see also:

• vertebral artery dissection
• non-traumatic upper neck pain

• these are rare aneurysms which usually develop intracranially at the junction of the vertebral artery and posterior inferior cerebellar artery (PICA) which account for 0.5-3% of intracranial aneurysms
• they may also occur extracranially although these are very rare and most commonly follow penetrating trauma
  • the vertebral artery enters the cervical spine via the transverse foramina at C6, once it is passing up through the spine it is reasonably well protected
  • aneurysms may also form at the origin of the artery as it branches off the subclavian artery ¹⁾

• penetrating trauma, especially gun shot wounds
• blunt trauma
• previous vertebral artery dissection
• atherosclerosis and primary prevention - hypertension, diabetes mellitus, etc
• rheumatoid arthritis
• syphilis

• if the aneurysm is in the cervical part, it may cause:
  • chronic non-traumatic upper neck pain
  • pulsatile mass
  • bruit and thrills which are aggravated when the carotid artery is compressed
• if the aneurysm is intrathoracic and large it may present as:
  • mediastinal mass
  • cough
  • shortness of breath
  • eg. see https://radiopaedia.org/cases/left-vertebral-artery-aneurysm

• headache
• decreased conscious state
• may also have:
  • vertigo, vomiting, nausea
  • Wallenberg syndrome (lateral medullary syndrome)
  • subarachnoid haemorrhage (SAH)

• MR angiography is the gold standard
• if not available, CT angio

• high rates of rebleeding, morbidity, and mortality, poor treatment outcomes, as well as low rate of surgical treatment
• prognosis is generally poor because the rupture rate is extremely high especially with large or giant aneurysms
• although the natural history of unruptured VA dissection is still unknown, endovascular treatment should be considered for patients with a relatively large or growing aneurysmal dilatation because prognosis of the patients with subsequent SAH is poor.²⁾