Experiences in diagnosis of occult traumatic dural lesions of the anterior cranial base

Background: Meningitis or cerebrospinal fluid rhinorrhea can occur years or even decades after trauma and can be the first indication of a previously unidentified dural lesion. In spite of being difficult, precise localization of an occult traumatic dural lesion is a necessary prerequisite for duraplasty.

Methods: In a retrospective study covering a period of 17 years, we identified 27 patients with occult traumatic dural lesions. The dural lesions were localized by high-resolution CT, MRI, fluorescein nasal endoscopy, and CT cisternography. In all cases the expected dural lesion was demonstrated and treated surgically.

Results: In 23 out of 27 patients (85%), the rhinobasal fistula was detected as a bony defect by CT. Furthermore MRI examination in 100% (5/5), a preoperative fluorescein nasal endoscopy in 50% (10/20) and CT cisternography in 56% (5/9) were able to localize the dural lesion.

Conclusions: We recommend high-resolution CT and MRI as diagnostic tools of choice in searching for occult dural lesions. Fluorescein nasal endoscopy and CT cisternography are justified as invasive techniques if CT and MRI are inconclusive but clinically CSF leakage is still suggested. The patient will remain at risk of potentially fatal meningitis until the lesion is appropriately repaired by duraplasty. Therefore modern clinical and radiological diagnostic methods should be used to search for an unknown dural lesion.