title: Acute external hydrocephalus complicating craniocervical decompression for syringomyelia-Chiari I complex: case report and review of the literature.
abstract: The occurrence of subdural cerebrospinal fluid collections and ventricular dilatation (external hydrocephalus) after foramen magnum decompression is extremely rare. The authors report on a 37-year-old man who developed symptomatic subdural fluid collections (SFC) after uncomplicated foramen magnum decompression for Chiari I-syringomyelia complex. Postoperative magnetic resonance imaging revealed a supratentorial SFC with prominent midline shift. In addition, bilateral infratentorial SFCs extending supratentorially through the tentorial notch, pseudomeningocele and initial shrinkage of the syrinx were observed. Few days after evacuation of supratentorial collection, the patient experienced increasing headache and a computerized tomography scan demonstrated a contralateral subdural collection as well as ventricular dilatation. A programmable ventriculoperitoneal shunt was placed with resolution of supratentorial collection and progressive improvement of infratentorial collections and pseudomeningocele. Although previous reports described the occurrence of extra-axial fluid collections and hydrocephalus after foramen magnum decompression for Chiari malformation, to our knowledge, this is the only report of acute external hydrocephalus after foramen magnum decompression requiring urgent evacuation of SFC in order to reduce the mass effect.
authors.affiliation: Department of Neurosurgery, Hope Hospital, Salford, Manchester, UK. perrinipaolo@hotmail.com
authors.forename: Paolo
authors.initials: P
authors.lastname: Perrini
authors.forename: Alexander
authors.initials: A
authors.lastname: Rawlinson
authors.forename: Richard Alfred
authors.initials: RA
authors.lastname: Cowie
authors.forename: Andrew Thomas
authors.initials: AT
authors.lastname: King
mesh_terms: D000328:Adult; D001139:Arnold-Chiari Malformation / Q000150:complications / Q000601:surgery*; D003388:Cranial Fossa, Posterior / Q000601:surgery; D019299:Decompression, Surgical / Q000009:adverse effects*; D006801:Humans; D006849:Hydrocephalus / Q000150:complications* / Q000209:etiology; D007714:Klippel-Feil Syndrome / Q000150:complications / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011183:Postoperative Complications / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed