Tegmen Defect Resulting in Spontaneous Cerebrospinal Fluid Leak Following Tympanostomy, with Treatment by Intradural Middle Cranial Fossa Repair: Two Case Reports

We present two case reports of spontaneous CSF leak due to tegmen defects that became apparent following tympanostomy or ventilation tube insertion (known as grommets in the UK). Both patients were treated for apparent chronic otitis media with tympanostomy, following which they complained of clear fluid leaking from the affected ear. This was subsequently shown to be CSF on biochemical analysis for the beta-2 transferrin glycoprotein. Imaging confirmed CSF exodus through a defective tegmen and thereby into the middle ear from the middle cranial fossa. Both patients underwent intradural middle cranial fossa repair as a joint procedure by Neurosurgery and ENT at our institution. The presenting features, imaging characteristics, and operative techniques are discussed, as well as a literature review of CSF leak presenting in this fashion.