Hear me out: rethinking internal auditory meatus magnetic resonance imaging in primary care. A cohort evaluation

Abstract

Background Imaging detects acoustic neuroma, a rare pathology associated with asymmetric sensorineural hearing loss and tinnitus, that is mostly managed conservatively. Scanning indication is debatable, without evaluation in primary care, despite the high burden of audiovestibular symptoms and commissioning of general practitioner imaging. Method Cohort evaluation of two years' internal auditory meatus magnetic resonance imaging in primary care. Results Of 200 scans requested by 77 general practitioners, only 33 per cent conformed to guideline indications. Most were referred to specialists, regardless of result. Only 10.5 per cent were appropriately imaged to rule out neuroma without specialist referral. One neuroma was detected (diagnostic yield 0.5 per cent) in a patient already referred. Incidental findings were shown in 44.5 per cent, triggering low-value cascades in 18 per cent. Whilst fewer than 1 in a 1000 imaged patients may improve through surgery, 1 in 5 can suffer negative imaging cascades. Conclusion Considering the bi-directional relationship between distress and audio-vestibular symptoms, anxiety-provoking imaging overuse should be minimised. In low-prevalence primary care, retrocochlear imaging could be limited to those with asymmetric sensorineural hearing loss. Alternatively, assessment and imaging could be shifted to audiologist-led settings, with a wider therapeutic offer, likely more beneficial and cost-effective than conventional surgical pathways.

Incidence of Vestibular Schwannoma in Patients with Unilateral Tinnitus: A Systematic Review and Meta-Analysis

“…Three studies (13,18,20) documented and reported exclusively on patients with nonpulsatile tinnitus only. Only one of the studies documented symptom duration (14) at the time of investigation.…”

“…The largest study included in our review (13) had 566 patients, and 24% had incidental findings on MRI IAM. Another study (14) reported that these incidental findings led to unnecessary onward referrals and patient distress without any resultant significant diagnosis or change in care. This represents a significant concern given the unnecessary distress and adverse effect on patients’ well-being it can cause.…”

“…Six of the studies recorded the audiogram results of the patients. The largest study (13) reported on 566 patients with unilateral tinnitus alone, whereas the smallest study (14) included had 23 such patients. Three of the studies did not mention the type of tinnitus of their patients and whether No it was pulsatile or not.…”

“…Three of the studies did not mention the type of tinnitus of their patients and whether No it was pulsatile or not. One study (14) made reference to the lack of documentation of tinnitus type in clinical records. Three studies (13,18,20) documented and reported exclusively on patients with nonpulsatile tinnitus only.…”

“…The utility of carrying out an MRI IAM to exclude a VS in patients presenting with unilateral tinnitus only has been called into question as studies have indicated that a very low proportion of these patients have the disease (13,14). Furthermore, most patients with a diagnosed VS undergo conservative management with serial MRI IAM to monitor growth.…”