Increased cerebral functional connectivity in ALS

Abstract

ObjectiveWe sought to assess cortical function in amyotrophic lateral sclerosis (ALS) using noninvasive neural signal recording.MethodsResting-state magnetoencephalography was used to measure power fluctuations in neuronal oscillations from distributed cortical parcels in 24 patients with ALS and 24 healthy controls. A further 9 patients with primary lateral sclerosis and a group of 15 asymptomatic carriers of genetic mutations associated with ALS were also studied.ResultsIncreased functional connectivity, particularly from the posterior cingulate cortex, was demonstrated in both patient groups compared to healthy controls. Directionally similar patterns were also evident in the asymptomatic genetic mutation carrier group.ConclusionIncreased cortical functional connectivity elevation is a quantitative marker that reflects ALS pathology across its clinical spectrum, and may develop during the presymptomatic period. The amelioration of pathologic magnetoencephalography signals might be a marker sensitive enough to provide proof-of-principle in the development of future neuroprotective therapeutics.

Loss of functional connectivity is an early imaging marker in primary lateral sclerosis

“…In the longitudinal analysis of the eight pre-PLS patients with scans at two timepoints, increased motor connectivity was not accompanied by changes in diffusion measures of callosal or corticospinal tracts, arguing against axonal regrowth as the mechanism. The return of motor connectivity is consistent with two previous studies suggesting that some functional re-organization occurs over time in PLS patients (14, 15, 25). One previous study using independent components analysis (ICA) showed that functional connectivity in sensorimotor networks was greater in PLS patients than controls (15).…”

Localization of Brain Networks Engaged by the Sustained Attention to Response Task Provides Quantitative Markers of Executive Impairment in Amyotrophic Lateral Sclerosis

“…Such posterior parietal hyperengagement has previously observed during involuntary attention switching ( McMackin et al 2019b , Dukic et al. 2019 ) and at rest ( Proudfoot et al. 2018 ; Dukic et al.…”

Cortical Circuit Dysfunction as a Potential Driver of Amyotrophic Lateral Sclerosis

“…Several functional magnetic resonance imaging (fRMI) studies reported increased functional connectivity (or hyperconnectivity) in the brain of ALS patients compared to controls (Lulé et al, 2007;Douaud et al, 2011;Menke et al, 2016;Schulthess et al, 2016;Agosta et al, 2018), which was also confirmed by electroencephalography (EEG) (Iyer et al, 2015) and resting state magnetoencephalography (MEG) (Proudfoot et al, 2018).…”