Backgrounds: Intracranial arterial calcification detected by computer tomography (CT) is found to be associated with ischemic stroke as an indicator of intracranial atherosclerosis. However, little is known about the histology of intracranial arterial calcification.
Methods: Based on a biobank collecting cerebral arteries from 32 adult autopsy cases, we described the distribution and patterns of arterial calcification in middle cerebral artery (MCA), vertebral artery (VA) and basilar artery (BA).
Results: Among the total 96 segments evaluated, 43 (45%) showed visible calcification, including 27 intimal calcification, 8 internal elastic lamina (IEL) calcification, 2 medial calcification, and 6 adventitial calcification. (Figure 1) Intimal calcification occurred more often in the VA compared with BA (41% vs. 16%, P=0.039). IEL calcification was more commonly detected in VA (22%). (Table 1) Among the 27 intimal calcification, 12 showed a stippling calcification pattern, 9 displayed a morula pattern and 6 had large calcium deposits. (Figure 2) Of the 96 arteries, 30 (31%) had Pre-atherosclerotic intimal lesions whereas 66 (69%) segments showed progressive atherosclerotic lesions. All of the 27 (100%) intimal calcification was present in the progressive atherosclerotic lesions (p<0.001), while only 3/8 IEL calcification, 1/2 medial calcification, and 4/6 adventitial calcification were associated with progressive plaques (all p>0.05). (Table 2)
Conclusions: Intracranial calcification predominantly occur in the intima, but also spread over IEL, media and adventitia, the latter may not being a proxy for the progressive atherosclerotic plaques.