Brain imaging in acquired immunodeficiency syndrome dementia complex

Area of Science:

• Neurology
• Infectious Diseases
• Radiology

Background:

• Human immunodeficiency virus (HIV) infection is associated with diverse neurological complications.
• Opportunistic infections and neoplasms, such as lymphoma, are common causes of neurological issues in acquired immunodeficiency syndrome (AIDS) patients.
• HIV itself significantly contributes to neurological disease in seropositive individuals, potentially preceding overt immunosuppression.

Purpose of the Study:

• To highlight the role of HIV in neurological complications.
• To discuss diagnostic methods for HIV-related neurological conditions.
• To evaluate the utility of functional neuroimaging in detecting and monitoring HIV encephalitis and AIDS dementia complex (ADC).

Main Methods:

• Cerebrospinal fluid (CSF) examination.
• Structural neuroimaging: contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI).
• Functional neuroimaging: 18fluorodeoxyglucose positron emission tomography (PET) for glucose metabolism and SPECT (123I iodoamphetamine or 99mTc-HMPAO) for cerebral perfusion.

Main Results:

• Structural neuroimaging (CT/MRI) may show atrophy and white matter changes but is relatively insensitive to HIV brain infection.
• Functional neuroimaging (PET/SPECT) can reveal abnormalities in subcortical gray matter and cerebral cortex in ADC patients.
• These functional imaging abnormalities can be detected early in ADC, even with negative MRI and minimal symptoms, and can track disease progression or treatment response.

Conclusions:

• HIV itself is a significant cause of neurological disease.
• Functional neuroimaging (PET/SPECT) offers superior sensitivity for early detection of brain abnormalities in HIV-associated neurological disorders compared to structural imaging.
• PET and SPECT are valuable tools for monitoring the progression and therapeutic response in patients with AIDS dementia complex.