A new neurogenic vestibular evoked potential (N6) recorded with the use of air-conducted sound.
BACKGROUND
Neurogenic vestibular evoked potentials that are recorded from the scalp have so far been recorded in the form of N3 (click air-conducted), N5 (tone air-conducted), and P10 (bone-conducted stimulus) waveforms. The purpose of this study is to find other vestibular waveforms obtained with air-conducted sound.


METHODS
The experiments were organized into 4 parts: 1) topographic scalp mapping; 2) determining the consistency in appearance of candidate vestibular waveforms; 3) further characteristics such as their relationship to vestibular evoked myogenic potentials, sensitivity to 5-kHz tone, and threshold of activation; and (D) recording of the new vestibular waveforms in a case of hearing loss.


RESULTS
A montage was discovered, O2-P3 and O1-P4 with left and right ear stimulation respectively, that yielded a negative wave at 6 milliseconds after stimulus onset and was labeled N6. It is not a vestibular evoked myogenic potential, disappears with 5-kHz tone stimuli, has a high threshold of stimulation, and is present in a case of hearing loss.


CONCLUSIONS
A new vestibular waveform is discovered that probably originates at or near the midbrain based on its latency. Together with the previously mentioned waves, lesions along the vestibular pathway can now be localized further.
Papathanasiou
Eleftherios S
ES
Clinical Sciences, The Cyprus Institute of Neurology & Genetics, 6 International Airport Avenue, Nicosia, Cyprus. neurophy@cing.ac.cy
Lemesiou
Athena
A
Hadjiloizou
Stavros
S
Myrianthopoulou
Panayiota
P
Pantzaris
Marios
M
Papacostas
Savvas S
SS
D000161:Acoustic Stimulation; D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D001309:Auditory Threshold / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D004576:Electromyography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000502:physiology*