Extradural hemorrhage (summary)

Extradural haemorrhages (EDHs(EDH) represent collections of blood in the extradural (epidural) space. The haemorrhage sits between the skull superficially and the dura which overlies the brain parenchyma.

SummaryReference article

Patients withThis is a summary article for extradural haemorrhages are usually young andhaemorrhage. However, we do have a history of more in-depth reference article: extradural haemorrhage.

Summary

• epidemiology
  • young patients
  • high-energy headimpact trauma (see investigation of head injury). The aetiology of EDH explains the relationship between EDH and skull fracture.

    Presentation

    Patients with EDH often describe

• presentation
  • a headache, although this may (may be the result of head injury and underlyingdue to associated fracture.

    EDH may result in

    )
  • localising signs secondary to mass effect which can cause localising signs (sixth cranial nerve palsy) or autonomic changes, followed by focal neurology and
  • loss of consciousness if
• pathophysiology
  • the mass effect is significant.

    Some patients have an initial loss of consciousness followed by a return to normal conscious level which is accompanied by a persistent severe headache. This is termed the "lucid interval" ¹ and is followed by subsequent drop in conscious level.

    See the article: EDH v SDH

    Treatment and prognosis

    Extradural haemorrhages necessitate urgent consultation with neurosurgical services ². Surgical treatment involves evacuation of the clot through a cranial burr hole. Smaller bleeds may be managed conservatively.

    EDHs generally have a good prognosis if appropriately treated ³. In high impact trauma, morbidity and mortality may be related to other associated injuries including brain injury.

    Pathophysiology

    The

    source of haemorrhage tends to be arterial and the result of an
  • associated skull fracture. The
  • the middle meningeal artery is particularly at risk because it sits under the thinnest part
• investigation
  • non-contrast CT head is quick and readily accessible
• treatment
  • urgent consideration of theneurosurgical intervention
  • surgical treatment: evacuation of clot through a burr hole
  • smaller bleeds may be managed conservatively

Role of imaging

• initial diagnosis
• assessment of associated mass effect
• assessment of associated injuries, e.g. skull between the ears and the eyes in the squamous temporal bone.

  The headache that patients experience is the result of the dura mater is stripped off the skull vault as the collection grows.

  fracture
• look for an underlying cause
• suggest further imaging
• follow up

Radiographic features

Non-contrast CT is the imaging modality of choice for the investigation because it is highly sensitive for haemorrhage and fracture. Moreover, it is quick and highly available, and is the safest option for a potentially sick patient.

CT

EDH will be seen peripherally as a biconvex area of hyperdensity. This has been described as looking like a lens (lentiform) or an egg ("eggs"-tradural haemorrhage). The haemorrhage is well demarcated as it sits between the skull and brain parenchyma and does not cross the skull sutures.

They tend to be hyperdense (bright). However, active haemorrhage will be seen as an area of hypodensity (the non-clotted blood appears dark within the rest of the clotted haematoma).

CT may illustrate skull fractures or other parenchymal injuries. If the haemorrhage is of sufficient size, mass effect may be seen, e.g. midline shift, herniation.