Head Injury in Children
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Direct answer
Head injury in children is most often minor, and CT is needed only when validated decision rules such as PECARN identify high-risk features. Extradural haematoma is typically a lens-shaped collection that does not cross suture lines, often following a temporal bone fracture and sometimes with a lucid interval. Abusive head trauma should be suspected when injuries are inconsistent with the history or occur in a non-mobile infant.
What you must remember
- Imaging rules: PECARN decision rules weigh features such as GCS below 15, persistent vomiting and signs of basal skull fracture.
- Extradural haematoma: biconvex on CT, usually arterial from a torn middle meningeal artery, with a classic lucid interval that is not always present.
- Subdural haematoma: crescent-shaped on CT, crossing suture lines, usually venous from bridging veins.
- Retinal haemorrhage: multilayered or extensive haemorrhages raise strong suspicion of abusive trauma.
- Non-accidental injury: bruising in a non-mobile infant, multiple injuries of different ages and a delay in seeking care.
- Linear skull fracture: often heals without surgery, whereas depressed fractures may need elevation.
- Concussion: usually managed with observation and a graded return to activity.
Extradural and subdural haematoma compared
Extradural and subdural haematomas are the two intracranial bleeds most often compared in children. Their imaging shape and source explain most exam questions, so the table sets them side by side.
| Feature | Extradural haematoma | Subdural haematoma |
|---|---|---|
| Shape on CT | Biconvex, lens-shaped | Crescent-shaped |
| Crosses suture lines | No | Yes |
| Typical source | Middle meningeal artery | Bridging veins |
| Lucid interval | Classic, though not always present | Uncommon |
| Common association | Skull fracture, often temporal | Abusive trauma or rotational injury |
| Surgical need | Often urgent when large | Depends on size and symptoms |
A lens-shaped collection that stops at a suture points towards extradural haematoma, which is usually an emergency because the arterial bleed can expand quickly. A crescent that crosses sutures points towards subdural bleeding, which may develop more slowly and is commonly linked to abusive trauma in infants. In suspected abuse, a subdural collection with retinal haemorrhage and skeletal injury raises the concern markedly and needs prompt multidisciplinary review.
Where the exam tries to catch you
Head injury questions often test imaging logic and child protection signs.
- Trap: ruling out extradural haematoma because no lucid interval was described Correct: the lucid interval is classic but not always present, so repeated neurological observation is still needed.
- Trap: attributing bruising in a non-mobile infant to ordinary handling Correct: bruising in a non-mobile infant is a red flag for abuse and needs a child protection assessment.
- Trap: scanning every child with minor head injury by default Correct: validated decision rules reduce unnecessary CT and radiation exposure in children.
- Trap: assuming every subdural haematoma needs surgery Correct: small collections may be managed conservatively, while large or symptomatic ones need evacuation.
Frequently asked questions
How does an extradural haematoma appear on CT in children?
An extradural haematoma appears on CT as a biconvex, lens-shaped collection that does not cross cranial suture lines. It most often arises from a torn middle meningeal artery, frequently after a temporal bone fracture.
What is the classic lucid interval in extradural haematoma?
The classic lucid interval in extradural haematoma is a brief period of consciousness after the head injury, followed by deterioration as the bleed expands. It is not always present, so repeated neurological observation remains essential.
Which features suggest abusive head trauma in an infant?
Features suggesting abusive head trauma in an infant include retinal haemorrhages, bruising in a non-mobile child and injuries inconsistent with the history. Subdural haematoma and fractures of different ages also raise concern and need a child protection referral.
When are imaging decision rules used in paediatric head injury?
Paediatric head injury decision rules such as PECARN guide when CT is needed, based on features like GCS below 15, persistent vomiting and signs of basal skull fracture. These rules reduce unnecessary radiation exposure in children with minor head injury.
Does every skull fracture in a child require surgery?
Not every skull fracture in a child requires surgery, because many linear fractures heal without intervention. Depressed fractures, or those with intracranial bleeding or dural tear, may need neurosurgical elevation or repair.