Csf Leaks
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This document summarizes CSF leaks, their causes, presentations, diagnostic testing, imaging, and treatment options. CSF leaks can be caused by trauma, inflammation, or congenital defects and present with symptoms like ear drainage, hearing loss, or meningitis. Diagnosis involves tests of drainage fluid and imaging modalities like CT, MRI, and radionuclide scans. Treatment depends on the location and cause but may include conservative measures, antibiotics, or surgical repair through various approaches to close defects.
Csf Leaks
- 2. CSF Leaks Abnormal communication between the subarachnoid space and the tympanomastoid space or nasal cavity. Presenting symptoms: Middle ear effusion, hearing loss Unilateral rhinorrhea Risk of meningitis is high 2-88%
- 3. CSF Rhinorrhea Diverse etiology Idiopathic Trauma-Surgical <1% Trauma-Nonsurgical 3% of all closed head injuries 30% of skull base fractures Frontal>Ethmoids>Sphenoids Inflammatory Congenital Neoplasm
- 4. Testing of Nasal Secretions Beta-2-transferrin is highly sensitive and specific 1/50 th of a drop Electronic nose has shown early success
- 5. Imaging High resolution CT CT Cisternography MRI Heavily weighted T2 Slow flow MRI MRI cisternography Radionuclide cisternography Intrathecal flourescin
- 6. Imaging HRCT Volume averaging Congenital dehiscences of Spenoid/cribiform niche.
- 7. Imaging CT cisternography Currently the optimal imaging modality (85% sensitive) Intrathecal administration of iodine, prone 6hrs 0% for inactive leaks Substantial radiation exposure ?neurotoxic potential
- 8. Imaging MRI cisternography heavily weighted T2 Intrathecal gadolinium
- 9. Imaging Slow flow MRI Diffusion weighted MRI Fluid motion down to 0.5mm/sec Ex. MRA/MRV
- 10. Imaging Radioisotope cisternography Intrathecal administration of technitium 99m Less spatial resolution and specificity Largely abandoned due to false positive and false negative results
- 11. Intrathecal Flourescin 0.1ml of 10% flourescin solution mixed in 10cc of CSF Blue light may enhance the flourescin Complications are low
- 12. Treatment of CSF Rhinorrhea Conservative measures Bed rest/Elev HOB>30 Stool softeners No sneezing/coughing +/- lumbar drains Early failures Assoc with hydrocephalus Recurrent or persistent leaks
- 13. Treatment of CSF Rhinorrhea Prophylactic antibiotics: Two conflicting meta-analysis regarding basilar skull fractures. Proponents argue less meningitis. Opponents argue organism resistance.
- 14. Surgical Options Intracranial Direct visualization Success rates 50-73% Significant morbidity Anosmia Cerebral edema Seizures
- 15. Surgical Options Extracranial approach Improved success rates (80%) Significant morbidity Frontal osteoplastic flap/infratemporal approach
- 16. Endoscopic repair Endoscopic intranasal repair Overall success rates: 90% 1st attempt 52-67% for 2 nd attempt Overall 97% Complications: Meningitis (0.3%) Brain abscess (0.9%) Subdural hematoma (0.3%) Headache (0.3%)
- 18. Overlay vs Underlay technique Meta-analysis showed that both techniques have similar success rates Onlay: adjacent structures at risk, or if the underlay is not possible
- 19. Surgical Techniques Use gelfoam and gelfilm (>90%) Use nasal packing (100%) Consider fibrin glue (>50%) Consider lumbar drain for idiopathathic/posttraumatic assoc with increased ICP 3-5 days Not required BR, stool softeners, antibiotics
- 20. CSF Otorrhea Acquired Postoperative (58%) Trauma (32%) Nontraumatic (11%) Spontaneous Bony defect theory Arachnoid granulation theory
- 21. Temporal bone fractures Longitudinal 70% Anterior to otic capsule 15-20% facial nerve involvement
- 22. Temporal bone fractures Transverse 20% High rate of SNHL 50% facial nerve involvement
- 23. Temporal bone fractures HRCT will demonstrate the fracture line and the likely site of CSF leak. Beta-2-transferrin Treatment Bedrest Elev HOB Stool softeners +/- lumbar drain
- 24. Temporal bone fractures Brodie and Thompson et al. 820 T-bone fractures/122 CSF leaks Spontaneous resolution 95/122: within 7 days 21/122: between 7-14 days 5/122: Persisted beyond 2 weeks
- 25. Temporal bone fractures Meningitis 9/121 (7%) developed meningitis. A later meta-analysis by the same author did reveal a statistically significant reduction in the incidence of meningitis with the use of prophylactic antibiotics.
- 26. Pediatric temporal bone fractures Much lower incidence (10:1, adult:pedi) Undeveloped sinuses, skull flexibility otorrhea>> rhinorrhea Prophylactic antibiotics did not influence the development of meningitis.
- 27. Spontaneous CSF otorrhea Congenital Defect Theory: 1) enlarged petrosal fallopian canal 2) patent tympanomeningeal (Hyrtl’s) fissure 3) Comminication of the IAC with the vestibule (Mondini’s dysplasia)-most common Childhood presentation 82% SNHL 93% Meningitis 83% Mondini Dysplasia
- 29. Spontaneous CSF otorrhea Arachnoid granulation theory Enlargement of arachnoid villi due to congenital entrapments/pressure variations Presentation Unilateral serous otitis media Meningitis (36%) No SNHL or Mondini dysplasia Sites are multiple, floor of the middle fossa most common
- 31. Spontaneous CSF otorrhea Stone et al. HRCT vs. CT cisternography/radionuclide cisternography. HRCT showed bony defects in 71%. 100% intraoperative findings correlated with HRCT. HRCT significantly identified more patients with CSF leak than radionuclide cisternography or CT cisternography.
- 32. Surgical approaches Transmastoid Not ideal for large defects (>2cm), multiple defects, or defects that extend anteriorly Middle cranial fossa Technically challenging Best exposure Combined approach
- 33. Technique of closure Muscle, fascia, fat, bone wax, etc.. The success rate is significantly higher for those patients who undergo primary closure with a multi-layer technique versus those patients who only get single-layer closure. Refractory cases may require closure of the EAC and obliteration.
- 34. Conclusions The clinical presentations of CSF leaks may be very subtle. The clinician must keep a low threshold for further testing with Beta-2-Transferrin. Imaging studies should be performed to anatomically localize the site. Success rates may be over 90% with proper patient and surgical selection