Which of the following is the most common site of traumatic CSF Rhinorrhea?

AETIOLOGY OF CSF RHINORRHEA * Trauma. Most of the cases follow trauma. It can be accidental or surgical. Surgical trauma includes endoscopic sinus surgery, trans-sphenoidal hypophysectomy, nasal polypectomy or skull base surgery. In endoscopic sinus surgery, CSF leak may be immediate or delayed in onset. * Inflammations. Mucoceles of sinuses, sinunasal polyposis, fungal infection of sinuses and osteomyelitis, can all erode the bone and dura. * Neoplasms. Tumours, both benign and malignant, invading the skull base. * Congenital lesions. Meningocele, meningoencephaloceles and gliomas can have associated skull base defect. * Idiopathic. Where cause is unknown and patient has spontaneous leak. SITES OF LEAKAGE CSF from anterior cranial fossa reaches the nose (i) cribriform plate, (ii) roof of ethmoid air cells or (iii) frontal sinus. CSF from middle cranial fossa follows injuries to sphenoid sinus. In fractures of temporal bone, CSF reaches the middle ear and then escapes through the eustachian tube into the nose (CSF otorhinorrhoea) Ref : ENT textbook by Dhingra 6th edition Pgno : 163