Classifying the head injury is the first step. To do this, the doctor will take a detailed history and perform an examination.
How did the injury happen? Which parts of the brain and skull have been injured? And what is the severity of the injury?" -- these are some of the important questions that the doctor will assess.
Categorising head injury severity
The severity of the injury is categorised into mild, moderate, or severe based on the Glasgow Coma Scale [1].
The cut-offs for severity are:
- 8 or less (severe),
- 9-12 (moderate),
- 13-15 (mild).
When is CT scan needed?
Generally, those with moderate and severe injury will require an immediate CT scan.
However, up to 95% of patients are in the mild category, and they may or may not require a CT scan. Out of this large group of patients, the risk of deterioration requiring neurosurgery is about 3.5%. Therefore, not all patient will need a CT given these relatively low risk.
A series of decision rules have been developed and can be used to further guide whether or not a CT scan is required. Factors such as age, seizure, neurological signs and vomiting are used to weigh the need for CT scan.
Ultimately though, the final decision should be based on the doctor’s assessment of the individual patient combined with detailed discussions with the patient.
References:
1. Abnormal Flexion. https://www.glasgowcomascale.org/downloads/GCS-Assessment-Aid-English.pdf?v=3.
