Late presentations of minor head injury

To determine the frequency with which a CT head is performed in patients presenting more than 4 h after minor head injury and the clinical features that predict an abnormal scan.

Observational cohort study.

Emergency department (ED) of the Royal London Hospital, London, UK.

500 patients presenting to the ED of the Royal London Hospital.

Chart review of all patients with minor head injury presenting more than 4 h from insult to the ED between December 2007 and May 2009. Inclusion criteria were: age over 16 years, Glasgow coma scale (GCS) 14 or 15 on first assessment, over 4 h post-injury. Exclusion criteria were: age under 16 years, GCS 13 and less, injuries limited to the face with no risk of intracranial injury; presentation less than 4 h after injury.

497 patients were identified: 147 patients had CT head; 11 had intracranial injuries on CT. Loss of consciousness (p=0.0005), potential coagulopathy (p=0.0015), injuries above the clavicles (p=0.0150), open/depressed skull fracture (p=0.0221), alcohol/drug intoxication (p=0.0406) and focal neurology (p=0.0562) were predictors of positive CT scan. Five patients (1% of sample, 45% of patients with abnormal CT) required a neurosurgical procedure. Two (18.2%) self-discharged and four (36.4%) were followed up as outpatients. One patient (0.09%) died as a result of intracranial injury.

Patients with minor head injury who present over 4 h post-insult exhibit a similar risk of intracranial pathology to those presenting within 4 h. The risk factors previously identified to predict intracranial injury are similar in this study.