Neurosurgery. 2012 May;70(5):1312-8; discussion 1318-9.
Anatomy and pathology of the cranial emissary veins: a review with surgical implications.
Mortazavi MM, Tubbs RS, Riech S, Verma K, Shoja MM, Zurada A, Benninger B, Loukas M, Cohen Gadol AA.
Section of Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama, USA.
Emissary veins connect the extracranial venous system with the intracranial venous sinuses. These include, but are not limited to, the posterior condyloid, mastoid, occipital, and parietal emissary veins. A review of the literature for the anatomy, embryology, pathology, and surgery of the intracranial emissary veins was performed. Detailed descriptions of these venous structures are lacking in the literature, and, to the authors', knowledge, this is the first detailed review to discuss the anatomy, pathology, anomalies, and clinical effects of the cranial emissary veins. Our hope is that such data will be useful to the neurosurgeon during surgery in the vicinity of the emissary veins.
This was just published last month. Dr. Sclafani mentioned awhile back that he's seen people with MS with either very small or very large emissary veins, both of which are abnormal. Your IR can only see these if he enters the venous sinuses to confirm that the jugular connects to the sinuses and to look for blockages there, which most IRs do not do. Dr. Schelling considers emissary veins of importance in MS. It's possible that the back of the brain headache (which I suffered today, and which goes away when I lie down) that some pwCCSVI have is due to dilatation of the emissary veins. The abstract mentions embrology of the emissary veins, and that is of interest, because in pwMS our abnormal emissary veins could only have developed while we were fetuses because the skull develops around the emissary veins leaving channels through the skull for these veins, thus meaning that abnormal emissary veins may be confirmation that our CCSVI and abnormal jugulars were present before birth. Anatomy, pathology, anomalies and clinical effects of the emissary veins are all of interest.
Here's a diagram of an emissary vein, if it helps to see how it travels through the skull from the venous sinuses of the brain: http://edutoolanatomy.wikispaces.com/fi ... 5B7%5D.jpg