Deep grey matter involvement and altered sensory gating in multiple sclerosis

Area of Science:

• Neuroscience
• Neurology
• Human Physiology

Background:

• Somatosensory temporal discrimination threshold (STDT) is altered in multiple sclerosis (MS).
• Voluntary movement modulates STDT in healthy subjects (HS) via subcortical sensory gating.
• Investigating sensory gating and sensorimotor integration in MS is crucial.

Purpose of the Study:

• To investigate sensory gating and sensorimotor integration in MS using neurophysiological and MRI techniques.
• To compare STDT and movement kinematics between MS patients and HS.
• To correlate neurophysiological findings with brain structure in MS.

Main Methods:

• Recruited 38 relapsing-remitting MS patients and 33 HS.
• Tested STDT at rest and during index finger abduction, recording movement kinematics.
• Utilized 3T MRI for brain imaging.

Main Results:

• MS patients had higher STDT, slower movements, and reduced thalamus, pallidum, and caudate nucleus volumes.
• Patients showed less STDT modulation during movement and decreased finger movement velocity.
• Altered sensorimotor integration correlated with thalamic and pallidal diffusivity and basal ganglia volumes.

Conclusions:

• Altered STDT and sensorimotor integration in MS are linked to structural damage in the thalamus and basal ganglia.
• These alterations likely impact motor performance and are associated with fatigue.
• Findings highlight the role of subcortical structures in MS-related sensory and motor deficits.