Pseudomeningocele

What it is

A pseudomeningocele is a collection of cerebrospinal fluid that accumulates under the skin near the surgical site after surgery, forming a fluid-filled swelling. It is a complication that can follow Chiari decompression with duraplasty, related to CSF escaping the dural closure.

Understanding Pseudomeningocele

When CSF leaks from the dural closure but is contained under the skin (rather than draining out), it can collect and form a pseudomeningocele — felt as a soft swelling at the back of the head or neck. Pseudomeningocele is related to CSF leak and is more associated with duraplasty than bony-only decompression. Many small pseudomeningoceles resolve on their own or with conservative measures over time. Larger or persistent ones, or those associated with other problems (such as an ongoing leak or symptoms), may require treatment — ranging from measures to reduce CSF pressure to a procedure to repair the leak. The likelihood is reduced by good surgical technique (watertight closure, arachnoid-sparing). Understanding pseudomeningocele clarifies a fluid-collection complication of decompression and how it is managed.

Why it matters

Understanding pseudomeningocele helps families recognize a fluid collection that can follow decompression with duraplasty — often resolving on its own, but sometimes needing treatment if large or persistent.