Quantitative MRI of rostral spinal cord and brain regions is predictive of functional recovery in acute spinal cord injury.

Maryam Seif,Patrick Freund,Alan J Thompson,Armin Curt,Nikolaus Weiskopf,Patrick Grabher

doi:10.1016/j.nicl.2018.08.026

Abstract

ObjectiveTo reveal the immediate extent of trauma-induced neurodegenerative changes rostral to the level of lesion and determine the predictive clinical value of quantitative MRI (qMRI) following acute spinal cord injury (SCI).MethodsTwenty-four acute SCI patients and 23 healthy controls underwent a high-resolution T1-weighted protocol. Eighteen of those patients and 20 of controls additionally underwent a multi-parameter mapping (MPM) MRI protocol sensitive to the content of tissue structure, including myelin and iron. Patients were examined clinically at baseline, 2, 6, 12, and 24 months post-SCI. We assessed volume and microstructural changes in the spinal cord and brain using T1-weighted MRI, magnetization transfer (MT), longitudinal relaxation rate (R1), and effective transverse relaxation rate (R2*) maps. Regression analysis determined associations between acute qMRI parameters and recovery.ResultsAt baseline, cord area and its anterior-posterior width were decreased in patients, whereas MT, R1, and R2* parameters remained unchanged in the cord. Within the cerebellum, volume decrease was paralleled by increases of MT and R2* parameters. Early grey matter changes were observed within the primary motor cortex and limbic system. Importantly, early volume and microstructural changes of the cord and cerebellum predicted functional recovery following injury.ConclusionsNeurodegenerative changes rostral to the level of lesion occur early in SCI, with varying temporal and spatial dynamics. Early qMRI markers of spinal cord and cerebellum are predictive of functional recovery. These neuroimaging biomarkers may supplement clinical assessments and provide insights into the potential of therapeutic interventions to enhance neural plasticity.

Highlights

Spinal cord injury (SCI) is a devastating neurological disorder that leads to immediate sensorimotor and autonomic dysfunction below the lesion level (Freund et al, 2013; Grabher et al, 2015)
At baseline Voxel based morphometry (VBM) analysis revealed significant grey matter (GM) volume decreases in a number of areas- the left anterior insula (z-score = 5.01, x = −35, y = 30, z = 5, p = .009, cluster extent (CE) = 743), the bilateral thalamus (z-score = 4.70, x = 0, y = −11, z = 6, p = .007, CE = 780), the bilateral anterior cingulate gyrus (z-score = 4.50, x = −2, y = 35, z = −15, p = .001, CE = 1203), and the right lingual gyrus extending into the right cerebellum and occipital gyrus (z-score = 5.83, x = 2, y = −62, z = 8, p < .0001, CE = 982) (Fig. 2)
We applied quantitative MRI (qMRI) early after SCI and determined remote atrophy and microstructural changes sensitive to different tissue components including myelin and iron at the rostral cord and brain level. To our knowledge this is the first study to investigate the microstructural changes in acute SCI

Summary

Introduction

Spinal cord injury (SCI) is a devastating neurological disorder that leads to immediate sensorimotor and autonomic dysfunction below the lesion level (Freund et al, 2013; Grabher et al, 2015). Intensive neurorehabilitation fosters functional recovery within the first months after SCI (Gassert and Dietz, 2018) which is accompanied by time dependent neurodegenerative changes. A cascade of secondary neurodegenerative processes accompanies the recovery in SCI (Freund et al, 2013; Grabher et al, 2015; Park et al, 2004; Tator and Fehlings, 1991; Ziegler et al, 2018, Seif et al, 2018). Understanding the interplay between neurodegenerative and reorganizational changes at the spinal and brain level during recovery would enable the development of evidence based rehabilitation therapy (Villiger et al, 2015)

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