Intracranial atherosclerotic disease: epidemiology, imaging and treatment.

Intracranial atherosclerosis accounts for 5 to 10% of all strokes. The natural history is poor, especially among patients with a greater than 70% stenosis. Studies of medical therapy have shown no benefit to warfarin over aspirin in these patients. In fact, patients with a greater than 70% stenosis who present with a stroke in the territory at risk have a 25% risk of stroke in the subsequent 24 months, despite medical therapy. First line therapy for these patients is aggressive risk factor management, including smoking cessation, blood pressure control, management of diabetes and correction ofdyslipidemia. Intracranial angioplasty has a low complication rate between 4-6%, and low post-treatment annual stroke rate between 2-4%. What was once considered a very high risk procedure has now shown to be as safe as carotid endarterectomy for symptomatic patients. Stent placement can be performed in select cases as an adjunct to primary angioplasty. While we await the results of the SAMMPRIS trial, we can still offer aggressive medical and endovascular options for patients with this lethal disease. From a management standpoint, we believe that intracranial imaging (TCD, MRA or CTA) should be performed in patients with stroke or TIA. Consultation with a neurologist would be helpful, as would consultation with a neurointerventional radiologist to help identify patients who may benefit from more aggressive endovascular therapy in conjunction with medical therapy.