TY - JOUR T1 - Test them all; an easily diagnosed and readily treatable cause of dementia with life-threatening consequences if missed JF - Practical Neurology JO - Pract Neurol SP - 354 LP - 356 DO - 10.1136/practneurol-2013-000689 VL - 13 IS - 6 AU - Sam Nightingale AU - Benedict D Michael AU - Sylviane Defres AU - Laura A Benjamin AU - Tom Solomon Y1 - 2013/12/01 UR - http://pn.bmj.com/content/13/6/354.abstract N2 - Over 90 000 people in the UK are infected with HIV, a quarter of whom are unaware of their diagnosis, and the number continues to rise.1 The prognosis of HIV infection for patients on treatment is now excellent, and life expectancy approaches normal in areas with access to combination antiretroviral treatment.2 As HIV frequently leads to neurological manifestations, it is crucially important that neurologists know the indications for HIV testing, and address the barriers to testing.We were recently involved in the care of a patient with no apparent risk factors for HIV. Multiple clinicians at several sites had made extensive investigations for isolated cognitive decline; at no point was HIV tested. A technetium-99m-HMPAO SPECT scan (figure 1) provided beautiful images but failed to identify the underlying cause. Two weeks after this scan the patient was admitted to intensive care with a fatal Pneumocystis jirovecii pneumonia associated with advanced HIV infection.Figure 1 Left: technetium-99m-HMPAO SPECT scan showing multifocal subcortical uptake in a patient with dementia due to undiagnosed HIV infection. This sophisticated technique failed to identify the underlying cause. Right: Cheap and reliable: HIV rapid antibody finger-prick card tests (2 bands=positive, 1 band=negative). Most UK clinics use a laboratory-based test combining HIV antibody and the p24 antigen, costing as little as £8.HIV enters the brain early in infection and establishes productive infection in perivascular macrophages, microglia and to some extent astrocytes.3 HIV-associated dementia occurs in advanced HIV disease due to several mechanisms, including neuronal damage from pro-inflammatory cytokines and toxic viral products, and loss of the homeostatic function of glia.4 It usually develops with CD4 T-cell counts below 200/µL, and is an AIDS-defining condition. HIV-associated dementia is typically subcortical: there is cognitive impairment alongside prominent apathy, social withdrawal, depression and motor features, such as pyramidal slowness of … ER -