What is a subgaleal hemorrhage?

Subgaleal Hemorrhage: Definition and Clinical Significance

A subgaleal hemorrhage is bleeding that occurs in the potential space between the periosteum of the skull and the galea aponeurotica, which can rapidly accumulate blood and lead to serious complications including hypovolemic shock and death in severe cases. 1

Anatomical Considerations

• The subgaleal space is a loose areolar tissue layer that extends from the orbital ridges anteriorly to the nuchal line posteriorly, and laterally to the temporal fascia 2
• This potential space can expand significantly, allowing for accumulation of large volumes of blood 3
• The bleeding typically occurs due to rupture of the emissary veins, which connect the dural sinuses and scalp veins 4

Etiology and Risk Factors

• Most commonly associated with birth trauma, particularly instrumental deliveries using vacuum extraction 1
• In older children and adults, causes include:
  • Head trauma (even mild trauma in patients on anticoagulation) 3
  • Coagulation disorders such as hemophilia 4
  • Hair pulling or scalp trauma with tearing forces 5
  • Skull base fractures 3

Clinical Presentation

• In neonates:
  • Progressive swelling of the scalp that crosses suture lines
  • Pallor, lethargy, and signs of hypovolemia
  • Severe anemia requiring transfusion 4
• In older children and adults:
  • Diffuse, fluctuant swelling of the scalp
  • Headache and local pain
  • Ecchymosis that may extend to the periorbital regions 3
  • The swelling may appear at a site distant from the trauma location 5

Diagnosis

• Clinical examination showing a fluctuant, mobile scalp mass that crosses suture lines 2
• Imaging:
  • CT scan is the preferred initial imaging modality, showing diffuse hematoma in the subaponeurotic space 3
  • MRI may be used to further characterize the hemorrhage and exclude other intracranial pathologies 6

Complications

• Hypovolemic shock (particularly in neonates) 1
• Anemia requiring blood transfusion 4
• Orbital compartment syndrome 2
• Airway compression (rare but potentially life-threatening) 3
• Infection including periorbital necrotizing fasciitis 3
• Permanent blindness in severe cases 3

Management

• Assessment of hemodynamic status and volume resuscitation if needed 1
• Most cases resolve spontaneously without intervention 3
• Indications for surgical drainage include:
  • Severe pain unresponsive to analgesics
  • Signs of compression of vital structures
  • Evidence of infection
  • Progressive enlargement despite conservative management 2
• Conservative management typically includes:
  • Direct compression with non-elastic bandage 5
  • Correction of coagulopathy if present 1
  • Close monitoring for signs of deterioration 5

Special Considerations

• In patients without obvious risk factors (like instrumental delivery), evaluation for underlying bleeding disorders is warranted 4
• Patients on anticoagulation therapy are at higher risk for developing significant subgaleal hemorrhage even after minor trauma 3
• In neonates with severe subgaleal hemorrhage, multiorgan support may be required along with correction of anemia and coagulopathy 1

Prognosis

• Most cases in adults and older children have favorable outcomes with conservative management 5
• In neonates, early recognition and prompt treatment are essential to prevent mortality 4
• Complete resolution typically occurs within 2-3 weeks in uncomplicated cases 3