Evoked Potential Analysis of Impact Acceleration Experiments

Abstract : This report focuses on the use of somatosensory evoked potentials (SEPs) as an assessment tool for transient injury in rhesus macaques undergoing impact acceleration in the - Gx direction. Adult male rhesus macaques, seated on a sled and restrained (except for the head and neck), were accelerated at peak sled accelerations ranging from 95.5 to 1039.6 m/sec2. The sled was decelerated by friction forces ranging from 0.7 to 3.0 m/sec2. Somatosensory stimuli were delivered prior to, during, and after impact. Amplified SEP activity was telemetered and recorded on magnetic tape. The raw SEP data were digitized and analyzed off-line. Results for cortical SEPs are consistent with and extend previous analyses, suggesting a threshold for transitory changes in cervical SEP latencies in macaques at peak -Gx sled accelerations below 550 m/sec2. (js)