Chiari I Malformation

This patient presented with headaches on coughing or sneezing. The sagittal T2-weighted image above shows a typical Chiari type I malformation, with peg-like tonsils descending well below the foramen magnum. In this case there is no cervical cord syrinx, a common association.

This video shows a time-resolved phase-contrast CSF flow study. It is short, and best appreciated by setting ‘repeat’ on your viewer. Movement is shown as either white or black, depending on direction. Stationary structures are grey. The normal pulsatile movement of CSF around the cord is shown. CSF movement in the prepontine cistern is somewhat attenuated. Flow in the 4th ventricle and aqueduct is markedly attenuated. Of note, the cerebellar tonsils are seen to dephase (move) during the cardiac cycle.

Credit: Dr Laughlin Dawes