There are more than 450,000 Emergency Department presentations each year for children with blunt head trauma. 25% of visits for blunt head trauma are in children less than 24 months of age. Scalp hematomas in this age group maybe the only sign of traumatic brain injury (TBI). An astute clinician must clinically assess those with possible TBI, while not overusing computed tomography (CT). Less use of the CT means less number of children exposed to radiation, which can lead to malignancy later on in life. Previous studies identified that patients who were younger, had non-frontal scalp hematoma locations, and had medium to large hematoma sizes were more likely to have skull fractures. However, the significance of an isolated scalp hematoma is unknown.
What is the association between an isolated scalp hematoma and TBI in children younger than 24 months of age?
Children younger than 24 months with minor head trauma (GCS 14-15) and an isolated scalp hematoma
Clinically important TBI injury (death from TBI, performance of neurosurgical procedure, intubation for at least 24 hours, or hospitalization for 2 or more nights) and TBI on CT
Secondary analysis of data from a prospective observational cohort study at 24 centers, in which a consecutive sample of children with GCS 14-15 after head trauma was enrolled
Trivial head trauma mechanisms, no signs of head trauma, scalp laceration or abrasion only, penetrating trauma, known brain tumors, preexisting neurological disorders, ventricular shunts, bleeding disorders, or previous neuroimaging
- Clinically important TBI: 12/2998 (0.4%; 95% CI 0.2% to 0.7%)
- All met this definition by requiring hospitalization for 2 or more nights
- 9/12 of those with clinically important TBI were less than 6 months of age
- 11/12 of those with clinically important TBI had non-frontal scalp hematomas
- 8/12 of those with clinically important TBI fell from heights > 3 feet
- Rate of TBI on CT: 50/570 (8.8%; 95% CI 6.6% to 11.4%)
- No patients > 3 months with small isolated scalp hematomas (< 1 cm or barely palpable) had TBI on head CT (0/65; 9% CI 0% to 5.5%)
- 10,569 children < 24 months with GCS 14-15 enrolled
- 2998 had isolated scalp hematomas
- 570 children defined as having isolated scalp hematomas underwent CT
- Highest prevalence of TBI on CT
- Infants < 3 months (23/120; 19.2%; 95% CI 12.6% to 27.4%)
- Temporal/parietal hematoma location (35/215; 16.3%; 11.6% to 21.9%)
- Fall > 3 feet (27/176; 15.3%; 95% CI 10.4% to 21.5%) vs fall < 3 feet (9/161; 5.6%; 95% CI 2.6% to 10.4%)
- Large database
- High likelihood that patient’s representations were captured
- Selection bias – likely patients with more concerning findings were ordered for CT scans, decreasing power to identify associations between prevalence of TBI on CT and age, scalp hematoma characteristics, and mechanisms of injury.
- CT scans not ordered uniformly, so do not have exact prevalence of TBI on CT for all ages, scalp hematoma characteristics, and mechanisms of injury.
“In patients younger than 24 months with isolated scalp hematomas, a minority received CTs. Despite the occasional presence of traumatic brain injuries on CT, the prevalence of clinically important traumatic brain injuries was very low, with no patients requiring neurosurgery. Clinicians should use patient age, scalp hematoma location and size, and injury mechanism to help determine which otherwise asymptomatic children should undergo neuroimaging after minor head trauma.”
We feel that this study further supports the idea that children with minor head trauma < 24 months of age who have isolated scalp hematoma are highly unlikely to have clinically important TBI. We can decrease the use of CT in evaluating these patients, unless they have certain characteristics such as age < 6 months, non-frontal hematomas, and large hematomas.
Potential Impact To Current Practice
This study recognizes the tendency to overuse CT scanning in younger children with isolated scalp hematoma, and supports observation in the place of imaging studies.
Imaging studies are unlikely necessary in children with minor head trauma and an isolated scalp hematoma who fit certain characteristics (older than 6 months, small hematoma size, frontal location). The incidence of traumatic brain injuries requiring an acute medical intervention is uncommon.