Brain contusion, also known as intracerebral hemorrhage 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 hemorrhage 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 hemorrhage 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.