This paper helps to further define the profile of ocular and cervical vestibular-evoked myogenic potentials (o and c VEMPs) in patients with congenital profound sensorineural hearing loss (PSHL). It highlights the prevalence of otolith (saccular and utricular) dysfunction that exists in patients with PSHL, despite balance problems not featuring significantly in their case notes. The authors use cVEMP to assess saccular function and oVEMP as likely to represent utricular function. Twenty-nine patients (aged 18-63) with congenital bilateral PSHL and normal inner ear anatomy (defined by CT scan) and 20 healthy volunteers were included. The response rate in the PSHL group was 38.9% for oVEMPs and 44.4% for cVEMPs. It was 100% for the control group for both oVEMPs and cVEMPs. In the control group 10% showed abnormal calorics. In the PSHL group, 74.1% demonstrated an abnormality.
The study demonstrated that utricular and saccular dysfunction appears to affect more than half of the adult cohort with congenital PSHL in addition to semicircular canal dysfunction.
In comparison with the control group, of those patients with PSHL who did demonstrate the presence of oVEMPS and cVEMPS, many showed impairment of these responses: namely, abnormal thresholds, amplitudes and latencies. Interestingly, in the analysis of their medical records, neither patients nor doctors referred to any balance or vestibular dysfunction. The authors conclude that visual sensory system compensation may help ‘conceal’ the otolithic dysfunction in these patients. I would certainly be interested in future prospective studies which ask more specifically about functional balance abilities in patients with PSHL and wonder whether this is something we should be asking about more in the assessment of patients with hearing loss.