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Adults: Should a CT Scan Take Place Every Time Someone Suffers a Head Injury?

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There are over 700,000 head injury attendances to A&E in England every year, about half of whom are children.

Many injuries are minor and require relatively simple treatment and advice about possible complications occurring. Generally speaking, patients are sent home with a head injury advice leaflet, detailing what signs and symptoms they should look out for and when they should seek further medical assistance.

Post-concussion syndrome is a well recognised condition, generally lasting up to about 4-6 weeks, and does not necessarily require admission to hospital. It may start after a few days following the head injury.

The red flags that mandate a return to A&E are: 

  • Loss of consciousness
  • Increasing disorientation
  • Deafness in one or both ears
  • Problems understanding or speaking
  • Loss of balance or problems walking
  • Blurred or double vision
  • Any weakness in one or both arms or legs
  • Inability to be woken
  • Any vomiting
  • Bleeding from one or both ears
  • Clear fluid coming out of your ears or nose
  • Any fits (collapsing or passing out suddenly)
  • Drowsiness when you would normally be wide awake
  • Severe headache not relieved by painkillers such as paracetamol


There were just over 162,000 admissions for serious head injury in 2013-14. In 2014 NICE (The National Institute for Health and Care Excellence)  produced guidelines on when CT scans are appropriate for head injuries.

A CT scan, also called a computerised axial tomography scan (CAT scan), makes use of computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images (virtual 'slices') of specific areas of the body - allowing the user to see inside the body without having to resort to exploratory surgery.

In some cases there may be underlying damage to the brain that is not easy to detect clinically from the outset, such as a gradual collection of blood in part of the lining of the brain which increases over hours or even days. At a critical size, the collection of blood will start to compress the brain tissue causing permanent damage. However this can be picked up (via CT scan) prior to serious complication arising, with surgery to evacuate the collection of blood.   

The CT scan can also provide vitally important information to the clinicians providing care to the patient, in determining the appropriate pathways of care to follow. However, there are radiation risks to performing CT scans, hence the guidelines have looked at the risk/benefit balance in its recommendations as to when to perform a CT of the head.

The guidance in listed in the following tables. It should be noted that patients with bleeding tendencies (e.g. on warfarin, an anticlotting agent) have now also been incorporated into the guidance following a number of serious incidents when people sustained harm owing to the lack of guidance about how to manage this group.

Head injury (2014) NICE guideline CG176

Criteria for performing a CT head scan


For adults who have sustained a head injury and have any of the following risk factors, perform a CT head scan within 1 hour of the risk factor being identified:

  • GCS (Glasgow coma scale is a  is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment) - less than 13 on initial assessment in the emergency department.
  • GCS less than 15 at 2 hours after the injury on assessment in the emergency department.
  • Suspected open or depressed skull fracture.
  • Any sign of basal skull fracture (haemotympanum, 'panda' eyes, cerebrospinal fluid leakage from the ear or nose, Battle's sign).
  • Post-traumatic seizure.
  • Focal neurological deficit.
  • More than 1 episode of vomiting.

A provisional written radiology report should be made available within 1 hour of the scan being performed. [new 2014]

For adults with any of the following risk factors who have experienced some loss of consciousness or amnesia since the injury, perform a CT head scan within 8 hours of the head injury:

  • Age 65 years or older.
  • Any history of bleeding or clotting disorders.
  • Dangerous mechanism of injury (a pedestrian or cyclist struck by a motor vehicle, an occupant ejected from a motor vehicle or a fall from a height of greater than 1 metre or 5 stairs).
  • More than 30 minutes' retrograde amnesia of events immediately before the head injury.
  • A provisional written radiology report should be made available within 1 hour of the scan being performed. [new 2014]

To establish if you or someone you know may have a potential claim for clinical negligence following a head injury, please do not hesitate to contact the Clinical Negligence Team at Dutton Gregory Solicitors on 01202 315005 or at 

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