Objective To report the authors' experiences in hearing preservation during acoustic neuroma (AN) resection procedures. Methods Two cases of AN removal via retrosigmoid approach were reviewed. Hearing preservation...Objective To report the authors' experiences in hearing preservation during acoustic neuroma (AN) resection procedures. Methods Two cases of AN removal via retrosigmoid approach were reviewed. Hearing preservation was attempted in the aid of endoscopic technique along with continuous monitoring of the compound action potential (CAP) and auditory brainstem response(ABR) during the surgery. Results The tumor in Case 1 was 1.5 cm in diameter. The average pure-tone hearing threshold was 30 dB HL and ABR was normal. Waves I, III and V of ABR were present following tumor removal. At 7th month follow-up, audiometric thresholds and ABR inter-peak intervals had recovered to pre-operative levels, with normal facial nerve function. The patient in Case 2 had bilateral AN. The tumors measured 4.0 cm(left) and 5.0 cm (right) on MRI scans. The AN on the right side was removed first, followed by removal of the left AN four months later. Intraoperative CAP monitoring was employed during removal of the left AN. While efforts to preserve the cochlear nerve were not successful, CAPs were still present after tumor removal. Conclusions Intraoperatively recorded CAPs are not reliable in predicting postoperative hearing outcomes. In contrast, ABRs are an indicator of function of the peripheral auditory pathway. Presence of waves I, III and V following tumor removal may represent preservation of useful hearing.展开更多
Purpose:The present systematic review examined imaging findings in the Auditory Neuropathy Spectrum Disorder(ANSD)population.Methods:Electronic databases such as Pub Med,Google Scholar,J Gate,and Science Direct were u...Purpose:The present systematic review examined imaging findings in the Auditory Neuropathy Spectrum Disorder(ANSD)population.Methods:Electronic databases such as Pub Med,Google Scholar,J Gate,and Science Direct were used to conduct a literature search.The articles retrieved through the literature search were assessed in two stages.In the first stage,title and abstract screening were done;in the second stage,a full-length article review was done.From the 379 shortlisted records,19 articles were chosen for the full-length review.Results:The selected articles performed imaging using Computerized tomography(CT)and magnetic resonance imaging(MRI).In most studies,cochlear nerve deficiency(CND)was the most prevalent anomaly in the ANSD group.Also,MRI was the imaging modality of choice recommended in most studies.It was also noted that CND was a characteristic feature of unilateral ANSD.Conclusion:From this systematic review,it is clear that integrating imaging studies into diagnostic protocol would help to understand the underlying pathology better and expedite decision-making and intervention for ANSD patients.展开更多
文摘Objective To report the authors' experiences in hearing preservation during acoustic neuroma (AN) resection procedures. Methods Two cases of AN removal via retrosigmoid approach were reviewed. Hearing preservation was attempted in the aid of endoscopic technique along with continuous monitoring of the compound action potential (CAP) and auditory brainstem response(ABR) during the surgery. Results The tumor in Case 1 was 1.5 cm in diameter. The average pure-tone hearing threshold was 30 dB HL and ABR was normal. Waves I, III and V of ABR were present following tumor removal. At 7th month follow-up, audiometric thresholds and ABR inter-peak intervals had recovered to pre-operative levels, with normal facial nerve function. The patient in Case 2 had bilateral AN. The tumors measured 4.0 cm(left) and 5.0 cm (right) on MRI scans. The AN on the right side was removed first, followed by removal of the left AN four months later. Intraoperative CAP monitoring was employed during removal of the left AN. While efforts to preserve the cochlear nerve were not successful, CAPs were still present after tumor removal. Conclusions Intraoperatively recorded CAPs are not reliable in predicting postoperative hearing outcomes. In contrast, ABRs are an indicator of function of the peripheral auditory pathway. Presence of waves I, III and V following tumor removal may represent preservation of useful hearing.
文摘Purpose:The present systematic review examined imaging findings in the Auditory Neuropathy Spectrum Disorder(ANSD)population.Methods:Electronic databases such as Pub Med,Google Scholar,J Gate,and Science Direct were used to conduct a literature search.The articles retrieved through the literature search were assessed in two stages.In the first stage,title and abstract screening were done;in the second stage,a full-length article review was done.From the 379 shortlisted records,19 articles were chosen for the full-length review.Results:The selected articles performed imaging using Computerized tomography(CT)and magnetic resonance imaging(MRI).In most studies,cochlear nerve deficiency(CND)was the most prevalent anomaly in the ANSD group.Also,MRI was the imaging modality of choice recommended in most studies.It was also noted that CND was a characteristic feature of unilateral ANSD.Conclusion:From this systematic review,it is clear that integrating imaging studies into diagnostic protocol would help to understand the underlying pathology better and expedite decision-making and intervention for ANSD patients.
