Neurology

Extradural haemorrhage

Trauma tears the middle meningeal artery against the thin temporal bone, and arterial pressure strips the dura off the skull, so the collection grows in hours rather than days.

In a nutshell

An extradural haemorrhage is arterial blood, usually from the middle meningeal artery, stripping the dura off the skull after a temporal fracture. If the GCS is 12 or less, give tranexamic acid 2 g intravenously and scan within 1 hour.

Classic presentation

A 20-year-old struck on the temple, briefly knocked out, walks and talks, then vomits, drops his GCS and develops a fixed dilated right pupil with left arm weakness.

Key points

The GCS scores eye opening out of 4, verbal response out of 5 and motor response out of 6, so the total runs 3 to 15, never 0.
NICE NG232 (head injury) grades severity as mild 13 to 15, moderate 9 to 12, severe 8 or less, and weights a falling motor score most.
Extradural is biconvex and stopped by sutures but crosses the falx and tentorium. Subdural crosses sutures but the falx stops it.
Only about 14% to 21% of extradural haematomas show the full knocked-out, lucid, deteriorating sequence, so its absence excludes nothing.
Ipsilateral fixed dilated pupil with contralateral weakness is uncal herniation. Same-side weakness is the Kernohan notch phenomenon, a false localising sign.
A trained member of staff must assess any head injury within 15 minutes of arrival, and a provisional written CT report follows within 1 hour.
Normal CT but GCS still below 15 after 24 hours of observation: consider a further CT or MRI.
Up to 10% of extradural bleeds are venous, from a torn sinus or diploic vein. They fill slowly and an early scan can look normal.

First-line investigation

Urgent non-contrast CT head, within 1 hour if the GCS is 12 or less on arrival or any other high-risk feature is present.

Management

Resuscitate and score

<C>ABCDE, catastrophic haemorrhage before airway. Protect the cervical spine, record GCS by component and pupils, treat seizures. Pre-alert for GCS 8 or less.^1,9
A trained member of staff assesses within 15 minutes of arrival, and immediately if the GCS is below 15.¹
GCS 8 or less: get an experienced clinician for advanced airway management now.¹

Tranexamic acid

GCS 12 or less with no suspected active extracranial bleeding: tranexamic acid 2 g intravenous bolus in people 16 and over.^1,10
Under 16: tranexamic acid 15 to 30 mg/kg intravenously, to a maximum of 2 g.¹
Give within 2 hours of injury, as early as possible, before imaging and pre-hospital if you can. Off-label in March 2023.¹

Image on the clock

Within 1 hour: GCS 12 or less on arrival, GCS below 15 at 2 hours, post-traumatic seizure, focal neurological deficit.¹
Also within 1 hour: suspected open or depressed skull fracture, any basal skull fracture sign, more than 1 episode of vomiting.¹
Basal skull fracture signs: haemotympanum, 'panda' eyes, CSF leak from the ear or nose, Battle's sign.¹
Within 8 hours if there was loss of consciousness or amnesia plus age 65 or over, a bleeding or clotting disorder, dangerous mechanism, or over 30 minutes retrograde amnesia.¹
Dangerous mechanism includes a fall from more than 1 metre or 5 stairs, a pedestrian or cyclist struck, or ejection from a vehicle.¹
Presenting more than 8 hours after the injury inverts the 8-hour window to within 1 hour.¹
On any anticoagulant, or an antiplatelet other than aspirin monotherapy, with no other CT indication: the same 8-hour or 1-hour rule.¹
A provisional written radiology report must be available within 1 hour of the scan. A biconvex, suture-limited hyperdensity is the finding.^1,3

Reverse the anticoagulant

Warfarin: immediate prothrombin complex concentrate (PCC) plus phytomenadione (vitamin K) 5 mg by slow intravenous injection. Stop warfarin, recheck the INR.^6,11
No UK numeric PCC dose exists. It is weight- and INR-banded, so take it from the local transfusion protocol or the BNF monograph.⁶
Dabigatran: idarucizumab. Apixaban or rivaroxaban: ring haematology, because NICE recommends andexanet alfa only for gastrointestinal bleeding.^7,8,9
Do not reverse anticoagulation in anyone without active or suspected bleeding.⁹

Neurosurgery and transfer

Discuss regardless of imaging: persisting coma (GCS 8 or less), unexplained confusion beyond 4 hours, any GCS deterioration, progressive focal signs.¹
Also discuss a seizure without full recovery, definite or suspected penetrating injury, and any CSF leak.¹
GCS 8 or less benefits from neuroscience-centre care whether or not surgery is needed.¹
Intubate for GCS 8 or less, lost laryngeal reflexes, arterial oxygen tension (PaO2) below 13 kPa on oxygen, carbon dioxide tension (PaCO2) above 6 kPa, or irregular breathing.¹
Ventilate to PaO2 above 13 kPa and PaCO2 4.5 to 5.0 kPa, and hold mean arterial pressure at 80 mmHg or more.¹
No UK volume, thickness or midline-shift threshold exists: NG232 delegates 'surgically significant' to local neurosurgical centres.¹

Observe, and define deterioration

Eight observations: GCS, pupil size and reactivity, limb movements, respiratory rate, heart rate, blood pressure, temperature, oxygen saturation.¹
Half-hourly until GCS 15, then half-hourly for 2 hours, 1-hourly for 4 hours, then 2-hourly. Revert to half-hourly on deterioration.¹
Deterioration is a 1-point GCS drop sustained at least 30 minutes, weighting motor most, or 3 points in eye or verbal, 2 in motor.¹
Normal CT but GCS below 15 at 24 hours: consider a further CT or MRI. Do not discharge until the GCS is 15 or baseline.¹

Exam traps

A lucid interval is classic for extradural but occurs in only a minority, and any expanding intracranial mass can produce one.
Aspirin monotherapy is excluded from the NG232 anticoagulant CT limb. Every other antiplatelet and anticoagulant is included.
Present more than 8 hours after injury and the 8-hour scan window inverts to within 1 hour.
Andexanet alfa reverses apixaban and rivaroxaban, but NICE recommends it only for gastrointestinal bleeding, so it is not the answer here.
The BNF lists intracranial bleeding, except during craniotomy, among mannitol's intravenous contra-indications, so hyperosmolar therapy is a neurocritical-care decision.
NICE gives no volume, thickness or midline-shift threshold: NG232 delegates 'surgically significant' to local neurosurgical centres.
Tranexamic acid in head injury is given before imaging, and only if active extracranial bleeding is not suspected.

Illustrations

Extradural haematoma on CTNon-contrast CT showing a biconvex, lentiform extra-axial collection adjacent to a temporal skull fracture.PassFinals source record · project source

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.