Click-evoked responses from the cochlear nucleus: a study in human.
Recordings from the vicinity of the cochlear nucleus in 9 patients undergoing microvascular decompression operations to relieve hemifacial spasm, trigeminal neuralgia, tinnitus, and disabling positional vertigo were conducted by placing a monopolar electrode in the lateral recess of the fourth ventricle (through the foramen of Luschka), the floor of which is the dorsolateral surface of the dorsal cochlear nucleus. The click-evoked potentials recorded by such an electrode display a slow negative wave with a peak latency of about 6-7 msec on which several sharp peaks are superimposed. None of the peaks in the recordings from the vicinity of the cochlear nucleus coincided with any vertex-positive peaks of the brain-stem auditory evoked potentials. In recordings from the lateral aspect of the floor of the fourth ventricle near the cochlear nucleus 1 patient showed 2 positive peaks, the earliest of which had a latency close to that of peak II and the second of which had a latency close to the negative peak between peaks III and IV of the brain-stem auditory evoked potentials. There is a distinct negative peak in the responses recorded from the midline of the floor of the fourth ventricle, the latency of which is only slightly shorter than that of peak V of the brain-stem auditory evoked potentials, supporting earlier findings that the sharp tip of peak V of the brain-stem auditory evoked potentials is generated by the termination of the lateral lemniscus in the inferior colliculus.
Møller
A R
AR
Department of Neurological Surgery, Presbyterian-University Hospital, University of Pittsburgh School of Medicine, PA 15213.
Jannetta
P J
PJ
Jho
H D
HD
D000161:Acoustic Stimulation; D002551:Cerebral Ventricle Neoplasms / Q000601:surgery; D002552:Cerebral Ventricles / Q000502:physiology*; D017626:Cochlear Nucleus / Q000502:physiology*; D004569:Electroencephalography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005152:Facial Muscles; D006801:Humans; D016343:Monitoring, Intraoperative; D011930:Reaction Time / Q000502:physiology; D013035:Spasm / Q000601:surgery; D014717:Vertigo / Q000601:surgery