Bursting at the Skull: Skull Fractures

Authors: Blake Davidson, MD (EM Resident Physician, University of Kentucky); Gena Cooper, MD (EM Attending Physician, University of Kentucky) // Reviewed by: Andy Grock, MD; Alex Koyfman, MD (@EMHighAK); Brit Long, MD (@long_brit)

Case

48-year-old male presents to the emergency department (ED) status post motor vehicle collision (MVC) approximately 2 hours prior. He was intubated on the scene for a low Glasgow coma scale (GCS) by emergency medical services (EMS). On ED arrival, IV access and vital sign monitoring was established while his primary survey revealed an intubated patient with stable vital signs and a GCS of 3T. His secondary survey revealed a fixed right pupil, left pupil blown, a large laceration over the left superior forehead, and a gross deformity of the left temporal skull. He was given a bolus of hypertonic saline  for suspected herniation, and cefepime, metronidazole, and levetiracetam were ordered for suspected open skull fracture. His emergent computed tomography (CT) showed multiple skull fractures, an associated intraparenchymal hemorrhage and mild uncal herniation. An arterial line was placed to maintain strict blood pressure less than 150 mmHg. A sodium goal was targeted for 145-150 mmol/L, and the head of the bed was elevated to 30 degrees. Additionally, his left intra-ocular pressure was elevated to 36 mmHg. A lateral canthotomy was performed with subsequent improvement in intraocular pressure.

The patient was admitted to the trauma surgery service and underwent multiple surgeries including hemicraniectomy for hematoma and increasing intracranial pressure on hospital day 2, evacuation of traumatic intracranial hemorrhage, repair of multiple dural lacerations, EVD placement, tracheostomy and PEG placement.  Eventually, he was discharged to a long-term care facility 1 month after presentation with continued minimal responsiveness with a discharge GCS documented of 7T.

Background

Skull fractures are a common finding in adult trauma patients, with an increase during the summer months when more people are outside riding ATV or other sporting vehicles. Some studies show that basilar skull fracturs are present in 7-15% of all nonpenetrating head trauma.¹⁰ Management in the ED focuses on injuries associated with these fractures such as intra-cranial hemorrhage. Here, we will focus on the different presentations for skull fractures, and when to consider additional work up.

Presentation

Skull fractures presentations vary, though more often occur in males in their mid 30’s.³ Of these a large majority occur from an MVC.³ Each trauma patient’s evaluation should begin with the primary and then secondary surveys. For head trauma patients, pay close attention for skin findings such as bruising on the head exam concerning for intracranial injuries.

While awake, alert patients would likely be able to tell us of any specific head trauma, trauma patients may be intubated or concussed. Thus, bruising may be the only clue that head trauma occurred. Specific bruising patterns indicate a skull fracture including: bruising around both orbits (racoon eyes) and posterior to the ears (Battle’s sign). Hemotympanum can also indicate severe head injury with associated temporal bone injury. The absence of bruising though does not rule out fractures.

Physical Exam Findings Concerning For Skull Fracture include:

• Bruising
  • Racoon eyes (Bruising around both orbits)
  • Battle’s Sign (Bruising posterior to ears)
  • May take a while to appear. Absence of bruising does not rule out fracture.
• Hemotympanum
• Clear nasal discharge
  • Double Ring Sign
• External Hematoma
• Decreased GCS
• Depressed skull fractures

Various clinical features may warrant a head CT. While gestalt can serve as a valuable guide among advanced clinicians, multiple clinical decision rules (CDR) can aid in the decision as to the necessity for a Head CT, including Nexus II, New Orleans Criteria, or the Canadian CT rule. The Canadian CT Rule appears to be the most sensitive CDR to evaluate for clinically significant intracranial pathology. In one study sensitivity for need of neurosurgical intervention using the Canadian CT rule was 100% (95% CI 90-100%) with 60% specificity.^1,2,4,5,6 Many other validation studies have proven superiority of the Canadian CT Rule over that of Nexus II and the New Orleans Criteria. ^1,2,4 ACEP has a clinical guidelines policy regarding imaging as stated:

Level A Recommendation:

• A noncontrast head CT is indicated in head trauma patients with loss of consciousness or posttraumatic amnesia only if one or more of the following is present: headache, vomiting, age greater than 60 years, drug or alcohol intoxication, deficits in short-term memory, physical evidence of trauma above the clavicle, posttraumatic seizure, GCS score less than 15, focal neurologic deficit, or coagulopathy.

Level B Recommendation:

• A noncontrast head CT should be considered in head trauma patients with no loss of consciousness or posttraumatic amnesia if there is a focal neurologic deficit, vomiting, severe headache, age 65 years or greater, physical signs of a basilar skull fracture, GCS score less than 15, coagulopathy, or a dangerous mechanism of injury.* *Dangerous mechanism of injury includes ejection from a motor vehicle, a pedestrian struck, and a fall from a height of more than 3 feet or 5 stairs.

Level C Recommendation:

• None

Currently ACEP has no policy recommending an MRI within the emergency department for evaluation of mild TBI.¹⁷

During a trauma patient’s primary survey, a laceration over a skull depression may indicate an open skull fracture. As such, emergent antibiotics may be indicated, though this is a consistently debated topic. No definitive randomized studies evaluating antibiotics versus no antibiotics for an actual improvement in mortality have been performed.^10,12,13 One study noted that the risk of meningitis between patients given and not given antibiotics was similar; however, the overall infectious complications between the two groups was lower in the prophylactic group.¹⁶ The decision to administer antibiotics should be based on current institutions in conjunction with discussion with neurosurgery consult.

Associated Injuries

When a traumatic skull fracture occurs, it is extremely important to evaluate for the following associated injuries.

• Lacerations: While some lacerations are more obvious, others can be hidden by dark hair or under the C-collar. Patients can lose a significant amount of blood from scalp lacerations especially in those that are difficult to find. It is important to clean the patient well and do a thorough skin examination as well as evaluate under the C-collar while stabilizing the c-spine. Address any active bleeding by either holding pressure or suturing any actively bleeding vessels. After the patient is stabilized, the laceration should be irrigated and sutured or stapled closed.
• Orbital injuries are also commonly associated with head trauma patients. Evaluate the eye for entrapment with extra-ocular movements as well as corneal abrasion, corneal laceration, or globe rupture as indicated.¹³
• Intracranial bleeding is commonly suspected with any skull fracture. They can be classified into subdural, epidural, intraparenchymal, and subarachnoid. Subdural hematomas are caused by shearing forces to the bridging veins between the dura and the brain and can occur with low force trauma. Subdural hematomas occur most commonly in elderly patients due to the extra space developed secondary to atrophy related decreased brain mass. Epidural hematomas are specifically associated with temporal bone fractures in the region of the middle meningeal artery.¹³ Classically, they present with high mechanism trauma and immediate loss of consciousness, followed by a lucid interval, and then ultimately resulting in subsequent loss of consciousness as the hematoma expands. Traumatic subarachnoid bleeds can also occur, and management depends on the case and neurosurgery consult.
• TBI: Skull fractures commonly result in traumatic brain injury (TBI). It is important to make sure the patient is at a baseline mental status and is not experiencing severe nausea to the extent they cannot tolerate PO intake before discharge. It is also important to provide these patients with return to work/play precautions depending on your hospital protocol.
• Superficial hematomas are a common and usually benign finding. Despite their potentially large size, they are only concerning when rapidly expanding due to an active arterial bleed.
• Cranial Nerve Trauma: A thorough neurological exam for every trauma patient is imperative in evaluating for both intracranial pathology and cranial nerve defects. Temporal bone fractures, especially those involving the petrous portion, can result in facial nerve injury.
• Dural Sinus Obstruction can also occur if the depressed skull fracture obstructs venous outflow.¹³

Frontal Bone Fractures

Frontal bone fractures are generally associated with high velocity trauma which commonly results in other facial trauma and injuries, which must be evaluated for on the secondary survey. Importantly, since the frontal sinus communicates with the middle meatus of the nose, a fracture there can lead to a mucocele, which can cause bony erosion, meningitis, or a brain abscess.¹³ If the posterior wall of the frontal bone is fractured, neurosurgery consult is indicated as the patient may end up needing antibiotics and possibly a sinus washout for definitive management.¹³

Temporal Bone Fractures

A thorough cranial nerve exam, especially for hearing as some of these fractures can be associated with conductive hearing loss, is required. Evaluate for otorrhea secondary to a cerebrospinal fluid (CSF) leak as well. Temporal bone fracture complications vary depending on the specific location of the fracture. Lateral temporal bone fractures are associated with epidural hematomas secondary to middle meningeal artery injury. Petrous fractures are associated with cranial nerve, carotid artery, and dural sinus injuries.¹³

Parietal/Occipital Fractures

Occipital and parietal bone fractures should be handled similarly. There are not many nerve or vessel structures that are associated with these fractures so general precautions should be taken. In general the largest complication of these fractures would be open skull fractures or venous sinus obstruction when associated with depressed skull fractures.

When to Consult

Neurosurgery consult is required for any depressed, open, or complicated skull fractures or any CSF leak. Be sure to perform a quality neurological exam with an in-depth cranial nerve exam and evaluation for CSF leak. Patients with nondisplaced fractures with no underlying intracranial processes can likely be safely discharged without neurosurgery consultation. Those with intracranial injuries, including bleeding, require further work-up, neurosurgical consultation, and likely admission. Prophylactic antibiotics may be provided depending on individual hospital protocol in conjunction with neurosurgery consultation.

Pitfalls and Pearls

– The Canadian Head CT Rule can help guide the decision to perform a head CT and is more sensitive than other clinical decision rules.

– The data for prophylactic antibiotic use in open skull fractures is poor. Know your hospital policy and discuss with neurosurgeon. Fractures such as frontal sinus fractures though, will often need antibiotics as they communicate with the other sinuses.

– Depressed skull fractures can be associated with obstructed venous sinuses requiring an emergent surgery for decompression.

– Basilar skull fracture signs can be missed initially as bruising may not have developed yet.

– Temporal bone fractures can be associated with multiple vessel and nerve injuries, so physical exam is extremely important.

References/Further Reading:

1. Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001;357(9266):1391-1396.
2. Bouida, W., Marghli, S., Souissi, S., et al. Prediction Value of the Canadian CT Head Rule and the New Orleans Criteria for Positive Head CT Scan and Acute Neurosurgical Procedures in Minor Head Trauma: A Multicenter External Validation Study. Ann Emerg Med; 2013;61(5):521-527.
3. Barve P, Raje V, Yadav S, et al. To study the association of CSF leaks in open and closed FrontoBasal Skull Fractures. Al Ameen Jour of Medl Sci. 2017;10(04):271-275.
4. Stein S, Fabbri A, Servadei F, Glick H. A critical comparison of clinical decision instruments for computed tomographic scanning in mild. Ann Emerg Med. 2009;53(2):180.
5. Mower, WR, Hoffman, JR, Herbert, M., et al. Developing a Decision Instrument to Guide Computed Tomographic Imaging of Blunt Head Injury Patients. Jour Trauma: Inj, Inf, Crit Care. 2005;59(4):954-959.
6. Haydel MJ, Preston CA, Mills TJ, et al. Indications for computed tomography in patients with minor head injury. N Engl J Med. 2000;343:100.
7. Robinson N, Clancy M. In patients with head injury undergoing rapid sequence intubation, does pretreatment with intravenous lignocaine/lidocaine lead to an improved neurological outcome? A review of the literature. Jour Emerg Med. 2001;18(6):453.
8. Tasker RC. Intracranial pressure: influence of head-of-bed elevation and beyond. Ped Crit Care Med. 2012;13(1):116-117.
9. Shokouhi G, Sattarnezhad N, Motlagh P, et al. Correlation of Fracture Depression Level and Dural Tear in Patients with Depressed Skull Fracture, Neurosurgery Quarterly. 2014;24(1):84-86.
10. Ross, M, Lang, E, Does Antibiotic Prophylaxis Prevent Meningitis in Patients with Basilar Skull Fracture? Ann Emerg Med. 2012;60(5):624-625.
11. Ahmad, S, Afzal, A, Rehman, L, et al. Impact of depressed skull fracture surgery on outcome of head injury patients. Pakistan Jour Med Sci. 2018;34(1).
12. Rolekar, N. Prospective study of outcome of depressed skull fracture and its management. Int Jour Med Sci Pub Health. 2014;3(12):1540.
13. Ellenbogen, RG, Sekhar, LN, & Kitchen, N. Princ of Neuro Surg: Tra Skull Fac Frac. Philadelphia, PA: Saunders/Elsevier. 2018;28:445-474.
14. Heegaard, W. “Skull Fractures in Adults.” 2020, https://www.uptodate.com/contents/skull-fractures-in-adults. Accessed 19 10 2020.
15. Patel, A, Groppo, E. Management of Temporal Bone Trauma. Cran Trau & Recon. 2010;3(2):105-113.
16. Demetriades, D, Charalambides, D, Lakhoo, M, et al. Role of prophylactic antibiotics in open and basilar fractures of the skull: A randomized study. Injury. 1992; 23(6):377-380.
17. ACEP Clinical Policy. Traumatic Brain Injury. https://www.acep.org/patient-care/clinical-policies/mild-traumatic-brain-injury2/ Accessed 1/18/2021