Neurological complications of acquired immune deficiency syndrome: analysis of 50 patients

Changes in cerebrospinal fluid proteins across the spectrum of untreated and treated chronic HIV-1 infection

Using the Olink Explore 1536 platform, we measured 1,463 unique proteins in 303 cerebrospinal fluid (CSF) specimens from four clinical centers contributed by uninfected controls and 12 groups of people living with HIV-1 infection representing the spectrum of progressive untreated and treated chronic infection. We present three initial analyses of these measurements: an overview of the CSF protein features of the sample; correlations of the CSF proteins with CSF HIV-1 RNA and neurofilament light chain protein (NfL) concentrations; and comparison of CSF proteins in HIV-associated dementia (HAD) and neurosymptomatic CSF escape (NSE). These reveal a complex but coherent picture of CSF protein changes with highest concentrations of many proteins during CNS injury in the HAD and NSE groups and variable protein changes across the course of systemic HIV-1 progression that included two common patterns, designated as lymphoid and myeloid patterns, related to principal involvement of their underlying inflammatory cell lineages. Antiretroviral therapy reduced CSF protein perturbations, though not always to control levels. The dataset of these CSF protein measurements, along with background clinical information, is posted online. Extended studies of this unique dataset will supplement this report to provide more detailed characterization of the dynamic impact of HIV-1 infection on the CSF proteome across the spectrum of HIV-1 infection, advancing the mechanistic understanding of HIV-1-related CNS pathobiology.

Machine learning for predicting cognitive deficits using auditory and demographic factors

IMPORTANCE

Predicting neurocognitive deficits using complex auditory assessments could change how cognitive dysfunction is identified, and monitored over time. Detecting cognitive impairment in people living with HIV (PLWH) is important for early intervention, especially in low- to middle-income countries where most cases exist. Auditory tests relate to neurocognitive test results, but the incremental predictive capability beyond demographic factors is unknown.

OBJECTIVE

Use machine learning to predict neurocognitive deficits, using auditory tests and demographic factors.

SETTING

The Infectious Disease Center in Dar es Salaam, Tanzania.

PARTICIPANTS

Participants were 939 Tanzanian individuals from Dar es Salaam living with and without HIV who were part of a longitudinal study. Patients who had only one visit, a positive history of ear drainage, concussion, significant noise or chemical exposure, neurological disease, mental illness, or exposure to ototoxic antibiotics (e.g., gentamycin), or chemotherapy were excluded. This provided 478 participants (349 PLWH, 129 HIV-negative). Participant data were randomized to training and test sets for machine learning.

MAIN OUTCOME(S) AND MEASURE(S)

The main outcome was whether auditory variables combined with relevant demographic variables could predict neurocognitive dysfunction (defined as a score of <26 on the Kiswahili Montreal Cognitive Assessment) better than demographic factors alone. The performance of predictive machine learning algorithms was primarily evaluated using the area under the receiver operational characteristic curve. Secondary metrics for evaluation included F1 scores, accuracies, and the Youden's indices for the algorithms.

RESULTS

The percentage of individuals with cognitive deficits was 36.2% (139 PLWH and 34 HIV-negative). The Gaussian and kernel naïve Bayes classifiers were the most predictive algorithms for neurocognitive impairment. Algorithms trained with auditory variables had average area under the curve values of 0.91 and 0.87, F1 scores (metric for precision and recall) of 0.81 and 0.76, and average accuracies of 86.3% and 81.9% respectively. Algorithms trained without auditory variables as features were statistically worse (p < .001) in both the primary measure of area under the curve (0.82/0.78) and the secondary measure of accuracy (72.3%/74.5%) for the Gaussian and kernel algorithms respectively.

CONCLUSIONS AND RELEVANCE

Auditory variables improved the prediction of cognitive function. Since auditory tests are easy-to-administer and often naturalistic tasks, they may offer objective measures or predictors of neurocognitive performance suitable for many global settings. Further research and development into using machine learning algorithms for predicting cognitive outcomes should be pursued.

Changes in Cerebrospinal Fluid Proteins across the Spectrum of Untreated and Treated Chronic HIV-1 Infection

Using the Olink Explore 1536 platform, we measured 1,463 unique proteins in 303 cerebrospinal fluid (CSF) specimens from four clinical centers that included uninfected controls and 12 groups of people living with HIV-1 infection representing the spectrum of progressive untreated and treated chronic infection. We present three initial analyses of these measurements: an overview of the CSF protein features of the sample; correlations of the CSF proteins with CSF HIV-1 RNA and neurofilament light chain protein (NfL) concentrations; and comparison of the CSF proteins in HIV-associated dementia ( HAD ) and neurosymptomatic CSF escape ( NSE ). These reveal a complex but coherent picture of CSF protein changes that includes highest concentrations of many proteins during CNS injury in the HAD and NSE groups and variable protein changes across the course of neuroasymptomatic systemic HIV-1 progression, including two common patterns, designated as lymphoid and myeloid patterns, related to the principal involvement of their underlying inflammatory cell lineages. Antiretroviral therapy reduced CSF protein perturbations, though not always to control levels. The dataset of these CSF protein measurements, along with background clinical information, is posted online. Extended studies of this unique dataset will provide more detailed characterization of the dynamic impact of HIV-1 infection on the CSF proteome across the spectrum of HIV-1 infection, and further the mechanistic understanding of HIV-1-related CNS pathobiology.

Antiretroviral drugs from multiple classes induce loss of excitatory synapses between hippocampal neurons in culture

Introduction: Antiretroviral (ARV) drugs have improved prognoses for people living with HIV. However, HIV-associated neurocognitive disorders (HAND) persist despite undetectable viral loads. Some ARVs have been linked to neuropsychiatric effects that may contribute to HAND. Synapse loss correlates with cognitive decline in HAND and synaptic deficits may contribute to the neuropsychiatric effects of ARV drugs. Methods: Using an automated high content assay, rat hippocampal neurons in culture expressing PSD95-eGFP to label glutamatergic synapses and mCherry to fill neuronal structures were imaged before and after treatment with 25 clinically used ARVs. Results and Discussion: At a concentration of 10 μM the protease inhibitors nelfinavir and saquinavir, the non-nucleoside reverse transcriptase inhibitors etravirine and the 8-OH metabolite of efavirenz, the integrase inhibitor bictegravir, and the capsid inhibitor lenacapavir produced synaptic toxicity. Only lenacapavir produced synapse loss at the nanomolar concentrations estimated free in the plasma, although all 4 ARV drugs induced synapse loss at Cmax. Evaluation of combination therapies did not reveal synergistic synaptic toxicity. Synapse loss developed fully by 24 h and persisted for at least 3 days. Bictegravir-induced synapse loss required activation of voltage-gated Ca2+ channels and bictegravir, etravirine, and lenacapavir produced synapse loss by an excitotoxic mechanism. These results indicate that select ARV drugs might contribute to neuropsychiatric effects in combination with drugs that bind serum proteins or in disease states in which synaptic function is altered. The high content imaging assay used here provides an efficient means to evaluate new drugs and drug combinations for potential CNS toxicity.

A review of movement disorders in persons living with HIV

BACKGROUND

The human immunodeficiency virus (HIV) causes movement disorders in persons living with HIV (PLH).

OBJECTIVES AND METHODS

We conducted a systematic review on the spectrum of movement disorders in PLH using standard terms for each of the phenomenologies and HIV.

RESULTS

Movement disorders in PLH were commonly attributed to opportunistic infections (OI), dopamine receptor blockade reactions, HIV-associated dementia (HAD), presented during seroconversion, developed due to drug reactions or antiretroviral therapy (ART) itself and lastly, movement disorders occurred as a consequence of the HIV-virus. Parkinsonism in ART naïve PLH was associated with shorter survival, however when Parkinsonism presented in PLH on ART, the syndrome was indistinguishable from Idiopathic Parkinson's disease and responded to therapy. Tremor was often postural due to HAD, drugs or OI. Generalized chorea was most frequent in HIV encephalopathy and toxoplasmosis gondii caused most cases of hemichorea. Ataxia was strongly associated with JCV infection, ART efavirenz toxicity or due to HIV itself. Dystonia was reported in HAD, secondary to drugs and atypical facial dystonias. Both cortical/subcortical and segmental/spinal origin myoclonus were noted mainly associated with HAD. In patients with HIV related opsoclonus-myoclonus-ataxia-syndrome, seroconversion illness was the commonest cause of followed by IRIS and CSF HIV viral escape phenomenon.

CONCLUSIONS

Aetiology of movement disorders in PLH depend on the treatment state. Untreated, PLH are prone to develop OI and HAD and movement disorders. However, as the number of PLH on ART increase and survive longer, the frequency of ART and non-AIDS related complications are likely to increase.

Assessment and Diagnosis of HIV-Associated Dementia

The modern combined antiretroviral treatment (cART) for human immunodeficiency virus (HIV) infection has substantially lowered the incidence of HIV-associated dementia (HAD). The dominant clinical features include deficits in cognitive processing speed, concentration, attention, and memory. As people living with HIV become older, with high rates of comorbidities and concomitant treatments, the prevalence and complexity of cognitive impairment are expected to increase. Currently, the management of HAD and milder forms of HAND is grounded on the best clinical practice, as there is no specific, evidence-based, proven intervention for managing cognitive impairment. The present article acknowledges the multifactorial nature of the cognitive impairments found in HIV patients, outlining the current concepts in the field of HAD. Major areas of interest include neuropsychological testing and neuroimaging to evaluate CNS status, focusing on greater reliability in the exclusion of associated diseases and allowing for earlier diagnosis. Additionally, we considered the evidence for neurological involvement in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the impact of the coronavirus (COVID-19) pandemic, with wider consequences to population health than can be attributed to the virus itself. The indirect effects of COVID-19, including the increased adoption of telehealth, decreased access to community resources, and social isolation, represent a significant health burden, disproportionately affecting older adults with dementia who have limited social networks and increased functional dependence on the community and health system. This synopsis reviews these aspects in greater detail, identifying key gaps and opportunities for researchers and clinicians; we provide an overview of the current concepts in the field of HAD, with suggestions for diagnosing and managing this important neurological complication, which is intended to be applicable across diverse populations, in line with clinical observations, and closely representative of HIV brain pathology.

Guillain-Barré syndrome spectrum as manifestation of HIV-related immune reconstitution inflammatory syndrome: case report and literature review

A 34-year-old man presented with a history of 21-days of gait unsteadiness and diplopia. Ten days before presentation, he developed limb weakness and in the last three days reduced consciousness. HIV infection was diagnosed three months ago (CD4+ = 160 cells/mm³; viral load HIV-1 = 144.000 copies/mL), and antiretroviral therapy was initiated. Impaired consciousness, ophthalmoplegia, limb weakness, ataxia, areflexia, and Babinsky´s sign were noted. At that moment, CD4+ count was 372 cells/mm 3 and viral load HIV-1 <50 copies/mL. The clinical, laboratory and neurophysiological findings suggest overlapping Guillain-Barre syndrome (GBS) and Bickerstaff brainstem encephalitis as manifestation of HIV-related immune reconstitution inflammatory syndrome (IRIS). Here, we review and discuss 7 cases (including the present report) of GBS spectrum as manifestation of HIV-related IRIS.

Evaluation of Computerized Cognitive Training and Cognitive and Daily Function in Patients Living With HIV: A Meta-analysis

IMPORTANCE

In the era of antiretroviral therapy (ART), the incidence of HIV-associated neurocognitive disorder (HAND) has not yet been controlled. With the exception of ART, there is no beneficial pharmacologic treatment. However, some studies have reported that computerized cognitive training (CCT) programs may improve cognitive function among people living with HIV.

OBJECTIVE

To examine the association between CCT programs and 8 domains measuring cognitive function (7 domains) and daily function (1 domain) among people living with HIV.

DATA SOURCES

Records from the Cochrane Library, PsycINFO, PubMed, and Web of Science were searched from database inception to December 15, 2020. Supplementary searches to identify missing studies were conducted in Google Scholar using updated search terms from database inception to November 18, 2021.

STUDY SELECTION

Studies that compared changes before and after a CCT intervention among people living with HIV were included. Search terms were a combination of words associated with HIV (eg, people living with HIV, HIV, and/or AIDS) and cognitive training (eg, cognitive intervention, nonpharmacology intervention, computer game, video game, computerized training, cognitive exercise, cognitive stimulation, and/or cognitive enhancement). Studies were included if they (1) used CCT as the primary intervention or combined CCT with other types of interventions; (2) used placebo, passive control conditions, traditional cognitive training, or single training tasks as control conditions; (3) reported changes between baseline and posttraining; (4) included participants 18 years or older; and (5) were randomized clinical trials (RCTs). Studies were excluded if they (1) were not associated with HIV, (2) were research protocols or feedback reports, (3) were case reports, or (4) did not report findings for domains of interest.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Random-effects models were used to quantitatively synthesize the existing data.

MAIN OUTCOMES AND MEASURES

Primary outcomes were the meta-synthesized changes in each domain after CCT.

RESULTS

Among 1245 records identified, 1043 were screened after removal of duplicates. Of those, 1019 records were excluded based on titles and abstracts, and 24 full-text articles were assessed for eligibility. After exclusions, 12 eligible RCTs were selected for inclusion in the meta-analysis. These RCTs involved 596 total participants, with 320 individuals in the CCT group (mean age, 47.5-59.7 years; 0%-94% female; 8.3-14.2 years of education) and 276 individuals in the control group (mean age, 44.2-60.0 years; 19%-90% female; 9.0-14.9 years of education). The average HIV inhibition ratio (the proportion of participants who achieved virological suppression) ranged from 30% to 100%, and the CD4+ T-cell count ranged from 471 to 833 cells/μL. The time since training ranged from 3 to 24 weeks. After receipt of CCT, function significantly improved in 6 of the 8 domains: abstraction and executive function (standardized mean difference [SMD], 0.58; 95% CI, 0.26-0.91; P < .001), attention and working memory (SMD, 0.62; 95% CI, 0.33-0.91; P < .001), memory (SMD, 0.59; 95% CI, 0.20-0.97; P = .003), motor skills (SMD, 0.50; 95% CI, 0.24-0.77; P < .001), speed of information processing (SMD, 0.65; 95% CI, 0.37-0.94; P < .001), and daily function (SMD, 0.44; 95% CI, 0.02-0.86; P = .04). Sensory and perceptual skills (SMD, 0.06; 95% CI, -0.36 to 0.48; P = .78) and verbal and language skills (SMD, 0.46; 95% CI, -0.07 to 0.99; P = .09) did not significantly improve after CCT.

CONCLUSIONS AND RELEVANCE

This meta-analysis of RCTs found that CCT programs were associated with improvements in cognitive and daily function among people living with HIV. Future studies are needed to design optimal specific training programs and use implementation science to enable the transformation of CCT from a scientific research tool to a real-world clinical intervention.

A pilot study of cognition and creativity among persons with HIV disease referred for neuropsychological evaluation

Creativity can help people to innovate, overcome obstacles, and successfully navigate challenges in daily life. Some aspects of creativity rely on the prefrontostriatal loops and executive functions, which can be compromised in persons with HIV (PWH). This pilot study examined whether neuropsychological functioning plays a role in creativity in PWH. A consecutive series of 41 PWH who were referred to an urban neuropsychology clinic in southeastern Texas were enrolled. Participants completed the Abbreviated Torrance Test for Adults (ATTA) to measure creativity, from which standardized creativity scores of fluency, originality, elaboration, and flexibility were derived. Participants also completed several measures of everyday functioning and a brief clinical neuropsychological battery measuring executive functions, motor skills, memory, and visuoconstruction. Global neuropsychological functioning showed a large, positive association with ATTA creativity performance that did not vary meaningfully by creativity domain and was independent of premorbid IQ. ATTA creativity scores were not associated with any measure of everyday functioning. Findings from this pilot study suggest that higher levels of neuropsychological functioning may support multiple dimensions of creativity in adults with HIV disease. Future studies might examine whether creativity moderates the association between HIV-associated neurocognitive impairment and various health behaviors (e.g., adherence, appointment attendance).

Advances in the Experimental Models of HIV-Associated Neurological Disorders

PURPOSE OF REVIEW

Involvement of the central nervous system (CNS) in HIV-1 infection is commonly associated with neurological disorders and cognitive impairment, commonly referred to as HIV-associated neurocognitive disorders (HAND). Severe and progressive neurocognitive impairment is rarely observed in the post-cART era; however, asymptomatic and mild neurocognitive disorders still exist, despite viral suppression. Additionally, comorbid conditions can also contribute to the pathogenesis of HAND.

RECENT FINDINGS

In this review, we summarize the characterization of HAND, factors contributing, and the functional impairments in both preclinical and clinical models. Specifically, we also discuss recent advances in the animal models of HAND and in in vitro cultures and the potential role of drugs of abuse in this model system of HAND. Potential peripheral biomarkers associated with HAND are also discussed. Overall, this review identifies some of the recent advances in the field of HAND in cell culture studies, animal models, clinical findings, and the limitations of each model system, which can play a key role in developing novel therapeutics in the field.

HIV-Associated Apathy/Depression and Neurocognitive Impairments Reflect Persistent Dopamine Deficits

Individuals living with human immunodeficiency virus type 1 (HIV-1) are often plagued by debilitating neurocognitive impairments and affective alterations;the pathophysiology underlying these deficits likely includes dopaminergic system dysfunction. The present review utilized four interrelated aims to critically examine the evidence for dopaminergic alterations following HIV-1 viral protein exposure. First, basal dopamine (DA) values are dependent upon both brain region andexperimental approach (i.e., high-performance liquid chromatography, microdialysis or fast-scan cyclic voltammetry). Second, neurochemical measurements overwhelmingly support decreased DA concentrations following chronic HIV-1 viral protein exposure. Neurocognitive impairments, including alterations in pre-attentive processes and attention, as well as apathetic behaviors, provide an additional line of evidence for dopaminergic deficits in HIV-1. Third, to date, there is no compelling evidence that combination antiretroviral therapy (cART), the primary treatment regimen for HIV-1 seropositive individuals, has any direct pharmacological action on the dopaminergic system. Fourth, the infection of microglia by HIV-1 viral proteins may mechanistically underlie the dopamine deficit observed following chronic HIV-1 viral protein exposure. An inclusive and critical evaluation of the literature, therefore, supports the fundamental conclusion that long-term HIV-1 viral protein exposure leads to a decreased dopaminergic state, which continues to persist despite the advent of cART. Thus, effective treatment of HIV-1-associated apathy/depression and neurocognitive impairments must focus on strategies for rectifying decreases in dopamine function.

Cerebrospinal fluid immune markers and HIV-associated neurocognitive impairments: A systematic review

HIV-1 is responsible for the development of a spectrum of cognitive impairments known as HIV-associated neurocognitive disorder (HAND). In the era of antiretroviral therapy (ART), HAND remains prevalent in people living with HIV (PLWH), despite low or undetectable viral loads. Persistent neuroinflammation likely plays an important role in the contributing biological mechanisms. Multiple cerebrospinal fluid (CSF) immune markers have been studied but it is unclear which markers most consistently correlate with neurocognitive impairment. We therefore conducted a systematic review of studies of the association of CSF immune markers with neurocognitive performance in ART-experienced PLWH. We aimed to synthesize the published data to determine consistent findings and to indicate the most noteworthy CSF markers of HAND. Twenty-nine studies were included, with 20 cross-sectional studies and 9 longitudinal studies. From the group of markers most often assayed, specific monocyte activation (higher levels of Neopterin, sCD163, sCD14) and neuroinflammatory markers (higher levels of IFN-γ, IL-1α, IL-7, IL-8, sTNFR-II and lower levels of IL-6) showed a consistent direction in association with HIV-associated neurocognitive impairment. Furthermore, significant differences exist in CSF immune markers between HIV-positive people with and without neurocognitive impairment, regardless of viral load and nadir/current CD4⁺ count. These markers may be useful in furthering our understanding of the neuropathology, diagnosis and prognosis of HAND. Studies using prospective designs (i.e. pre- and post-interventions), "multi-modal" methods (e.g. imaging, inflammation and neurocognitive evaluations) and utilizing a combination of the markers most commonly associated with HAND may help delineate the mechanisms of HAND.

Neuropathic pain: Spotlighting anatomy, experimental models, mechanisms, and therapeutic aspects

The International Association for the Study of Pain defines neuropathic pain as "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". The associated changes can be observed in the peripheral as well as the central nervous system. The available literature discusses a wide variety of causes as predisposing for the development and amplification of neuropathic pain. Further, key interactions within sensory pathways have been discovered, but no common molecular mechanism leading to neuropathic pain has been identified until now. In the first part of this review, the pain mediating lateral spinothalamic tract is described. Different in vivo models are presented that allow studying trauma-, chemotherapy-, virus-, and diabetes-induced neuropathic pain in rodents. We furthermore discuss approaches to assess neuropathic pain in these models. Second, the current knowledge about cellular and molecular mechanisms suggested to underlie the development of neuropathic pain is presented and discussed. A summary of established therapies that are already applied in the clinic and novel, promising approaches closes the paper. In conclusion, the established animal models are able to emulate the diversity of neuropathic pain observed in the clinics. However, the assessment of neuropathic pain in the presented in vivo models should be improved. The determination of common molecular markers with suitable in vitro models would simplify the assessment of neuropathic pain in vivo. This would furthermore provide insights into common molecular mechanisms of the disease and establish a basis to search for satisfying therapeutic approaches.

Bilateral peripheral facial paralysis during pregnancy: a presentation of acute HIV seroconversion

A G7P5A1 woman in her 40s presented to the emergency department at 37 weeks 3 days' estimated gestational age (EGA) with headache, lip tingling and several days of difficulty speaking. Physical examination demonstrated bilateral facial weakness in a peripheral distribution, as well as decreased corneal reflexes and cervical lymphadenopathy. Routine fourth generation HIV screening had previously been negative at 14 and 28 weeks' EGA. Brain MRI was unremarkable, and lumbar puncture disclosed a low-grade, mononuclear cerebrospinal fluid pleocytosis; the patient was treated supportively. She returned for induction of labour at 39 weeks, at which time HIV infection was unexpectedly diagnosed. While unilateral idiopathic peripheral facial paralysis is associated with the third trimester of pregnancy and the early postpartum period, bilateral facial paralysis is rare and should prompt work-up for an underlying systemic cause, such as HIV infection.

Compartmentalization of cerebrospinal fluid inflammation across the spectrum of untreated HIV-1 infection, central nervous system injury and viral suppression

OBJECTIVE

To characterize the evolution of central nervous system (CNS) inflammation in HIV-1 infection applying a panel of cerebrospinal fluid (CSF) inflammatory biomarkers to grouped subjects representing a broad spectrum of systemic HIV-1 immune suppression, CNS injury and viral control.

METHODS

This is a cross-sectional analysis of archived CSF and blood samples, assessing concentrations of 10 functionally diverse soluble inflammatory biomarkers by immunoassays in 143 HIV-1-infected subjects divided into 8 groups: untreated primary HIV-1 infection (PHI); four untreated groups defined by their blood CD4+ T lymphocyte counts; untreated patients presenting with subacute HIV-associated dementia (HAD); antiretroviral-treated subjects with ≥1 years of plasma viral suppression; and untreated elite controllers. Twenty HIV-1-uninfected controls were included for comparison. Background biomarkers included blood CD4+ and CD8+ T lymphocytes, CSF and blood HIV-1 RNA, CSF white blood cell (WBC) count, CSF/blood albumin ratio, CSF neurofilament light chain (NfL), and CSF t-tau.

FINDINGS

HIV-1 infection was associated with a broad compartmentalized CSF inflammatory response that developed early in its course and changed with systemic disease progression, development of neurological injury, and viral suppression. CSF inflammation in untreated individuals without overt HAD exhibited at least two overall patterns of inflammation as blood CD4+ T lymphocytes decreased: one that peaked at 200-350 blood CD4+ T cells/μL and associated with lymphocytic CSF inflammation and HIV-1 RNA concentrations; and a second that steadily increased through the full range of CD4+ T cell decline and associated with macrophage responses and increasing CNS injury. Subacute HAD was distinguished by a third inflammatory profile with increased blood-brain barrier permeability and robust combined lymphocytic and macrophage CSF inflammation. Suppression of CSF and blood HIV-1 infections by antiretroviral treatment and elite viral control were associated with reduced CSF inflammation, though not fully to levels found in HIV-1 seronegative controls.

Persistent neurologic symptoms and cognitive dysfunction in non-hospitalized Covid-19 "long haulers"

OBJECTIVE

Most SARS-CoV-2-infected individuals never require hospitalization. However, some develop prolonged symptoms. We sought to characterize the spectrum of neurologic manifestations in non-hospitalized Covid-19 "long haulers".

METHODS

This is a prospective study of the first 100 consecutive patients (50 SARS-CoV-2 laboratory-positive (SARS-CoV-2+ ) and 50 laboratory-negative (SARS-CoV-2- ) individuals) presenting to our Neuro-Covid-19 clinic between May and November 2020. Due to early pandemic testing limitations, patients were included if they met Infectious Diseases Society of America symptoms of Covid-19, were never hospitalized for pneumonia or hypoxemia, and had neurologic symptoms lasting over 6 weeks. We recorded the frequency of neurologic symptoms and analyzed patient-reported quality of life measures and standardized cognitive assessments.

RESULTS

Mean age was 43.2 ± 11.3 years, 70% were female, and 48% were evaluated in televisits. The most frequent comorbidities were depression/anxiety (42%) and autoimmune disease (16%). The main neurologic manifestations were: "brain fog" (81%), headache (68%), numbness/tingling (60%), dysgeusia (59%), anosmia (55%), and myalgias (55%), with only anosmia being more frequent in SARS-CoV-2+ than SARS-CoV-2- patients (37/50 [74%] vs. 18/50 [36%]; p < 0.001). Moreover, 85% also experienced fatigue. There was no correlation between time from disease onset and subjective impression of recovery. Both groups exhibited impaired quality of life in cognitive and fatigue domains. SARS-CoV-2+ patients performed worse in attention and working memory cognitive tasks compared to a demographic-matched US population (T-score 41.5 [37, 48.25] and 43 [37.5, 48.75], respectively; both p < 0.01).

INTERPRETATION

Non-hospitalized Covid-19 "long haulers" experience prominent and persistent "brain fog" and fatigue that affect their cognition and quality of life.

Stroke and HIV-associated neurological complications: A retrospective nationwide study

There is an increased risk of stroke and other neurological complications in human immunodeficiency virus (HIV) infected patients with no large population-based studies in the literature. We aim to evaluate the prevalence of stroke, HIV-associated neurological complications, and identify risk factors associated with poor outcomes of stroke among HIV admissions in the United States. In the nationwide inpatient sample with adult HIV hospitalizations, patients with primary cerebrovascular disease (CeVDs) and HIV-associated neurological complications were identified by ICD-9-CM codes. We performed a retrospective study with weighted analysis to evaluate the prevalence of stroke and neurological complications and outcomes of stroke among HIV patients. We included 1,559,351 HIV admissions from 2003 to 2014, of which 22470 (1.4%) patients had CeVDs (transient ischemic attack [TIA]: 3240 [0.2%], acute ischemic stroke [AIS]: 14895 [0.93%], and hemorrhagic stroke [HS]: 4334 [0.27%]), 7781 (0.49%) had neurosyphilis, 29,925 (1.87%) meningitis, 39,190 (2.45%) cytomegalovirus encephalitis, 4699 (0.29%) toxoplasmosis, 9964 (0.62%) progressive multifocal leukoencephalopathy, and 142,910 (8.94%) epilepsy. There is increased overall prevalence trend for CeVDs (TIA: 0.17%-0.24%; AIS: 0.62%-1.29%; HS: 0.26%-0.31%; pTrend < .0001) from 2003 to 2014. Among HIV admissions, variables associated with AIS were neurosyphilis (odds ratio: 4.38; 95% confidence interval: 3.21-5.97), meningitis (4.87 [4.10-5.79]), and central nervous system tuberculosis (6.72 [3.85-11.71]). Toxoplasmosis [4.27 [2.34-7.76]), meningitis (2.91 [2.09-4.06)], and cytomegalovirus encephalitis (1.62 [1.11-2.37]) were associated with higher odds of HS compared to patients without HS. There was an increasing trend of CeVDs over time among HIV hospitalizations. HIV-associated neurological complications were associated with the risk of stroke, together with increased mortality, morbidity, disability, and discharge to long-term care facilities. Further research would clarify stroke risk factors in HIV patients to mitigate adverse outcomes.

Review of the neurological aspects of HIV infection

There are almost 40 million people in the world who live with the human immunodeficiency virus (HIV). The neurological manifestations associated with HIV contribute to significant morbidity and mortality despite the advances made with anti-retroviral therapy (ART). This review presents an approach to classification of neurological disorders in HIV, differentiating diseases due to the virus itself and those due to opportunistic infection. The effects of antiretroviral therapy are also discussed. The emphasis is on the developing world where advanced complications of HIV itself and infections such as tuberculosis (TB), toxoplasmosis and cryptococcal meningitis remain prevalent.

Paraparesis in a patient with advanced HIV infection: a diagnostic conundrum

In patients with HIV infection, lower limb weakness is a result of the pathological involvement of the brain, spinal cord or peripheral nervous system. The pathological process can be opportunistic infections, nutrient deficiencies, neoplastic infiltration or HIV itself. Here, we present the case of a 50-year-old manual labourer who presented with gradually progressive lower limb weakness, sensory disturbances, impotence and urinary urgency. He was diagnosed with HIV during evaluation. Based on the presentation and other supportive laboratory and radiological evidence, the following differentials were considered: vacuolar myelopathy, amyotrophic lateral sclerosis and myeloradiculopathy. The patient was initiated on antiretroviral therapy, and he showed significant improvement of symptoms on follow-up. We report this case to discuss the diagnostic puzzle.

Brain-derived neurotrophic factor (BDNF) is associated with depressive symptoms in older adults with HIV disease

Symptoms of depression are common among persons with HIV (PWH) and can have a significant impact on socioeconomic and personal well-being, but little is known about their neurobiological substrates in the context of HIV disease. This study examined the possible role of brain-derived neurotrophic factor (BDNF) in symptoms of depression and other aspects of mood in 109 PWH and 43 seronegative participants aged 50 and older. Participants completed the Profile of Mood States (POMS) which measured six dimensions of mood and was normatively adjusted for sex. A model controlling for medical comorbidities and substance use diagnoses among PWH showed a significant interaction between BDNF and POMS subscales. Planned post hoc analyses revealed that lower BDNF was only associated with higher scores on Depression-Dejection and Confusion-Bewilderment POMS subscales among PWH and at small-to-medium effect sizes. Lower levels of BDNF were associated with AIDS diagnoses and CD4 count, but not with viremia or duration of infection. BDNF levels did not differ between the PWH and HIV - samples, and there were no significant correlations between BDNF and any POMS variable in the HIV - group. Findings implicate BDNF in the neuropathophysiology of specific depressive symptoms in the context of HIV disease. Future studies may examine whether BDNF levels change over time, are sensitive to other aspects of mood disorders in HIV, and are associated with markers of HIV-associated neural injury.

Machine learning models reveal neurocognitive impairment type and prevalence are associated with distinct variables in HIV/AIDS

Neurocognitive impairment (NCI) among HIV-infected patients is heterogeneous in its reported presentations and frequencies. To determine the prevalence of NCI and its associated subtypes as well as predictive variables, we investigated patients with HIV/AIDS receiving universal health care. Recruited adult HIV-infected subjects underwent a neuropsychological (NP) test battery with established normative (sex-, age-, and education-matched) values together with assessment of their demographic and clinical variables. Three patient groups were identified including neurocognitively normal (NN, n = 246), HIV-associated neurocognitive disorders (HAND, n = 78), and neurocognitively impaired-other disorders (NCI-OD, n = 46). Univariate, multiple logistic regression and machine learning analyses were applied. Univariate analyses showed variables differed significantly between groups including birth continent, quality of life, substance use, and PHQ-9. Multiple logistic regression models revealed groups again differed significantly for substance use, PHQ-9 score, VACS index, and head injury. Random forest (RF) models disclosed that classification algorithms distinguished HAND from NN and NCI-OD from NN with area under the curve (AUC) values of 0.87 and 0.77, respectively. Relative importance plots derived from the RF model exhibited distinct variable rankings that were predictive of NCI status for both NN versus HAND and NN versus NCI-OD comparisons. Thus, NCI was frequently detected (33.5%) although HAND prevalence (21%) was lower than in several earlier reports underscoring the potential contribution of other factors to NCI. Machine learning models uncovered variables related to individual NCI types that were not identified by univariate or multiple logistic regression analyses, highlighting the value of other approaches to understanding NCI in HIV/AIDS.

Seroprevalence and associated factors of Toxoplasma gondii among HIV-infected patients in Tokyo: A cross sectional study

HIV infection, in particular in patients with developing AIDS, carries a risk of causing toxoplasmosis with encephalitis, which is mostly caused by a form (bradyzoite) of the protozoan parasite Toxoplasma gondii. HIV/AIDS in Japan has been recognized as a serious health issue in recent years. In this study, to elucidate T. gondii seroprevalence in HIV-positive patients in Japan and associated characteristics with Toxoplasma parasite infection, the titer of T. gondii IgG (Tg-IgG) was measured in 399 HIV-positive patients who visited a hospital in Tokyo, Japan, between 2015 and 2017. A questionnaire survey was also conducted to investigate associations between lifestyle and customs. As a result, the overall prevalence of Tg-IgG-positive serum was 8.27% (33 cases of 399). All the cases positive for Tg-IgG were confirmed using the Sabin-Feldman dye test; the titers between each examination correlated robustly (p < 0.001, r = 0.6). A correlation between Toxoplasma infection rate and age was determined (p < 0.001), whereas there was no significant correlation with lifestyle customs such as consuming undercooked meat or owning a cat. An association between Toxoplasma infection and experience of dwelling in the Hokkaido area, the northern part of Japan, was observed (p = 0.001). These results suggested that the proportion of those who were previously exposed to Toxoplasma parasites in the HIV-positive population has been maintained at a similar level as that of the HIV-negative population in Japan, providing clear information about the potential risk of toxoplasmic encephalitis.

Central Nervous System Vasculitis Due to Substance Abuse

Illicit drug abuse is a common differential diagnosis of acquired central nervous system vasculitis even though there are only a handful of histopathologically confirmed patients in the literature from among the many potential classes of abused drugs traditionally implicated in this disease. This article considers the major classes of illicit drugs in those with and without human immunodeficiency virus type-1 infection and acquired immune deficiency syndrome.

Global HIV neurology: a comprehensive review

: Neurological conditions associated with HIV remain major contributors to morbidity and mortality and are increasingly recognized in the aging population on long-standing combination antiretroviral therapy (cART). Importantly, growing evidence shows that the central nervous system (CNS) may serve as a reservoir for viral replication, which has major implications for HIV eradication strategies. Although there has been major progress in the last decade in our understanding of the pathogenesis, burden, and impact of neurological conditions associated with HIV infection, significant scientific gaps remain. In many resource-limited settings, antiretrovirals considered second or third line in the United States, which carry substantial neurotoxicity, remain mainstays of treatment, and patients continue to present with severe immunosuppression and CNS opportunistic infections. Despite this, increased global access to cART has coincided with an aging HIV-positive population with cognitive sequelae, cerebrovascular disease, and peripheral neuropathy. Further neurological research in low-income and middle-income countries (LMICs) is needed to address the burden of neurological complications in HIV-positive patients, particularly regarding CNS viral reservoirs and their effects on eradication.

HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease

Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.

Peripheral Neuropathy Due to Common Variable Immunodeficiency: Case Report and Narrative Review

A 63-year-old woman with common variable immunodeficiency (CVID) presented with 1 year of insidious onset lower extremity pain and weakness. She underwent a circuitous workup, failed to improve despite treatment for various presumed diagnoses. She presented to a University physical medicine and rehabilitation clinic with continued symptoms. Electrophysiologic testing was recommended revealing a lower extremity motor greater than sensory axonal neuropathy. While CVID has known central nervous system complications, to our knowledge, this represents the second known reported case of peripheral neuropathy. We review the literature on CVID and summarize neurological disease mechanisms and manifestations. Although peripheral neuropathy is a rarely documented complication of CVID, providers need to be aware of potential peripheral nervous system complications of primary immune deficiencies such as CVID due to its significant impact on physical performance, balance, and fall risks.

Altered intrinsic local activity and cognitive dysfunction in HIV patients: A resting-state fMRI study

PURPOSE

To characterize resting-state brain activation patterns and investigate altered areas for cognitive decline in HIV patients.

METHODS

Twelve male HIV patients with intact cognition (HIV-IC), 10 with HIV-associated neurocognitive disorder (HAND), and 11 male healthy controls (HC) underwent resting-state functional MRI (rsfMRI). Three rsfMRI values, regional homogeneity (ReHo), amplitude of low-frequency fluctuation (ALFF), and fractional ALFF (fALFF) were calculated and compared between groups. Correlation analyses were performed between rsfMRI values and neuropsychological tests.

RESULTS

rsfMRI analyses revealed decreased rsfMRI values in the frontal areas, and increases in the posterior brain regions for both HIV-IC and HAND compared to HC. When directly compared to HIV-IC, HAND showed lower fALFF in the orbitofrontal cortex and higher ReHo in the primary sensorimotor area. Additionally, decreased orbitofrontal fALFF, increased sensorimotor ReHo, and a larger difference between the two values were highly correlated with decreased verbal memory and executive function in HIV patients.

CONCLUSIONS

Regardless of cognitive status, altered local intrinsic activities were found in HIV patients. The orbitofrontal cortex and primary sensorimotor area were more disrupted in HAND relative to HIV-IC and correlated with behavioral performance, suggesting these areas are relevant to cognitive impairment in HIV patients.

Withaferin A Suppresses Beta Amyloid in APP Expressing Cells: Studies for Tat and Cocaine Associated Neurological Dysfunctions

Neurological disorders are the biggest concern globally. Out of ~36 million human immunodeficiency virus (HIV) positive people, about 30%-60% exhibit neurological disorders, including dementia and Alzheimer's disease (AD) like pathology. In AD or AD like neurological disorders, the pathogenesis is mainly due to the abnormal accumulation of extracellular amyloid beta (Aβ). In this era of antiretroviral therapy, the life span of the HIV-infected individuals has increased leading towards increased neurocognitive dysfunction in nearly 30% of HIV-infected individuals, specifically older people. Deposition of the Aβ plaques in the CNS is one the major phenomenon happening in aging HIV patients. ART suppresses the viral replication, but the neurotoxic protein (Tat) is still produced and results in increased levels of Aβ. Furthermore, drugs of abuse like cocaine (coc) is known to induce the HIV associated neurocognitive disorders as well as the Aβ secretion. To target the Tat and coc induced Aβ secretion, we propose a potent bifunctional molecule Withaferin A (WA) which may act as a neuro-protectant against Aβ neurotoxicity. In this study, we show that WA reduces secreted Aβ and induced neurotoxicity in amyloid precursor protein (APP)-plasmid transfected SH-SY5Y cells (SH-APP). In this study, we show that in SH-APP cells, Aβ secretion is induced in the presence of HIV-1 Tat (neurotoxic) and drug of abuse coc. Our fluorescent microscopy studies show the increased concentration of Aβ40 in Tat (50 ng/ml) and coc (0.1 μM) treated SH-APP cells as compared to control. Our dose optimization study show, lower concentrations (0.5-2 μM) of WA significantly reduce the Aβ40 levels, without inducing cytotoxicity in the SH-APP cells. Additionally, WA reduces the Tat and cocaine induced Aβ levels. Therefore, we propose that Aβ aggregation is induced by the presence of Tat and coc and WA is potent in reducing the secreted Aβ and induced neurotoxicity. Our study provides new opportunities for exploring the pathophysiology and targeting the neurological disorders.

Neuropathogenesis of human immunodeficiency virus infection

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain a common end-organ manifestation of viral infection. Subclinical and mild symptoms lead to neurocognitive and behavioral abnormalities. These are associated, in part, with viral penetrance and persistence in the central nervous system. Infections of peripheral blood monocytes, macrophages, and microglia are the primary drivers of neuroinflammation and neuronal impairments. While current antiretroviral therapy (ART) has reduced the incidence of HIV-associated dementia, milder forms of HAND continue. Depression, comorbid conditions such as infectious liver disease, drugs of abuse, antiretroviral drugs themselves, age-related neurodegenerative diseases, gastrointestinal maladies, and concurrent social and economic issues can make accurate diagnosis of HAND challenging. Increased life expectancy as a result of ART clearly creates this variety of comorbid conditions that often blur the link between the virus and disease. With the discovery of novel biomarkers, neuropsychologic testing, and imaging techniques to better diagnose HAND, the emergence of brain-penetrant ART, adjunctive therapies, longer life expectancy, and better understanding of disease pathogenesis, disease elimination is perhaps a realistic possibility. This review focuses on HIV-associated disease pathobiology with an eye towards changing trends in the face of widespread availability of ART.

Drug-associated progressive multifocal leukoencephalopathy in multiple sclerosis patients

Objective:

To investigate characteristics of multifocal leukoencephalopathy (PML) in multiple sclerosis (MS) patients associated with drugs other than natalizumab since our experience in other disease-modifying drugs (DMD) is still limited.

Methods:

This is a descriptive observational study within the FAERS database, registered between July 2015 and June 2017.

Results:

The primary cohort for the analysis consisted of 100,921 MS patients (mean (standard deviation (sd)) age, 48.9 (12.8) years, 20.9% male). Among them 786 (0.78%) developed PML. The adjusted odds ratio of PML for each drug was as follows; natalizumab 115.72 (95% CI; 83.83, 159.74), fingolimod 4.98 (3.64, 6.81) followed by dimethyl fumarate 1.77 (1.2, 2.62) and rituximab 3.22 (1.07, 9.72). The median time from the start of suspected drugs to the onset of PML for natalizumab and other agents were 1463 and 178 days, respectively. The proportion of PML appeared higher in Japan (2.4%) compared to that in the United States (0.24%).

Conclusion:

The reporting proportion of PML was relatively higher in natalizumab followed by fingolimod, dimethyl fumarate and rituximab. Other characteristics of PML associated with DMDs, including the time to onset and differences in reporting among countries, are described.

Peripheral facial paralysis associated with HIV infection: A case series and literature review

OBJECTIVE

The association between peripheral facial paralysis (PFP) and HIV infection has been scarcely explained. The authors aimed to describe the association between PFP and HIV infection status, along with the related co-morbidities and the outcomes of PFP, as well as the literature review on this topic.

PATIENTS AND METHODS

All HIV-infected patients who experienced PFP, both before and after a positive HIV serology test, between January 2002 and June 2015 were retrospectively reviewed. The patients' demographic data, clinical characteristics, HIV co-morbidities and outcomes of PFP were summarized. A literature review of PFP in HIV infection was also performed. Descriptive statistics were used in the data analysis. The Mann-Whitney U test was performed to compare the parameters between the current case series and cases from literature review to determine statistical significant differences (p <  0.05).

RESULTS

Sixteen patients (6 males and 10 females) were enrolled. Their median age was significantly higher than that of the cases in the literature review [46 (38, 49.75) vs. 33 (26, 41) years (p =  0.004)]. Nonetheless, a non-significant lower median CD4 count was observed [274 (134.5, 425.5) vs. 373 (265, 718) cells/μL (p =  0.058)]. In our series, unilateral PFP (UFP) was the most frequent, and it typically occurred long after a positive HIV serology test. However, bilateral PFP (BFP) was commonly found in the literature, and a simultaneous positive HIV serology test was reported in almost all cases. Consequently, most of our cases, except for those with HIV-related complications or co-morbidities, experienced a satisfactory recovery from PFP regardless of treatments received.

CONCLUSIONS

Most of the cases in our series were UPF with a higher median age and a lower median CD4 count. Moreover, facial paralysis presented later in our series than in the previously reported cases in the literature. Most of our cases experienced satisfactory recovery of facial weakness.

Peripheral nerve abnormality in HIV leprosy patients

BACKGROUND

The geographical overlap of HIV (human immunodeficiency virus) and leprosy infection has become increasingly frequent and worrying, bringing many clinical issues. Peripheral neuropathy is very frequent in leprosy because of the predilection of its etiologic agent by Schwann cells of the peripheral nervous system, and it also affects individuals with HIV as one of the most common neurological manifestations.

METHODOLOGY/PRINCIPAL FINDINGS

The present study compared a cohort of 63 patients diagnosed with leprosy and coinfected with HIV with a cohort of 64 patients with leprosy alone, who were followed at the outpatient clinic of the Nucleus of Tropical Medicine of the Federal University of Pará, Brazil. We observed that HIV-coinfected leprosy patients presented greater odds of overall peripheral nerve damage (nerve function impairment-NFI) than patients with leprosy alone. More sensitive damage was observed, especially in patients coinfected with multibacillary forms. Leprosy patients coinfected with HIV presented higher chances of motor damage with improvement over time using multidrug therapy (MDT) and highly active antiretroviral therapy (HAART), along with a greater extent of damage and occurrence of neuritis. The data suggest that in addition to patients presenting possible damage caused by leprosy, they also had a greater damage gradient attributable to HIV disease, but not related to HAART because most of these patients had been on the treatment for less than a year. Neuritis was treated with prednisone at doses recommended by the WHO, and coinfected patients had the highest rate of clinical improvement in the first 60 days.

CONCLUSIONS/SIGNIFICANCE

The clinical characteristics of the two diseases should be considered in leprosy patients coinfected with HIV for better diagnosis and treatment of peripheral neuropathy. We suggest that new simplified assessment tools that allow the evaluation of the NFI of these patients be developed for use in the service.

Neurological Presentations of AIDS-when to Test for HIV

Nine of 122 patients dead from AIDS in central London presented with neurological disease, confirmed pathologically in seven. Seven had no other major systemic manifestations. AIDS needs to be considered in the differential diagnosis of meningitis, dementia, diffuse and focal encephalopathies, brainstem syndromes, myelopathy, visual failure and peripheral nerve syndromes. As AIDS becomes more widespread there will be an increasing need for diagnostic HIV testing in many neurological syndromes.

AIDS: Neurological Opportunist Infections in Central London

Twenty six (41%) of 64 central London cases of AIDS with nervous system involvement during the course of the illness had neurological opportunist infection. Cytomegalovirus and Toxoplasma gondii were the commonest agents in 22 cases with central nervous system (CNS) infection. Eight cases had herpes zoster radiculopathy. Other infections included those caused by Cryptococcus neoformans, Mycobacterium tuberculosis and papova JC virus. Prognosis was generally poor, irrespective of whether the opportunist infection was treatable.

Ageing with HIV

The population of people living with HIV (PLWH) is growing older with an estimated 4 million over the age of 50 years, a figure which has doubled since the introduction of effective antiretroviral therapy (ART) and which is increasing globally. Despite effective ART, PLWH still experience excess morbidity and mortality compared to the general population with increased prevalence of age-related, non-AIDS illnesses (NAI) such as cardiovascular disease, malignancies, cognitive impairment and reduced bone mineral density, which impact disability and everyday functioning. This review will discuss the challenges presented by comorbidities in ageing PLWH and discuss the aetiology and management of age-related illnesses in this vulnerable population.

Burkitt's Lymphoma Presenting as Oculomotor Palsy in an HIV-Positive Patient

Purpose

To report a case of Burkitt's lymphoma (BL) in an HIV-positive patient presenting as complete third nerve palsy.

Methods

Interventional case report. A 34-year-old man presented with headache, left eye pain, diplopia, and complete ptosis of several hours’ duration. Left eye examination disclosed complete third nerve palsy with pupillary involvement. Significant hepatomegalia was noted at physical examination and computed tomography (CT) scan of the abdomen showed multiple solid lesions.

Results

Liver biopsy was consistent with Burkitt's lymphoma. Bone marrow biopsy was normal. Brain imaging was normal. Work-up also revealed positivity for human immunodeficiency virus. Chemotherapy treatment was started. Two months later, ocular motility examination was normal.

Conclusions

Although BL affects the central nervous system very rarely, BL should be considered in any immunosuppressed patient presenting with diplopia or ophthalmoparesis.

Global developments in HIV neurology

Neurologic conditions associated with HIV remain major contributors to morbidity and mortality, and are increasingly recognized in the aging population on long-standing combination antiretroviral therapy (cART). Importantly, growing evidence suggests that the central nervous system (CNS) serves as a reservoir for viral replication with major implications for human immunodeficiency virus (HIV) eradication strategies. Though there has been major progress in the last decade in our understanding of the pathogenesis, burden, and impact of HIV-associated neurologic conditions, significant scientific gaps remain. In many low-income settings, second- and third-line cART regimens that carry substantial neurotoxicity remain treatment mainstays. Further, patients continue to present severely immunosuppressed with CNS opportunistic infections. Public health efforts should emphasize improvements in access and optimizing treatment of HIV-positive patients, specifically in resource-limited settings, to reduce the risk of neurologic sequelae.

HIV neuropathology

Primary human immunodeficiency virus (HIV) neuropathologies can affect all levels of the neuraxis and occur in all stages of natural history disease. Some, like HIV encephalitis, HIV myelitis, and diffuse infiltrative lymphocytosis of peripheral nerve, reflect productive infection of the nervous system; others, like vacuolar myelopathy, distal symmetric polyneuropathy, and central and peripheral nervous system demyelination, are not clearly related to regional viral replication, and reflect more complex cascades of dysregulated host immunity and metabolic dysfunction. In pediatric patients, the spectrum of neuropathology is altered by the impacts of HIV on a developing nervous system, with microcephaly, abundant brain mineralization, and corticospinal tract degeneration as examples of this unique interaction. With efficacious therapies, CD8 T-cell encephalitis is emerging as a significant entity; often this is clinically recognized as immune reconstitution inflammatory syndrome, but has also been described in the context of viral escape and treatment interruption. The relationship of HIV neuropathology to clinical symptoms is sometimes straightforward, and sometimes mysterious, as individuals can manifest significant deficits in the absence of discrete lesions. However, at all stages of the natural history disease, neuroinflammation is abundant, and critical to the generation of clinical abnormality. Neuropathologic and neurobiologic investigations will be central to understanding HIV nervous system disorders in the era of efficacious therapies.

Neuromuscular complications of HIV infection

With the introduction of combination antiretroviral therapy, human immunodeficiency virus (HIV)-infected individuals are living longer, and are commonly confronted with chronic neuromuscular complications. The spectrum of neuromuscular disorders in patients living with HIV infection is wide, and is caused by HIV per se and its products, particular antiretroviral drugs, or a combination of both. The purpose of this chapter is to review peripheral nervous system disorders in the setting of HIV infection, and to provide a general approach to diagnosis and management of these disorders. The early identification of these conditions may help with early intervention and management, allow prevention of morbidities associated with these disorders, and contribute to future research efforts in the field of HIV.

Brain-specific HIV Nef identified in multiple patients with neurological disease

HIV-1 Nef is a flexible, multifunctional protein with several cellular targets that is required for pathogenicity of the virus. This protein maintains a high degree of genetic variation among intra- and inter-host isolates. HIV Nef is relevant to HIV-associated neurological diseases (HAND) in patients treated with combined antiretroviral therapy because of the protein's role in promoting survival and migration of infected brain macrophages. In this study, we analyzed 2020 HIV Nef sequences derived from 22 different tissues and 31 subjects using a novel computational approach. This approach combines statistical regression and evolved neural networks (ENNs) to classify brain sequences based on the physical and chemical characteristics of functional Nef domains. Based on training, testing, and validation data, the method successfully classified brain Nef sequences at 84.5% and provided informative features for further examination. These included physicochemical features associated with the Src-homology-3 binding domain, the Nef loop (including the AP-2 Binding region), and a cytokine-binding domain. Non-brain sequences from patients with HIV-associated neurological disease were frequently classified as brain, suggesting that the approach could indicate neurological risk using blood-derived virus or for the development of biomarkers for use in assay systems aimed at drug efficacy studies for the treatment of HIV-associated neurological diseases.

Incidence of Neurological Disorders Among HIV-Infected Individuals With Universal Health Care in Taiwan From 2000 to 2010

OBJECTIVE

To determine the incidence of and factors associated with neurological disorders in a large Taiwanese cohort of HIV-infected persons with free access to highly active antiretroviral therapy (HAART).

DESIGN

A retrospective population-based cohort study was conducted using the National Health Insurance Research Database for the years 2000-2010.

METHODS

We identified 13,316 HIV-positive persons from 2000 through 2010. We used direct standardization to calculate age-adjusted and sex-adjusted incidence rates based on the 2000 World Health Organization world standard population. Factors associated with neurological disorders were analyzed using a Cox proportional hazards model.

RESULTS

The standardized incidence of neurological disorders among HIV-infected persons increased from 22.16 per 1000 person-years in 2000 to 25.23 per 1000 person-years in 2010. Cognitive disorders increased significantly from 0.36 per 1000 person-years in 2001 to 7.44 per 1000 person-years in 2010 (trend P < 0.001). The rate of neurological disorders increased with age ≥55 years [adjusted hazard ratios (AHRs) 2.54, 95% confidence interval (CI): 1.89 to 3.40], hypertension (AHR 1.41, 95% CI: 1.12 to 1.76), substance abuse (AHR 1.65, 95% CI: 1.36 to 2.02), opportunistic infection (AHR 1.76, 95% CI: 1.47 to 2.11), syphilis (AHR 1.27, 95% CI: 1.10 to 1.47), and emergency department visits >5 (AHR 2.41, 95% CI: 1.96 to 2.97). The incidence of neurological disorders was negatively associated with adherence to HAART (adherence ≥85% AHR: 0.79, 95% CI: 0.64 to 0.97).

CONCLUSIONS

The rising incidence of cognitive disorders among HIV-positive persons highlights the need to provide routine neurological evaluations at clinical visits. Receiving HAART with adherence ≥85% contributes to a reduced risk of neurological disorders.

Progressive Multifocal Leukoencephalopathy and Monoclonal Antibodies: A Review

Progressive multifocal leukoencephalopathy (PML) is a viral infection predominantly seen in patients with HIV infection. However, with the increased use of monoclonal antibodies (MAB) for various lymphoproliferative disorders, we are now seeing this infection in non-HIV patients on drugs such as natalizumab, rituximab, and so on. The aim of this article is to review the relationship between the occurrence of PML and MAB used in the treatment of hematological malignancies and autoimmune diseases. Review of articles from PubMed-indexed journals which study PML in relation to the use of MAB. Relevant literature demonstrated an increased risk of reactivation of latent John Cunningham polyomavirus (JCV) resulting in development of PML in patients on long-term therapy with MAB. The highest incidence of 1 PML case per 1000 treated patients and 1 case per 32 000 was observed in patients treated with natalizumab and rituximab, respectively. Serological and polymerase chain reaction tests for the detection of JCV can be helpful in risk stratification of patients for the development of PML before and during therapy with MAB. Treatment with MAB can result in development of PML. Clinicians should include PML in differential diagnosis in patients treated with these agents if they manifest central nervous system symptoms.

Diagnostic capability of retinal thickness measures in diabetic peripheral neuropathy

PURPOSE

To examine the diagnostic capability of the full retinal and inner retinal thickness measures in differentiating individuals with diabetic peripheral neuropathy (DPN) from those without neuropathy and non-diabetic controls.

METHODS

Individuals with (n=44) and without (n=107) diabetic neuropathy and non-diabetic control (n=42) participants underwent spectral domain optical coherence tomography (SDOCT). Retinal thickness in the central 1mm zone (including the fovea), parafovea and perifovea was assessed in addition to ganglion cell complex (GCC) global loss volume (GCC GLV) and focal loss volume (GCC FLV), and retinal nerve fiber layer (RNFL) thickness. Diabetic neuropathy was defined using a modified neuropathy disability score (NDS) recorded on a 0-10 scale, wherein, NDS ≥3 indicated neuropathy and NDS indicated <3 no neuropathy. Diagnostic performance was assessed by areas under the receiver operating characteristic curves (AUCs), 95 per cent confidence intervals (CI), sensitivities at fixed specificities, positive likelihood ratio (+LR), negative likelihood ratio (-LR) and the cut-off points for the best AUCs obtained.

RESULTS

The AUC for GCC FLV was 0.732 (95% CI: 0.624-0.840, p<0.001) with a sensitivity of 53% and specificity of 80% for differentiating DPN from controls. Evaluation of the LRs showed that GCC FLV was associated with only small effects on the post-test probability of the disease. The cut-off point calculated using the Youden index was 0.48% (67% sensitivity and 73% specificity) for GCC FLV. For distinguishing those with neuropathy from those without neuropathy, the AUCs of retinal parameters ranged from 0.508 for the central zone to 0.690 for the inferior RNFL thickness. For distinguishing those with moderate or advanced neuropathy from those with mild or no neuropathy, the inferior RNFL thickness demonstrated the highest AUC of 0.820, (95% CI: 0.731-0.909, p<0.001) with a sensitivity of 69% and 80% specificity. The cut-off-point for the inferior RNFL thickness was 97μm, with 81% sensitivity and 72% specificity.

CONCLUSIONS

The GCC FLV can differentiate individuals with diabetic neuropathy from healthy controls, while the inferior RNFL thickness is able to differentiate those with greater degrees of neuropathy from those with mild or no neuropathy, both with an acceptable level of accuracy. Optical coherence tomography represents a non-invasive technology that aids in detection of retinal structural changes in patients with established diabetic neuropathy. Further refinement of the technique and the analytical approaches may be required to identify patients with minimal neuropathy.

HIV-1-associated neurocognitive disorder: epidemiology, pathogenesis, diagnosis, and treatment

The modern antiretroviral treatment of human immunodeficiency virus (HIV-1) infection has considerably lowered the incidence of opportunistic infections. With the exception of the most severe dementia manifestations, the incidence and prevalence of HIV-associated neurocognitive disorders (HAND) have not decreased, and HAND continues to be relevant in daily clinical practice. Now, HAND occurs in earlier stages of HIV infection, and the clinical course differs from that before the widespread use of combination antiretroviral treatment (cART). The predominant clinical feature is a subcortical dementia with deficits in the domains concentration, attention, and memory. Motor signs such as gait disturbance and impaired manual dexterity have become less prominent. Prior to the advent of cART, the cerebral dysfunction could at least partially be explained by the viral load and by virus-associated histopathological findings. In subjects where cART has led to undetectable or at least very low viral load, the pathogenic virus-brain interaction is less direct, and an array of poorly understood immunological and probably toxic phenomena are discussed. This paper gives an overview of the current concepts in the field of HAND and provides suggestions for the diagnostic and therapeutic management.

Intracranial Aneurysms Involving Circle of Willis in a Child with Human Immunodeficiency Virus Associated Vasculitis- A Rare Case Report

Intracranial Arterial Aneurysms (IAAs) are relatively rare in paediatric population and they account for at least 10%-15% of haemorrhagic strokes which occur during the first two decades of life. Here we present a unique and unusual case of Human Immunodeficiency Virus (HIV) infected child who presented with intracranial aneurysms with formation of collaterals and vasculopathy, demonstrating low viral count despite receiving adequate antiretroviral treatment. Intracranial vascular involvement, their complications and its incidence in these patients may become increasingly common as the management of human immunodeficiency virus infection continues to improve and afflicted patients survive for longer periods because of advancement in the antiretroviral treatment. Diagnosing aneurysm of cerebral circulation needs high degree of suspicion and correlation between clinical and radiological findings.