Auditory neuropathy in patients with features of tropical ataxic neuropathy in Tanzania

Objective: This study aimed to describe the diagnosis of auditory neuropathy (AN) in patients with features of tropical ataxic neuropathy (TAN) at a private audiology facility in Dar es Salaam, Tanzania. Method: A retrospective chart review of thirty-two patients with suspected AN and features of TAN seen in 2019. Results: The 32 patients complained of hearing impairment and all were diagnosed with AN (100%) via audiometry, otoacoustic emissions (OAE), and auditory brainstem response (ABR). The mean age was 24.8 ± 7.7 years, between 10.3 and 47.0 years. Sixteen (50%) reported tinnitus, eight (25%) reported imbalance while walking, 10 (31.3%) reported vertigo/dizziness, 13 (40.6%) had visual problems, and 19 (59.4%) reported peripheral neuropathy/weakness. Audiometric thresholds ranged from normal to profound, with the most common degree of severity being moderate (59.4%, n = 19). All except one patient had present OAEs, regardless of the severity of hearing loss. ABR was examined in 10 patients and found to be abnormal at 90 dB nHL in all of them. Conclusion: The investigation of hearing impairments requires more than tuning fork or audiometry to understand the true nature of the patient’s hearing loss. Awareness of AN pattern in TAN among audiologists and other professionals within the hearing care field in low-and-middle-income countries, such as Tanzania should be strengthened.