Are Structural Changes Induced by Lithium in the HIV Brain Accompanied by Changes in Functional Connectivity?

Area of Science:

• Neuroimaging
• Neuroscience
• Pharmacology

Background:

• Cognitive impairment is common in HIV-infected individuals.
• Lithium therapy has shown effects on brain microstructure in this population.
• The impact of lithium on functional connectivity in HIV cognitive impairment remains underexplored.

Purpose of the Study:

• To investigate if lithium therapy alters functional brain connectivity in HIV-infected individuals with cognitive impairment.
• To explore the relationship between microstructural changes and functional connectivity.
• To assess the utility of generalized partial directed coherence (gPDC) in quantifying these changes.

Main Methods:

• Functional MRI data from seven HIV-infected individuals undergoing lithium therapy were analyzed.
• Seven regions of interest (ROIs) were selected based on prior Diffusion Tensor Imaging (DTI) findings.
• Generalized partial directed coherence (gPDC) was employed to measure functional connectivity between ROIs.

Main Results:

• Lithium treatment led to significant differences in average node strength.
• A notable increase in functional connectivity strength was observed post-lithium therapy.
• gPDC effectively quantified connectivity changes related to the lithium intervention.

Conclusions:

• Lithium therapy appears to increase functional connectivity in cognitively impaired HIV-infected individuals.
• The gPDC methodology provides a quantitative measure of intervention-induced network changes.
• This approach may help interpret clinical changes in the context of brain network modulation.