MRI metrics at the epicenter of spinal cord injury are correlated with the stepping process in rhesus monkeys

Abstract

Clinical evaluations of long-term outcomes in the early-stage spinal cord injury (SCI) focus on macroscopic motor performance and are limited in their prognostic precision. This study was designed to investigate the sensitivity of the magnetic resonance imaging (MRI) indexes to the data-driven gait process after SCI. Ten adult female rhesus monkeys were subjected to thoracic SCI. Kinematics-based gait examinations were performed at 1 (early stage) and 12 (chronic stage) months post-SCI. The proportion of stepping (PS) and gait stability (GS) were calculated as the outcome measures. MRI metrics, which were derived from structural imaging (spinal cord cross-sectional area, SCA) and diffusion tensor imaging (fractional anisotropy, FA; axial diffusivity, λ // ), were acquired in the early stage and compared with functional outcomes by using correlation analysis and stepwise multivariable linear regression. Residual tissue SCA at the injury epicenter and residual tissue FA/remote normal-like tissue FA were correlated with the early-stage PS and GS. The extent of lesion site λ // /residual tissue λ // in the early stage after SCI was correlated with the chronic-stage GS. The ratios of lesion site λ // to residual tissue λ // and early-stage GS were predictive of the improvement in the PS at follow-up. Similarly, the ratios of lesion site λ // to residual tissue λ // and early-stage PS best predicted chronic GS recovery. Our findings demonstrate the predictive power of MRI combined with the early data-driven gait indexes for long-term outcomes. Such an approach may help clinicians to predict functional recovery accurately.

Effects of comprehensive functional nursing on functional recovery and quality of life in patients with spinal cord injury

“…[ 32 , 33 ] Patients with SCI can experience a variety of complications, which has adverse effects on their cure and process of rehabilitation. [ 34 ] Therefore, active prevention and treatment of complications are important for the rehabilitation of SCI. This study showed that the RMI, BI, and BBS scores of patients receiving comprehensive strengthening function interventions were significantly higher than those of patients in the general care group, indicating that the neurological and motor function recovery of patients who received the comprehensive intensive functional intervention was significant, which is consistent with the results of previous studies.…”

Brain Plasticity in Patients with Spinal Cord Injuries: A Systematic Review

“…MRI studies using animal models, from a rehabilitation perspective, have shown that primates (monkeys and humans) can achieve significantly better locomotor recovery than rodents after unilateral SCIs through a different circuit. Structural reorganization, such as synaptic remodeling, axonal dendritic growth, and circuit reorganization in the supralesional and sublesional spinal cord, can restore function after an injury [82][83][84].To understand the effects of brain plasticity after SCIs from a functional point of view, scales such as the Functional Index Measure [85] and more recent and diagnosis-specific measures such as the Spinal Cord Independence Measure, which fit well with the overall assessment of patient functionality, can be used [86,87]. Additionally, various analyses on different potentials have been developed to investigate how different types of neural signals are transmitted through the same pathway (including motor control) in SCIs.…”