Medulla Compression by Bilateral Aberrant Vertebral Artery With Mild Chiari Malformation

A 48-year-old woman developed progressive right lower extremity numbness and lancinating pain of pharynx. T2-weighted MRI revealed a flow-void area that corresponded to the both aberrant vertebral arteries (persistent first intersegmental arteries) severely compressing distorting medulla oblongata tonsilar herniation consistent with mild Chiari malformation. Mild hydrocephalus was also noted thinning corpus callosum partial empty sella (figure).