1. What is the most common cause of CSF fistulas?
2. What test confirms the presence of CSF?
3. What is the best management of this patient?
4. Which of the following describes you?
5. I practice in one of the following locations.
Please subit your answers to see the case explanation.
- Ziu M, Savage JG, Jimenez DF. Diagnosis and treatment of cerebrospinal fluid rhinorrhea following accidental traumatic anterior skull base fractures. Neurosurg Focus, 2012; 32(6):E3.
- Komotar R, Starke R, Raper D, Anand V, Schwartz T. Endoscopic Endonasal versus Open Repair of Anterior Skull Base CSF Leak, Meningocele, and Encephalocele: A Systemic Review of Outcomes. J Neurol Surg A, 2013; 239-250.
- Muscatello L, Lenzi R, Dallan I, Seccia V, Marchetti M, Sellari-Franceschini S. Endoscopic transnasal management of cerebrospinal fluid leaks of the sphenoid sinus. J Craniomaxillofac Surg. 2010;38(5):396-402.
- Kwon JE, Kim E. Middle fossa approach to a temporosphenoidal encephalocele -technical note-. Neurol Med Chir (Tokyo). 2010;50(5):434-8.
- Warnecke A, Averbeck T, Wurster U, Harmening M, Lenarz T, Stӧver T. Diagnostic relevance of beta2-transferrin for the detection of cerebrospinal fluid fistulas. Arch Otolaryngol Head Neck Surg, 2004;130(10):1178-84.
Question 1 – answer D. CSF fistulas are an abnormal communication between CSF and nasal cavity, paranasal sinuses and/or middle ear. Defects in the cranial floor allow meninges and/or brain (cephaloceles) to connect to these extra-cranial locations. Lateral Sphenoidal-temporal cephaloceles are rare. Risk factors for development include excessive sphenoid sinus (SS) peumatization and possibly obesity (impaired CSF dynamics, idiopathic intracranial hypertension). Clear, positional, rhinorrhea is the most common presentation. Symptoms include headaches and meningitis. Trauma is responsible for 80% of all CSF fistulas, but can be a result of iatrogenic injury, congenital (Sternberg canal) or tumors. High resolution CT scan is the best option for identifying skull base defects in 80% of cases. MRI (FLAIR/cisternography) can help distinguish mucosal edema from cephaloceles.
Question 2 – answer B. Diagnosis requires a high clinical suspicion and is confirmed with Beta-2 transferrin (specific for CSF, perilymph and vitreous humor). Sensitivity and specificity, 97 and 99% respectively
Question 3 – answer A. Treatment options include transcranial and endonasal (trans-ethmoidal-pterygoid) exposure and repair. Endonasal visualization of the lateral sphenoid sinus recess is limited; this approach can result in vascular injury, cranial nerve (V2) damage and impede adequate multilayer repair. Both approaches are an option in this case. The endonasal approach offers an advantage for repair of medial-perisellar pathology and has lower rates of postoperative meningitis, abscess, wound infection and sepsis. Although, contemporary literature supports an endonasal repair of all sphenoidal cephaloceles and CSF fistulas, a middle fossa approach offers a reasonable alternative for laterally based lesions. Surgical approach is influenced by: the defect size, SS pneumatization, CSF pressure, leak recurrence, prior treatment failure, associated brain injury or intracranial lesion, repair of simultaneous facial fractures, and surgeon experience/preference.
SANS: Trauma and Neurocritical Care Module
SANS: Trauma and Neurocritical Care Module for Residents