What is the management and treatment of subdural hygroma?

Management and Treatment of Subdural Hygroma

Treatment of subdural hygroma should be guided by the underlying etiology and symptom severity: small or asymptomatic hygromas require only conservative management while treating any underlying CSF leak, whereas symptomatic hygromas with significant mass effect require burr hole drainage in conjunction with addressing the CSF leak. 1

Initial Diagnostic Evaluation

• MRI of the brain with intravenous contrast and whole spine MRI should be performed as first-line investigations to identify subdural hygroma and investigate for spontaneous intracranial hypotension (SIH) as the underlying cause. 2, 1
• Brain MRI protocol must include T2-weighted sequences, FLAIR, T2*-weighted gradient echo or susceptibility-weighted imaging, and pre/post-contrast 3D volumetric T1-weighted acquisitions to detect pachymeningeal enhancement and venous engorgement. 2
• Spine MRI should include fat-suppressed T2-weighted sequences (STIR), high-resolution heavily T2-weighted 3D sequences (CISS, FIESTA, or equivalent), and axial imaging of select spinal segments to identify CSF leaks. 2

Treatment Algorithm Based on Etiology and Clinical Presentation

For SIH-Associated Subdural Hygromas

• Epidural blood patch (EBP) should be prioritized as the initial treatment for subdural hygromas associated with spontaneous intracranial hypotension. 1
• Patients with SIH and subdural collections require referral to a specialist neuroscience center for multidisciplinary team discussion, particularly if first-line treatments fail or there is rapid clinical deterioration. 2, 1
• The specialist center must have neuroradiological expertise (CT myelography, digital subtraction myelography), practitioners skilled in epidural blood patching, expertise in targeted patching, and surgical capability to repair spinal CSF leaks. 2

For Small or Asymptomatic Hygromas

• Conservative management is appropriate while treating the underlying CSF leak, as most subdural hygromas resolve when the brain is well expanded and do not show significant mass effect. 1, 3
• Patients should maintain bed rest in supine position as much as possible to facilitate brain re-expansion. 1
• The majority of post-traumatic subdural hygromas are clinically silent and resolve spontaneously without surgical intervention. 3, 4

For Symptomatic Hygromas with Mass Effect

• Burr hole drainage should be performed for symptomatic hygromas causing significant mass effect, in conjunction with treating any underlying CSF leak. 1, 4
• Simple burr hole irrigation is preferred over large craniotomy, as it effectively reduces mass effect with less invasive intervention. 5, 4
• Surgery is rarely required since most subdural hygromas do not produce mass effect, and outcome is closely related to the primary head injury rather than the hygroma itself. 3

Referral Timing and Urgency

• Patients able to care for themselves should be referred within 2-4 weeks depending on symptom severity and mental health impact. 2
• Patients unable to care for themselves but with available help require referral within 48 hours. 2
• Emergency admission is indicated for patients unable to care for themselves without help, or those with subdural hematoma with mass effect requiring urgent tertiary neuroscience center referral. 2

Post-Treatment Management

• After EBP for SIH-related subdural hygromas, maintain supine position with head elevated as comfortable, and advise lying flat as much as possible for 1-3 days. 1
• Minimize bending, straining, stretching, and other activities for 4-6 weeks post-procedure. 1
• Consider thromboprophylaxis during immobilization periods. 1
• Clinical review prior to discharge and follow-up the next day are recommended. 1

Critical Pitfalls to Avoid

• Do not delay neuroimaging when subdural hygroma is suspected, as this can miss underlying pathology requiring urgent intervention. 6
• Avoid overlooking the need to identify and treat underlying CSF leaks, as persistent leaks can lead to complications including superficial siderosis. 1
• Do not assume all hygromas require surgical intervention—the majority resolve with conservative management and treatment of the primary cause. 3, 4
• Be vigilant for cerebral venous thrombosis in cases associated with SIH, as this represents a serious complication. 1
• Recognize that traumatic subdural hygromas can occasionally mimic acute subdural hematomas on imaging, requiring careful radiological examination to prevent unnecessary extensive surgical procedures. 5