Idiopathic perilymphatic fistulas. A temporal bone histopathologic study with clinical, surgical, and histopathologic correlations.

OBJECTIVE

To report a case of idiopathic perilymphatic fistulas diagnosed and successfully treated during life and confirmed histopathologically post mortem.

METHODS

Perilymphatic fistulas were diagnosed clinically and repaired surgically. Light microscopic histopathologic studies were made of both temporal bones after death.

RESULTS

Vestibular symptoms had improved postoperatively. Postmortem histopathologic examination of the temporal bones demonstrated patencies of the labyrinth capsule that had been predicted clinically during life, the qualities of the membranous labyrinth in both the operated-on and the unoperated-on ears, and the elements of the surgical repair. Notably, there was no evidence of endolymphatic hydrops.

CONCLUSIONS

The histopathologic findings document the relationships of the fistula ante fenestram and the fissure connecting the round window niche and the posterior semicircular canal to idiopathic perilymphatic fistulas. Also, the diagnostic features reported herein allowed this patient with fluctuating hearing loss, episodic vertigo, and tinnitus to be distinguished from a patient with Meniere's syndrome. These findings have implications regarding past and future studies of vestibular and cochlear disorders.