Front.aging neurosci : Cortical atrophy in patients with asymptomatic carotid artery stenosis associated with memory impairment

Carotid artery stenosis (CAS) is a vascular degenerative disease that can cause damage to the nervous system such as cerebral ischemia, which seriously threatens the life and health
of patients.

Therefore, it is proposed that the thinning of the cerebral cortex in CAS patients may lead to memory decline, but its internal mechanism is not clear
.

Research results

Basic information about the subjects included age, gender, details of brain stenosis, and educational background
.

In addition, CAS patients had lower scores for memory, association learning, free image recall and feature recall than healthy control groups
.

Table 1 Brain volume in different parts of CAS patients and healthy control groups

As shown in Figures 1 and Table 2, the patient's gray matter loss is not limited to the narrow-sided hemisphere, but is also manifested
in the contralateral hemisphere.

Table 2 Comparison of details in the gray matter area

Figure 1 3D and slice view of asymptomatic CAS patients with a healthy control group

Atrophy is widely distributed in the frontal, temporal, and parietal lobes, as well as in smaller areas of the occipital lobes of the ipsilateral and contralateral hemispheres
.

Figure 2 Narrow areas of the hemisphere and contralateral hemisphere

The results are discussed

1) Atrophy of the cortical region

The study confirmed cortical atrophy and increased
CSF volume in patients with CAS by analyzing volumes relative to GM and CSF as well as VBM.

The authors found that the average reduction rate of brain GM in patients with asymptomatic severe CAS was 3.

Carotid artery occlusion has been shown to lead to cortical atrophy in mouse models and has found a correlation between cortical
atrophy and cerebral hypoperfusion.

The authors also found that atrophy on the narrow side of the cerebral hemisphere was more severe
than atrophy in the contralateral cerebral hemisphere.

The authors used the DARTEL algorithm to ensure region specificity and accurate spatial response through spatial normalization of images in symmetric TPMs, and with some modifications, to maximize the accuracy
of the study.

2) Cognitive impairment

In this study, the authors found that CAS patients had memory impairment, and the scores of directional memory, association ability, free image recall, and portrait feature reperfusion were significantly lower than those of the healthy control group, suggesting that there were differences in memory function, but the degree of cognitive impairment in asymptomatic patients was relatively mild
.

In addition, lower scores on direct memory and association learning tests indicate impaired
semantic memory function.

3) Relationship between memory influence and regional GM capacity and general memory function

The authors found that the GM volume of the left frontal triangular, left frontal cover, and left mid-frontal glyph was significantly positively correlated
with the total CMS score.

Conclusion

Patients with CAS showed greater memory impairment
compared to healthy control groups.

The study had some limitations, with the sample size analyzed by the authors being the largest compared to previous reports, but the absolute number of patients remained small
.

Finally, the structural analysis of 7T-MRI images is still controversial at this stage, and although the best correction and processing procedures are used, there may still be deficiencies that require further study to suffice up to this conclusion
.
In summary, in this study, the authors not only identified specific cortical regions that form extensively atrophied regions, but also demonstrated their relationship to memory function, and these findings provide theoretical support and implications
for clinical practice and further research.