The leakage of cerebrospinal fluid (CSF) into nasal, oral or ear cavities or leakage from a dermal sinus and its subsequent drainage from these cavities may be the result of trauma, intracranial surgical procedures, infection, hydrocephalus, congenital malformations or neoplasms. The most severe consequence of a CSF leak is microorganism contamination and the development of meningitis.
Epidemiology
- Prevalence – 70-80% are related to accidental trauma
- 2-4% of head injuries result in CSF leaks
- Age – middle age for spontaneous leaks, newborn for dermal sinus leakage
- Sex – M<F for spontaneous leaks
Etiology
- Trauma
- Nontraumatic
- Surgery (usually spinal or neurosurgery)
- Infection
- Tumor obstruction
- Congenital defects at the base of the skull or at the end of the spinal cord
- Hydrocephalus
- Spontaneous – no known defect or trauma
Pathophysiology
- Beta-2 transferrin, a protein produced by neuraminidase activity in the brain, is uniquely found in CSF and perilymph fluid
- Interruption of the anterior cranial fossa floor allows leaks of CSF through the cribriform plate
- 80% of post-traumatic leaks occur ≤48 hours post-trauma
- Presence of beta-2 transferrin in nasal or ear fluid highly suggestive of CSF leak
Clinical Presentation
- CSF leakage most commonly presents as otorrhea or rhinorrhea
- Patient may complain of salty or sweet taste; intermittent clear nasal discharge exacerbated by Valsalva maneuver
- Most often unilateral drainage
- Presence of halo sign on used tissues or bed linen