Alterations in the functional connectivity of thalamic subregions after basal ganglia stroke

TL;DR

This study shows how brain connectivity changes after a stroke in the basal ganglia, affecting movement and thinking, and suggests these changes could help guide better treatments.

Contribution

The study identifies specific thalamocortical connectivity patterns after basal ganglia stroke and links them to motor and cognitive impairments.

Findings

Hyperconnectivity was found between sensory thalamus and precuneus/angular gyrus in stroke patients.

Hypoconnectivity was observed in thalamic subregions linked to prefrontal, temporal, and motor cortices.

Functional connectivity changes correlated with motor and cognitive assessment scores.

Abstract

Motor and cognitive impairments are common symptoms of basal ganglia (BG) stroke, although the underlying neurobiological mechanisms remain unclear. Therefore, we aimed to explore the alterations in functional connectivity (FC) between thalamic subregions post-BG stroke via resting-state functional magnetic resonance imaging (rs-fMRI) measurements.

This cross-sectional study compared 40 patients with BG stroke and 35 healthy controls (HCs). Seed-based FC analysis was performed for 14 thalamic subregions. Correlations between FC changes and Fugl–Meyer Assessment (FMA)/Mini-Mental State Examination (MMSE) scores were assessed.

Patients exhibited hyperconnectivity between the left thalamic subregion connected with the sensory cortex (SC_thalamus) and left precuneus (t = 3.97, pFWE = 0.041) and the right SC_thalamus–left angular gyrus (t = 4.50, pFWE = 0.032). Hypoconnectivity emerged between the left thalamic subregion connected with the prefrontal cortex (PFC_thalamus) and right supramarginal gyrus (t = −5.54, pFWE = 0.015), left thalamic subregion connected with the temporal cortex (TC_thalamus) and right postcentral gyrus (t = −4.95, pFWE = 0.022), and right thalamic subregion connected with the primary motor cortex (M1_thalamus) and right medial suprafrontal gyrus (t = −5.62, pFWE = 0.012). FC strength between the right M1_thalamus and right medial suprafrontal gyrus was positively correlated with FMA (r = 0.484, pFDR = 0.033), while left PFC_thalamus–right supramarginal connectivity predicted MMSE performance (r = 0.490, pFDR = 0.021).

BG stroke disrupts thalamocortical circuitry at subregional levels, with distinct FC patterns linking to motor/cognitive deficits. These network-level insights may guide targeted neuromodulation therapies. The identified FC alterations could serve as biomarkers for monitoring recovery and personalizing interventions to improve post-stroke rehabilitation outcomes.

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