Basics
Description
A subdural hematoma (SDH) is a collection of blood between the outer pial and inner dural meningeal layers. The bleeding is usually venous in origin, although either cortical arteries or bridging veins may be torn.
Epidemiology
- Heterogeneous causes; occur in all age groups
- Incidence in infants <1 year old estimated at 20 " 25/100,000.
Risk Factors
- In infants and young children, SDHs are frequently the result of abusive head trauma.
- In older children, SDHs are often the result of motor vehicle collisions.
- Neonatal SDHs occur with spontaneous deliveries but may be more frequent following deliveries with forceps or vacuum extraction. SDHs related to birth usually resolve.
- Risk factors for abusive head trauma include disability or prematurity of the child, unstable family situations, parents of young age, and low socioeconomic status.
- 1 study found that fathers were the most frequent perpetrators, followed by boyfriends, female babysitters, and mothers, in descending order of frequency.
- Accidental trauma
Genetics
There is no clear genetic predisposition except when hereditary coagulopathy or metabolic disease is implicated.
General Prevention
- Parents should be counseled about appropriate methods to channel frustration and anger toward infants and children. Shaking an infant when the parent is angry is never appropriate.
- Bicycle helmets, car seats, and seat belts are all valuable in preventing head injuries in children.
Pathophysiology
- SDHs may be acute or chronic:
- Arterial SDHs grow quickly, whereas venous SDHs may accumulate slowly, remaining undetected for weeks or months.
- Acute SDHs contain blood, whereas chronic SDHs contain proteinaceous exudate and blood-breakdown products.
- Rebleeding may be the underlying cause of many chronic SDHs.
- Significant force is usually required for SDH unless there are predisposing circumstances; SDH is only rarely due to trivial or minor trauma. However, SDH can occur with relatively minor trauma in individuals with bleeding disorders, children on chronic dialysis, and those with enlarged extracerebral spaces or cortical atrophy.
- SDHs in abusive head trauma may be due to the striking of the infant 's head against a surface (such as a mattress):
- The sudden deceleration associated with the impact may tear bridging veins traveling in the subdural space.
- The term shaking-impact syndrome may be more accurate than shaken baby syndrome.
Etiology
- See "Risk Factors. "
- SDHs can also occur after ventricular shunting and extracorporeal membrane oxygenation (ECMO).
Commonly Associated Conditions
- Some metabolic disorders, such as glutaric aciduria type I and Menkes disease, can be associated with both acute and chronic SDHs.
- Victims of motor vehicle collisions with SDH may have other intracranial injuries such as diffuse axonal injury.
- Traumatic SDHs are often associated with cerebral contusions. Other associated injuries include skull fractures, diffuse axonal injury, and penetrating injuries.
- Sequelae: epilepsy, developmental delay, cerebral palsy
Diagnosis
A careful history and detailed physical exam are essential to explore possible causes of the SDH, assess the child 's neurologic status, and look for evidence of other injuries. Prompt neuroimaging is critical.
History
- Newborns: SDHs due to birth trauma may present with lethargy, pallor, poor feeding, apnea, and seizures. However, many term newborns with small SDHs are asymptomatic.
- Infants and young children: SDHs may also present with a nonspecific history of lethargy, irritability, vomiting, poor feeding, apnea, and seizures.
- Older children: present with a history of trauma and alteration of consciousness
- Caution
- Be suspicious if the stated history does not fit with the pattern or severity of the injury.
- Physicians and other health care professionals with experience in child abuse should be consulted early if abuse is suspected.
Physical Exam
- Newborns may present with decreased responsiveness, a bulging fontanelle, hypotonia, or hypertonia. Retinal hemorrhages are not specific at this age because they are seen in up to 40% of newborns following a vaginal delivery.
- Infants and young children may also present with nonspecific physical signs, but focal neurologic signs may be present. Retinal hemorrhages are most often associated with abusive head trauma, but they have been reported after accidental trauma leading to SDH. Bilateral retinal hemorrhages with retinal folds or detachments are particularly associated with abusive head trauma.
- Other signs of child abuse include burns, lacerations, and bruises in various stages of healing and belt marks, choke marks, and multiple fractures of different ages.
- Older children present with signs of external head trauma, decreased responsiveness, and focal neurologic signs.
- SDHs present with nonspecific signs such as vomiting, irritability, lethargy, failure to thrive, anemia, and seizures.
Diagnostic Tests & Interpretation
Imaging
- CT scan is the imaging study of choice in acute head trauma with neurologic signs:
- SDH appears as an extra-axial area of increased density, crescentic in shape, and often associated with cerebral contusion or mass effect.
- CT also may show evidence of cerebral edema, with loss of gray matter/white matter differentiation and small ventricles.
- Subacute SDHs may be difficult to distinguish from adjacent gray matter on CT scan.
- Loss of gray/white matter differentiation may occur.
- Chronic SDHs appear as areas of low density on CT scan, often bilateral.
- MRI is helpful to clarify subacute and chronic SDHs and to identify small SDHs missed by CT.
- Ultrasound is less helpful because it may be difficult to distinguish the subdural space from the subarachnoid space.
- If child abuse is suspected, a skeletal survey or bone scan is useful to look for fractures of different ages.
- Incidental SDH may be found on neuroimaging studies in newborns; frequently, no intervention is required other than close follow-up.
Differential Diagnosis
- SDHs are usually traumatic, but separating accidental from abusive head trauma may be difficult: Falls in infants may cause linear skull fractures but rarely SDHs. On noncontrast head CT, homogeneous hyperdense SDH is more common following accidental trauma, whereas mixed-density SDH is more common following abusive head trauma.
- Macrocephaly or other signs/symptoms since birth may help to date the origin of the SDH to the perinatal or neonatal period.
- Epidural hematomas, subarachnoid hemorrhages, and acute SDHs cannot be distinguished clinically:
- The lucid interval sometimes seen with epidural hematomas in adults is not a reliable sign.
- A head CT should differentiate the different entities.
- Chronic SDHs must be differentiated from benign enlargement of the subarachnoid spaces, a self-limited condition characterized by progressive macrocrania and extra-axial fluid collections with the density of spinal fluid:
- MRI can differentiate benign enlargement of the subarachnoid spaces from SDH.
- Rarely, SDH can also occur in children with benign enlargement of the subarachnoid spaces.
Treatment
Medication
Seizures
- Phenytoin and levetiracetam are good choices if IV medication is needed, with phenobarbital as a reasonable alternative, especially in neonates.
- Prophylactic anticonvulsants given for a few weeks are effective in reducing early posttraumatic seizures but may not affect long-term risk of epilepsy.
Additional Therapies
General Measures
- The treatment of choice for large, acute SDHs is surgical evacuation. Smaller SDHs may be managed conservatively, with careful monitoring for signs of neurologic deterioration.
- While awaiting surgery, attention to airway, breathing, and circulation (ABCs) is critical. Tracheal intubation should be performed if the child 's Glasgow Coma Scale score is <8 or if airway protective reflexes are impaired.
- Measures to control intracranial pressure (ICP) include elevating the head of the bed 30 degrees to promote venous drainage and osmotic therapy with mannitol:
- ICP monitoring should be considered.
- Mild hyperventilation (Pco2 30 " 35 mm Hg) may be helpful but should not be instituted prophylactically.
- The efficacy of these measures in improving long-term outcome following large SDHs has not been established. Mild hypothermia and hypertonic saline have been used in some cases of traumatic brain injury in adults, but these are not proven therapies in children.
- Seizures should be treated promptly.
- Treatment of chronic SDHs is more controversial:
- If there are no signs of elevated ICP, conservative treatment is reasonable, and most collections will resolve.
- Subdural taps are indicated if ICP rises.
- If taps are not successful, a subdural peritoneal shunt may be placed.
- Treatment of SDHs that develop after ventricular shunting is particularly challenging.
Issues for Referral
Social work services should be consulted in cases of known or suspected child abuse.
Surgery/Other Procedures
The treatment of choice for large, acute SDHs is surgical evacuation.
Inpatient Considerations
Initial Stabilization
- Children with SDHs may be critically ill on presentation.
- The aggressiveness of acute therapy depends on the child 's clinical condition.
- Neuroimaging studies and, if necessary, prompt neurosurgical consultation should be performed.
IV Fluids
Isotonic fluids should be given because hypotonic fluids may worsen cerebral edema.
Ongoing Care
Follow-up Recommendations
Children with neurologic sequelae from head injury may benefit from admission to a rehabilitation hospital.
Prognosis
- In general, long-term outcome is related to the condition of the child at time of presentation. Prolonged elevation of ICP, concomitant ischemic brain injury, or significant cerebral edema before treatment is worrisome and indicates a poor prognosis.
- Children typically have a better outcome from head injury than do adults, but children <7 years of age often do worse than older children, especially if the SDH is the result of abusive head trauma.
Complications
- SDHs may result in mass effect, focal neurologic signs, and coma.
- Increased ICP and seizures are other serious complications.
- Neurologic sequelae of SDHs are more severe than epidural hematomas because of associated cerebral contusions.
- Long-term problems include headache, seizures, hydrocephalus, cerebral palsy, difficulty concentrating, poor school performance, fixed neurologic deficits, and neurobehavioral problems.
- Epilepsy eventually develops in ¢ ¼10 " 15% of patients after severe head injury: This risk generally does not warrant the use of prophylactic anticonvulsants.
Additional Reading
- Foerster BR, Petrou M, Lin D, et al. Neuroimaging evaluation of non-accidental head trauma with correlation to clinical outcomes: a review of 57 cases. J Pediatr. 2009;154(4):573 " 577. [View Abstract]
- Matschke J, Voss J, Obi N, et al. Nonaccidental head injury is the most common cause of subdural bleeding in infants <1 year of age. Pediatrics. 2009;124(6):1587 " 1594. [View Abstract]
- McNeely PD, Atkinson JD, Saigal G, et al. Subdural hematomas in infants with benign enlargement of the subarachnoid spaces are not pathognomonic for child abuse. AJNR Am J Neuroradiol. 2006;27(8):1725 " 1728. [View Abstract]
- Swift DM, McBride L. Chronic subdural hematoma in children. Neurosurg Clin North Am. 2000;11(3):439 " 446. [View Abstract]
- Tung GA, Kumar M, Richardson RC, et al. Comparison of accidental and nonaccidental traumatic head injury in children on noncontrast computed tomography. Pediatrics. 2006;118(2):626 " 633. [View Abstract]
Codes
ICD09
- 852.20 Subdural hemorrhage following injury without mention of open intracranial wound, unspecified state of consciousness
- 767.0 Subdural and cerebral hemorrhage
- 432.1 Subdural hemorrhage
ICD10
- S06.5X0A Traum subdr hem w/o loss of consciousness, init
- P52.8 Other intracranial (nontraumatic) hemorrhages of newborn
- P10.0 Subdural hemorrhage due to birth injury
- I62.00 Nontraumatic subdural hemorrhage, unspecified
SNOMED
- 206191000 Local subdural hematoma due to birth trauma (disorder)
- 281864001 Non-traumatic intracranial subdural hematoma (disorder)
- 262952002 Traumatic intracranial subdural hematoma (disorder)
FAQ
- Q: When did the bleed occur?
- A: With chronic SDHs, the time and type of injury may be difficult to establish because no trauma may be reported and the trauma may have occurred weeks or months before. Neuroimaging can give some indication of the injury 's timing.
- Q: What limitations should be imposed after an acute SDH?
- A: Because SDH may recur with minor trauma, it is prudent to avoid any activities that have significant risk of fall or a blow to the head for weeks to months or until neuroradiologic resolution of the hematoma.
- Q: Why are anticonvulsants not used to prevent seizures following SDHs?
- A: Seizure medications may be given for a few weeks to prevent early seizures following an SDH. After a few weeks, the risks and side effects of the medications outweigh the risk of developing seizures. If seizures begin at a time remote from the injury, then seizure medications can be restarted.
- Q: My baby twisted out of my arms, fell head first onto a tile floor, and suffered a head injury. Will I be reported for child abuse?
- A: Not if the injuries fit with the stated history. In this case, the most likely injury would be a linear skull fracture. If more serious intracranial injuries occur, they will probably not be associated with retinal hemorrhages or other injuries such as older fractures in multiple stages of healing.