Influence of tonic reflex activities on the slow auditory evoked potential

Possible influences of tonic reflex activities on the slow auditory evoked potential were investigated. For this purpose, the slow auditory evoked potential was picked up in 18 volunteers with normal hearing in relaxed position and in postures corresponding to reflex-induced positions and in 15 patients with cerebral palsy (CP) in tonic reflex patterns. No influence on latency for N120 and P215 due to postures could be observed. Latency within CP patients was age-dependent. The effect of the reflex-inhibiting pattern (RIP) - the pattern inhibiting tonic reflex activity in CP patients as far as possible - on potential amplitude was different in the two groups. The effect of RIP in CP patients was comparable to the relaxed position in volunteers. This difference points toward an influence of tonic reflex activity on the slow auditory evoked potential.