AIDS dementia complex: brain high-energy phosphate metabolite deficits

Area of Science:

• Neuroscience
• Biochemistry
• Medical Imaging

Background:

• Acquired immunodeficiency syndrome dementia complex (ADC) is a neurological disorder associated with HIV infection.
• The underlying mechanisms of neurological impairment in ADC are not fully understood.
• Compromised high-energy phosphate metabolism is a potential factor in ADC-related brain dysfunction.

Purpose of the Study:

• To investigate the role of high-energy phosphate metabolism in the neurologic impairment of ADC.
• To quantify brain phosphate metabolite concentrations and ratios in patients with ADC compared to healthy controls.

Main Methods:

• Utilized localized phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy and proton (hydrogen-1) magnetic resonance (MR) imaging.
• Measured brain metabolite concentrations and ratios in 12 patients with mild to moderate ADC and 29 healthy volunteers.
• Analyzed metabolite levels in sections through the centrum semiovale.

Main Results:

• Significantly reduced concentrations of brain phosphocreatine (PCr) and nucleoside triphosphate (NTP) were observed in ADC patients compared to controls (P < .0001).
• The ratios of detectable metabolites did not show significant differences between ADC patients and healthy subjects.
• The observed deficits in PCr and NTP were not explained by focal abnormalities or cerebral atrophy.

Conclusions:

• The findings support the hypothesis of a generalized virus-associated toxic process affecting brain cell function in ADC.
• Noninvasive NMR spectroscopy offers valuable functional information for assessing disease progression and therapeutic response in ADC.
• Compromised high-energy phosphate metabolism is implicated in the neurologic deficits associated with ADC.