Cerebral haemorrhagic contusions and subdural haemorrhage in a trauma patient
Presentation
This middle aged male was involved in a serious assault, with multiple blows to the face. A CT trauma series was performed.
Patient Data
Bifrontotemporal haemorrhagic contusions and extra-axial haemorrhage with moderate mass effect.
Large haemorrhagic contusions involve the inferior frontal lobes bilaterally as well as the anterior temporal poles, more extensive on right.
Extra-axial blood along the frontal and temporal convexities and anteriorly in the middle cranial fossa, to a maximal depth of 5 mm, likely a combination of subarachnoid and subdural blood. There is also a thin layer of parafalcine subdural haematoma and a small amount of traumatic subarachnoid blood in the sylvian fissures.
- Extensive skull, skull base, left petrous temporal and facial fractures as described below:
- An undisplaced fracture line extends along the right orbital roof and medial wall to reach the floor of the sphenoid sinus (which contains fluid), with possible involvement of the cribriform plate. The maxillary sinuses and ethmoid air cells are opacified with fluid, and irregularity of the intervening bone (superior aspects of medial walls of the maxillary sinuses) is suspicious for fracture.
- Undisplaced skull fracture extends in sagittal plane through the frontal bone in the midline, extending posteriorly in line with the sagittal suture, before curving to the left of the midline as it crosses the lambdoid suture into the occipital bone before crossing the left petrous temporal bones in longitudinal plane
- CT venogram may be performed to assess the venous sinuses, given fracture involvement of the sagittal suture and possibly sagittal sinus.
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 neurones, 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:
- Acute haemorrhage is difficult to see on MR
- CT allows support equipment to be taken into the room, unlike MRI
- MR imaging requires more time
Subdural haemorrhage is a collection of blood in between the dura mater and the arachnoid mater of the brain. In young adults, subdural haemorrhage is typically caused by traumatic head injury associated with motor vehicle accidents. It is said to have an incidence of 12-29% of patients presenting with severe traumatic brain injury 3.
Patients with subdural haemorrhage can often present with neurological signs, such as a decreased conscious state or pupillary changes.
Treatment of subdural haematomas depends on the chronicity (acute vs chronic) as well as the degree of mass effect that is being produced. In this particular patient, we have an acute subdural haematoma which is producing significant mass effect, causing effacement of the right ventricle and ambient cisterns. Surgical intervention in acute subdural haematoma can be dictated by the following guidelines 4:
- SDH thickness greater than 10mm
- Midline shift greater than 5mm
- Neurological changes - GCS drop by 2 or more points; asymmetric pupils; intracranial pressure > 20mm Hg
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 otorrhoea
- 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.
Case contributed by A/Prof. Pramit Phal.
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