Evidence of CNS impairment in HIV infection: clinical, neuropsychological, EEG, and MRI/MRS study

Abstract

Objectives-Toidentify by clinical examination, EEG, MRI, and proton spectroscopy, and neuropsychological assessment the prevalence of signs of CNS involvement in patients infected with HIV, and to relate such findings to the evidence of immunosuppression. Methods-The design was a cross sectional analysis of a cohort of male patients with infected HIV with an AIDS defining diagnosis or low CD4 count (<350), and seropositive asymptomatic subjects, both groups being followed up in a longitudinal study. Control groups consisted of seronegative subjects from the same genitourinary medicine clinics. Results-This report sets out the cross sectional findings at the seventh visit in the longitudinal study. Patients with AIDS had more signs of neurological dysfunction, poorer performance on a neuropsychological test battery, were more likely to have an abnormal EEG, and to have abnormalities on MRI. They more often had cerebral atrophy, abnormal appearing white matter, , and abnormal relaxometry and spectroscopy. There was little evidence of abnormality in seropositive people who had a CD4 count >350 compared with seronegative people from a similar background. Conclusions-Detailed testing failed to disclose significant CNS impairment without immunosuppression in men infected with HIV. Findings from MRI and magnetic resonance spectroscopy (MRS) correlated with those of the neurological examination and neuropsychogical assessment. A combination of such assessments oVers a simple surrogate for studies of CNS involvement in HIV disease. (J Neurol Neurosurg Psychiatry 1998;65:301-307)

3D pattern of brain atrophy in HIV/AIDS visualized using tensor-based morphometry

“…Aylward et al (1995) showed that the white matter volume in demented AIDS patients was less than in those who were non-demented. Harrison et al (1998) found that patients who performed poorly on neurocognitive tests were more likely to have T2-hyperintense white matter abnormalities on MRI. Neither of these studies specified white matter regions associated with this neuropsychological impairment.…”

Cortical Atrophy and White Matter Hyperintensities in HIV: The Hawaii Aging with HIV Cohort Study

“…While the association between presence of WMHs and cognitive decline in the general population is well recognized, the relationship between WMHs and cognitive performance in individuals living with HIV infection is still somewhat controversial. WMHs have been reported to be associated with some cognitive measures, including worse performance on tests of psychomotor speed and verbal memory (34). Additionally, decreased white matter volume in HIV seropositive individuals has been associated with dementia (35).…”

The Role of Medical Imaging in Defining CNS Abnormalities Associated with HIV-Infection and Opportunistic Infections

“…These studies consistently revealed a severe reduction of NAA in the cortex and frontal white matter in those with more severe cognitive impairment [54][55][56][57][63][64][65][66][67][68]. Furthermore, increasing levels of Cho and mI in the basal ganglia and the frontal white matter were also associated with an increasing severity of cognitive impairment and a greater decline in CD4 count [12,54]. While these findings are fundamental to our understanding of the underlying metabolic mechanisms behind the progression of cognitive decay in patients with HIV dementia, more research is needed to determine how HIV affects those in the early disease stage as well as asymptomatic subjects.…”

“…The most common findings included regional gray matter atrophy, particularly in the basal ganglia [4][5][6], Electronic supplementary material The online version of this article (doi:10.1007/s13311-010-0010-4) contains supplementary material, which is available to authorized users. white matter lesions [7,8], ventricular expansion [9], and global cerebral atrophy [7,[10][11][12]. More recent studies have further elucidated these effects using more advanced image acquisition and volumetric measurement techniques.…”

“…By quantifying N-acetylaspartate (NAA), creatine (Cr), choline (Cho), lactate and myo-inositol (mI), MRS offers insight into the neuronal integrity, cell membrane synthesis and turnover, macrophage infiltration, inflammation status, and levels of microglial activation and astrogliosis within the sampled CNS tissue. Marked differences between metabolite concentrations and their ratios in the CNS of both HIV-infected and simian immunodeficiency virus (SIV)-infected subjects and controls are very well documented [12,[52][53][54][55][56][57][58][59][60][61][62]. By studying these metabolite differences at different stages of the infection, it is possible to chronicle when and how regions of interest are impacted.…”