Magnitude and pattern of hearing loss among post-head injury outpatients at Neurosurgical clinic, Muhimbili Orthopaedic Institute (MOI)

Abstract

Background: Hearing loss is a common sequela of traumatic head injury, associated with substantial social and economic costs as it compromises communication. Objective: To determine the magnitude and pattern of hearing loss among post-head injury adult outpatients attending Neurosurgical clinic at Muhimbili Orthopaedic Institute (MOI). Methodology: This was a hospital-based descriptive cross-sectional study, involving post-head injury adult outpatients at Neurosurgical clinic, MOI. Information on demography, cause and duration of injury was collected using a structured questionnaire; each participant then underwent a pure tone audiometric (PTA) test to assess the hearing status. Head computed tomography (CT) scans taken post-admission were reviewed for evaluation of the temporal bone. The data were entered into the Statistical Package for Social Sciences (SPSS) version 23.0 and analyzed. Fisher’s Exact test was used to test for associations between variables, with a p-value of < 0.05 accepted as statistically significant. Results: A total of 226 participants were enrolled. Their ages ranged from 18 to 65 years with a mean age of 34.1±11.3 years. The majority 132(58.4%) were in the age group of 18-35 years. Males constituted more than three quarters 195(86.3%) of the participants, with a male to female ratio of 6.3:1. Out of 226 participants, 37(16.4%) were found to have hearing loss which was unilateral in more than 90% of the affected individuals, and nearly half 18(48.7%) had sensorineural hearing loss (SNHL). The severity of hearing loss ranged from mild to severe, with the majority 21(56.8%) exhibiting mild hearing loss. Longitudinal temporal bone fractures were the commonest 18(48.7%) temporal bone CT scan findings among the affected individuals, followed by transverse fractures, and were associated with conductive (p <0.01) and sensorineural (p = 0.034) types of hearing loss respectively. Conclusion: The study showed that 37(16.4%) individuals out of the studied population had hearing loss, with sensorineural type of hearing loss being the commonest, and the severity of hearing loss was significantly increasing as the severity of head injury raised. Recommendations: A multidisciplinary approach involving Neurosurgeons, Otorhinolaryngologists, Radiologists, and Audiologists is important in the early diagnosis of hearing loss, treatment and audiological follow up of patients with head injury.