CSF- Rhinorrhoea is commonest in fracture to

(Cribriform plate) (155- Dhingra 4th)Localisation of CSF leak* Olfactory slit - Cribriform plate* Middle meatus - Frontal or ethmoid sinus* Sphenoethmoidal recess - Sphenoidal sinus* Inferior meatus near the - (eustachian tube) Temporal Bone* CSF from anterior cranial fossa reaches the nose by way of cribriform plate ethmoid air cells or frontal sinus* CSF from middle cranial fossa reaches the nose via sphenoidal sinus, Sometimes injuries of temporal bone result in leakage of CSF in to the middle ear and thence via the eustachian tube into the nose (otorhinorrhoea)* The commonest area of fracture is the cribriform plate as this is extremely thin, other possible are a includes posterior wall of the frontal sinus and the floor of the anterior cranial fossa post operative trans-sphenoid hypophysectomy