High prevalence of intracranial artery calcification in stroke patients with CKD: a retrospective study

Abstract

Background and objectives: Intracranial artery calcification (IAC) is frequently observed on brain computed tomography (CT) scans in stroke patients. This retrospective study was designed to determine the prevalence, risk factors, and clinical relevance of IAC in a cohort of patients with ischemic stroke.

Design, setting, participants, & measurements: We included all eligible patients admitted to Amiens University Hospital for acute ischemic stroke between January and December 2006 and assessed using 64-slice multidetector-row CT (n = 340). Patients were classified according to the presence or absence of IAC in the internal carotid arteries, middle cerebral arteries, vertebral arteries, and basilar artery. GFR was estimated using the MDRD equation. Chronic kidney disease (CKD) was defined as a GFR < 60 ml/min/1.73 m(2). We also studied a control group of patients admitted for neurologic diseases other than stroke.

Results: Two hundred fifty-nine stroke patients (76.2%) displayed IAC, which was independently associated with carotid atherosclerosis > 50%, age, and GFR. One hundred three nonstroke patients (60.2%) had IAC, with age, arterial hypertension, and GFR as independently associated factors. For all patients taken together, age, arterial hypertension, stroke, and GFR were independently associated with IAC.

Conclusion: These results confirm the high prevalence of IAC in patients with and without ischemic stroke and show for the first time that IAC is associated with the presence of CKD in these patients. The frequency of IAC was significantly higher in stroke patients than in nonstroke patients. The association between IAC and stroke outcome requires further investigation.

Figure 1.

Bone window computed tomography (CT) images illustrating the intracranial artery calcification score used. (A) CT scan showing thick, confluent calcification in both carotid siphons (score = 1 for each carotid artery. (B) CT scan showing thick, contiguous calcification in the right carotid artery (score = 1) and tiny, scattered calcification foci seen on only one slice in the left carotid artery (score = 0). (C) CT scan showing tiny, scattered calcification foci seen on at least two adjacent slices in the right middle cerebral artery (score 1) and tiny, scattered calcification foci seen on only one slice in the left middle cerebral artery (score = 0). (D) CT scan showing thick, contiguous calcification foci on both vertebral arteries (score 1 for each vertebral artery). (E) CT scan showing thick, interrupted calcification in the right vertebral artery (score = 1) and tiny, scattered calcification foci seen on only one slice in the left vertebral artery (score = 0). (F) CT scan showing thick, interrupted calcification in the basilar artery (score = 1). Arrows show calcification.

Figure 2.

Intracranial artery calcification (IAC) score, according to the CKD subgroups (estimated using the four-component Modification of Diet in Renal Disease (MDRD) equation) in stroke patients. Results are means ± SD; *P < 0.05 versus I, †P < 0.05 versus II. Stages are I: GFR: ≥90 ml/min; II: GFR between 60 and 89 ml/min; III: GFR between 30 and 59 ml/min; IV: GFR between 15 and 29 ml/min; V: GFR <15 ml/min)