Posterior Circulation TIA

The symptoms of TIA in the posterior circulation (vertebrobasilar system, PCA, cerebellum) include:

• Bilateral motor and/or sensory deficits

• Cortical blindness

• Diplopia

• Vertigo (although not usually in isolation)

Why posterior circulation TIAs may be difficult to diagnose

Posterior circulation TIAs may be difficult to diagnose because of the similarity of symptoms with more benign conditions, such as labyrinthitis or benign paroxysmal positional vertigo.

Suspicion, assessment of risk factors and referral for imaging (MRI) through your local TIA workup system may be the only way of making the diagnosis.

Clinical information to guide treatment has been less available because of difficulties imaging the posterior circulation.

Symptoms of posterior circulation TIAs

Posterior circulation TIAs can have a variety of symptoms because the posterior circulation supplies:

• Brain stem

• Midbrain

• Cerebellum

• Thalamus

• Parietal and occipital cortex.

Symptoms should represent focal neurology and be understandable by considering the possible vascular territory.

TIA origin in the posterior circulation may occur as a result of large vessel or small vessel ischaemia.

Large vessel vertebrobasilar TIAs may be due to large vessel atheroma or dissection, or emboli from the heart or aortic arch.

Important symptoms are:

• Vertigo

• Diplopia

• Nausea and vomiting

Risk of stroke

As with anterior circulation TIAs, patients with posterior circulation TIAs have a significant risk of suffering a stroke in that territory, which may be devastating. The clinical approach to posterior circulation TIAs should be the same as that for anterior TIAs.

There may be some future in vertebrobasilar stenting procedures.