Posterior Circulation Transient Ischaemic Attack

Approximately 20% of all strokes are preceded by transient ischaemic attacks, of which 20% of TIAs occur in the posterior circulation. A 70-year-old man with hypertension, diabetes and hypothyroidism attending the emergency department has acute dizziness and had vomited previously. CT angiogram revealed left vertebral atherosclerosis, and MRI revealed a DWI positive hyperintensity with restriction on ADC, diagnosing him with a recurrent posterior circulation TIA in the left cerebellum. Posterior circulation TIA can be difficult to diagnose as non-consensus isolated brainstem transient symptoms such as vertigo are more common. They are also less likely to present with DWI positive MRI. High risk of recurrence following TIA can be associated with ABCD2 score above 4, however 22% of recurrent strokes occur in patients with scores below 4. Both POINT and CHANCE trial compared aspirin and clopidogrel dual-therapy to aspirin monotherapy initiated within 24 hours in patients with high-risk TIA, showed greater efficacy of dual-therapy, a reduction of subsequent stroke risk by 25-32%. This patient was commenced on aspirin and clopidogrel 75mg with 300mg loading dose, Atorvastatin 80mg and antihypertensives increased, which is the maximal medical treatment.