Vestibular schwannoma diagnosis: evaluation of a neuro-otological test battery

Abstract

Objective: Gadolinium-enhanced Magnetic Resonance Imaging (MRI) constitutes the gold standard technique in detecting vestibular schwannomas (VS). The investigation aimed to verify whether it is possible to reach high sensitivity in the early diagnosis of VS, combining Auditory Brainstem Responses (ABRs) with other bedside and electrophysiological neuro-otological tests.Methods: Fifty-five patients suffering from VS smaller than 2 cm in major diameter, detected by gadolinium-enhanced MRI, were submitted to: Pure Tone Audiometry, Speech Audiometry, Vestibular Examination, Caloric Test, Head Shaking Test (HST), Head Impulse Test (HIT), Hyperventilation Test (HT), Vibration Test (VT), ABRs, Cervical Vestibular Evoked Myogenic Potentials (cVEMPs).Results: HST showed pathological results in 34 cases (61.82% sensitivity), HIT in 29 (52.73% sensitivity), HT in 38 (69.09% sensitivity), VT in 27 (49.1% sensitivity), ABRs in 35 (in 12 cases this examination was not conducted because of the high pure tone hearing threshold level, 81.39% sensitivity), cVEMPs in 34 (61.82% sensitivity). If we consider only symptomatic patients (54 out of 55), in all cases we observed at least one pathological test (100% sensitivity).Conclusion: In patients suffering from unilateral or asymmetrical sensorineural hearing loss, we suggest the use of bedside and electrophysiological tests in order to reduce the use of imaging to high suspicion cases of retrocochlear disease, lowering costs and waiting lists.