Widespread Microstructural White Matter Involvement in Amyotrophic Lateral Sclerosis: A Whole-Brain DTI Study

Abstract

BACKGROUND AND PURPOSE:The extensive application of advanced MR imaging techniques to the study of ALS has undoubtedly improved our knowledge of disease pathophysiology, even if the actual spread of the neurodegenerative process throughout the central nervous system is not fully understood. The present study aimed to detect WM patterns of microstructural abnormalities to better investigate the pathologic process in ALS, within but also beyond CSTs, in a whole-brain analysis.

Motor and extramotor neurodegeneration in amyotrophic lateral sclerosis: A 3T high angular resolution diffusion imaging (HARDI) study

“…It is worth speculating that such a pattern of predominantly frontal WM injury, also described in other cohorts of patients with ALS (50,51), may refl ect the executive and behavioural dysfunctions that characterize our patients. Along this line of evidence, our fi ndings reinforce the patterns of degeneration detected by DTI analyses in patients with ALS (13,15,52,53) or frontotemporal dementia (FTD) (53) or both (53,54), supporting the concept of a continuum between ALS and FTD not only on a pathological and genetic level, but also on a microstructural degeneration level (1). In this regard, a recent structural neuroimaging study using voxel based morphometry (VBM) and DTI in the three subtypes of the ALS-FTD continuum (i.e.…”

“…With respect to GFA measures within the CTSs, the signifi cant decrease of GFA in ALS patients compared with controls, observed within both rostral (underneath the primary motor cortices) and caudal (at the left ponto-mesencephalic junction) WM tracts, confi rms and strengthens previous DTI TBSS results (14,15,18,34). This pattern of widespread microstructural impairment of the CSTs might be interpreted as an advanced stage of pathology characterized by a wider extension of the degenerative process, similar to what has been reported in post mortem examinations of patients with sporadic ALS, especially in case of long survival (3,44).…”

25 years of neuroimaging in amyotrophic lateral sclerosis

“…98 Axonal degeneration and disorganization 99 is thought to give rise to alterations in water diffusivity 100 in the setting of ALS, and the FA reductions have been posited to reflect gliosis, increased extracellular matrix, Wallerian degeneration, and/or axonal loss. 68,83,101 …”

Relationships of DTI findings with neurocognitive dysfunction in children with Type 1 diabetes mellitus

“…Decrease in FA values is observed in situations such as white matter disintegration, axonal degeneration and axonal structural irregularity. 18 Previous studies performed with DTI have shown a correlation between the decreased FA values and neurocognitive impairment in various disorders including schizophrenia, depression, chronic alcoholism, Alzheimer disease and chronic drug abuse. 19 Apparent diffusion coefficient (ADC) is a measure of total degree of water diffusion within a tissue.…”