Structural and functional connectome alterations across King’s stages in amyotrophic lateral sclerosis (S33.006)

Abstract

<h3>Objective:</h3> To explore the rearrangements of structural and functional connectivity within and among brain networks underlying the clinical spreading of amyotrophic lateral sclerosis (ALS), as described by the King’s staging system, in order to suggest objective, continuous measures mirroring disease progression. <h3>Background:</h3> The identification of quantitative and reproducible markers of disease progression in ALS is of paramount importance for study design and inclusion of homogenous patient cohorts into clinical trials, as there is currently no validated disease-stage biomarker for ALS. <h3>Design/Methods:</h3> 104 patients with ALS and 61 age- and sex-matched healthy controls underwent clinical and brain magnetic resonance imaging (MRI) on a 3T scanner. Patients were stratified into four groups, according to the King’s staging system. No patient had comorbid frontotemporal dementia. Structural and functional connectivity values within and between different anatomical brain regions were obtained using diffusion tensor and resting-state functional MRI data, respectively. Comparisons between groups were performed using age- and sex-adjusted ANOVA models. Correlations were tested using Pearson’s coefficient. <h3>Results:</h3> Compared with controls, a significant, progressive reduction of structural connectivity within brain nodes of the sensorimotor network was observed in ALS patients across King’s stages 2, 3 and 4 (p&lt;0.006). Patients in stages 3 and 4 also showed significant loss of structural connectivity between frontal and sensorimotor regions (p=0.001). A significant disruption of functional connectivity within frontotemporal regions was found only in stage 4 (p=0.025). Sensorimotor structural connectivity showed a strong correlation with ALSFRS-r scores (r=0.31, p=0.001). <h3>Conclusions:</h3> Brain MRI allows to demonstrate and quantify increasing disruption of structural connectivity involving the sensorimotor and frontal networks in ALS, mirroring disease progression. Frontotemporal functional disconnection seems to characterize only advanced disease stages. Our findings demonstrate the utility of MRI connectomics to stratify patients and stage brain pathology in ALS in a reproducible way, which mirrors clinical progression. <b>Disclosure:</b> Dr. Spinelli has nothing to disclose. Miss Ghirelli has nothing to disclose. Silvia Basaia has nothing to disclose. Ms. Cividini has nothing to disclose. Nilo Riva has nothing to disclose. Dr. Russo has nothing to disclose. The institution of Elisa Canu has received research support from Italian Ministry of Health . Dr. Castelnovo has nothing to disclose. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda, and Teva Pharmaceutical Industries. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda, and Teva Pharmaceutical Industries. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Nature. The institution of Dr. Filippi has received research support from Biogen Idec, Merck-Serono, Novartis, Roche, Teva Pharmaceutical Industries, Italian Ministry of Health, Fondazione Italiana Sclerosi Multipla, and ARiSLA (Fondazione Italiana di Ricerca per la SLA). Federica Agosta has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Philips. Federica Agosta has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier INC.