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HIV-associated neurocognitive disorders (HAND) are neurological disorders associated with HIV infection and AIDS. HAND may include neurological disorders of various severity such as AIDS dementia complex (ADC) also known as HIV dementia and HIV-associated dementia (HAD), HIV encephalopathy, and Mild Neurocognitive Disorder (MND). HIV-associated neurocognitive disorders are associated with a metabolic encephalopathy induced by HIV infection and fueled by immune activation of macrophages and microglia.〔 〕 These cells are actively infected with HIV and secrete neurotoxins of both host and viral origin. The essential features of ADC are disabling cognitive impairment accompanied by motor dysfunction, speech problems and behavioral change. Cognitive impairment is characterised by mental slowness, trouble with memory and poor concentration. Motor symptoms include a loss of fine motor control leading to clumsiness, poor balance and tremors. Behavioral changes may include apathy, lethargy and diminished emotional responses and spontaneity. Histopathologically, it is identified by the infiltration of monocytes and macrophages into the central nervous system (CNS), gliosis, pallor of myelin sheaths, abnormalities of dendritic processes and neuronal loss.〔〔 〕 ADC typically occurs after years of HIV infection and is associated with low CD4+ T cell levels and high plasma viral loads. It is sometimes seen as the first sign of the onset of AIDS. Prevalence is between 10-24% in Western countries〔 〕 and has only been seen in 1-2% of India-based infections.〔 〕〔 〕 With the advent of highly active antiretroviral therapy (HAART), the incidence of ADC has declined in developed countries, although its prevalence is increasing.〔 〕〔 〕 HAART may prevent or delay the onset of ADC in people with HIV infection, and may also improve mental function in people who already have ADC. Dementia only exists when neurocognitive impairment in the patient is severe enough to interfere markedly with day-to-day function. That is, the patient is typically unable to work and may not be able to take care of him or herself. Before this, the patient is said to have a mild neurocognitive disorder. ==Diagnostic criteria== #Marked acquired impairment of at least two ability domains of cognitive function (e.g. memory, attention): typically, the impairment is in multiple domains, especially in learning, information processing and concentration/attention. The cognitive impairment is ascertained by medical history, mental status examination or neuropsychological testing. #Cognitive impairments identified in 1 interfere markedly with day-to-day functioning. #Cognitive impairments identified in 1 are present for at least one month. #Cognitive impairments identified in 1 do not meet the criteria for delirium, or if delirium is present, dementia was diagnosed when delirium was not present. #No evidence of another, pre-existing aetiology that could explain the dementia (e.g. another CNS infection, CNS neoplasm, cerebrovascular disease, pre-existing neurological disease, severe substance abuse compatible with CNS disorder.〔 〕 While the progression of dysfunction is variable, it is regarded as a serious complication and untreated can progress to a fatal outcome. Diagnosis is made by neurologists who carefully rule out alternative diagnoses. This routinely requires a careful neurological examination, brain scans (MRI or CT scan) and a lumbar puncture to evaluate the cerebrospinal fluid. No single test is available to confirm the diagnosis, but the constellation of history, laboratory findings and examination can reliably establish the diagnosis when performed by experienced clinicians. The amount of virus in the brain does not correlate well with the degree of dementia, suggesting that secondary mechanisms are also important in the manifestation of ADC. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「HIV-associated neurocognitive disorder」の詳細全文を読む スポンサード リンク
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