Ans is 'b' i.e. Wait & watch for 7 days + antibiotics CSF rhinorrhea may be classified as:Traumatic (>90%) - Approximately 80% of all traumatic leaks occur in the setting of accidental trauma, and the remaining traumatic leaks occur after neurosurgical and rhinological proceduresNontraumatic (<10%)- Nontraumatic etiologies include neoplasms and hydrocephalus High pressure flow- intracranial tumours & hydrocephalousLow pressure flow- congenital defectsMost common site for leak is through cribriform plate and ethmoidal air sinuses.Less common sites are through frontal and sphenoidal sinuses.Rarely, the leak can originate in the middle or posterior cranial fossa and can reach the nasal cavity by way of the middle ear and eustachian tubeDiagnosis:Basic clinical tests-Rhinoscopy-visualization of CSF leakage from paranasal sinusesTissue test-unlike nasal mucous ,CSF does not cause a tissue to stiffenFilter paper test-sample of nasal discharge on a filter paper exhibits a light CSF border and a dark central area of blood 'double ring sign ' or ' halo sign' (in cases of traumatic CSF leak where blood and CSF are mixed.)Queckenstedt test-compression of jugular veins leads to increased CSF leakage d/t increase in ICPBiochemical tests:Concentrations of glucose & protein are higher in CSF than in nasal discharge.b2-transferrin is the preferred biochemical marker of CSF. It helps in distinguishing CSF from other nasal secretions.Beta-trace protein (bTP) is another chemical marker that could be used for the detection of CSFCSF tracers:Intrathecal fluorescein dye administration, radionuclide cisternography, CT cisternographyRadiological studies:High-resolution CT provides detailed information about the bony skull base anatomy, and MRI assesses soft tissues , including unrecognized tumors and coincidental meningoencephalocelesTreatment:Traumatic rhinorrhea often stops spontaneouslyConservative treatment consists of 1-2 weeks trial of-Strict bed restHead elevationStool softenersAdvising patient to avoid coughing, sneezing, nose blowing, and strainingProphylactic antibioticsSubarachnoid drainage through a lumbar catheterSurgical repair is generally advocated in patients with large fistulas especially in the presence of pneumocephalus.