Effect of steady hypothermia and normothermia on multimodality evoked potentials in human poikilothermia
M. A. MacKenzie, D. M. Vingerhoets, E. J. Colon, A. J. Pinckers and S. L. Notermans
Department of Medicine, University Hospital Nijmegen, The Netherlands.
OBJECTIVE: To assess the effects of steady-state spontaneous hypothermia on
multimodality evoked potentials and on peripheral nerve conduction in human
poikilothermia. DESIGN AND SETTING: Case series at a university hospital.
PATIENTS: Four patients (four women, aged 28 to 37 years) with acquired
poikilothermia. MAIN OUTCOME MEASURES: Short-latency somatosensory,
brain-stem auditory, and visual evoked potentials as well as motor and
sensory peripheral nerve conduction velocity during steady-state
spontaneous hypothermia and normothermia. RESULTS: The marked latency
prolongation of all evoked potentials and decreased peripheral nerve
conduction velocity observed during steady-state spontaneous hypothermia
(mean +/- SD core temperature, 33.5 +/- 0.3 degrees C) compared with
normothermia (36.9 +/- 0.4 degrees C) agrees with previous findings during
short-term induced hypothermia. CONCLUSIONS: The unequivocal effect of
sustained mild spontaneous hypothermia on evoked potentials and peripheral
nerve conduction velocity underlines the importance of meticulous attention
to even small alterations in core temperature in interpreting
neurophysiological investigations.