Clinical and imaging characteristics of patients*

Patient	Age at Diagnosis of Subdural Hematoma (mo)/Sex	Head Circumference at Subdural Hematoma Diagnosis (cm)	Presenting Signs and Symptoms	Imaging Findings	Treatment
1	8.5/M	47.5 (normal)	Bulging fontanelle, nausea, and lethargy	4-mm-thick right acute SDH	Observation alone
2	3.9/M	44 (macrocephalic)	Macrocephalic but otherwise asymptomatic; HC >98th percentile corrected for age; normal fundi; developmentally normal	Thin SDH present bilaterally measuring 5 mm thick	Observation alone
3	4.7/F	45.8 (macrocephalic)	Macrocephalic, bulging fontanelle; irritable, spasticity	Bilateral 18-mm-thick chronic SDHs	Bilateral subdural–peritoneal shunts Bifrontal craniotomy
4	17.8/M	50 (normal)	Fall from own height causing linear right parietal skull fracture and bilateral SDHs; returned 6 weeks later with irritability and bulging fontanelle	Bilateral subacute SDHs measuring 10 mm on right and 9 mm on left, and right parietal linear nondisplaced skull fracture	Burrhole drainage 6 weeks following trauma Required bilateral subdural peritoneal shunts 12 weeks after the trauma
5	3.6/M	45.9 (macrocephalic)	Macrocephalic but otherwise asymptomatic; fundus normal	Prominent pericerebral fluid spaces noted on referral for evaluation of macrocephaly; MRI 1 week later showed thin bilateral subdural hemorrhage with membranes (11 mm on right and 18 mm on left)	Bilateral burrhole drainage 19 days following referral Left subdural peritoneal shunt inserted 1 week later
6	6.3/F	Not recorded	Fever and upper respiratory tract infection symptoms, lethargy, and spasticity	Initial MRI showed prominent SAS; second MRI done during hospitalization showed an 8-mm left subdural hematoma	Observation alone
7	7/M	45.5	Motor vehicle crash— Patient was in a proper car seat, not ejected; Presented with decreased level of consciousness, vomiting, and respiratory pauses, and was therefore intubated and admitted to an intensive care unit. Found to have retinal and preretinal hemorrhages on fundoscopy	Initial CT showed an 11-mm-thick left acute SDH with a 4-mm midline shift and pericerebral fluid collections. MRI done in the days that followed was interpreted as showing SDHs of various ages in multiple compartments including the perifalcine region	No surgical intervention for the subdural hematoma; developed seizures that were treated with carbamazepine

HC indicates head circumference; SDH, subdural hematoma; SAS, subarachnoid space.
* Patients younger than 18 months of age evaluated at Montreal Children’s Hospital between 1998 and 2004 who were found to have BESS and a concomitant subdural hematoma on imaging. NAT was ruled out in every case.