Most common cause of traumatic CSF rhinorrhea -

Ans, is 'a' Injury to ethmoidal air sinusCSF Rhinorrheao Disruption of the barriers between the sinonasal cavity and the anterior and middle cranial fossae can lead to the discharge of cerebrospinal fluid (CSF) into the nasal cavity which is referred to as CSF rhinorrhea.o Regardless of the etiology, the underlying defect responsible for CSF leaks is the same, i.e., disruption in the arachnoid and dura mater coupled with an osseous defect,o The cribriform plate and air cells of the ethmoid sinus account for maximum number of leaks, i.e., through anterior cranial fossa.o Other sites are frontal sinus, area of sella tursica and sphenoid sinus.o Rare sites of leak are middle or posterior cranial fossa and CSF can reach the nasal cavity by way of the middle ear and Eustachian tube.Causes of CSF rhinorrheao Depending upon the etiology, CSF rhinorrhea can be classified.TraumaticIt is the most common type of CSF rhinorrhea (> 90% of cases).The most common sites of leak are the roof of the ethmoid sinus cells (fovea ethmoidalis) and the cribriborm plate.Accidental trauma is the most common cause and Head trauma accounts for almost 90% of cases of CSF rhinorrhea.The remaining traumatic leaks are due to surgical trauma e.g., neurosurgical and rhinological procedures.Mon-traumatic (spontaneous)The most common site of leak is cribriform plate. It may either due to congenital defects or intracranial tumors.