Frontoparietal white matter integrity predicts haptic performance in chronic stroke

Area of Science:

• Neuroscience
• Neurorehabilitation
• Biomedical Engineering

Background:

• Frontoparietal white matter facilitates complex haptic tasks, including somatosensory discrimination.
• Understanding white matter integrity's role in post-stroke haptic deficits is crucial for effective rehabilitation.

Purpose of the Study:

• To investigate the relationship between frontoparietal white matter microstructure and haptic performance in chronic stroke survivors.
• To compare frontoparietal network integrity between individuals with stroke and age-matched controls.

Main Methods:

• Diffusion-weighted MRI and probabilistic tractography were used to analyze 10 frontoparietal tracts in 19 stroke patients and 16 controls.
• Haptic performance was assessed using the Hand Active Sensation Test (HASTe).
• Diffusion metrics including fractional anisotropy (FA) and mean diffusivity (MD) were quantified for each tract.

Main Results:

• Nine of ten frontoparietal tracts showed diminished structural integrity in the stroke group compared to controls.
• Reduced white matter integrity (higher MD) in the ipsilesional thalamus to motor cortex (T-M1) tract correlated with poorer haptic performance.
• Frontoparietal white matter integrity significantly predicted haptic performance variance in both stroke (90%) and control (87%) groups.

Conclusions:

• Frontoparietal white matter integrity is vital for mediating haptic performance post-stroke.
• The T-M1 and precuneus interhemispheric tracts are potential targets for interventions aimed at improving post-stroke haptic function.
• Noninvasive brain stimulation techniques targeting these tracts may enhance tactile sensory recovery.