# Resolution of tension pseudomeningocele complicating foramen magnum decompression for Chiari I malformation after ventriculoperitoneal shunt: A case report

## TL;DR

A 15-year-old girl with a rare complication after surgery for a brain condition was successfully treated with a shunt to resolve cerebrospinal fluid leakage.

## Contribution

This case report presents a successful treatment of tension pseudomeningocele using a ventriculoperitoneal shunt after foramen magnum decompression.

## Key findings

- Tension pseudomeningocele can develop after foramen magnum decompression in Chiari I malformation patients.
- A ventriculoperitoneal shunt effectively resolved the pseudomeningocele and cerebrospinal fluid leakage.
- Cerebrospinal fluid diversion techniques can address pressure imbalances causing the condition.

## Abstract

Tension pseudomeningocele is a rare complication that arose after foramen magnum decompression in a patient with Chiari I malformation and syringomyelia. This article presents a case that was effectively managed through cerebrospinal fluid diversion methods, highlighting the mechanisms involved and the treatment option used.

A 15-year-old girl came to our clinic with allodynia in the right anterior chest wall that had lasted for six months. An MRI showed a type 1 Chiari malformation along with syringomyelia from C2 to C6. After performing foramen magnum decompression and duraplasty, there was an improvement in the syringomyelia; however, the patient developed a tension pseudomeningocele in the posterior fossa. She then had a ventriculoperitoneal shunt placed, which successfully resolved the tension pseudomeningocele and the cerebrospinal fluid leakage.

Pseudomeningocele is a significant postoperative complication that can occur following foramen magnum decompression, potentially worsening neurological outcomes through mechanisms such as cord edema and the progression of syringomyelia. This condition may arise from a sustained craniospinal pressure gradient at the foramen magnum, which promotes the accumulation of cerebrospinal fluid within the pseudomeningocele cavity. As a result, cerebrospinal fluid diversion techniques, such as pseudomeningocele-peritoneal shunts or ventriculoperitoneal shunts, may be employed to reduce pressure within the cavity and restore balance to the craniospinal pressure gradient, thereby enhancing the patient's clinical status.

The implementation of cerebrospinal fluid diversion procedures may be pivotal in addressing tension pseudomeningocele in patients with Chiari I malformation.

•Tension pseudomeningocele represents a potential complication following foramen magnum decompression with duraplasty in patients with Chiari I malformation.•The underlying mechanism may be associated with a sustained craniospinal pressure gradient between the obex and the surrounding cavity.•Resolution of the pseudomeningocele can be achieved through shunting surgery, as this procedure effectively addresses the pressure gradient.

Tension pseudomeningocele represents a potential complication following foramen magnum decompression with duraplasty in patients with Chiari I malformation.

The underlying mechanism may be associated with a sustained craniospinal pressure gradient between the obex and the surrounding cavity.

Resolution of the pseudomeningocele can be achieved through shunting surgery, as this procedure effectively addresses the pressure gradient.