Abstract
To elicit brain stem auditory evoked potentials (BAEPs), a click delivered at a stimulation rate of 10–11 Hz is usually used. If this frequency is changed to 40 Hz and the analysis time is increased from 10 to 50 ms, two identical responses are elicited, as a click is delivered every 25 ms. If the bandpass filter is reduced to an upper frequency: lower frequency of 1–100 Hz, a sinusoidal reproducible response is obtained, the 40-Hz auditory evoked potential (40-Hz AEP) (see Fig. 1). As GALAMBOS et al. discovered in 1981, this response is maximal if the stimulation rate is increased to 40 Hz and then decreases again at higher stimulation rates (see Fig. 2). The location of the generator of this response is unclear; a midbrain/thalamic generator has been suggested by Spydell et al. As the amplitude of this response depends on the stimulation frequency, a resonance phenomenon has been discussed (9).
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© 1988 Springer-Verlag Berlin Heidelberg
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Firsching, R., Frowein, R.A. (1988). The 40-Hz Middle Latency Auditory Evoked Potential in Comatose Patients. In: Walter, W., Brandt, M., Klinger, M., Brock, M. (eds) Modern Methods in Neurosurgery. Advances in Neurosurgery, vol 16. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-73294-2_22
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DOI: https://doi.org/10.1007/978-3-642-73294-2_22
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