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Brain functional connectome abnormalities in amyotrophic lateral sclerosis are associated with disability and cortical hyperexcitability
Author(s) -
Geevasinga N.,
Korgaonkar M. S.,
Me P.,
Van den Bos M.,
Gomes L.,
Foster S.,
Kiernan M. C.,
Vucic S.
Publication year - 2017
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1111/ene.13461
Subject(s) - functional magnetic resonance imaging , neuroscience , connectome , magnetic resonance imaging , medicine , resting state fmri , superior frontal gyrus , connectomics , functional connectivity , psychology , radiology
Background and purpose The present study utilized a multimodal approach encompassing connectome networks combined with brain volume analysis, and assessment of cortical excitability to provide novel insights into amyotrophic lateral sclerosis ( ALS ) pathogenesis. Methods Magnetic resonance images were acquired using a 3.0‐Tesla Signa HD x scanner (GE Healthcare, Milwaukee, WI, USA), using an eight‐channel head coil. Magnetic resonance images for the resting‐state scan were acquired using an echo‐planar imaging magnetic resonance sequence, acquiring 40 contiguous axial/oblique slices. Structural magnetic resonance imaging three‐dimensional T1‐weighted images were acquired in the sagittal plane using three‐dimensional spoiled gradient echo sequences. For structural imaging, a T1‐weighted high‐resolution (3.0‐Tesla) magnetic resonance imaging scan was used. Cortical excitability was assessed by using the threshold‐tracking transcranial magnetic stimulation paradigm. Network‐based statistics and whole‐brain functional topology (using graph theoretical approaches) assessed functional connectivity. Results Using a global network‐based statistical analysis approach, functional connectivity was increased in 12 network edges connecting 14 nodes ( P < 0.05) within the frontal, temporal, parietal and subcortical regions. Analysis of local connectedness disclosed dichotomous effects with reduced connectivity in frontal regions and increased connectivity in occipital regions in ALS . Cortical hyperexcitability was evident in patients with ALS , negatively correlated with functional connectivity changes in the pre‐central gyrus ( P < 0.01). Connectivity changes in the frontal regions were negatively associated with functional disability ( P < 0.05). Conclusions Multimodal assessment of cortical function in patients with ALS identified deficits in functional connectivity associated with cortical hyperexcitability that correlated with patient disability. Novel integration of functional brain assessment further contributes to the understanding of disease pathogenesis in ALS .