Magnetic Resonance Imaging in Cerebral Small Vessel Disease and its Use as a Surrogate Disease Marker

Abstract

Cerebral small vessel disease is an important cause of vascular cognitive impairment and dementia. On brain imaging, discrete lacunar infarcts and/or more diffuse regions of white matter hyperintensities or leucoaraiosis are seen. Magnetic resonance imaging plays a crucial role in diagnosis, and advanced magnetic resonance imaging techniques are providing new information on disease mechanisms and offering potential as surrogate disease markers. Longitudinal studies have demonstrated detectable progression of lesion load over short time periods, and weak correlations with cognition. Stronger correlations with cognition have been found with diffusion tensor imaging, which is more sensitive to white matter tract structure, supporting a role for disconnection in the pathogenesis of cognitive impairment. Brain volume also consistently correlates with cognition in asymptomatic small vessel disease, sporadic small vessel disease, and Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy. Gradient echo magnetic resonance imaging identifies microbleeds in a significant proportion of patients with small vessel disease, although their role in clinical management remains to be determined. Surrogate markers to monitor disease progression and evaluate new therapies would have major clinical use. The greater sensitivity of diffusion tensor imaging parameters and brain volume to change, and the stronger correlation of these parameters with cognition, suggest that they may be more powerful surrogates. However, data from longitudinal and intervention studies are required to determine if this is indeed the case. In this systematic review, we describe the use of both conventional and advanced magnetic resonance imaging techniques in patient groups with the full spectrum of clinical small vessel disease, from normal populations with WMH to patients groups with lacunar stroke and dementia.

Silent brain infarct is independently associated with arterial stiffness indicated by cardio-ankle vascular index (CAVI)

“…2,10-12 Indeed, SBI is related to arteriolosclerosis such as lipohyalinosis and microatheroma, while WMHs are associated with the extravasation of toxic plasma constituents into the cerebral parenchyma due to endothelial dysfunction. [8][9][10][11][12] Finally, CAVI is independent of blood pressure because of the adjustment of blood pressure based on a stiffness parameter b, which is an index of local stiffness of a blood vessel, [20][21][22][23] and the stiffness parameter b may not be associated with WMHs. In the present study, both hypertension and age were independently associated with WMHs, which is consistent with observations from previous reports.…”

“…35 Finally, other factors may also be associated with SBI and WMHs, including central systolic blood pressure, chronic kidney disease and cerebral microbleeds. 2, 10,11,15,17,25,30 Further research is needed to validate an appropriate stroke prevention strategy for patients with both SBI and WMHs.…”

“…[7][8][9][10][11][12][13][14][15][16] Likewise, white-matter hyperintensities (WMHs) are associated with cognitive impairment, executive function deficits and gait disturbance. [7][8][9][10][11][16][17][18] The etiology of SBI, a cerebral arterial occlusive lesion, is related to mainly arteriolosclerosis such as lipohyalinosis, microatheroma and fibrinoid necrosis, while the etiology of WMHs is related to cerebral disruption of the blood-brain barrier or leakage of plasma due to SVD or cerebral microvascular arteriosclerosis. [8][9][10][11][12][13] Therefore, both SBI and WMHs may be associated with arterial stiffness.…”

Randomized Clinical Trial of Dialysate Cooling and Effects on Brain White Matter

“…Diffusivity represents the degree of random water motion and is also sensitive to WM structural damage. 19 Diffusivity along the direction of maximal diffusion is called axial diffusivity (AD), which is equal to the first eigenvalue ʎ1. Diffusion along the two orthogonal directions perpendicular to the main diffusion direction is called radial diffusivity (RD) and expressed as the average of the second and third eigenvalues [RD=(ʎ 2 +ʎ 3 )/2].…”

Clinical and Pathophysiological Considerations of Gait Limitations and High Prevalence of Falls, in Elderly with Most Common, Disabling Neurological Diseases

“…Conventional MRI and DTI emphasized the widespread disruption of WM integrity, responsible for the gait disturbances and cognitive impairment in lacunar stroke [45]. Extensive disconnections of bilateral cortical regions involved in executive control on motor performance, especially the prefrontal cortex (fibers in centrum semiovale and periventricular frontal lobe) were responsible for a lower gait velocity, shorter stride length and broader stride width [45]. Smoking aggravated the microstructural integrity of the cerebral WM (already affected by the small-vessel disease), and was associated with poorer cognitive functioning [46].…”