Audiological assessment in organophosphorous poisoning

Mahender Singh, R. S. Minhas, Prem Machhan, Ramesh Kumar Azad, Shobha Mohindroo


Background: Organophosphate (OP) poisoning is a common cause of significant mortality and morbidity all over the world. In Asia, OP poisoning is the most common form of fatal self harm. Previous studies have suggested hearing loss due to OP poisoning. The aim of the study was to study audiological assessment in the patients with OP poisoning.

Methods: 26 patients (age <50 years) of OP poisoning over a period of one year were included in the study following ethical approval from Institute Ethics Committee. 25 healthy subjects served as control. Each subject was subjected to brainstem evoked response audiometry (BERA) examination.  

Results: 50% patients with OP poisoning were aged between 20-29 years. Male outnumbered females in the patients (M:F- 17:9) as well as controls (M:F- 17:8). Only absolute wave-v latency (ms) was statistically significantly prolonged in cases when compared with controls in both right (0.035) as well as left ears (0.048). We found no statistical significant difference in interpeak wave I-III, III-V, I-V latency of both ears in cases when compared with controls. On second assessment in the patients, we observed a statistical significant decrease in absolute wave III and V latency, and interpeak I-III interval in right ear when compared with wave latency at first assessment. In left ear on second assessment, a significant decrease in absolute wave I, III, and V latency was observed in the patients.

Conclusions: OP compounds may affect entire neural auditory pathway. Further studies with a large sample size are required for the assessment.


Organophosphate, Brainstem evoked response audiometry

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