Fistular Hearing Loss

What is Fistular Hearing Loss?

Fistular hearing loss, also known as conductive hearing loss due to a fistula of the inner ear, occurs when an abnormal opening (a fistula) forms between the inner ear’s fluid‑filled compartments and the middle ear or mastoid cavity. The leak of perilymphatic fluid disrupts the delicate mechanics of the cochlea and vestibular system, leading to a reduction in sound transmission and, in some cases, balance disturbances. Unlike sensorineural loss that damages hair cells, fistular loss is typically “conductive” – sound waves cannot be efficiently transferred to the inner ear because the pressure dynamics are altered.

Although the term “fistular hearing loss” is not commonly used in everyday clinical conversation, it appears in otologic literature when describing the hearing deficit that follows a perilymphatic fistula (PLF) or a labyrinthine fistula (often caused by cholesteatoma or trauma). Recognizing this specific type of loss helps guide appropriate evaluation and management.

Common Causes

• Perilymphatic fistula (PLF) – an abnormal connection between the perilymph‑filled inner ear and the middle ear, usually after head trauma, barotrauma, or sudden pressure changes.
• Labyrinthine fistula from cholesteatoma – a destructive middle‑ear growth can erode the bony labyrinth, creating a fistula.
• Temporal bone fracture – high‑impact injuries can fracture the otic capsule, allowing fluid leakage.
• Explosive or blast injuries – rapid pressure spikes damage the otic capsule.
• Barotrauma – rapid altitude changes (e.g., diving, airplane take‑off) cause pressure gradients that may rupture the round or oval windows.
• Otosclerosis surgery complications – stapedectomy or stapedotomy can inadvertently create a fistula.
• Congenital inner‑ear abnormalities – rare developmental defects can predispose an individual to a fistula.
• Infectious erosion – chronic otitis media or mastoiditis can break down bone surrounding the labyrinth.
• Tumors – vestibular schwannoma or other aggressive lesions may erode the bony capsule.
• Iatrogenic injury – surgical procedures in the ear (e.g., cochlear implantation) may unintentionally create an opening.

Associated Symptoms

Fistular hearing loss rarely occurs in isolation. The following symptoms often accompany the hearing change:

• Vertigo or dizziness – due to disturbance of vestibular fluid.
• Tinnitus – ringing or buzzing in the affected ear.
• Fullness or pressure sensation in the ear.
• Autophony – hearing one’s own voice, breathing, or pulse