White matter integrity and cognitive dysfunction: Radiological and neuropsychological correlations

Abstract

Cerebral white matter (WM) is comprised of nerve fibers interconnecting neurons in the cerebral cortex or the deep structures. With advancing age, WM frequently shows hyperintense lesions in T2-weighted or fluid-attenuated inversion recovery images in both the periventricular and deep WM. Patients with these WM lesions might manifest a variety of symptoms, such as parkinsonism, cognitive impairment, depression and apathy, when these WM lesions become sufficiently confluent and diffuse. However, there are inconsistencies with respect to their clinical significance, because patients with extensive WM lesions might remain asymptomatic. The present review focuses on the pathological mechanism underlying why the loss of integrity of nerve fibers in the WM induces neuropsychological symptoms. Geriatr Gerontol Int 2015; 15 (Suppl. 1): 3-9.

Postprandial Hyperglycemia Is Associated With White Matter Hyperintensity and Brain Atrophy in Older Patients With Type 2 Diabetes Mellitus

“…WMH volume increased markedly with aging, particularly in the frontal lobe in patients aged 75 years and over who were in the AD/aMCI cohort ( Ogama et al, 2016 ). The pathogenesis of WMH is most likely driven by ischemia resulting from hypertensive small vessel disease, but amyloid angiopathy may also be another underlying cause of extensive WMH ( Tomimoto, 2015 ). More recently, carriage of the apolipoprotein E4 genotype was reported to affect the relationship between glucose alterations and WMH ( Livny et al, 2016 ; Cox et al, 2017 ).…”

“…WMH are associated with white matter atrophy and cortical thinning ( Wardlaw et al, 2015 ). Importantly, WMH in AD patients involves both vascular changes and neurodegenerative mechanisms ( Tomimoto, 2015 ). Thus, it is necessary to separately measure gray and white matter volume to assess the burden of WMH in AD brain.…”

“…White matter hyperintensity (WMH), one of the cerebral small vessel diseases, presents as hyperintense areas on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images and as isointense or hypointense areas on T1-weighted images on magnetic resonance (MR) imaging. WMH is a common finding in the aging brain and plays pivotal roles in several geriatric syndromes, including cognitive impairment, gait disturbances and functional decline of the elderly ( Akisaki et al, 2006 ; Ogama et al, 2014 , 2017 ; Tomimoto, 2015 ; Tamura et al, 2017 ). Thus, preventive strategies capable of delaying WMH progression should be identified to successfully manage older people with diabetes.…”

“…Currently, age and hypertension are recognized as consistent risk factors for WMH ( Tomimoto, 2015 ). However, whether diabetes is independently associated with WMH has not been clarified.…”

Prediction of Cognitive Decline from White Matter Hyperintensity and Single-Photon Emission Computed Tomography in Alzheimer’s Disease

“…Previous studies have reported that the WMH posterior volume was larger than the anterior volume ( 56 – 58 ) in patients with cerebral amyloid angiopathy (CAA) as well as AD ( 59 ). CAA induces cerebral hypoperfusion in the white matter as a result of amyloid β deposition in the microvessels of the cerebral cortices and is found in more than 80% of all patients with AD ( 60 ). It is, therefore, likely that most patients in our cohort had comorbid CAA.…”