Subdural effusion

Definition

A subdural effusion is a collection of fluid beneath the outer lining of the brain. If this fluid becomes infected, the condition is called a subdural empyema.

Alternative Names

Causes, incidence, and risk factors

A subdural effusion is a rare complication of bacterial meningitis. Subdural effusion is more common in infants and in persons who have meningitis caused by Haemophilus influenzae.

Symptoms

• Bulging fontanelles
• Increased head circumference
• Lethargy
• Persistent fever
• Seizures
• Separated sutures
• Vomiting
• Weakness

Signs and tests

There is often a recent history of bacterial meningitis. Tests include:

• CT scan of the head
• MRI scan of the head
• Ultrasound of the head

Treatment

Surgery to drain the effusion is often necessary. Rarely, a permanent drainage device (shunt) is needed to drain fluid. Antibiotics may need to be given through a vein.

Support Groups

Expectations (prognosis)

Full recovery from a subdural effusion is expected. If neurological problems continue, they are generally due to the meningitis, not the effusion. Long-term use of antibiotics is usually not necessary.

Complications

Complications from surgery include:

• Bleeding
• Brain damage
• Infection

Calling your health care provider

Call your health care provider if:

• Your child has recently been treated for meningitis and symptoms continue
• New symptoms develop

Prevention

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References

Swartz MN. Meningitis: bacterial, viral, and other. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 437.