Long-term study after perforation of the round window. Animal experiments using electric response audiometry

Area of Science:

• Ototoxicity and Auditory Neuroscience
• Inner ear physiology and injury models

Background:

• The round-window membrane (RWM) is crucial for inner ear function.
• Understanding RWM injury effects on auditory function is vital for developing treatments.

Purpose of the Study:

• To investigate the impact of round-window membrane perforation on auditory nerve and brainstem responses in guinea pigs.
• To assess the effects of spontaneous and surgical healing on auditory function.

Main Methods:

• Round-window membrane perforation in guinea pigs under ketamine-xylazine anesthesia.
• Auditory Brainstem Response (ABR) testing at various stimulus loudnesses (100 dB HL, 60 dB HL).
• Observation of membrane healing and organ of Corti integrity over 7 days.

Main Results:

• Perforation caused temporary increases in wave I and V latencies at 100 dB HL.
• No significant changes in interpeak latencies or responses at 60 dB HL.
• Fibrin tissue closure did not alter auditory nerve or brainstem responses; normal function returned within 7 days.

Conclusions:

• Round-window membrane perforation causes transient auditory pathway changes.
• Spontaneous healing of the RWM within 7 days restores normal auditory function.
• The integrity of the organ of Corti remains intact following perforation and healing.