A 20 y/o M arrives to your ED following an assault with a baseball bat. He had a transient LOC but is currently AAOx3. He has a multiple facial lacerations with significant left periorbital edema and ecchymosis. CT scan showed no ICH but several fractures. There is a severe comminuted bilateral nasal bone fracture extending to the frontal process of the left maxilla and fractures through the right frontal sinus and bilateral ethmoid sinuses. And lastly, there is a fracture of the left orbital floor and left lamina papyracea with a retrobulbar hemotoma.

When the patient returns from CT, he has fluid draining from his right nares. Which of the following is the best test to determine if the patient has a CSF leak? (scroll down for the answer)

a) Test the fluid for beta-transferrin

b) Check for a positive halo sign

c) Glucose-content determination on glucose oxidase paper

d) High-resolution CT scan facial bones

e) MRI Facial Bones

The correct answer is a) test the fluid for beta-transferrin. Beta2-transferrin is located only in CSF, perilymph and aqueous humor. It has a high sensitivity and specificity. 

The halo sign is not specific to CSF; it is seen with saliva and tears

The glucose oxidase paper is rapid but unreliable as false positives can occur with lacrimal secretions and nasal mucus.

A CT scan can detect defects in the skull base that are not sites of CSF and cannot be used to determine the presence of a leak.

MRI is not recommended as a first-line imaging modality in the evaluation of CSF rhinorrhea.

70-85% of defects close spontaneously or after decreasing the CSF pressure the external lumbar drainage. Fractures with CSF leak has a high risk of the development of meningitis. For more information suspected CSF Rhinorrhea, head over to Medscape:   http://emedicine.medscape.com/article/861126-overview

Kuhnel, T; Reichert, T. Trauma of the midface. GMS Curr Top Otorhinolaryngol Head Neck Surg. 2015: 14: Doc06.