Progression of white matter degeneration in amyotrophic lateral sclerosis: A diffusion tensor imaging study

Abstract

Whether longitudinal diffusion tensor MRI imaging (DTI) can capture disease progression in patients with amyotrophic lateral sclerosis (ALS) is unclear. The primary goal of this study was to determine if DTI detects progression of the corticospinal tracts (CST) degeneration in ALS. Seventeen ALS patients and 19 age- and gender-matched healthy controls were scanned with DTI at baseline for cross-sectional analyses. For longitudinal analyses, the ALS patients had repeat DTI scans after eight months. Tractography of the CST was used to guide regions-of-interest (ROI) analysis and complemented by a voxelwise analysis. Cross-sectional study found that baseline FA of the right superior CST was markedly reduced in ALS patients compared to controls. The FA reductions in this region correlated with the disease severity in ALS patients. Longitudinal study found that FA change rate of the right superior CST significantly declined over time. In conclusion, longitudinal DTI study captures progression of upper motor fiber degeneration in ALS. DTI can be useful for monitoring ALS progression and efficacy of treatment interventions.

Measuring the progression of upper motor neuron disease using diffusion MRI and its correlation with Clinical phenotype

“…Microstructural degeneration of the caudal WM tracts confirms previous DTI studies (van der Graaff, de Jong et al 2009, Prudlo, Bissbort et al 2012, Sheelakumari, Madhusoodanan et al 2015. Previous DTI studies using an ROI method showed a bilateral reduction in FA along the CST (Jacob, Finsterbusch et al 2003) while other studies found changes in CST to be confined to the right hemisphere (Zhang, Schuff et al 2011). The changes in motor pathways over time are consistent with the known atrophy in ALS (Jacob, Finsterbusch et al 2003, Keil, Prell et al 2012).…”

“…There was reduced FA in the CC (Matsuo, Mizuno et al 2008, Avants, Cook et al 2010, Whitwell, Avula et al 2010, McMillan, Brun et al 2012) and more anteriorly when not corrected for multiple comparisons (Zhang, Schuff et al 2011). …”

“…However, the few longitudinal DTI studies of ALS have small numbers of subjects and inconsistent findings , Zhang, Schuff et al 2011, Keil, Prell et al 2012. Some have reported the progression of ALS by demonstrating decreasing FA over time along the corticospinal tract (CST) (Sage, Peeters et al 2007).…”

Fractional Anisotropy in the Posterior Limb of the Internal Capsule and Prognosis in Amyotrophic Lateral Sclerosis

“…Other DTI studies in ALS have reported apparent lateralization of CST involvement to the right upper CST. 13,40 There is also an under-recognized post mortem observation of potential relevance that the human CST is asymmetric in 75% of individuals, with 75% of these cases having a larger decussation to the right-sided cord CST. 41 However, FA changes have been observed in the PLIC on both affected and nonaffected sides according to disease burden, 32 and they appear bilaterally in DTI metaanalysis.…”

“…8,9 Longitudinal studies in ALS have demonstrated a range of FA reductions over time. [10][11][12][13] In 2 cross-sectional studies, greater FA values were noted among those patients with the longest disease durations, 6,9 with the possibility that absolute FA values might have inherent prognostic value. In a survival analysis using whole CST FA measurement, lower values were a significantly adverse covariate.…”