledge of what factors may prolong them in the absence of disease. Hypothermia appears to be one such factor--in 5 neurologically and audiometrically normal patients, mean esophageal temperatures as high as 34.5 degrees C resulted in prolongations of central auditory conduction time. Interwave latency prolongations that were abnormal relative to an age-matched normal population were seen at 32.1 degrees +/- 0.3 degrees C in patients with both spontaneous and induced hypothermia, and these abnormalities disappeared after rewarming to normothermia. Hypothermia often accompanies intoxication and coma and should therefore be considered when brainstem auditory response abnormalities are being interpreted in these two clinical conditions.

Effect of hypothermia upon the electrocochleogram and auditory evoked brainstem response.

“…Kawakami (1981) also reported the latency prolongation of ABR in case of thiopental anesthesia in human. The effect of hypothermia upon waves III and V were reported by Stockard et al (1978) and Kaga et al (1979). The resuts obtained in the present study are in agreement with their results.…”

“…Therefore, it is conceivable that the responses evoked in the auditory tract are also influenced by temperature. The effect of hypothermia upon auditory evoked brainstem response (ABR) was reported by Stockard et al (1978) and Kaga et al (1979). Electrocochleographical studies in human, however, have not been reported, although several animal experiments on cochlear potentials have been reported since 1950.…”

Somatosensory and brainstem auditory evoked potentials in cardiac arrest patients treated with hypothermia*

“…The measurement of BAEPs has been used to monitor neuronal function at the level of the brainstem. Hypothermia increases the BAEP interwave latencies (5,11,12). BAEP components have also been reported to be abolished at temperatures below 20°C (12).…”

Rapid Increase in Neural Conduction Time in the Adult Human Auditory Brainstem Following Sudden Unilateral Deafness

“…An increase in body temperature leads to an increase in neural conduction speed and a reduction in ABR latency (Stockard et al 1978;Markand et al 1987). Therefore, it is important to account for any change in temperature in serially recorded ABR data.…”