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Updated: May 3, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Neural correlates of forward and backward walking in MS: insights from myelin water imaging
Patrick G Monaghan1,2, Taylor N Takla3, Maryam M Abbawi4
1Department of Health Care Sciences, Wayne State University, Eugene Applebaum College of Pharmacy and Health Care Sciences, 259 Mack Avenue, Detroit, MI, USA. patrick.monaghan@wayne.edu.
Abstract:
Mobility impairments and increased fall risk are common in multiple sclerosis (MS), resulting from myelin degradation in motor pathways. While forward walking is a common mobility assessment, backward walking shows greater sensitivity in distinguishing fallers due to its increased postural and cognitive demands. However, the neurobiological mechanisms underlying backward walking deficits remain unclear. This study examined associations among myelin water imaging (MWI) metrics-myelin water fraction (MWF) and geometric mean of intermediate-T2 relaxation times (geomT2IEW)-in motor pathways and forward and backward walking performance in MS. Forty-three individuals with relapsing-remitting MS completed forward and backward walking assessments. MWI assessed MWF and geomT2IEW in four motor tracts: corpus callosum body (CCbody), superior and inferior cerebellar peduncles (SCP, ICP), and corticospinal tract (CST). Multiple regression models examined associations between regional MWF and geomT2IEW and walking velocity in each direction, controlling for age and disease severity, measured via the Patient-Determined Disease Steps (PDDS). Higher MWF in the SCP was significantly associated with faster backward velocity (b = 0.046, p = 0.026), while MWF in the CCbody was the strongest predictor of forward velocity (b = 0.019, p = 0.030). GeomT2IEW was not significantly associated with walking velocity. PDDS was a significant covariate, with greater impairment linked to slower speeds (p < 0.001). Forward and backward walking involve distinct neural networks, with SCP myelin content linked to backward walking and CCbody myelin to forward walking. Findings highlight the utility of backward walking assessments in identifying MS-related mobility deficits and suggest targeting cerebellar pathways in rehabilitation to improve gait and reduce fall risk.
Insights
Backward walking is more sensitive for detecting mobility issues in multiple sclerosis (MS). Myelin in specific brain pathways, like the superior cerebellar peduncle, is linked to backward walking speed, while the corpus callosum impacts forward walking.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Rehabilitation Science
Background:
- Multiple sclerosis (MS) commonly causes mobility impairments and increased fall risk due to myelin damage in motor pathways.
- Backward walking is a more sensitive measure than forward walking for identifying fall risk in MS due to higher postural and cognitive demands.
- The specific neurobiological underpinnings of backward walking deficits in MS are not well understood.
Purpose of the Study:
- To investigate the relationship between myelin integrity in key motor pathways and forward/backward walking performance in individuals with MS.
- To identify specific myelin water imaging (MWI) metrics associated with gait velocity in different directions.
Main Methods:
- Forty-three individuals with relapsing-remitting MS underwent forward and backward walking assessments.
- Myelin water imaging (MWI) was used to measure myelin water fraction (MWF) and geometric mean of intermediate-T2 relaxation times (geomT2IEW) in the corpus callosum body (CCbody), superior and inferior cerebellar peduncles (SCP, ICP), and corticospinal tract (CST).
- Multiple regression analyses were performed to examine associations between MWI metrics and walking velocity, controlling for age and disease severity (PDDS).
Main Results:
- Higher MWF in the superior cerebellar peduncle (SCP) was significantly associated with faster backward walking velocity.
- MWF in the corpus callosum body (CCbody) was the strongest predictor of forward walking velocity.
- Myelin water imaging metrics were direction-specific in their association with walking performance, and disease severity (PDDS) was a significant covariate impacting walking speed.
Conclusions:
- Forward and backward walking rely on distinct neural networks, with SCP myelin integrity crucial for backward walking and CCbody myelin for forward walking.
- Backward walking assessments are valuable for detecting MS-related mobility deficits.
- Targeting cerebellar pathways in rehabilitation may enhance gait and reduce fall risk in MS patients.
