Severe, demyelinating leukoencephalopathy in AIDS patients on antiretroviral therapy

Changing incidence of central nervous system diseases in the EuroSIDA cohort

A drastic decrease in incidence has been observed for most human immunodeficiency virus (HIV)-related opportunistic manifestations after use of highly active antiretroviral therapy (HAART). We assessed the trend of incidence of central nervous system (CNS) diseases in a prospective multicenter observational study involving 9,803 patients across Europe in the period 1994 to 2002 and analyzed patient and treatment variables associated with these conditions. Overall, 568 patients (5.8%) received a diagnosis of a new CNS disease. Incidence decreased significantly from 5.9 per 100 person-year in 1994 to 0.5 in 2002. Overall, the decrease was 40% per calendar year, and it was similar to that of non-CNS diseases and less evident after year 1998. In multivariable models, low CD4 cell count and high plasma viral load, but not HAART or calendar year, were significantly associated with risk to develop CNS disease, indicating that the effect of HAART was likely mediated by both improved immunological conditions and inhibition of viral replication. In contrast, use of nucleoside reverse transcriptase inhibitors, irrespective of use of protease inhibitors or non-nucleoside reverse transcriptase inhibitors, appeared to protect specifically against acquired immunodeficiency disease syndrome dementia complex, suggesting that, in this condition, therapy might have a direct, additive effect in the CNS.

A Fatal Case of Spongiform Leukoencephalopathy Linked to “Chasing the Dragon”

BACKGROUND

"Chasing the dragon" involves placing heroin on aluminum foil, heating it from below with a flame, and inhaling the pyrolysate through a straw. It has rarely been associated with the development of a progressive spongiform leukoencephalopathy.

CASE REPORT

A 43-year-old woman presented with 2 weeks of bizarre behavior, forgetfulness, and slowed speech and movements. Serum, cerebrospinal fluid, and head computed tomography (CT) scan were normal. The patient progressed to coma and expired during week 4 of hospital admission. The family confirmed that she "chased the dragon." Cause of death at post mortem examination was spongiform leukoencephalopathy.

CONCLUSION

The diagnosis of heroin pyrolysate-induced spongiform leukoencephalopathy should be considered in a patient with a history of "chasing the dragon" and neurobehavioral changes, including confusion, apathy, cerebellar signs, and motor restlessness.

Challenges for clinical trials to treat progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy is a lethal complication of immunodeficiency for which no direct therapy has been achieved. The issues that have made this disease especially difficult to address are discussed, and an outline for development of future interventions is provided. A controlled trial of therapy utilizing an international group of trial groups is proposed.

Toxic leukoencephalopathy: a review and report of two chemotherapy-related cases

Leukoencephalopathy syndrome is a rare disorder that results from structural alterations of cerebral white matter, is characterized by cerebral edema, and can occur in patients of any age. Cranial irradiation and certain chemotherapy agents, especially those used in high-dose protocols, are causal agents. The prevalence of toxic leukoencephalopathy is unknown; however, this syndrome has been reported increasingly in the literature in patients who develop neurobehavioral changes following exposure to various toxins. Diagnosis must confirm exposure to a toxin and the presence of neurobehavioral deficits and neuroradiologic abnormalities. In most reported cases, clinical symptoms are reversible after the offending toxin is withdrawn. This article describes two cases of chemotherapy-related leukoencephalopathy and reviews the nursing care of patients experiencing this syndrome.

Immune Restoration Inflammatory Syndromes: The Dark Side of Successful Antiretroviral Treatment

The prevalence of cellular immunodeficiency has increased due to rising use of immunosuppressive therapies and the pandemic spread of HIV infection. More recently, the introduction of highly active antiretroviral therapy (HAART) in HIV has led to significant immune reconstitution, even in patients with previously long-lasting secondary immunodeficiency. HAART reduces morbidity and mortality in HIV infection and also changes the clinical course of prevalent subclinical opportunistic infections or autoimmune diseases. Atypical inflammatory disorders develop after initiation of HAART and have been summarized as "immune reconstitution syndrome," "immune restoration disease," and "immune restoration inflammatory syndrome." However, diagnostic criteria and standards of therapy are yet to be defined. The awareness for these diseases is of increasing importance from a clinical point of view. This review summarizes the variety of immunoreconstitution disorders and describes possible diagnostic pitfalls. We also propose possible therapeutic options.

The changing pattern of HIV neuropathology in the HAART era

Highly active antiretroviral treatment (HAART), which has been available for most AIDS patients in France since 1996, has resulted in a dramatic improvement of the progression of the disease. From the survey of our series of 343 brains with acquired immunodeficiency syndrome (AIDS) from patients who died between 1985 and 2002, we found both quantitative and qualitative changes in the pattern of human immunodeficiency virus (HIV) neuropathology. Quantitatively, despite a dramatic decrease in the number of autopsies, brain involvement remained a major cause of death. There was an overall decrease in incidence of cerebral toxoplasmosis, cytomegalovirus encephalitis (CMVE), and HIV encephalitis (HIVE), for which successful treatment is available. This contrasted with the unchanged incidence of progressive multifocal leukoencephalopathy (PML) and malignant non-Hodgkin lymphomas (MNHL). However, when looking closer at the 3 last years, the incidence of diseases affecting patients with severe immunodepression (CMVE, PML, and MNHL) decreased between 2000 and 2002, whereas infections occurring in patients with milder immunodeficiency, toxoplasmosis, varicella-zoster encephalitis (VZVE), or herpes simplex virus encephalitis (HSVE) became more frequent. In addition, we found uncommon types of brain infection such as BK virus encephalitis or general paresis. Finally, we described new variants of HIVE: severe leukoencephalopathy with intense perivascular macrophage and lymphocyte infiltration, possibly due to an exaggerated response from a newly reconstituted immune system, and chronic "burnt out" forms of HIVE as VZVE, toxoplasmosis, or PML, possibly associated with prolonged survival, in which neither inflammation nor organisms could be detected. These findings are compared with those reported in other neuropathological studies from different developed countries.

Human immunodeficiency virus-associated dementia: an evolving disease

This article reviews the changing epidemiology of HIV-associated dementia, current concepts of the different patterns of dementia under the influence of highly active antiretroviral therapy, and reviews therapeutic aspects.

Microglia in human immunodeficiency virus-associated neurodegeneration

Infection with the human immunodeficiency virus (HIV) is associated with a syndrome of cognitive and motor abnormalities that may develop in the absence of opportunistic infections. Neurons are not productively infected by HIV. Thus, one hypothesis to explain the pathophysiology of HIV-associated dementia (HAD) suggests that signals released from other infected cell types in the CNS secondarily lead to neuronal injury. Microglia are the predominant resident CNS cell type productively infected by HIV-1. Neurologic dysfunction in HAD appears to be a consequence of microglial infection and activation. Several neurotoxic immunomodulatory factors are released from infected and activated microglia, leading to altered neuronal function, synaptic and dendritic degeneration, and eventual neuronal apoptosis. This review summarizes findings from clinical/pathological studies, animal models, and in vitro models of HAD. Most of these studies support the hypothesis that altered microglial physiology is the nidus for a cascade of events leading to neuronal dysfunction and death. Several molecular mediators of neuronal injury in HAD that emanate from microglia have been identified, and strategies for altering the impact of these neurotoxins are discussed.