Vestibulofibrosis

Vestibulofibrosis Written by Deepseek AI on 09-04-2026

Vestibulofibrosis refers to the progressive formation of fibrous scar tissue within the vestibular apparatus of the inner ear. This scarring can distort the normal anatomy of the membranous inner ear, disturb the dynamics of perilymph and, in some cases, create or mimic an abnormal opening between the fluid-filled inner ear and the air-filled middle ear. The clinical picture often includes profound dizziness, unsteadiness, and disabling vertigo.

The Role of the Oval and Round Window

Two thin membranes serve as a window between the middle and inner ear: the oval window and the round window. The oval window receives the footplate of the stapes, while the round window buffers pressure changes of the inner ear fluids. When fibrotic tissue from vestibulofibrosis thickens or retracts these membranes, it can disrupt normal pressure transfer. In more serious cases, an actual tear or defect develops at the window, leading to a perilymph fistula.

Perilymph Fistulas and Fluid Leakage

A perilymph fistula is an abnormal communication that allows the watery perilymph fluid to escape from the inner ear into the middle ear cavity. Small fistulas may close on their own, but persistent leaks reduce pressure in the vestibular labyrinth and cause chemical irritation of the vestibular nerve endings. Inner ear fistulas are frequently associated with trauma, such as rapid barometric pressure changes, head injury, or a penetrating injury through the canal bone.

Trauma and Erosion of the Temporal Bone

The inner ear is housed within the hard temporal bone. A fracture of this bone, particularly a longitudinal fracture involving the otic capsule, can create a fistulous track that connects the perilymphatic space with the middle ear. In vestibulofibrosis, chronic inflammation can erode the thin bone overlying the semicircular canal, producing a “third window” phenomenon. This condition causes sound-induced vertigo, pressure-induced dizziness, and sometimes oscillopsia, as the fibrous tissue fails to provide the rigid enclosure normally required for perilymph motion.

Why Fistulas Cause Dizziness and Vertigo

When a fistula opens, changes in middle ear pressure—such as from coughing, sneezing, lifting, or loud noise—are transmitted directly to the perilymph fluid. The resultant movement of fluid within the canal triggers inappropriate firing of vestibular hair cells. Patients may experience a sudden sensation of spinning vertigo, accompanied by nausea, imbalance, and brief episodes of dizziness. Unlike central causes of vertigo, fistula-associated vertigo is typically reproducible by applied pressure to the tragus or by performing a Valsalva maneuver.

Alternatively, in vestibulofibrosis without a true fistula, fibrous adhesions can tether the stapes footplate at the oval window, producing similar symptoms of pressure-induced dizziness. This clinical mimicry highlights the importance of a thorough evaluation by an ear specialist.

Diagnosis and Imaging

Diagnosis is based on history, physical examination, and high-resolution imaging. Computed tomography of the temporal bone can sometimes show a defect in the canal wall or the presence of fluid within the middle ear adjacent to the oval or round window. However, many tiny perilymph fistulas cannot be seen on imaging, so the diagnosis remains largely clinical. In some centers, a blood-derived marker or a fluid test obtained during exploratory surgery may be used to confirm the leak.

Treatment Considerations

Initial treatment of a suspected perilymph fistula consists of strict bed rest, elevation of the head, and avoidance of straining, sneezing, and lifting. This reduces the hydrostatic pressure in the inner ear and may allow the fistula to seal spontaneously. If symptoms persist or the dizziness remains disabling, surgical exploration of the middle ear can be performed. During surgery, the tissue around the oval window and the round window is inspected. If a fistula is identified, a small piece of connective tissue is placed over the leak to close the window and prevent further loss of perilymph fluid.

For vestibulofibrosis that produces recurrent vertigo without a visible fistula, surgical adhesion lysis or excision of fibrous bands may be considered. In end-stage cases, where fibrosis has destroyed vestibular function, patients may benefit from vestibular rehabilitation therapy. The goal of therapy is to help the brain adapt to loss of signals from the affected inner ear and thus reduce dizziness and vertigo.