Figure 7.

Audiological assessment in a subject with Brown–Vialetto–Van Laere syndrome-related auditory neuropathy spectrum disorder (ANSD), resulting in neural impairment of the 8th and 12th cranial nerves and the optic nerves. Unaided pure-tone audiometry ((a), both ears) shows bilateral hearing loss mainly for low frequencies. Unaided free field speech discrimination is poor ((b), 10% gray dot at 80 dB). Aided tonal and speech perception outcomes with acoustical hearing aids remain poor and comparable to unaided perception. The latter clearly improves after cochlear implantation (CI) ((b), black line). Otoacoustic emissions (OAEs) are present ((c), spectral analysis of OAEs in the white area, compared to noise in the black area), whereas auditory brainstem responses (ABRs) synchronization was abnormal with no wave V but a clear cochlear microphonic (CM) in both rarefaction (R) and condensation (C) polarities and in the subtraction R − C (d). Cortical auditory evoked responses (e) show a P3 complex after stimulation with an oddball paradigm and in selective attentive conditions only, even if no recordable N100 or P200 waves are present in responses to the frequent stimuli (not shown).