HIV-associated neurocognitive disorders remain common despite use of potent antiretroviral therapy (ART). Ongoing viral replication due to poor distribution of antivirals into the CNS may increase risk for HIV-associated neurocognitive disorders. This study's objective was to determine penetration of a commonly prescribed antiretroviral drug, efavirenz, into CSF.
CHARTER is an ongoing, North American, multicentre, observational study to determine the effects of ART on HIV-associated neurological disease. Single random plasma and CSF samples were drawn within 1 h of each other from subjects taking efavirenz between September 2003 and July 2007. Samples were assayed by HPLC or HPLC/mass spectrometry with detection limits of 39 ng/mL (plasma) and <0.1 ng/mL (CSF).
Eighty participants (age 44 ± 8 years; 79 ± 15 kg; 20 females) had samples drawn 12.5 ± 5.4 h post-dose. The median efavirenz concentrations after a median of 7 months [interquartile range (IQR) 2–17] of therapy were 2145 ng/mL in plasma (IQR 1384–4423) and 13.9 ng/mL in CSF (IQR 4.1–21.2). The CSF/plasma concentration ratio from paired samples drawn within 1 h of each other was 0.005 (IQR 0.0026–0.0076; n = 69). The CSF/IC50 ratio was 26 (IQR 8–41) using the published IC50 for wild-type HIV (0.51 ng/mL). Two CSF samples had concentrations below the efavirenz IC50 for wild-type HIV.
Efavirenz concentrations in the CSF are only 0.5% of plasma concentrations but exceed the wild-type IC50 in nearly all individuals. Since CSF drug concentrations reflect those in brain interstitial fluids, efavirenz reaches therapeutic concentrations in brain tissue.
CNS; pharmacology; non-nucleoside reverse transcriptase inhibitors
The HIV Dementia Scale (HDS) was developed to screen for HIV-associated Neurocognitive Disorders (HAND), but concerns have persisted regarding its substandard sensitivity. This study aimed to examine the classification accuracy of the HDS using raw and norm-based cutpoints, and to evaluate the contribution of the HDS subtests to predicting HAND.
1,580 HIV-infected participants from 6 U.S. sites completed the HDS, and a gold standard neuropsychological battery, on which 51% of participants were impaired. Results: Sensitivity and specificity to HAND using the standard raw HDS cutpoint were 24% and 92%, respectively. The raw HDS subtests of attention, recall, and psychomotor speed significantly contributed to classification of HAND, while visuomotor construction contributed the least. A modified raw cutpoint of 14 yielded sensitivity of 66% and specificity of 61%, with cross-validation. Using norms also significantly improved sensitivity to 69% with a concomitant reduction of specificity to 56%, while the positive predictive value declined from 75% to 62% and negative predictive value improved from 54% to 64%. The HDS showed similarly modest rates of sensitivity and specificity among subpopulations of individuals with minimal comorbidity and successful viral suppression.
Findings indicate that while the HDS is a statistically significant predictor of HAND, particularly when adjusted for demographic factors, its relatively low diagnostic classification accuracy continues to hinder its clinical utility. A raw cutpoint of 14 greatly improved the sensitivity of the previously established raw cutscore, but may be subject to ceiling effects, particularly on repeat assessments.
HIV; cognition; HIV-associated neurocognitive disorders; screening measures; HIV dementia scale
Apathy is a relatively common psychiatric syndrome in HIV infection, but little is known about its neural correlates. In the present study, we examined the associations between apathy and diffusion tensor imaging (DTI) indices in key frontal white matter regions in the thalamocorticostriatal circuit that has been implicated in the expression of apathy. Nineteen participants with HIV infection and 19 demographically comparable seronegative comparison subjects completed the Apathy subscale of the Frontal Systems Behavioral Scale as a part of a comprehensive neuropsychiatric research evaluation. When compared to the seronegative participants, the HIV+ group had significantly more frontal white matter abnormalities. Within HIV+ persons, and as predicted, higher ratings of apathy were associated with greater white matter alterations in the anterior corona radiata, genu, and orbital medial prefrontal cortex. The associations between white matter alterations and apathy were independent of depression and were stronger among participants with lower current CD4 counts. All told, these findings indicate that apathy is independently associated with white matter abnormalities in anterior, medial brain regions in persons infected with HIV, particularly in the setting of lower current immune functioning, which may have implications for antiretroviral therapy.
Diffusion tensor imaging; apathy; HIV/AIDS; Prefrontal cortex; depression
Genetic elements in HIV-1 subtype B tat and env are associated with neurotoxicity yet less is known about other subtypes. HIV-1 sub-type C tat and env sequences were analyzed to determine viral genetic elements associated with neurocognitive impairment in a large Indian cohort. Population-based sequences of HIV-1 tat (exon 1) and env (C2-V3 coding region) were generated from blood plasma of HIV-infected patients in Pune, India. Participants were classified as cognitively normal or impaired based on neuropsychological assessment. Tests for signature residues, positive and negative selection, entropy, and ambiguous bases were performed using tools available through Los Alamos National Laboratory (http://www.hiv.lanl.gov) and Datamonkey (http://www.datamonkey.org). HIV-1 subtype C tat and env sequences were analyzed for 155 and 160 participants, of which 34–36% were impaired. Two signature residues were unique to impaired participants in exon 1 of tat at codons 29 (arginine) and 68 (proline). Positive selection was noted at codon 29 among normal participants and at codon 68 in both groups. The signature at codon 29 was also a signature for low CD4+ (<200 cells/mm3) counts but remained associated with impairment after exclusion of those with low CD4+ counts. No unique genetic signatures were noted in env. In conclusion, two signature residues were identified in exon 1 of HIV-1 subtype C tat that were associated with neurocognitive impairment in India and not completely accounted for by HIV disease progression. These signatures support a linkage between diversifying selection in HIV-1 subtype C tat and neurocognitive impairment.
neuropsychological testing; impairment; sequence; signature; residue; clade C
Neurocognitive (NC) impairment (NCI) occurs commonly in people living with HIV. Despite substantial effort, no biomarkers have been sufficiently validated for diagnosis and prognosis of NCI in the clinic. The goal of this project was to identify diagnostic or prognostic biomarkers for NCI in a comprehensively characterized HIV cohort.
Multidisciplinary case review selected 98 HIV-infected individuals and categorized them into four NC groups using normative data: stably normal (SN), stably impaired (SI), worsening (Wo), or improving (Im). All subjects underwent comprehensive NC testing, phlebotomy, and lumbar puncture at two timepoints separated by a median of 6.2 months. Eight biomarkers were measured in CSF and blood by immunoassay. Results were analyzed using mixed model linear regression and staged recursive partitioning.
At the first visit, subjects were mostly middle-aged (median 45) white (58%) men (84%) who had AIDS (70%). Of the 73% who took antiretroviral therapy (ART), 54% had HIV RNA levels below 50 c/mL in plasma. Mixed model linear regression identified that only MCP-1 in CSF was associated with neurocognitive change group. Recursive partitioning models aimed at diagnosis (i.e., correctly classifying neurocognitive status at the first visit) were complex and required most biomarkers to achieve misclassification limits. In contrast, prognostic models were more efficient. A combination of three biomarkers (sCD14, MCP-1, SDF-1α) correctly classified 82% of Wo and SN subjects, including 88% of SN subjects. A combination of two biomarkers (MCP-1, TNF-α) correctly classified 81% of Im and SI subjects, including 100% of SI subjects.
This analysis of well-characterized individuals identified concise panels of biomarkers associated with NC change. Across all analyses, the two most frequently identified biomarkers were sCD14 and MCP-1, indicators of monocyte/macrophage activation. While the panels differed depending on the outcome and on the degree of misclassification, nearly all stable patients were correctly classified.
HIV; Neurocognitive Disorders; Cerebrospinal Fluid; Biomarkers
Brazil accounts for the largest number of HIV+ persons in Latin America, and this epidemic poses a significant public health burden in this country. Little is known about the neuropsychiatric and functional consequences of HIV infection in this population.
Participants were 43 HIV+ and 29 HIV- individuals who underwent a neuropsychological, psychiatric and neurological evaluation that included self-report measures of mood (Beck Depression Inventory-II; BDI-II), neurocognitive complaints (Patient's Assessment of Own Functioning Inventory) and declines in instrumental activities of daily living (Activities of Daily Living questionnaire). The MINI-Plus generated Major depressive disorder (MDD) diagnoses. Apathy, defined as social withdrawal, decision-making difficulty, loss of interest and pleasure, was measured using items from the BDI-II and the neurological evaluation.
When compared with seronegative participants, HIV+ individuals endorsed higher levels of apathy spectrum symptoms. After adjusting for mood and other covariates, apathy significantly predicted worse everyday functioning.
Limitations: The small sample size, along with the self-report measures used to evaluate apathy and functional difficulties limit the inferences that may be drawn from our findings.
Our Brazilian HIV+ cohort endorsed apathy and depression as well as significant functional complaints. Although correlated with depression, apathy was uniquely associated with functional difficulties. Clinical attention to apathy and depression in HIV-infected Brazilians may help identify patients at risk for functional difficulties who may benefit from additional support to maintain independence.
HIV/AIDS; Activities of Daily Living; Apathy; Depression; Brazil; Everyday functioning
The aim of this work is to study the possible association between retinal nerve fiber layer (NFL) thickness and driving ability.
Thirty-eight drivers including 22 HIV-positive (HIV+) and 16 age-matched HIV-negative controls participants underwent a full ophthalmologic evaluation, including assessment of retinal NFL thickness. In the undilated state with standard optical correction and under standard illumination they also completed a computer-based, wide field-of-view driving simulation in which they were to obey traffic laws, engage in crash avoidance, and pass slower automobiles. Crashes, speeding and traffic light tickets, and off-road excursions contributed to a weighted score of driving errors.
HIV-seropositive participants had a significantly higher weighted error score than control participants (18.4 [9.2] vs. 11.1 [4.5], p=0.006). NFL thickness was significantly correlated with driving errors (r=−0.51, p=0.025); there was a trend for participants with a CD4 nadir <100 to have more errors than those with a nadir >100 (29.7 [13.2] vs. 19.3 [8.4], p = 0.056). The highest number of driving errors occurred in individuals with both CD4 <100 and NFL thickness <80.
Driving ability may be impacted by reductions in retinal nerve fiber layer thickness. Physicians should consider the potential impact that more complex ophthalmologic conditions in HIV-infected patients may have on driving performance.
HIV infection; Retinal nerve fiber layer thinning; Automobile driving; Vision function; Driving simulation
Etravirine has high affinity for plasma drug-binding proteins, such as albumin and α1-acid glycoprotein, which limits the amount of unbound etravirine available to enter the CNS. The objective of this study was to compare total and unbound etravirine concentrations in CSF with plasma concentrations and the in vitro median inhibitory concentration (IC50) for wild-type HIV (0.9 ng/mL).
Total and bound etravirine concentrations were measured in 17 CSF and plasma pairs by isotope-dilution liquid chromatography tandem mass spectroscopy, radioligand displacement and ultracentrifugation. Unbound etravirine concentrations were calculated from the bound fraction. The dynamic range of the assay was 7.8–2000 (plasma) and 0.78–200 (CSF) ng/mL.
Subjects were mostly middle-aged (median 43 years) white (78%) men (89%). All CSF etravirine concentrations were above the limit of quantification. Total and unbound median etravirine concentrations in CSF were 9.5 (IQR 6.4, 26.4) and 0.13 (IQR 0.08, 0.27) ng/mL, respectively. Etravirine was 96% (IQR 94.5, 97.2) protein bound in plasma and 98.4% (IQR 97.8, 98.8) in CSF. Total etravirine in CSF was 4.3% (IQR 3, 5.9) of total and 101% (IQR 76, 160) of unbound etravirine in plasma. There were no significant correlations between unbound etravirine concentrations and concentrations of albumin in plasma or CSF. Unbound etravirine concentrations in CSF did not reach the wild-type IC50 in any of the specimens.
Unbound etravirine may not achieve optimal concentrations to inhibit HIV replication in the CNS.
HIV; antiretroviral therapy; central nervous system; CNS; protein binding; CSF
Optimal antiretroviral therapy (ART) effectiveness depends upon medication adherence, which is a complex behavior with many contributing factors including neurocognitive function. Pharmacy refill records offer a promising and practical tool to assess adherence.
A substudy of the CHARTER (CNS HIV Anti-Retroviral Therapy Effects Research) study was conducted at the Johns Hopkins University (JHU) and the University of Washington (UW). Pharmacy refill records were the primary method to measure ART adherence, indexed to a “sentinel” drug with the highest central nervous system penetration effectiveness score.
Standardized neuromedical, neuropsychological, psychiatric and substance use assessments were performed at enrollment and at 6 months. Regression models were used to determine factors associated with adherence and the relationships between adherence and change in plasma and cerebrospinal fluid HIV RNA concentrations between visits.
Among 80 (33 JHU, 47 UW) participants, the mean adherence score was 86.4% with no difference by site. In the final multivariable model, better neurocognitive function was associated with better adherence, especially among participants who were at JHU, male, and HIV-infected for a longer time-period. Worse performance on working memory tests was associated with worse adherence. Better adherence predicted greater decreases in cerebrospinal fluid HIV RNA between visits.
Poorer global neurocognitive functioning and deficits in working memory were associated with lower adherence defined by a pharmacy refill record measure, suggesting that assessments of cognitive function, and working memory in particular, may identify patients at risk for poor ART adherence who would benefit from adherence support.
HIV; adherence; cognitive impairment; pharmacy refill records; HAND; CPE
We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling either medium dose (3.53%), low dose (1.29%), or placebo cannabis with the primary outcome being VAS pain intensity. Psychoactive side-effects, and neuropsychological performance were also evaluated. Mixed effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the two active dose groups’ results (p>0.7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo vs. low dose, 2.9 for placebo vs. medium dose, and 25 for medium vs. low dose. As these NNT are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being, for all intents and purposes, as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well-tolerated, and neuropsychological effects were of limited duration and readily reversible within 1–2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain.
neuropathic pain; analgesia; cannabis; clinical trial; neuropsychological testing
Binge drinking is common among adolescents. Alcohol use, and binge-drinking in particular, has been associated with neurocognitive deficits as well as risk-taking behaviors, which may contribute to negative driving outcomes among adolescents even while sober.
To examine differences in self-reported driving behaviors between adolescent binge-drinkers and a matched sample of controls, including (a) compliance with graduated licensing laws, (b) high risk driving behaviors, and (c) driving outcomes (crashes, traffic tickets).
The present study examined driving behaviors and outcomes in adolescent recent binge drinkers (n=21) and demographically and driving history matched controls (n=17), ages 16-18.
Binge drinkers more frequently violated graduated licensing laws (e.g., driving late at night), and engaged in more “high risk” driving behaviors, such as speeding and using a cell-phone while driving. Binge drinkers had more traffic tickets, crashes and “near crashes” than the control group. In a multivariate analysis, binge drinker status and speeding were the most robust predictors of a crash.
Binge drinking teens consistently engage in more dangerous driving behaviors and experience more frequent crashes and traffic tickets. They are also less compliant with preventative restrictions placed on youth while they are learning critical safe driving skills.
These findings highlight a need to examine the contribution of underlying traits (such as sensation seeking) and binge-related cognitive changes to these high-risk driving behaviors, which may assist researchers in establishing alternative prevention and policy efforts targeting this population.
adolescent alcohol use; graduated licensing laws; risky driving
Among English-speaking adults, HIV-associated neuropsychological (NP) impairments have been associated with problems in everyday functioning, including ability to function at work and drive an automobile. Latinos account for a disproportionate number of HIV/AIDS cases nationwide, and a significant segment of this population is primarily Spanish speaking. We have previously developed an assessment that evaluates English-speakers on a variety of instrumental activities of daily living. In this pilot study, we used Spanish-language translations of our functional battery to investigate the cultural relevance of such measures, and to explore relationships between NP status and ability to perform important everyday tasks in HIV-infected Spanish-speakers. Sixteen HIV-infected monolingual Spanish-speaking adults received comprehensive, Spanish language NP testing and functional assessments included the following domains: Medication Management, Cooking, Finances, Shopping, and Restaurant Scenario. Results revealed that most of the functional tasks appeared culturally relevant and appropriate with minor modifications. NP-impaired participants were significantly more functionally impaired compared to NP-normals (88% vs. 13%, p<.01). Performances on the functional assessment and the NP battery were also related to indicators of real world functioning, including employment status and quality of life. These results, though preliminary, suggest that Spanish language functional assessments are potentially valid tools for detecting everyday functioning deficits associated with NP impairments in HIV-infected Spanish-speakers.
Apathy is a relatively common clinical feature of HIV-Associated Neurocognitive Disorders, but little is known about its implications for everyday functioning outcomes. In the present study, we examined the associations between apathy and self-reported instrumental activities of daily living (IADL) and neurocognitive complaints in 75 participants with HIV infection and 52 demographically comparable seronegative comparison subjects. All volunteers completed the apathy subscale of the Frontal Systems Behavioral Scale as part of a comprehensive neuromedical, psychiatric, and neurocognitive research evaluation. When compared with the seronegative comparison participants, the HIV+ group reported significantly higher current levels of apathy, but did not differ in self-report of prior (i.e., pre-seroconversion) apathy. Higher current apathy self-ratings were associated with greater severity of IADL declines and more numerous cognitive complaints in the HIV+ sample, even after adjusting for potential psychiatric (e.g., depression), medical (e.g., hepatitis C co-infection), and neurocognitive predictors. Cognitive complaints, but not IADLs, were also uniquely associated with ratings of executive dysfunction and disinhibition. All told, these findings suggest that apathy may make a unique contribution to important everyday functioning outcomes among persons living with HIV infection. The clinical detection of apathy may help identify HIV-infected individuals at particular risk for functional impairments who may require additional support to maintain independence.
HIV/AIDS; Activities of daily living; Apathy; Everyday functioning
In May 2012, the Division of AIDS Research at the National Institute of Mental Health (NIMH) organized the “Global NeuroAIDS Roundtable” in conjunction with the 11th International Symposium on Neurovirology and the 2012 Conference on HIV in the Nervous System. The meeting was held in New York, NY, USA and brought together NIMH-funded investigators who are currently working on projects related to the neurological complications of AIDS (NeuroAIDS) in Africa, Asia, Eastern Europe, and Latin America in order to provide an opportunity to share their recent findings and discuss the challenges encountered within each country. The major goals of the roundtable were to evaluate HIV-associated neurocognitive impairment and determine if it may be directly attributable to distinct HIV subtypes or clades and to discuss the future priorities for global NeuroAIDS research. At the “Global NeuroAIDS Roundtable”, presentations of preliminary research indicated that HIV-associated neurocognitive impairment is prevalent in all countries examined regardless of which HIV clade is present in the region. The only clear-cut difference between HIV-1 clades was in relation to subtypes A and D in Uganda. However, a key point that emerged from the discussions was that there is an urgent need to standardize neurocognitive assessment methodologies across the globe before definitive conclusions can be drawn regarding the relationship between HIV clade diversity and neuropathogenesis. Future research directions were also discussed at the roundtable with particular emphasis on the potential of viral and host factor molecular interactions to impact the pathophysiology of HIV-associated neurocognitive disorders (HAND) from a global perspective.
Human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2); Acquired immunodeficiency syndrome (AIDS); HIV clade; NeuroAIDS; HIV-associated neurocognitive disorders (HAND); Neuropathogenesis
The HIV epidemic in China has expanded rapidly in recent years, but little is known about the prevalence and features of HIV Associated Neurocognitive Disorders (HANDs) in this part of the world. We administered a comprehensive Western neuropsychological (NP) test battery to 203 HIV+ and 198 HIV-former plasma donors in the rural area of Anhui province. We found that 26% in the HIV- sample, and 46% in the HIV+ sample were infected with HCV, which can also have CNS effects. To classify NP impairment, we developed demographically corrected test norms based upon individuals free of both infections (N=141). Using a global summary score, NP impairment was found in 34.2% of the HIV mono-infected group and 39.7% of the co-infected group, as compared to 12.7% of the uninfected controls (p<.001). HIV+ participants with AIDS were more likely to be impaired (43%) than non-AIDS individuals (29%, p<.05). Lastly, when all infection groups were combined, participants with NP impairment reported more cognitive complaints (p<.01) and increased dependence in everyday functioning (p=.01). In sum, NP impairment in this large rural Chinese sample was associated with both HIV and HCV infections, and the impairment's prevalence, severity, and pattern were similar to those reported by Western studies. Clinical significance of NP impairment in this population is suggested by the participants’ reports of reduced everyday functioning. These findings indicate that HAND is likely to be an important feature of HIV infection in developing countries, underscoring the need for international efforts to develop CNS relevant treatments.
HIV; HCV; neurocognitive disorders; China
Depression frequently co-occurs with HIV infection and can result in self-reported overestimates of cognitive deficits. Conversely, genuine cognitive dysfunction can lead to an under-appreciation of cognitive deficits. The degree to which depression and cognition influence self-report of capacity for instrumental activities of daily living (IADLs) requires further investigation. This study examined the effects of depression and cognitive deficits on self-appraisal of functional competence among 107 HIV-infected adults. As hypothesized, higher levels of depression were found among those who over-reported problems in medication management, driving, and cognition when compared to those who under-reported or provided accurate self-assessments. In contrast, genuine cognitive dysfunction was predictive of under-reporting of functional deficits. Together, these results suggest that over-reliance on self-reported functional status poses risk for error when diagnoses require documentation of both cognitive impairment and associated functional disability in everyday life.
Depression; Self-report; Functional ability; Cognition; HIV
The present study aimed to examine if bilingualism affects executive functions and verbal fluency in Marathi and Hindi, two major languages in India, with a considerable cognate (e.g., activity is actividad in Spanish) overlap. A total of 174 native Marathi speakers from Pune, India, with varying levels of Hindi proficiency were administered tests of executive functioning and verbal performance in Marathi. A bilingualism index was generated using self-reported Hindi and Marathi proficiency. After controlling for demographic variables, the association between bilingualism and cognitive performance was examined. Degree of bilingualism predicted better performance on the switching (Color Trails-2) and inhibition (Stroop Color-Word) components of executive functioning; but not for the abstraction component (Halstead Category Test). In the verbal domain, bilingualism was more closely associated with noun generation (where the languages share many cognates) than verb generation (which are more disparate across these languages), as predicted. However, contrary to our hypothesis that the bilingualism “disadvantage” would be attenuated on noun generation, bilingualism was associated with an advantage on these measures. These findings suggest distinct patterns of bilingualism effects on cognition for this previously unexamined language pair, and that the rate of cognates may modulate the association between bilingualism and verbal performance on neuropsychological tests.
Multilingualism; Neuropsychological tests; India; Adult; Executive functions; Cognition
Since HIV-1 Tat has been associated with neurocognitive dysfunction, we investigated 60 HIV-1 subtype B infected individuals who were characterized for neurocognitive functioning and had paired CSF and blood plasma samples available. To avoid issues with repeated sampling, we generated population-based HIV-1 tat sequences from each compartment and evaluated these data using a battery of phylogenetic, statistical and machine learning tools. These analyses identified position HXB2 5905 within the cysteine-rich domain of tat as a signature of CSF-derived HIV-1, and a higher number of mixed bases in CSF, measure of diversity, was associated with HIV-associated neurocognitive disorder. Since identified mutations were synonymous, we evaluated the predicted secondary RNA structures, which showed that this mutation altered secondary structure. As a measure of divergence, the genetic distance between the blood and CSF derived tat was inversely correlated with current and nadir CD4+ T cell counts. These data suggest that specific HIV-1 features of tat influence neurotropism and neurocognitive impairment.
HIV; central nervous system; tat; compartmentalization
To describe a severe form of demyelinating HIV-associated leukoencephalopathy in AIDS patients failing highly active antiretroviral therapy (HAART), its relationship to clinical and neuroimaging findings, and suggest hypotheses regarding pathogenesis.
Design and methods
AIDS patients who failed HAART and displayed severe leukoencephalopathy were included. All cases had detailed neuromedical, neuropsychological, neuroimaging and postmortem neuropathological examination. Immunocytochemical and PCR analyses were performed to determine brain HIV levels and to exclude other viruses.
Seven recent autopsy cases of leukoencephalopathy in antiretroviral-experienced patients with AIDS were identified. Clinically, all were severely immunosuppressed, six (86%) had poorly controlled HIV replication despite combination antiretroviral therapy, and five (71%) had HIV-associated dementia. Neuropathologically, all seven had intense perivascular infiltration by HIV-gp41 immunoreactive monocytes/macrophages and lymphocytes, widespread myelin loss, axonal injury, microgliosis and astrogliosis. The extent of damage exceeds that described prior to the use of HAART. Brain tissue demonstrated high levels of HIV RNA but evidence of other pathogens, such as JC virus, Epstein–Barr virus, cytomegalovirus, human herpes virus type-8, and herpes simplex virus types 1 and 2, was absent. Comparison of the stages of pathology suggests a temporal sequence of events. In this model, white matter damage begins with perivascular infiltration by HIV-infected monocytes, which may occur as a consequence of antiretroviral-associated immune restoration. Intense infiltration by immune cells injures brain endothelial cells and is followed by myelin loss, axonal damage, and finally, astrogliosis.
Taken together, our findings provide evidence for the emergence of a severe form of HIV-associated leukoencephalopathy. This condition warrants further study and increased vigilance among those who provide care for HIV-infected individuals.
HIV leukoencephalopathy; antiretroviral therapy
Script generation describes one’s ability to produce complex, sequential action plans derived from mental representations of everyday activities. The aim of this study was to assess the effect of HIV infection on script generation performance. Sixty HIV+ individuals (48% of whom had HIV-associated neurocognitive disorders [HAND]) and 26 demographically comparable HIV− participants were administered a novel, standardized test of script generation, which required participants to verbally generate and organize the necessary steps for completing six daily activities. HAND participants evidenced significantly more total errors, intrusions, and script boundary errors compared to the HIV-sample, indicating difficulties inhibiting irrelevant actions and staying within the prescribed boundaries of scripts, but had adequate knowledge of the relevant actions required for each script. These findings are generally consistent with the executive dysfunction and slowing common in HAND and suggest that script generation may play a role in everyday functioning problems in HIV.
Human immunodeficiency virus; cognition; neuropsychology; activities of daily living; executive functions; frontal lobes
Spasticity is a common and poorly controlled symptom of multiple sclerosis. Our objective was to determine the short-term effect of smoked cannabis on this symptom.
We conducted a placebo-controlled, crossover trial involving adult patients with multiple sclerosis and spasticity. We recruited participants from a regional clinic or by referral from specialists. We randomly assigned participants to either the intervention (smoked cannabis, once daily for three days) or control (identical placebo cigarettes, once daily for three days). Each participant was assessed daily before and after treatment. After a washout interval of 11 days, participants crossed over to the opposite group. Our primary outcome was change in spasticity as measured by patient score on the modified Ashworth scale. Our secondary outcomes included patients’ perception of pain (as measured using a visual analogue scale), a timed walk and changes in cognitive function (as measured by patient performance on the Paced Auditory Serial Addition Test), in addition to ratings of fatigue.
Thirty-seven participants were randomized at the start of the study, 30 of whom completed the trial. Treatment with smoked cannabis resulted in a reduction in patient scores on the modified Ashworth scale by an average of 2.74 points more than placebo (p < 0.0001). In addition, treatment reduced pain scores on a visual analogue scale by an average of 5.28 points more than placebo (p = 0.008). Scores for the timed walk did not differ significantly between treatment and placebo (p = 0.2). Scores on the Paced Auditory Serial Addition Test decreased by 8.67 points more with treatment than with placebo (p = 0.003). No serious adverse events occurred during the trial.
Smoked cannabis was superior to placebo in symptom and pain reduction in participants with treatment-resistant spasticity. Future studies should examine whether different doses can result in similar beneficial effects with less cognitive impact.
A subset of individuals with HIV-associated neurocognitive impairment experience related deficits in “real world” functioning (i.e., independently performing instrumental activities of daily living [IADL]). While performance-based tests of everyday functioning are reasonably sensitive to HIV-associated IADL declines, questions remain regarding the extent to which these tests’ highly structured nature fully captures the inherent complexities of daily life. The aim of this study was to assess the predictive and ecological validity of a novel multitasking measure in HIV infection.
Participants included 60 individuals with HIV infection (HIV+) and 25 demographically comparable seronegative adults (HIV−). Participants were administered a comprehensive neuropsychological battery, questionnaires assessing mood and everyday functioning, and a novel standardized test of multitasking, which involved balancing the demands of four interconnected performance-based functional tasks (i.e., financial management, cooking, medication management, and telephone communication).
HIV+ individuals demonstrated significantly worse overall performance, fewer simultaneous task attempts, and increased errors on the multitasking test as compared to the HIV− sample. Within the HIV+ sample, multitasking impairments were modestly associated with deficits on standard neuropsychological measures of executive functions, episodic memory, attention/working memory, and information processing speed, providing preliminary evidence for convergent validity. More importantly, multivariate prediction models revealed that multitasking deficits were uniquely predictive of IADL dependence beyond the effects of depression and global neurocognitive impairment, with excellent sensitivity (86%), but modest specificity (57%).
Taken together, these data indicate that multitasking ability may play an important role in successful everyday functioning in HIV+ individuals.
HIV; cognition; neuropsychology; activities of daily living; executive functions
China’s HIV epidemic commenced in its agrarian provinces through contaminated commercial plasma donation centers and is now becoming a public health concern nationwide. Little is known of the psychiatric and substance use disorder characteristics of this population, or their impact on everyday function, employment, and life quality.
HIV infected (HIV+) former plasma donors (N = 203) and HIV-negative (HIV-) donor controls (N = 198) completed the World Mental Health Survey Composite International Diagnostic Interview to determine lifetime major depressive disorder (MDD), substance use disorders, and suicidality. Current mood and suicidality were assessed with the Beck Depression Inventory-II. Everyday function was measured by an Activity of Daily Living questionnaire; life quality was evaluated by the Medical Outcomes Study-HIV.
According to the multi-process theory of prospective memory (ProM), time-based tasks rely more heavily on strategic processes dependent on prefrontal systems than do event-based tasks. Given the prominent frontostriatal pathophysiology of HIV infection, one would expect HIV-infected individuals to demonstrate greater deficits in time-based versus event-based ProM. However, the two prior studies examining this question have produced variable results. We evaluated this hypothesis in 143 individuals with HIV infection and 43 demographically similar seronegative adults (HIV−) who completed the research version of the Memory for Intentions Screening Test, which yields parallel subscales of time- and event-based ProM. Results showed main effects of HIV serostatus and cue type, but no interaction between serostatus and cue. Planned pair-wise comparisons showed a significant effect of HIV on time-based ProM and a trend-level effect on event-based ProM that was driven primarily by the subset of participants with HIV-associated neurocognitive disorders. Nevertheless, time-based ProM was more strongly correlated with measures of executive functions, attention/working memory, and verbal fluency in HIV-infected persons. Although HIV-associated deficits in time- and event-based ProM appear to be of comparable severity, the cognitive architecture of time-based ProM may be more strongly influenced by strategic monitoring and retrieval processes.
AIDS dementia complex; Episodic memory; Executive functions; Neuropsychological assessment
Combination antiretroviral therapy (CART) has greatly reduced medical morbidity and mortality with HIV infection, but high rates of HIV-associated neurocognitive disorders (HAND) continue to be reported. Because large HIV-infected (HIV+) and uninfected (HIV−) groups have not been studied with similar methods in the pre-CART and CART eras, it is unclear whether CART has changed the prevalence, nature, and clinical correlates of HAND. We used comparable methods of subject screening and assessments to classify neurocognitive impairment (NCI) in large groups of HIV + and HIV − participants from the pre-CART era (1988–1995; N = 857) and CART era (2000–2007; N = 937). Impairment rate increased with successive disease stages (CDC stages A, B, and C) in both eras: 25%, 42%, and 52% in pre-CART era and 36%, 40%, and 45% in CART era. In the medically asymptomatic stage (CDC-A), NCI was significantly more common in the CART era. Low nadir CD4 predicted NCI in both eras, whereas degree of current immunosuppression, estimated duration of infection, and viral suppression in CSF (on treatment) were related to impairment only pre-CART. Pattern of NCI also differed: pre-CART had more impairment in motor skills, cognitive speed, and verbal fluency, whereas CART era involved more memory (learning) and executive function impairment. High rates of mild NCI persist at all stages of HIV infection, despite improved viral suppression and immune reconstitution with CART. The consistent association of NCI with nadir CD4 across eras suggests that earlier treatment to prevent severe immunosuppression may also help prevent HAND. Clinical trials targeting HAND prevention should specifically examine timing of ART initiation.
HIV; Combination antiretroviral therapy; HIV dementia