Alterations of resting-state regional and network-level neural function after acute spinal cord injury

Abstract

Object: The purpose of this study was to investigate functional alterations of the brain in the early stage of spinal cord injury (SCI) and further investigate how these functional alterations relate to SCI patients' sensorimotor functions.

Methods: Twenty-five patients with SCI and 25 matched healthy controls underwent imaging by using resting-state functional magnetic resonance imaging (fMRI). The amplitude of low-frequency fluctuations (ALFF) were used to characterize regional neural function, and the seed-based functional connectivity (FC) was used to evaluate the functional integration of the brain network.

Results: Compared to healthy controls, patients with SCI showed decreased ALFF in the bilateral primary sensorimotor cortex, and increased ALFF in the bilateral cerebellum and right orbitofrontal cortex (OFC). The ALFF value in the left cerebellum was negatively correlated with the clinical total motor score in patients with SCI. Furthermore, SCI patients mainly showed decreased inter-hemispheric FC between the bilateral primary sensorimotor cortex, as well as increased intra-hemispheric FC within the motor network, including the primary sensorimotor cortex, premotor cortex, supplementary motor area (SMA), thalamus and cerebellum. Subsequent correlation analyses revealed that increased FC within the primary sensorimotor cortex, SMA, and cerebellum negatively correlated with the total American Spinal Cord Injury Association (ASIA) motor score.

Conclusions: Our findings provide evidence that SCI can induce significant regional and network-level functional alterations in the early stage of the disease. We hypothesized these alterations may be an adaptive phenomenon following SCI, reflecting a compensatory mechanism during the early stage of SCI.

Keywords: functional MRI; functional organization; resting state; spinal cord injury.