EM@3AM: Basilar Skull Fractures

Author: Rachel Bridwell, MD (@rebridwell, EM Resident Physician, San Antonio, TX) // Edited by: Brit Long, MD (@long_brit, EM Attending Physician, San Antonio, TX) and Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW / Parkland Memorial Hospital)

Welcome to EM@3AM, an emDocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.


A 19-year-old male is brought to the ED by EMS status post MVC with a C-collar in place. The patient was restrained, there was no intrusion, and airbags deployed with the car traveling at 50 mph. Another passenger reports that the patient hit his head on the seat in front of him.

Triage vital signs (VS): BP 105/60, HR 88, T 99.2, RR 11, SpO2 94% on room air, GCS 12. Pertinent physical examination reveals hemotympanum, serosanguineous discharge bilaterally from the nares, and CN III palsy.

What’s the next step in your evaluation and treatment?


Answer: Basilar skull fracture (BSF)1-26

Epidemiology:

  • Generated by blunt head or facial trauma
  • Represent 19-21% of skull fractures1
    • 18% of basilar skull fractures have CSF leakage, with degree of fracture and leakage correlating with injury severity1
  • In patients <18 years old with head trauma, BSF is the most common skull fracture with MVCs the most mechanism of injury, followed by falls2,3
    • 22% of these patient have an associated injury2
  • 1% of pediatrics patients with blunt head trauma have clinical or CT evidence of BSF4

 

Pathophysiology and anatomy:
Table 1. Anatomical locations and complications of BSF5

Clinical Presentation:

  • Vital sign abnormalities may be due to other injuries, though AMS portends poor outcome
  • Combination of raccoon eyes, Battle sign, rhinorrhea/otorrhea, and abbreviated injury scale have a sensitivity and specificity of 67.8% and 52.8% in the ED, respectively7
  • In pediatric patients with mechanism concerning for BSF, 30.9% had only CT evidence and no clinical evidence of BSF, and 19.8% had both CT and clinical evidence of BSF4

 

Evaluation:

  • ABCs with potential for airway management as well as assessment for concomitant injuries in a potential polytrauma patient
  • High rate of C-spine injuries, prompting C-spine immobilization
  • Perform a complete physical examination.
    • Ocular: Raccoon eyes, periorbital ecchymoses with tarsal sparing, delayed by 1-3 days8
      • Bilateral ecchymoses high predictive value
    • Neuro: Focal neurologic deficits, CN III, IV, VI palsies
    • ENT: Look for Battle sign, hemotympanum, CSF otorrhea or rhinorrhea, or other evidence of facial fracture
      • 80% traumatic CSF leakage presents as rhinorrhea9
      • Battle sign takes 1-2 days to develop, can be confused with a spreading hematoma from a mandibular condyle fracture7
      • Anosmia can occur in up to 7% patients5
    • Imaging: CT head—multidetector CT preferred to include face, skull base, and mastoids
      • Evaluate for other fractures: ethmoid, basilar occipital, temporal petrous, mastoid aspect of temporal, orbital roof of frontal, or base or wing of sphenoid5
      • Transverse middle cranial fossa fractures can extend through the carotid canal, and angiography should be obtained5
    • CSF leakage can be confirmed with analysis for glucose and β2-transferrin, but the former may more expedient the ED10
      • β2-transferrin SN 79-100%, SP 95-100%11
    • Classic “halo” sign seen if any other clear liquid (e.g. tears) mixes with blood; not specific to CSF12

 

Treatment:

  • ABCs—often require ventilatory support; propofol for induction and sedation13
  • Avoid nasotracheal intubation and NG tube placement14
  • Elevate head of bed to 30 degrees
  • Respiratory goals: SaO2>90%, PaO2>60 mmHg, PCO235-45 mmHg14
  • Hemodynamic goals: SBP> 100 mmHg if 50-69 years old, SBP>110 if 15-49 years old or >70 years old (per Brain Trauma Guidelines)15
    • SBP<90 mmHg risk factor for mortality in brain trauma16
  • If evidence of increased ICP: 3% hypertonic saline and then mannitol if refractory, though fluid repletion should be administered if mannitol is used, especially in a polytrauma patient17
  • Anti-epileptics are reasonable for administration within the first 7 days to prevent early seizures, though no evidence for long term administration
    • Seizures correlate with intracranial hemorrhage and dural penetration in adults and children17–19

 

Disposition and complications:

  • Consult neurosurgery for management and CSF leak repair
    • The degree of comminution and displacement portends greatest CSF leak risk
      • If unrepaired, 50% of communications with middle ear or nasal cavities result in meningitis20
        • 1% risk in first 24 hours, rising to 18% by 2 weeks21
      • No current evidence to support prophylactic antibiotics for meningitis22
      • Rates of meningitis between pediatric and adults patients are similar in hospital (0.48%, 0.64%) at 90 days (0.17%, 0.37%)23
  • Pediatric considerations:
    • If neurologically normal after CT and with normal observation period, discharge from ED with follow up; no evidence of adverse outcomes according to current literature4
    • Increased readmission for LOC>1 hour, hematoma, and CSF leak23
  • Common complication is traumatic facial nerve palsy24
    • 2-3 days after injury
    • Glucocorticoids and ENT consultation24
    • Many resolve on their own spontaneously
  • In BSFs involving vascular complications of carotid, 31% of patients with dissection will have a CVA as a result, stressing the importance of imaging with angiography25
  • Carotid cavernous fistula, is a rare, but feared complication in middle fossa fractures, especially oblique or transverse, causing exophthalmos, blindness, CVA, and death26

 

Pearls:

  • Head CT is crucial even in the absence of clinical evidence
  • Discharge criteria for isolated basilar skull fracture in pediatric patient: normal neuro exam after NCHCT and successful observation
  • Nasogastric tube placement is contraindicated with potential for intracranial placement
  • No indication for prophylactic antibiotics in basilar skull fracture to prevent meningitis22

Which of the following signs or symptoms is seen most frequently in the initial evaluation of a patient with a basilar skull fracture?

A) Cerebrospinal fluid otorrhea

B) Hemotympanum

C) Mastoid ecchymosis

D) Periorbital ecchymosis

 

 

Answer: B

Basilar skull fractures are linear fractures that occur anywhere along the skull base from the cribriform plate to the occipital condyles. The most common basilar skull fracture involves the petrous portion of the temporal bone, the auditory canal, and the tympanic membrane. There can be an associated dural tear leading to cerebrospinal fluid (CSF) otorrhea or rhinorrhea. The presence of a leak provides a means for introduction of infection putting these patients at increased risk for development of meningitis. Given the close proximity of these fractures to the middle meningeal artery, patients are also at increased risk for extra-axial hematomas, particularly epidural hematomas. Hemotympanum is the most frequent finding on physical examination. The tympanic membrane will appear blue to purple in color. Other symptoms include evidence of a CSF leak, mastoid ecchymosis (Battle’s sign), periorbital ecchymosis (raccoon eyes), vertigo, decreased hearing, and seventh nerve palsy. Diagnosis is made via noncontrast CT of the head. Neurosurgical consultation and admission is warranted. The decision to give prophylactic antibiotics in patients with evidence of a CSF leak is somewhat controversial and should be made in conjunction with the neurosurgeon.

Mastoid ecchymosis, also known as Battle sign (C) and periorbital ecchymosis, known as raccoon eyes (D) are both signs concerning for a basilar skull fracture, but are not commonly seen during the acute evaluation as they take 1-3 days to appear. CSF otorrhea (A) is another concerning sign for a basilar skull fracture, but is often difficult to diagnose. The leaks may develop one to many days after the initial injury. Fluid can be collected and analyzed for the presence of ß transferrin which is only found in cerebrospinal fluid. The majority of CSF leaks resolve within one week without complication.

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References

  1. Potapov AA, Gavrilov AG, Kravchuk AD, et al. [Basilar skull fractures: clinical and prognostic aspects]. Zh Vopr Neirokhir Im N N Burdenko. (3):17-23; discussion 23-4. http://www.ncbi.nlm.nih.gov/pubmed/15490634. Accessed March 20, 2019.
  2. Wang H, Zhou Y, Liu J, Ou L, Han J, Xiang L. Traumatic skull fractures in children and adolescents: A retrospective observational study. Injury. 2018;49(2):219-225.
  3. Alhelali I, Stewart TC, Foster J, et al. Basal skull fractures are associated with mortality in pediatric severe traumatic brain injury. J Trauma Acute Care Surg. 2015;78(6):1155-1161.
  4. Tunik MG, Powell EC, Mahajan P, et al. Clinical Presentations and Outcomes of Children With Basilar Skull Fractures After Blunt Head Trauma. Ann Emerg Med. 2016;68(4):431-440.e1.
  5. Baugnon KL, Hudgins PA. Skull base fractures and their complications. Neuroimaging Clin N Am. 2014;24(3):439-65, vii-viii.
  6. Leestma JE. Forensic Neuropathology. CRC Press; 2009. https://radiopaedia.org/articles/base-of-skull-fracture?lang=us. Accessed March 24, 2019.
  7. Solai CA, Domingues C de A, Nogueira L de S, de Sousa RMC. Clinical Signs of Basilar Skull Fracture and Their Predictive Value in Diagnosis of This Injury. J Trauma Nurs. 2018;25(5):301-306.
  8. Simon L V., Newton EJ. Basilar Skull Fractures. StatPearls Publishing; 2019. http://www.ncbi.nlm.nih.gov/pubmed/29261908. Accessed March 20, 2019.
  9. Wax MK, Ramadan HH, Ortiz O, Wetmore SJ. Contemporary management of cerebrospinal fluid rhinorrhea. Otolaryngol Head Neck Surg. 1997;116(4):442-449.
  10. Ackland GL, O’Beirne J, Platts AR, Ward SC. False-Positive Presentation of Battle’s Sign During Hepatic Encephalopathy. Neurocrit Care. 2008;9(2):253-255.
  11. Deisenhammer F, Egg R, Giovannoni G, et al. EFNS guidelines on disease-specific CSF investigations. doi:10.1111/j.1468-1331.2009.02595.x
  12. Lin DT, Lin AC. Surgical Treatment of Traumatic Injuries of the Cranial Base. Otolaryngol Clin North Am. 2013;46(5):749-757.
  13. Bratton SL, Chestnut RM, Ghajar J, et al. IX. Cerebral Perfusion Thresholds. J Neurotrauma. 2007;24(supplement 1):S-59-S-64.
  14. Tintinalli JE, Stapczynski JS, Ma OJ, Yealy DM, Meckler GD, Cline D. Tintinalli’s Emergency Medicine : A Comprehensive Study Guide.
  15. Carney N, Totten AM, OʼReilly C, et al. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2016;80(1):1.
  16. Schreiber MA, Aoki N, Scott BG, Beck JR. Determinants of Mortality in Patients With Severe Blunt Head Injury. Arch Surg. 2002;137(3):285.
  17. McCafferty RR, Neal CJ, Marshall SA, et al. Neurosurgery and Medical Management of Severe Head Injury. Mil Med. 2018;183(suppl_2):67-72.
  18. Savitsky EA, Votey SR. Current controversies in the management of minor pediatric head injuries. Am J Emerg Med. 2000;18(1):96-101.
  19. Wat R, Mammi M, Paredes J, et al. The Effectiveness of Antiepileptic Medications as Prophylaxis of Early Seizure in Patients with Traumatic Brain Injury Compared with Placebo or No Treatment: A Systematic Review and Meta-Analysis. World Neurosurg. 2019;122:433-440.
  20. Aarabi B, Leibrock LG. Neurosurgical approaches to cerebrospinal fluid rhinorrhea. Ear Nose Throat J. 1992;71(7):300-305. http://www.ncbi.nlm.nih.gov/pubmed/1505377. Accessed March 20, 2019.
  21. 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.
  22. Ratilal BO, Costa J, Pappamikail L, Sampaio C. Antibiotic prophylaxis for preventing meningitis in patients with basilar skull fractures.Cochrane Database Syst Rev. 2015;(4):CD004884.
  23. McCutcheon BA, Orosco RK, Chang DC, et al. Outcomes of Isolated Basilar Skull Fracture. Otolaryngol Neck Surg. 2013;149(6):931-939.
  24. Adegbite AB, Khan MI, Tan L. Predicting recovery of facial nerve function following injury from a basilar skull fracture. J Neurosurg. 1991;75(5):759-762.
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  26. Liang W, Xiaofeng Y, Weiguo L, Wusi Q, Gang S, Xuesheng Z. Traumatic Carotid Cavernous Fistula Accompanying Basilar Skull Fracture: a Study on the Incidence of Traumatic Carotid Cavernous Fistula in the Patients With Basilar Skull Fracture and the Prognostic Analysis About Traumatic Carotid Cavernous Fistula. J Trauma Inj Infect Crit Care. 2007;63(5):1014-1020.

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