Subdural effusion
Definition
A subdural effusion is a collection of fluid trapped between the surface of the brain and the outer lining of the brain (the dura matter). If this fluid becomes infected, the condition is called a subdural empyema.
Causes
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 in babies
- Increased head circumference
- Lethargy
- Persistent fever
- Seizures
- Separated sutures in babies
- Vomiting
- Weakness or loss of movement on both sides of the body
Exams and Tests
The doctor or nurse will examine you. Tests include:
- CT scan of the head
- Head size (circumference) measurements
- 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.
Outlook (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.
Possible Complications
Complications from surgery include:
- Bleeding
- Brain damage
- Infection
When to Contact a Medical Professional
Call your health care provider if:
- Your child has recently been treated for meningitis and symptoms continue
- New symptoms develop
References
Koshy A, Roos K. Infections of the nervous system: bacterial and fungal. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 53C.
Swartz MN, Nath A. Meningitis: bacterial, viral, and other. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 420.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Luc Jasmin, MD, PhD, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles, and Department of Anatomy at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

