Audiologic prognostic factors for hearing preservation following vestibular schwannoma surgery

Abstract

Background. Postoperative hearing loss after vestibular schwannoma (VS) removal still remains a lifelong problem for the patients. The present study analyzes the problem of hearing preservation after VS removal from a different angle than available professional literature on this topic.Objectives. To identify audiologic factors which determine the extent of hearing loss in patients operated on for VS. Material and methods.The study group included 86 patients operated on due to VS accessed via the middle cranial fossa. The analyses involved the effect on absolute hearing loss, which was calculated on the basis of the results of pure-tone audiometry performed pre-and postoperatively, and factors included in the preoperative audiologic tests, such as pure-tone audiometry, speech audiometry, auditory brainstem response (ABR), and impedance audiometry. Results.The following parameters were demonstrated to have a prognostic value: 1. hearing thresholds at 125 Hz, 500 Hz and 1,000 Hz for the operated ear, Pure Tone Average (PTA) -calculated specifically at 500 Hz, 1,000 Hz and 2,000 Hz and at 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz for the operated ear, and normal audiometric curve; 2. speech discrimination ranging from 55 dB to 75 dB for the operated ear, speech detection threshold (SDT) in the operated ear and interaural difference at 25-35 dB (non-operated vs operated ear); 3. presence of wave V, the values of I-V and III-V intervals for the operated ear, the amplitude of wave V, and the interaural ratio of wave V amplitudes; 4. intensity level for obtaining stapedial reflex or an abnormal reflex at Ipsi 500 Hz,

A Novel Imaging Grading Biomarker for Predicting Hearing Loss in Acoustic Neuromas

“…Previous studies showed that GR class prior to microsurgery was found to be an independent predictor of GR class at follow-up [4,20,[27][28][29]. We found a similar result.…”

Auditory Brain Stem Response Predictors of Hearing Outcomes after Middle Fossa Resection of Vestibular Schwannomas

“…22 53 55 62 63 There are both primary studies supporting and arguing against each of the following variables as predictors of HP: good preoperative hearing, tumor location, calorics, and other ABR parameters such as wave amplitude, latency, or interpeak interval. 22 25 39 42 45 47 51 53 55 59 60 64 65 66 67…”

“…In regard to intraoperative ABR data, a diminished or absent wave V has been found to be a significant predictor of hearing loss. 33,40,[43][44][45][46][47][48] Some argued that a normal intraoperative wave I is a better prognosticator of HP than wave V, whereas others suggest wave III is the earliest and most sensitive sign of hearing loss. 46,49 A loss or diminished wave V occurred typically when extensive surgical dissection of the tumor from the nerve was performed, which often resulted in traction and manipulation of the cochlear nerve and potential disruption to the associated blood supply.…”

“…22,53,55,62,63 There are both primary studies supporting and arguing against each of the following variables as predictors of HP: good preoperative hearing, tumor location, calorics, and other ABR parameters such as wave amplitude, latency, or interpeak interval. 22,25,39,42,45,47,51,53,55,59,60,[64][65][66][67] A literature review was performed to analyze data on hearing outcomes after MCF resection (►Table 5). While ABR was the most commonly utilized technique, a wide variety of monitoring methodologies were used.…”

Soft and stretchable organic bioelectronics for continuous intra-operative neurophysiological monitoring during microsurgery

“…Within the schwannoma family, the most prevalent type is vestibular schwannomas (VS), which accounts for ~60% of total cases 4,[27][28][29] . Without CINM of near field signals evoked from the auditory nerves, i.e., cochlear nerve action potentials (CNAP), ~70% of the patients after the surgery would suffer from ipsilateral sensorineural hypoacusis 30,31 . In this work, we describe a new surgical scheme to implant the soft and stretchable conducting polymer electrodes.…”