HIV-Associated Microstructural Abnormalities in Default Mode, Executive Control, and Salience Networks: Insights from...

Area of Science:

• Neuroimaging
• Neuroscience
• Infectious Disease

Background:

• Cognitive impairment persists in people with HIV (PWH) despite combination antiretroviral therapy.
• White matter microstructural abnormalities may underlie HIV-associated cognitive impairment.
• Diffusion MRI (dMRI) is sensitive to brain microstructural integrity.

Purpose of the Study:

• To investigate brain microstructural integrity using tensor-valued dMRI in PWH.
• To explore associations between dMRI metrics and neurocognitive function across brain networks.
• To identify potential biomarkers for HIV-associated cognitive impairment.

Main Methods:

• Exploratory cross-sectional study comparing 31 healthy controls (HCs) and 24 PWH.
• Utilized 3T MRI with tensor-valued dMRI and conventional DTI/DKI metrics.
• Assessed neurocognitive performance across six functionally defined brain networks.

Main Results:

• PWH showed reduced FA, µFA, and MKa in specific brain networks compared to HCs.
• PWH exhibited altered MKi in the salience and executive control networks.
• PWH performed worse on learning, memory, and language, with associations between MKi and cognitive functions.

Conclusions:

• Tensor-valued dMRI reveals network-specific microstructural alterations in PWH.
• dMRI metrics, particularly MKi, are associated with cognitive deficits in HIV.
• Tensor-valued dMRI shows promise as a biomarker for neurocognitive vulnerability in HIV.