Multiple skull fractures in a trauma patient

Case contributed by Dr Dayu Gai

Presentation

This 20 year old male was involved in a motorbike accident. Clinically, he had a disfiguring, open wound of the skull. A CT brain was performed.

Patient Data

Age: 20 years
Gender: Male
Modality: CT
  • Complex anterior right frontal, intracranial, extraaxial and intraparenchymal gas containing haematoma. Extraaxial right frontal gas containing haematoma associated with the depressed skull fracture continuous medially with a right frontal pole contusion and the subarachnoid spaces of the interhemispheric fissure and inferior frontal poles. Local mass effect and surrounding oedema and ipsilateral sulcal effacement. Very minor subfalcine herniation (4 mm). Basal cisterns patent. No descending transtentorial herniation. Small focus of subarachnoid haemorrhage in the interpeduncular cistern. Small volume sub dural haematoma layering over the falx.
  • Complex comminuted open right anterior calvarial, anterior and central skull base, and facial fractures.
    • Right frontal and squamous temporal calvarial skull fracture depressed by 12mm.
    • Depressed comminuted frontal air sinus fracture.
    • Anterior skull base; laterally compressed frontal bone and lesser sphenoid wing (orbital roof) overlapped fracture extending medially into the ethmoid air cells. Posterior displacement of the superior orbital rim, intra-orbital extraconal gas and relative proptosis.
    • Central skull base; Posterior ethmoid / sphenoid sinus fracture involving the medial to the anterior clinoid process in the region of the cavernous ICA anterior genu and the optic canal. Laterally compressed comminuted sphenoid ridge fracture, extending laterally into the lateral orbital wall and inferiorly to involve the pterygopalatine fossa (minimally displaced). No involvement of foramina rotundum, ovale, or spinous.
    • Undisplaced longitudinal left petrous temporal bone fracture passing through the medial opacified mastoid air cells, and the anterior external auditory canal wall into the temporomandibular joint. Ossicular chain intact. No involvement of the inner ear or neurovascular canals identified. Associated temporomandibular joint and adjacent parapharyngeal soft tissue gas.

Case Discussion

Brain contusion, also known as intracerebral haemorrhage 3, is a common type of traumatic brain injury 2. This injury occurs as a direct result of physical destruction of brain tissue within moments of impact 3. This injury includes damage to the primary brain cells including neurons, astrocytes and oligodendrocytes. Additional secondary injury occurs due to many responses, one of which is the maladaptive physiological 'clean up' process by which endogenous neutrophils and phagocytes release harmful free radicals to the area.

CT is usually the mainstay for imaging in brain contusions. It is preferred over MRI because of three reasons1:

  1. Acute haemorrhage is difficult to see on MR
  2. CT allows support equipment to be taken into the room, unlike MRI
  3. MR imaging requires more time

In this case study, note the hyperdense (white) well demarcated region containing hypodense (black) gas locules. This represents an open brain injury with active haemorrhage from intraparenchymal blood vessels.

This patient also multiple skull fractures, including a frontal sinus fracture, skull base fractures and a left sided temporal bone fracture.

Frontal sinus fractures are seen in 5 to 15% of traumatic craniofacial fractures 4. As with other craniofacial injury, it is associated with blunt trauma, particularly motor vehicle accidents. Interestingly, the incidence of frontal sinus fractures has decreased recently with the advent of airbag installation in motor vehicles. Nowadays, interpersonal altercation is the most common cause.

Over the last few decades, there has been an increasing tendency to manage frontal sinus fractures conservatively, either without surgery or with endoscopic sinus repair. Features which are indicative for surgery include:

  • A displaced anterior table injury
    • This can pose a cosmetic disfiguration if not surgically corrected
  • Severe posterior table injuries
    • This can cause CSF leak, post nasal drip, or entrapment of mucosa and the formation of mucocoeles
  • Compromised nasofrontal outflow tracts
    • This can also lead to mucocoele formation

Base of skull fractures are commonly seen in craniofacial trauma. Up to 24% of patients with blunt head trauma sustain a skull base fracture 5

Base of skull fractures are clinically relevant due to the possibility of endangerment of nearby structures including:

  • Cranial nerves
  • Internal carotid artery
  • Cavernous sinus

Definitive management for skull base fracture depends on the degree of fracture and the clinical state of the patient. Indications for operative management include:

  • Neurological deficits - facial nerve paralysis, hearing loss or blindness
  • CSF fistula - manifests as rinorrhea and otorrhea
  • Temporal bone fracture

Operative management includes a subtotal petrosectomy. This involves exenteration of the temporal bone air cell tracts and obliteration of the eustachian tube. Once the injured structures are repaired, the remaining cavity is obliterated with an endogenous fat graft and temporalis muscle flap. 

In the absence of the above features, conservative, expectant management is carried out. This includes a 5 day course of intravenous antibiotics.

Another point to note, is that nasogastric tube placement is to be avoided in patients with confirmed or suspected base of skull fracture. This is due to the risk of intracranial nasogastric tube placement, whereby the tube traverses into the cranium via a fractured cribriform plate 6.

Temporal bone trauma commonly results from blunt head injury, in particular motor vehicle accidents 7. 30-70% of cases of blunt head trauma are associated with temporal bone injuries.
Anatomically, the temporal bones are paired structures located in the lateral skull. They form parts of the middle and posterior cranial fossae and are hence part of the skull base. Important nearby anatomical structures include:

  • The cochlea and vestibule
  • Vestibulocochlear nerve - compromisation may cause hearling loss and tinnitus
  • Facial nerve - compromisation may cause facial nerve paralysis
  • Internal carotid artery
  • Jugular vein

The temporal bone has six key portions to it:

  • Squamour portion
  • Mastoid process
  • Tympanic surface
  • Styloid process
  • Zygomatic process
  • Petrous portion

Urgent emergency surgical management is required in the following two situations after temporal bone trauma. These are:

  1. Brain herniation into the middle ear, mastoid or external acoustic meatus
  2. Internal carotid artery laceration

Case contributed by A/Prof. Pramit Phal.

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Case Information

rID: 34088
Case created: 4th Feb 2015
Last edited: 20th Mar 2017
Inclusion in quiz mode: Included

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