Frontostriatal fiber bundle compromise in HIV infection without dementia.
BACKGROUND
Quantitative fiber tracking derived from diffusion tensor imaging (DTI) was used to determine whether white matter association, projection, or commissural tracts are affected in nondemented individuals with HIV infection and to identify the regional distribution of sparing and impairment of fiber systems.


METHODS
DTI measured fractional anisotropy and diffusivity, quantified separately for longitudinal (lambdaL) diffusivity (index of axonal injury) and transverse (lambdaT) diffusivity (index of myelin injury), in 11 association and projection white matter tracts and six commissural tracts in 29 men and 13 women with HIV infection and 88 healthy, age-matched controls (42 men and 46 women).


RESULTS
The total group of HIV-infected individuals had higher diffusivity (principally longitudinal) than controls in the posterior sectors of the corpus callosum, internal and external capsules, and superior cingulate bundles. High longitudinal diffusivity, indicative of axonal compromise, was especially prominent in posterior callosal sectors, fornix, and superior cingulate bundle in HIV with AIDS. Unmedicated patients had notably high transverse diffusivity, indicative of myelin compromise, in the occipital forceps, inferior cingulate bundle, and superior longitudinal fasciculus. Pontocerebellar projection fibers were resistant to HIV effects as were commissural fibers coursing through premotor and sensorimotor callosal sectors.


CONCLUSIONS
This quantitative survey of brain fiber tract integrity indicates that even nondemented HIV patients can have neuroradiological evidence for damage to association and commissural tracts. These abnormalities were vulnerable to exacerbation with AIDS and possibly mitigated by HAART.
Pfefferbaum
Adolf
A
Neuroscience Program, SRI International, San Jose, California, USA.
Rosenbloom
Margaret J
MJ
Rohlfing
Torsten
T
Kemper
Carol A
CA
Deresinski
Stanley
S
Sullivan
Edith V
EV
D000163:Acquired Immunodeficiency Syndrome / Q000473:pathology; D000328:Adult; D016880:Anisotropy; D019380:Anti-HIV Agents / Q000494:pharmacology; D001931:Brain Mapping / Q000379:methods; D003342:Corpus Striatum / Q000473:pathology; D003704:Dementia / Q000209:etiology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D015658:HIV Infections / Q000188:drug therapy / Q000473:pathology* / Q000523:psychology / Q000821:virology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology; D010523:Peripheral Nervous System Diseases / Q000821:virology; D012959:Socioeconomic Factors; D019562:Viral Load
D019380:Anti-HIV Agents