A clinical observation of acute low-frequency sensorineural hearing loss

Objective To report clinical characteristics and treatment outcomes of acute low-frequency sensorineural hearing loss (ALHL) and to raise awareness of the disease. Methods Clinical presentation,audiometric data and follow-up (2-5 years) data in 42 cases of ALHL (42 ears) were reviewed. Results The patients were 27-44 years old. There were 16 males (38.10%) and 26 females (61.90%). All presented with acute onset of hearing loss. Other complaints included low pitched tinnitus (n=20),stuffiness (n=17),sound sensitivity (n=11) and dizziness (n=6). The average hearing threshold before treatment was 38.74 ± 4.62 dB HL for 0.125 -1 kHz and 13.52 ± 3.86 dB HL for 2 -8 kHz. After treatment,the hearing threshold average was 21.05 ± 9.74 dB HL and 19.85 ± 9.44 dB HL respectively. Auditory brainstem response (ABR) latencies and interwave intervals were normal. Distortion product otoacoustic emissions (DPOAE) were present in low frequency range in 16.67% of the cases and in high-frequency range in 85.71% of the cas-es. Conclusion ALHL appears to occur unilaterally,often accompanied by a low-pitch tinnitus and sense of fullness. The disease is particularly prevalent in young women. Audiometric tests are characterized by low-frequency threshold elevation and normal ABRs. The causal lesion is suspected to be located in the apical cochlea.