[Post-traumatic perilymphatic fistulas].
Perilymphatic fistulas (often secondary to trauma) are abnormal communications between the middle ear and the perilymphatic space involving a flow of perilymphatic fluid into the middle ear. The diagnosis is suggested by the association of cochleovestibular symptomatology in a traumatic context. The clinical context is of considerable importance in establishing the diagnosis. Thus, different etiological forms of post-traumatic fistula have been described, i.e., after stapedectomy (those initially reported), due to head trauma, resulting from direct ear injury, or by excessive pressure changes. Lesions are found at the level of round or oval windows, or between the two, at a fracture site of the typed noted after head trauma. Paraclinical explorations are of little value. Only caloric hypo-excitability or unexcitability associated with even partial conservation of cochlear function is a very good indicator. The diagnosis is determined during careful surgical exploration of the middle ear. Treatment requires closing the fistula with connective tissues such as temporal aponeurosis or stapedectomy with interposition in the event of marked dehiscence of the oval window. There are notable differences in the various therapeutic results reported. Vertigo was improved or cured in more than half the cases, whereas hearing was much less improved.