Hypercholesterolemia was defined as total cholesterol >5.0 mmol/l, LDL cholesterol >3.0 mmol/l, or cholesterol lowering treatment. Diabetes was defined as history or treatment for diabetes, fasting glucose >6.9 mmol/l, or any glucose >10.9 mmol/l. Peripheral artery disease was defined as history of claudication, or ankle-brachial index <0.9. Our study was approved by the local ethics committee (protocol number 20060188). We identified 203 patients fulfilling the diagnostic Navitoclax chemical structure criteria for TIA.
The characteristics of the patients are shown in Table 1. In 195 patients we conducted TCCS of the pre- or intracranial vessels. In 39 patients the transcranial part of the examination was partly inconclusive due to insufficient bone window. Ultrasound contrast agents were not used in this study. Any stenoses or occlusion and symptomatic stenoses or occlusion was found in 27.2% and 22.6%, respectively. We found extracranial carotid
artery stenoses in 14.4% and 10.4%, carotid occlusion in 4.1% and 3.1%, extracranial vertebral artery stenoses in 5.6% and 2.1% (including one dissection), and intracranial artery stenoses in 12.3% and 8.2%, respectively (Table 2). In our population-based TIA study, the prevalence of symptomatic ICAS diagnosed according to TCCS criteria was only slightly lower than the prevalence of symptomatic carotid stenosis. Furthermore, the estimated prevalence of ICAS may even be conservative due to
the PARP activity incomplete intracranial vascular assessment in 20% of the patients. To the best of our knowledge, no other population-based data on the prevalence of ICAS are available. In the French SOS-TIA study, 1.823 unselected consecutive patients admitted at an acute TIA-clinic were examined with transcranial Doppler, and a prevalence of 8.8% for any ICAS or intracranial occlusion was Phosphatidylinositol diacylglycerol-lyase found. Restricting the analysis in that study to patients defined as with definite TIA or minor stroke, the prevalence of ICAS increased to 11.5%, and about half of them were symptomatic [7]. In Denmark only a minority of patients with acute TIA or stroke is currently evaluated for ICAS. This may be explained by the assumption that intracranial atherosclerotic disease in Caucasians is rare, and by the lack of evidence for a specific treatment. Recently published data provides some evidence for the efficacy of dual platelet inhibition [8], and preliminary data on rapid and aggressive treatment seem to show a reduction of the risk of stroke in patients with TIA and intracranial stenoses [9]. Moreover, intra-arterial stenting may be an option in unstable ICAS not responding to medical treatment, even if this cannot be recommended as standard procedure [10]. The prevalence of ICAS in TIA-patients was substantial in a population-based cohort of Caucasians.