Carotid and basilar artery wall shear stress in Alzheimer's disease and mild cognitive impairment.

BACKGROUND/AIMS: Vascular pathology is increasingly seen as a factor contributing to the development of Alzheimer's disease (AD). With this in mind we hypothesized that this vascular pathology could be directly detected in the arteries contributing to the cerebral circulation of mild cognitive impairment (MCI) and AD patients by means of wall shear stress (WSS) measurements.

METHODS

In this study we investigated the mean wall shear stress (MWSS), diastolic wall shear stress (DWSS) and systolic wall shear stress (SWSS) in the carotid and basilar arteries of control subjects (mean age: 72; SD: 8.8), patients suffering from MCI (mean age: 76; SD: 6.7), and patients suffering from AD (mean age: 72; SD: 8.2) that were consecutively referred to our outpatient memory clinic using in-house developed software on gradient echo phase-contrast MRI sequences.

RESULTS

We found that all these parameters were significantly lower in the carotid arteries of patients suffering from AD or MCI when compared to control subjects. In the basilar artery only DWSS was lower in MCI or AD patients compared to control subjects. In none of the arteries a difference was found for any WSS parameter between MCI and AD patients. WSS parameters were significantly associated (corrected for age and sex) with the degree of cognitive impairment.

CONCLUSION

Increased vascular pathology, as expressed by lower WSS measures, was found in patients suffering from MCI and AD compared to normal controls. This might point to the involvement of vascular pathology in the development of AD.