Improvement in Sudden Sensorineural Hearing Loss with Steroid Therapy Does Not Preclude the Need for MRI to Rule out Vestibular Schwannoma

Background Sudden sensorineural hearing loss (SSNHL) is the presenting symptom of vestibular schwannoma (VS) in ∼10% of cases. In patients initially presenting with SSNHL, steroid therapy is often instituted immediately upon diagnosis of hearing loss, often before an MRI of the head has obtained to rule out retrocochlear causes. There is a common misconception that improvement in hearing after treatment with steroids effectively excludes the possibility of a VS and in such cases, an MRI is not indicated. The authors have encountered several patients who have had an initial delay in VS diagnosis as a result. Paralleling this, it is not uncommon that steroid therapy is withheld for SSNHL in patients with an existing diagnosis of VS, believing that this condition is not steroid responsive.

Methods A retrospective chart review was performed (2002–2017) and all patients with VS who, as a presenting symptom or as a symptom prior to surgical or radiation treatment, developed SSNHL and received steroid treatment were reviewed. Patient demographics, tumor characteristics, steroid regimen, and data regarding treatment response were recorded.

Results A total of 30 patients (53% women; median age of 46 years) met inclusion criteria. Fifteen (50%) cases had objective audiometric documentation of SSNHL, while 15 (50%) had either subjective report only or incomplete audiometric data available.

Ten (67%) had a single event, while 10 (33%) had more than one episode of SSNHL that was treated with steroids prior to diagnosis or treatment of VS. The median time between SSNHL and diagnosis was 2.1 months (range: 0.17–148.7 months). At the time of diagnosis, 15 cases were purely intracanalicular, while 16 had cerebellopontine angle extension. Of the latter, the median cisternal tumor size was 16.1 mm (range: 5.3–33). Twenty-six (87%) cases were treated with oral steroid therapy alone, 2 (6.7%) were treated with intratympanic steroid therapy alone, and 2 (6.7%) were treated with combination therapy. The median pure tone average improvement with steroid therapy was 26.7 dB HL (range: −20–121.7) and the median word recognition score improvement was 36% (range: 4–100%).

Conclusion A therapeutic response to steroid therapy for SSNHL does not exclude the diagnosis of VS. All patients with SSNHL should undergo an appropriate imaging evaluation to prevent delays in diagnosis and possible treatment. Steroids may be beneficial for treating SSNHL in the setting of a known diagnosis of VS, before diagnosis, during the course of observation and perhaps even following treatment.