inner ear fistula
inner ear fistulaENT An abnormal communication between the perilymphatic space and middle ear or an intramembranous communication between the endolymphatic and perilymphatic spaces Etiology Barotrauma, penetrating trauma, surgery–eg, stapedectomy, cholesteatoma surgery, trauma following physical exertion, may rupture the labyrinth's limiting membranes Clinical Positional vertigo, motion intolerance, occasional disequilibrium, auditory Sx–eg, episodic incapacitating (Meniere's attack-like) vertigo, which may follow ↑ CSF pressure such as nose blowing or lifting, or vertigo after exposure to loud noises DiffDx Meniere's disease, infection, acoustic neuroma, CNS lesions Diagnosis Fistula test–positive pressure introduced into the suspect ear, either by rapid pressure on the tragus, compressing the external canal, or via a pneumatic otoscope, while observing the eyes; a positive fistula sign consists of conjugate contralateral slow deviation of eyes followed by 3 or 4 ipsilaterally directed beats of nystagmus; fiberoptic examination of the middle ear by myringotomy may help select Pts for surgical exploration, especially in Pts with a clinically suspicious Hx and a positive fistula sign Treatment Bed rest; head elevation; laxatives for ↑ intracranial pressure; surgical exploration if hearing loss worsens or vestibular Sx persist. See Hennebert's phenomenon, Tulio's phenomenon.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.