"The proximal arteries, arising from the internal carotid and vertebral arteries have differing distribution of elastic fibres compared to similar sized vessels elsewhere (this has been disputed by FT Merei; 1980). 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."
"The proximal arteries, arising from the internal carotid and vertebral arteries have differing distribution of elastic fibres compared to similar sized vessels elsewhere (this has been disputed by FT Merei; 1980). 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."
Expected headings
"Proximal larger arteries"
"Distal smaller arteries and arterioles"
"The proximal arteries, arising from the internal carotid and vertebral arteries have differing distribution of elastic fibres compared to similar sized vessels elsewhere (this has been disputed by FT Merei; 1980). 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."