Hypo- and hyperthermia in clinical auditory brain stem response measurement: two case reports.
Two case reports are presented to highlight the important effects of body temperature in clinical auditory brain stem response (ABR) measurement. Case 1 is an 11 year old boy in coma secondary to severe head injury. High dose barbiturate therapy suppressed brain stem neurologic signs and the ABR was relied on as a monitor of CNS status. Hypothermia during this period of intensive care was a crucial factor for meaningful interpretation of ABR findings. The second case was a 26 year old male undergoing hyperthermic therapy for advanced cancer. As body temperature increased from 38 to 42 degrees Centigrade (107.6 degrees Fahrenheit), there was a systematic decrease in latency for waves III and V. An overall hyperthermia-related decrease in the wave I-V latency interval of 0.5 to 0.6 milliseconds was observed on two test dates. ABR results for these two cases are discussed in the context of basic knowledge on body temperature and auditory electrophysiology.
D000328:Adult; D001831:Body Temperature; D001933:Brain Stem / Q000503:physiopathology*; D002648:Child; D003128:Coma / Q000503:physiopathology; D005072:Evoked Potentials, Auditory; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods; D007035:Hypothermia / Q000209:etiology; D008113:Liver Neoplasms / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008545:Melanoma / Q000503:physiopathology / Q000628:therapy