Bihemispheric changes associated with cognition in patients with chronic brainstem stroke

Area of Science:

• Neuroscience
• Radiology
• Neurology

Background:

• Chronic brainstem stroke can lead to cognitive impairments.
• Understanding compensatory brain changes is crucial for managing neurological deficits.

Purpose of the Study:

• To identify brain structural and functional connectivity changes associated with preserved cognitive function in patients with chronic brainstem stroke.

Main Methods:

• Retrospective study of 12 patients with chronic brainstem stroke and 24 controls.
• Utilized T1-weighted, diffusion tensor imaging (DTI), and resting-state functional MRI (rs-fMRI).
• Analyzed gray matter density, fractional anisotropy, mean diffusivity, and functional connectivity maps.

Main Results:

• Patients showed decreased bilateral cerebellum volume and cerebral hemisphere structural connectivity.
• Increased gray matter volume and structural connectivity were observed in the temporal lobe and basal forebrain.
• Significantly higher intra-network functional connectivity in frontal and temporal lobes was found in patients.

Conclusions:

• Brainstem stroke patients exhibit altered brain connectivity patterns, with decreased cerebellar and corticopontocerebellar pathways.
• Compensatory increases in cholinergic system regions' volume, structural, and functional connectivity were noted.
• Enhanced frontal and temporal inter-network connectivity may underlie preserved cognitive function in these patients.