Correlating audiological results with location of intracochlear schwannoma assessed by routine and Hydrops MRI.

Background: Whether an intracochlear schwannoma (ICS) concomitant with endolymphatic hydrops (EH) remains unclear.

Objective: This study had two objectives: first, to correlate the location of ICS with audiological results using routine MRI; and second, to determine whether an ICS is associated with EH using Hydrops MRI.

Methods: Four cases with ICS demonstrated by routine MRI underwent an inner ear test battery, followed by 3 T Hydrops MRI.

Results: Audiometry revealed total deafness in 2 patients, flat-type hearing loss in one and 2 kHz dip type hearing loss in 1. Routine MRI demonstrated an ICS at cochlear basal turn in 3, and cochlear middle turn in 2 (one case showed ICS at the basal and middle turns). Correlating audiological results with the location of ICS suggests that hearing deterioration may be associated with affected cochlear turn. Hydrops MRI identified Grade II cochlear EH in two ICS patients with vertigo, but not in another two ICS patients without vertigo.

Conclusion: For an ICS patient with vertiginous episode, routine MRI along with Hydrops MRI may help identify both the ICS and EH, simultaneously.

Significance: A 'wait and scan' approach, which includes routine MRI along with Hydrops MRI, is recommended for the follow-up of ICS patients.