Cognitive impairment in HIV infection and AIDS
Among the primary neurological complications of AIDS have cognitive deficits such as HIV-associated dementia and milder forms, such as cognitive impairment / smaller engine, both of which can alter the activities of daily living and reduce the quality of life of patients. HIV-1 is the most common, predictable and treatable cause of cognitive deficits in individuals with less than 50 years. Despite the advances in the knowledge of the clinical features, pathogenesis, neurobiological aspects and the widespread use of highly active antiretroviral therapy (HAART or HAART), neurological complications and cognitive deficits persist leading to serious personal and socio-economic consequences becoming one major therapeutic challenge. In the pre-HAART era, dementia was a common complication of infection, though in the HAART era the incidence of dementia decreased, but the prevalence has increased particularly of milder forms due to the increase in the number of infected people and increased life expectancy . cognitive impairment associated with HIV are typically subcortical and may be associated with behavioral impairments and engines. These syndromes are a clinical diagnosis, and neuropsychological testing, neuroimaging and cerebrospinal fluid corroborate the diagnosis. This review is an update of the current state of the epidemiology, clinical features and diagnosis of cognitive complications in the course of HIV infection.
Since its recognition in the early 80, the Acquired Immune Deficiency Syndrome (AIDS-AIDS) spread around the world making it one of the greatest public health challenges of the last three decades.
The World Health Organization (WHO) estimates that worldwide, approximately 33,2 million people are infected with HIV or have the disease and to 2007 2,1 occurred million deaths and about 2,5 million new cases1.
In Brazil, since the identification of the first AIDS patient in 1982, 2007 until June, it has been identified about 474 thousand cases of the disease. It is estimated that approximately 593 thousand people are living today with HIV or AIDS and, according to WHO criteria, the prevalence of HIV infection is 0,61% of the population of 15 to 49 years, 0,42% among women and 0,80% between men2.
In the early cases it was evident the serious and progressive immunological impairment of HIV-infected patients, particularly their cellular immunity. This fact had just predisposing them to cancer and infections, most opportunistic character and this one in particular always brought high morbidity and mortality for patients with AIDS, and marker elements of the syndrome.
Beside the lymphoid system, central nervous system (CNS) is a major target for HIV and the virus has frequently been detected in cerebrospinal fluid (CSF) and the brain tissue from the beginning of the infection and throughout their evolution, regardless of present neurological symptoms3. The virus infects and replicates in macrophages, microglia and multinucleated glial cells, but is primarily free and acellular present in cerebrospinal fluid 4.
The CNS is the second most common site of clinical manifestations. This can be explained by the fact that the virus is neurotró- peak and the CNS a 'sanctuary' for him, in addition to poor penetration of antiretroviral drugs in the presence of an intact blood-brain barrier5.
Neurological involvement occurs 40% to 70% of patients with HIV in the course of their infection67, And, in autopsy studies, the frequency can reach more than 90%8. About 46% of patients hospitalized with AIDS may have neurological disease, either as a main reason for hospital admission or as complications during hospitalization 9
The nature of neurological changes is diverse and any part of neuraxial may be affected. The most important determinant of susceptibility is the degree of immunosuppression. The differential diagnosis is broad and involves infectious etiologies, neoplastic, cerebrovascular, toxic-metabolic, nutritional,
autoimmune and related to the virus itself as neuropathy, myelopathy and cognitive changes. They can also occur etiologies associations in the same patient, which is a feature of the immunocompromised.
In the course of HIV infection, the virus enters the CNS may result in disorders of cognitive function causing deficits of mental processes such as attention, learning, memory, speed of information processing, problem solving ability and sensory and motor symptoms.
Recent advances in the treatment of HIV infection increased the life expectancy of patients, making it more likely that doctors and psychologists are in the daily clinical practice patients with neuropsychiatric manifestations of the disease.
The most common neurological manifestations, directly linked to HIV, are tra nstorno cognitive and smaller engine and HIV-associated dementia. In Brazil, the consequences related to opportunistic diseases of the CNS, such as toxoplasmosis, tuberculous meningitis and cryptococcal meningitis, are also important causes of cognitive and psychiatric damage. Therefore, the correct and early diagnosis of these conditions and prompt therapeutic intervention can minimize the neuropsychiatric complications.
It is very important to quantify the number of patients with cognitive impairment, since they affect the quality of life, decreased labor and adherence due to highly active antiretroviral therapy (HAART) 10,11. cognitive impairment is associated with increased risk of mortality, increased risk of developing dementia and high rates of unemployment and this occurs even in the HAART era