A tear in the vertebral artery, is a common cause of stroke in young people. The tear has a clot and causes a false blockage - causing an ischaemic stroke. It can happen spontaneously or after minor trauma to the neck, including yoga and chiropractice.
A recent respiratory tract infection may also predispose - making vertebral artery dissection seasonal.
There are two types:
Infarction - ischaemia of the vertebrobasillar circulation due to arterial narrowing and thromboembolism
Haemorrhagic type - presents as a SAH
They may not present with problems, because of the contralateral vessel. Acutely ruptured dissections have a high mortality, and may rebleed (mostly in the month immediately after).
Severe neck pain, followed later by neurological symptoms
May get a spinal cord infarction
Maybe with a headache and horners syndrome
Normally treated with anticoagulants