Vertebrobasilar insufficiency is a clinical syndrome caused by transient ischemia of the vertebrobasilar circulation, formed by the vertebral and basilar arteries, which forms the posterior circulation of the brain 1.
Vertebrobasilar insufficiency is largely caused by atherosclerosis, and shares many of the same risk factors as other atherosclerotic disease.
Risk factors include:
Up to 25% of the elderly population will present with imbalance or falls secondary to vertebrobasilar insufficiency 2.
Patients with vertebrobasilar insufficiency will present with symptoms related to ischemia of the posterior circulation. The most common symptoms include:
- visual field deficits
- unilateral weakness
Patient most commonly present with multiple symptoms, which are often short-lived and reproducible 1. A classic description of vertebrobasilar insufficiency is that of reproducible symptoms that occur with head rotation.
The vertebral arteries join to form the basilar artery which forms the posterior circulation of the brain. Vertebrobasilar insufficiency is most commonly caused by atherosclerosis and/or embolism. Other causes include arterial dissection, fibromuscular dysplasia, and coagulopathies 1.
Most commonly, atherosclerosis causes reduced blood flow and therefore perfusion of the posterior circulation. Symptoms may then be precipitated by a further reduction in perfusion, such as with orthostatic hypotension upon standing.
CT and MR angiography are most useful in defining the level and the degree of stenosis of arteries supplying the posterior circulation. The gold standard is intra-arterial angiography but this is not employed as first line as it is invasive and carries a 1-2% risk of stroke. Contrast-enhanced MR angiography (MRA) is more sensitive than CT angiography (CTA) in detection of >50% stenosis, however CTA is similar to MRA in the detection of >70% stenosis 4.
Treatment and prognosis
Treatment largely consists of risk factor reduction and stroke prevention, such as managing blood pressure, cholesterol, smoking cessation and lifestyle modifications 1.
Surgical/interventional procedures (arterial stenting) may be considered in addition to above when clinically indicated, especially patients that are symptomatic and those with >50% stenosis 5,6.
- 1. Lima Neto AC, Bittar R, Gattas GS, Bor-Seng-Shu E, Oliveira ML, Monsanto RDC, Bittar LF. Pathophysiology and Diagnosis of Vertebrobasilar Insufficiency: A Review of the Literature. (2017) International archives of otorhinolaryngology. 21 (3): 302-307. doi:10.1055/s-0036-1593448 - Pubmed
- 2. Simoceli L, Bittar R, Bottino M, Bento R. Perfil diagnóstico do idoso portador de desequilíbrio corporal: resultados preliminares. (2003) Revista Brasileira de Otorrinolaringologia. 69 (6): 772-777.
- 3. Schneider JI, Olshaker JS. Vertigo, vertebrobasilar disease, and posterior circulation ischemic stroke. (2012) Emergency medicine clinics of North America. 30 (3): 681-93. doi:10.1016/j.emc.2012.06.004 - Pubmed
- 4. Khan S, Rich P, Clifton A, Markus HS. Noninvasive detection of vertebral artery stenosis: a comparison of contrast-enhanced MR angiography, CT angiography, and ultrasound. (2009) Stroke. 40 (11): 3499-503. doi:10.1161/STROKEAHA.109.556035 - Pubmed
- 5. Markus HS, Larsson SC, Kuker W, Schulz UG, Ford I, Rothwell PM, Clifton A. Stenting for symptomatic vertebral artery stenosis: The Vertebral Artery Ischaemia Stenting Trial. (2017) Neurology. 89 (12): 1229-1236. doi:10.1212/WNL.0000000000004385 - Pubmed
- 6. Stayman AN, Nogueira RG, Gupta R. A systematic review of stenting and angioplasty of symptomatic extracranial vertebral artery stenosis. (2011) Stroke. 42 (8): 2212-6. doi:10.1161/STROKEAHA.110.611459 - Pubmed