This study aimed to evaluate the presence of the N3 potential (acoustically evoked short latency negative response) in profound sensorineural hearing loss, its association with the cervical vestibular evoked myogenic potential and the relationship between both potentials and loss of auditory function.

Otological examinations of 66 ears from 50 patients aged from 4 to 36 years were performed, and the vestibular evoked myogenic potential and auditory brainstem response were measured.

The N3 potential was recorded in 36 out of 66 ears (55 per cent) and a vestibular evoked myogenic potential was recorded in 34 (52 per cent). The N3 potential was recorded in 23 out of 34 ears (68 per cent) with a vestibular evoked myogenic potential response and absent in 19 out of 32 ears (59 per cent) without a vestibular evoked myogenic potential response. The presence of an N3 potential was significantly associated with a vestibular evoked myogenic potential response (p = 0.028), but there was no significant difference in the latency or amplitude of the N3 potential in either the presence or absence of a vestibular evoked myogenic potential.

The presence of an N3 potential in profound sensorineural hearing loss with good or poor vestibular function can be explained by the contribution of the efferent cochlear pathway through olivocochlear fibres that join the inferior vestibular nerve. This theory is supported by its early latency and reversed polarity, which is masked in normal hearing by auditory brainstem response waves.

A dilemma occurs in the treatment of second-sided Ménière's disease in the only hearing ear, particularly in patients with severe symptoms such as ‘drop attacks’. This paper describes a patient treated with contralateral cochlear implantation prior to vestibular nerve section of the symptomatic ear.

A 53-year-old man, with second-sided Ménière's disease and drop attacks in the only serviceable right ear, underwent successful left cochlear implantation 30 years after hearing loss, followed by right vestibular nerve section. The patient achieved control of Ménière's attacks and improved hearing. Although the patient experienced oscillopsia post-operatively, he was satisfied with his improved everyday functioning.

Patients with severe second-sided Ménière's disease in the only hearing ear are a small but difficult treatment group. In those that are suitable for cochlear implantation in the non-serviceable ear, it is suggested that this be employed prior to surgical treatment of the Ménière's symptoms, even if the implanted ear has had no auditory stimulation for many years.

The vestibulocochlear nerve is a sensory nerve that serves the organs of hearing and equilibrium. Neuropathies of the nerve, particularly auditory neuropathy, may be caused by primary demyelination or axonal disease. Cochlear amplification function is normal in cases of auditory neuropathy, but afferent neural conduction in the auditory pathway is disordered. It is highly probable that the vestibular nerve has some involvement in disorders affecting the cochlear nerve.

To provide an overview of vestibular test findings in individuals with auditory neuropathy.

A structured literature search was carried out, with no restrictions to the dates searched.

Auditory neuropathy implicated the vestibular branch of the VIIIth cranial nerve as well as the cochlear nerve. However, there was variability in terms of vestibular test findings.

Vestibular nerve section is a highly effective procedure for the control of vertigo in patients with Ménière's disease. However, hearing loss is a possible complication. If hearing loss occurs after vestibular nerve section, magnetic resonance imaging should make it possible to establish the presence or absence of an intact cochlear nerve.

Case report and review of the world literature concerning cochlear implantation after vestibular nerve section.

We present a patient who developed subtotal hearing loss after vestibular nerve section. Magnetic resonance imaging was used to verify the presence of an intact cochlear nerve, enabling successful cochlear implantation.

To our knowledge, this is the first reported case of cochlear implantation carried out after selective vestibular nerve section. Given recent advances in cochlear implantation, this case indicates that it is essential to make every effort to spare the cochlear nerve if vestibular nerve section is required. If hearing loss occurs after vestibular nerve section, magnetic resonance imaging should be undertaken to establish whether the cochlear nerve is intact.

To report eight cases of inferior vestibular neuritis, in order to raise awareness of this new subtype of vestibular neuritis.

We retrospectively analysed 216 patients (104 males and 112 females; age range 10–64 years; mean age 38.4 years) with full clinical documentation who had attended our hospital's vertigo clinic between May 2007 and December 2008. All patients underwent systematic investigation, including hearing tests, radiology, caloric testing and vestibular evoked myogenic potential testing.

Of 216 patients with vestibular neuritis, eight cases were diagnosed as inferior vestibular neuritis, based on comprehensive analysis of test data. The clinical features of these eight patients were consistent with the characteristics of vestibular neuritis. The results of pure tone audiometry and caloric testing were normal, and the possibility of central lesions was excluded by cerebral computed tomography or magnetic resonance imaging on admission. Six cases had unilateral loss of vestibular evoked myogenic potentials, whereas two had a unilateral lower amplitude of vestibular evoked myogenic potentials.

Inferior vestibular neuritis is a novel subtype of vestibular neuritis, which involves the inferior vestibular nerve alone. Vestibular evoked myogenic potential testing is a useful aid to the diagnosis of inferior vestibular neuritis.

The origin of vestibular schwannoma has always been a matter of debate. The aim of our study was to identify the nerve origin of this tumour.

Prospective case review. This study was conducted at Gruppo Otologico, a private referral centre for neurotology and skull base surgery.

A total of 200 cases of vestibular schwannoma were included in the study. All the tumours were removed surgically utilising the translabyrinthine approach. The origin of the tumour was sought at the fundus of the internal auditory canal.

A total of 200 consecutive cases was included in the study. The origin of the tumour was limited to one nerve at the fundus in 152 cases (76 per cent). Out of these cases, the tumour originated from the inferior vestibular nerve in 139 cases (91.4 per cent), from the superior vestibular nerve in nine cases (6 per cent), from the cochlear nerve in two cases (1.3 per cent) and from the facial nerve in two cases (1.3 per cent).

The vast majority of vestibular schwannomas originate from the inferior vestibular nerve; the incidence of involvement of this nerve increases as the tumour size increases. An origin of vestibular schwannoma from the inferior vestibular nerve can be considered as one of the explanatory factors for the poor functional outcome of the extended middle cranial fossa approach, and probably accounts also for the better hearing preservation rate reported in some series for the retrosigmoid approach.