ASYMMETRIC HEARING-LOSS - TOWARD COST-EFFECTIVE DIAGNOSIS

Objective: Unilateral audiovestibular symptoms are commonly seen in cl inical practice, and the treating physician frequently considers retro cochlear disease in the differential diagnosis. These considerations o ften precipitate a lengthy and expensive battery of tests. This study was conducted to evaluate the diagnostic yield of the various tests av ailable in the investigation of these symptoms and to recommend change s to practice patterns, if appropriate. Methods: We examined a cohort of 310 patients with unilateral audiovestibular symptoms who were refe rred to our radiology department for investigation. All patients had c omplete auditory assessments, and 144 underwent auditory evoked potent ial testing (ABR). There were 258 contrast-enhanced CT (CECT) scans an d 86 gadolinium-enhanced MRI (Gd-MRI) scans performed. Results: A tota l of 12 cerebellopontine angle (CPA) rumours were diagnosed. Conclusio ns: MRI is the diagnostic tool of choice in patients with asymmetric s ensory neural hearing loss (ASHL), but it is expensive and not always easily available. Analysis of diagnostic accuracy of CECT and ABR, bot h used as screening tests, demonstrate their limitations and reveals t hat CECT is no more accurate than ABR, although it is three times more costly. Based on these data, we have changed our diagnostic approach to patients with unilateral audiovestibular symptoms. Patients are eit her evaluated with MRI or are screened initially with ABR based on cli nical suspicion. CECT is no longer routinely included in the evaluatio n of patients with ASHL. Finally, newer emerging MRI techniques promis e faster and less expensive examinations with increased diagnostic acc uracy.