Abstract
Background Chiari malformations, usually congenital, can rarely be associated with arteriovenous
(AV) fistulas. We present the first case involving a type IV dural AV fistula with
a Chiari type I malformation.
Methods Retrospective chart review was performed to obtain pertinent details regarding history
and examination, pathologic findings, and treatment course.
Results A 63-year-old woman with a 2-year history of migraines presented with 5 months of
occipital, right-sided headaches and neck pain exacerbated by Valsalva maneuvers.
Computed tomography (CT) and magnetic resonance imaging (MRI) of the head showed a
possible right occipital AV malformation, bilateral cerebellar subdural hygromas,
and tonsillar crowding at the foramen magnum indicating an acquired Chiari type I
malformation. Angiography demonstrated a Cognardtype IV right posterior occipital
dural AV fistula supplied by bilateral middle meningeal and posterior meningeal arteries.
Conclusion After treatment of the dural AV fistula, hygroma evacuation, and decompression of
the acquired Chiari malformation, the patient's Valsalva-induced headaches abated.
Keywords
Chiari I malformation - acquiredchiari malformation - dural AV fistula - dural arteriovenous
- case report
