Inclusion Criteria:  Male (in order to eliminate the hormonal influences on the levels of brain metabolites), older than 18 years, HIV seropositivity confirmed on PCR testing, undetectable viral load for over one year, conventional magnetic resonance imaging (MRI) normal. In group I, the additional criterion would be stable cART not containing INSTI for over one year. In group II, the inclusion criteria will be the INSTI base regimen introduced at least one year prior to imaging.  Exclusion Criteria:  active infiltrative or infective/opportunistic neurological illness, chronic neurological diseases (multiple sclerosis, vascular and non-vascular dementia, other neurodegenerative conditions), active abuse of narcotic drugs, hepatitis B or C coinfection, deep white matter lesions (focal or diffuse, such as lacunar stroke, leukoaraiosis, infiltrative or infective foci, metastases etc.), International HIV Dementia Scale (IHDS) score <10 (only neuro-asymptomatic subjects would be included in the study), and contraindications for MRI examination