[Cerebro-spinal fluid otorrhea and a spontaneous defect of the tegmen tympani or antri. A report of 3 cases . Rôle of arachnoid granulations].

UNLABELLED: Less than 150 cases of cerebro-spinal fluid leak with spontaneous defect of the roof of the temporal bone have been described in the international literature.

THE AIM OF THIS WORK: Is to define this pathology, to describe the clinical features, to suggest a diagnostic strategy, and to clarify the treatment method and the hypotheses on causation.

MATERIALS AND

METHODS

This is a retrospective study of 3 cases.

RESULTS

At the first medical examination, the most common clinical feature is serous otitis media or otorrhea after myringotomy. Rhinorrhea is rarely pointed out by the patients but exists in our 3 observations. The diagnosis of cerebro-spinal fluid leak with spontaneous defect of the roof of the temporal bone needs; cerebro-spinal fluid leakage, absence of an otologic history or cranial trauma and a bony defect on CT scan. CT scan with millimeter slices is able to show the location and the size of the bony defect(s) of the roof of the temporal bone and often shows partial or total opacity of the middle ear cavities. MRI is able to show if this opacity exists in conjunction with meningeal hernia or cerebro-meningeal hernia. Surgical repair consists of placing an autologous graft over the bony defect by the middle fossa approach. The origin of a spontaneous defect of the temporal bone is discussed. We study the hypothesis in which arachnoïd granulations could be responsible for a temporal bone defect.