Intradural spinal vein enlargement in craniospinal hypotension

Abstract

We present a case of craniospinal hypotension in a 45-year-old woman with an associated epidural pseudomeningocele extending the entire length of the spine. The epidural pseudomeningocele was caused by a CSF leak at the T8 level. In addition to typical low-pressure symptoms, the epidural pseudomeningocele caused atypical symptoms characterized by positional thoracic radiculopathy. Craniospinal hypotension was associated with massive cervical epidural venous engorgement, as well as enlargement of the posterior spinal cord vein, which was reminiscent of a dural arteriovenous fistula at CT myelography. Enlargement of the posterior spinal vein is explained by the Monro-Kellie hypothesis, and the spinal analog to enlarged cerebral veins known to be associated with intracranial hypotension.

Fig 1.

Cervicothoracic epidural pseudomeningocele with dilated cervical epidural venous plexus and spinal dural enhancement. A, Contrast-enhanced axial CT scan demonstrates dilated cervical epidural venous plexus (black arrows), an epidural fluid collection (black arrowheads), and spinal dural enhancement (long arrows). B, Sagittal reformatted CT images of the cervical spine demonstrates further the epidural fluid collection (black arrowheads) and dural enhancement. C, Sagittal T2-weighted MR image of the cervical spine shows the epidural fluid collection (thin white arrows) and a cervicothoracic posterior dural margin (thick white arrows).

Fig 2.

Large epidural pseudomeningocele and dilated posterior thoracic spinal vein. Axial CT myelogram of the cervical and thoracic spine shows dura marginating the epidural pseudomeningocele (highlighted black arrows). Coronal and sagittal reformatted CT myelogram images of the thoracic spine demonstrate a tortuous, dilated posterior thoracic spinal vein (black arrows) and dura (arrowheads) separating intradural and epidural CSF.

Fig 3.

Large epidural pseudomeningocele. Axial CT myelogram of the midthoracic spine demonstrates an epidural pseudomeningocele extending into the neural foramina, outlining thoracic nerve roots (e.g., black arrows). Note faint opacification of the compressed subarachnoid space (black arrowhead) surrounding the cord (dotted outline), best seen at bottom right image.

Fig 4.

Illustration of intradural-extradural venous anastomosis. Daniels after Netter.