Case contributed by Ammar Haouimi
Diagnosis almost certain


Had decompressive craniotomy for Chiari 1 malformation one year ago. Follow-up MRI was requested.

Patient Data

Age: 60 years
Gender: Female
  • extradural fluid collection of CSF signal overlying the occipital craniotomy defect, communicating with the adjacent CSF spaces and extending to the posterior subcutaneous tissues of the neck in keeping with pseudomeningocele
  • associated cervical cord syrinx seen as an intramedullary cystic lesion of low signal on T1, high signal on T2 and STIR, extending from the bulbomedullary junction to the distal spinal cord
  • normal CSF flow surrounding the cervicomedullary junction on CSF flow studies

Case Discussion

MRI features of occipital pseudomeningocele following a decompressive craniotomy for Chiari 1 malformation with syrinx.

Pseudomeningoceles are defined as abnormal collections of cerebrospinal fluid (CSF) due to leakage from the CSF-filled spaces surrounding the brain and/or spinal cord as a result of trauma or surgery.

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