| ORIGINAL ARTICLE
|Year : 2020 | Volume
| Issue : 2 | Page : 333--339
Postoperative Tinnitus after Vestibular Schwannoma Surgery: A Neglected Entity
Jayesh Sardhara, Arun K Srivastava, Satya deo Pandey, Amit Keshri, Anant Mehrotra, Kuntal K Das, Kamleshsingh Bhaishora, Awadesh Jaiswal, Sanjay Behari
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
Background: This prospective study analyzes the factors responsible for pre and postoperative persistent tinnitus following vestibular schwannoma (VS) surgery and discusses the possible etiopathogenetic mechanisms.
Materials and Methods: Sixty-seven consecutive patients with unilateral VS operated via the retrosigmoid–suboccipital approach were included in the study. The Cochlear nerve, often unidentifiable from the tumor capsule, was resected during the surgery. Tinnitus Handicap Inventory (THI) score assessed the severity of pre and postoperative tinnitus.
Result: Twenty-eight (41%) patients had preoperative tinnitus. Out of those 28 patients, 24(85%) had significantly improvement in postoperative THI score. In 15 of the 24 patients, tinnitus subsided completely. In 3 of the 28 (10%) patients, THI scores were unaltered, and in 1 of the 28 (3.5%) patients, THI scores worsened. In 39 (58.2%) patients without preoperative tinnitus, 4 (10%) developed a new-onset postoperative tinnitus. Patients with severe sensory neural hearing loss (SNHL) had significantly higher incidence of postoperative persistent tinnitus (PPT) (P = 0.00) compared to those with mild-to-moderate SNHL. Patients with profound SNHL, however, had a much lower incidence of PPT (P = 0.007; odds ratio = 0. 0.077; 95% CI: 0.009–0.637). Large (P = 0.07) and giant schwannomas (P = 0.03) VS had an increased risk of PPT. Patients with PPT further analyzed with brain stem auditory evoked response (BAER) showed normal contralateral waveform.
Conclusion: Assessment of tinnitus is mandatory during the management of VS as there are high chances (nearly 46%) of PPT. Preoperative tinnitus, linked to the degree of SNHL (higher incidence in severe SNHL compared to mild-to-moderate/profound SNHL), is dependent on an intact cochlear nerve functioning. However, PPT is dependent on other mechanisms (brain stem/ipsilateral cochlear nuclei compression, and cortical reorganization) as it persists despite cochlear nerve resection.
Dr. Arun K Srivastava
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow - 226 014, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
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