"In intracranial dissection, there is a high risk of subarachnoid haemorrhage (up to 50% for vertebrobasilar dissections 3) on account of the anatomy of intracranial arteries. Although the tunica media and tunica adventitia are present, they are only a third as thick as their extracranial counterparts, with the vast majority of elastic fibres located in a subendothelial elastic lamina. This fundamental difference accounts for the markedly different natural history of intracranial arterial dissections compared to their extracranial counterparts. When a tear breaches the aforementioned subendothelial elastic layer, then there is little tissue preventing extension into the subarachnoid space, thus accounting for the very high rate of subarachnoid haemorrhage."
"Marfan's disease"
"Dissections are mostly located in the pars transversaria segment (V2) ~35% or in the atlas loop segment (V3) ~34% 2,3,11. It is important to note that, in addition to the identification of the dissections, the next most important feature is to assess whether or not the dissection involves the intradural portion of the vertebral artery (V4), and thus the origin of the PICA 3."
"extracranial dissection (with or without intracranial extension)"
Expected headings
"Complications"
"Patients present with a variety of signs and symptoms, most frequently with neck pain and headache (typically occipital) as well as posterior fossa ischaemic events (e.g. transient ischaemic attack or stroke) manifesting as nausea, ataxia, dysarthria, lateral medullary syndrome, or even collapse and coma 11,13. Intradural extension is quite common, with a high frequency of subarachnoid haemorrhage (SAH) 13. Other presentations include spinal cord infarction and even cervical nerve root impairment 1."
"Conventional angiography is traditionally considered the gold standard. It may demonstrate focal dilatation, proximal or distal stenosis, or fusiform aneurysmal dilatation 9."