Audiological Signatures of Posterior Fossa Lesions: Insights from Hearing Thresholds and Brainstem Responses

Authors

  • Noor Abdulazeez Abdulhameed Alrawi Otorhinolaryngology Unit, Department of Surgery, College of Medicine, Mustansiriyah University, Baghdad, Iraq
  • Haider Wahab Alsarhan College of Medicine, Ibn Sina University for Medical and Pharmaceutical Sciences, Baghdad, Iraq
  • Mohamed Abduljalil Altamimi Department of Neurosurgery, College of Medicine, Mustansiriyah University, Baghdad, Iraq

DOI:

https://doi.org/10.18502/avr.v35i4.22892

Keywords:

Auditory brain stem response; hearing loss; posterior cranial fossa; pure-tone audiometry; vascular loops; vestibular schwannomas

Abstract

Background and Aim:  Posterior fossa lesions often present with slowly progressiveBrainstem Response (ABR) are essential tools for assessing retro-cochlear involvement and establishing hearing thresholds. This study aimed to assess the audiometric profiles of patients with posterior fossa lesions and ascertain whether they could distinguish between different types of lesions.

Methods: A cross-sectional study was conducted on 36 patients aged 10–65 years. Each participant underwent otoscopic examination, tympanometry, PTA, and ABR testing. The data were analyzed using the chi-square and Kruskal-Wallis tests in SPSS version 25, with Cohen’s f and Cramer’s V for effect size. A p-value of less than 0.05 was considered significant.

Results: Lesion types showed a strong correlation with clinical presentation. Vascular loops were associated with tinnitus, vestibular schwannomas with facial numbness and hearing loss, and meningiomas with vertigo and headache. Schwannoma cases exhibited significantly higher ipsilateral hearing thresholds, especially at high frequencies (p<0.05). ABR results varied by lesion type: vascular loops mostly caused delayed wave III, meningiomas produced prolonged wave V and I-V intervals, while schwannomas showed the most severe abnormalities, including missing or delayed waves and interpeak intervals. Contralaterally, only schwannomas displayed ABR delays in wave V and I-V interval.

Conclusion: Lesion differentiation was aided by the clinical and audiological characteristics of posterior fossa lesions. ABR offers objective data on retro-cochlear involvement, while PTA identifies changes in hearing threshold. When used together, they improved diagnostic precision and patient care.

Published

2026-10-05

Issue

Volume (35) issue (4)

Section

Articles