Prevalence of intracranial large artery stenosis and occlusion in patients with acute ischaemic stroke or TIA

Intracranial large artery stenosis and occlusion disease has been considered to be the cause of 8–10 % of ischaemic strokes in North America, and 30–50 % of strokes and more than 50 % of transient ischaemic attacks in Chinese population. So far we do not know the real prevalence of intracranial disease (ID) and the distribution of its risk factors in European population. We aimed to determine the prevalence and risk factors of ID in a European stroke population with computed tomography angiography (CTA). A retrospective study of consecutive ischaemic patients at the Stroke Unit of Utrecht, The Netherlands, from September 2006 to August 2008 was conducted. We assessed the presence of occlusion and/or stenosis of intracranial Internal Carotid Artery (ICA) and Middle Cerebral Artery on post-contrast 30-mm reconstruction axial CTA images. We analyzed the proportion of patients with ID, and the association of ID with risk factors and stroke subtype. In 220 patients (187 with stroke, 33 with TIA; mean age was 65 years, 57.3 % were male), intracranial stenosis was found in 6.4 % (95 % CI 3.9–10.4), intracranial occlusion in 34.5 % (95 % CI 28.6–41.0), and both occlusion and stenosis in 2.3 % (95 % CI 1.0–5.2). Multivariate analysis showed that the variables independently associated with ID were: extracranial ICA atherosclerosis (OR, 24.64; 95 % CI 6.30–96.38) and stroke subtypes TACS–PACS (OR, 7.61; 95 % CI 3.31–17.49). In conclusion, prevalence of intracranial stenosis in our study may well be consistent with previous observations in European and non-European population. ID may have been an underestimated condition in ischaemic Caucasian population.