Neural Correlates of Fall Risk in People Aged 50 and Over With Chronic Low Back Pain: A Multimodal MRI Study.

BACKGROUND

Chronic low back pain (CLBP) is common in older people and contributes to disability, physical inactivity, cognitive deficits and neural alterations that may increase fall risk. We examined associations between multimodal brain measures and daily-life gait quality and other fall risk factors in older people with CLBP.

METHODS

Thirty-three adults aged ≥ 50 years with CLBP completed assessments of physical function, physical activity, and executive function. Daily-life gait quality was assessed using a waist-worn accelerometer. Neuroimaging included diffusion MRI, T1-weighted MRI and magnetic resonance electrical properties tomography.

RESULTS

Gait quality was associated with tissue conductivity in bilateral cerebellar white matter, pallidum and thalamus, but not with structural measures. Short Physical Performance Battery (SPPB) score was associated with fibre density in visual and thalamo-occipital tracts, and hippocampal, thalamic and putamen volumes. Walking duration and daily-life gait speed were associated with cerebellar and subcortical volumes and frontal-parietal conductivity. Physical activity was associated with hippocampal, cerebellar, parietal, and frontal conductivity. Inhibitory control was associated with sensorimotor fibre density and medial orbitofrontal conductivity.

CONCLUSIONS

In older people with CLBP, gait, physical function and executive function are supported by complementary neural networks, with tissue conductivity providing additional insight into real-world gait performance and physical function.

SIGNIFICANCE STATEMENT: This study highlights brain mechanisms underlying fall risk in older people with chronic low back pain. Tissue conductivity in cerebellar, subcortical and orbitofrontal regions was linked to balance, gait quality and inhibitory control, providing insights beyond structural MRI. Findings suggest that alterations across neural circuits involved in motor control, cognitive processing and physical activity may contribute to mobility decline. Understanding these neural pathways may help guide targeted interventions to improve balance and reduce fall risk in people with chronic low back pain.