Reclassification of traumatic brain injury: a new framework

Following on from our previous article advising that a TBI Classification Working Group had been set up to consider a reclassification system for traumatic brain injuries, it has been reported by the Brain Injury Association of America that they are moving towards a new system.

The current Glasgow Coma Scale (GCS) defines TBIs as ‘mild’, moderate’ or ‘severe’. It is solely based on a person’s level of consciousness and is seen as simplistic and outdated, as it only includes clinical assessment of a patient’s response to eye, verbal and motor commands. The classification often does not correlate with the cognitive outcome for patients.

The new classification proposal, called CBI-M, consists of four guides to assessing brain injury – clinical, biomarker, imaging and modifiers. It therefore considers more factors before classifying a TBI.

• Clinical: The GCS score will remain as the clinical part of the assessment
• Biomarker: This will use biomarkers identified in blood tests to provide an indicator of any tissue damage. If the levels are low, patients will not require a CT scan.
• Imaging: CT and MRI imaging to assess blood clots, bleeding and lesions particularly for patients with more severe injuries.
• Modifiers: This is an assessment of how the injury occurred, will include pre-existing conditions, medications, prior TBI, substance abuse and any relevant living circumstances.

GCS and imaging are used in the UK but the introduction of biomarkers from blood tests and the patient’s background information to include the mechanics of the injury will no doubt be welcomed. They are important factors, and it has long been argued they should be considered when assessing a TBI.

The new classification system is to be phased in at trauma centres in the US on a trial basis. There will be further work before it is fully implemented.

Matters have progressed swiftly since our last article and depending on how quickly the trial is rolled out and tested, it seems likely the new re-classification system will be introduced in the US. The trial and any changes do not of course apply to the UK classification system but if it is accepted in the US, changes are likely to happen with the UK classification too. It will just be a matter of time.

For more information, get in touch with our Brain Injury Special Interest Group.