Brain problems and peripheral neuropathy under-diagnosed in Asia and the Pacific

HIV-related neurological illnesses are much more prevalent in the Asia Pacific region than was previously thought, according to research presented to the Sixteenth International AIDS Conference on Monday August 14^th. Conditions such as dementia, peripheral neuropathy and depression had been reported as uncommon amongst HIV-infected individuals in the Asia Pacific, but investigators found that they were highly prevalent and often undiagnosed amongst patients receiving outpatient care.

Presenting the findings, Edwina Wright of Alfred Hospital in Melbourne, Australia, representing the Asia Pacific NeuroAIDS consortium, said the group's findings imply that 1.5 million people with HIV in the Asia-Pacific region may have sensory neuropathy, predominantly related to prior use of `d`- drugs such as stavudine (d4T), while one million may have unrecognised HIV-related dementia and one-third of all HIV-positive people may suffer undiagnosed depression.

As the exact prevalence of HIV-related neurocognitive impairment in Asia Pacific countries is unknown, investigators undertook a cross-sectional study involving 658 HIV-positive patients and 161 HIV-negative control patients in Thailand, Indonesia, China, Malaysia and the Asia-Pacific region. The aim of the study was to determine the prevalence of cognitive impairment, peripheral neuropathy and depression and the patients enrolled on the study were assessed using a battery of tests. Data were also gather on demographics, HIV disease history, CD4 cell count, and the use of potent anti-HIV therapy.

Median age of the patients was 36 years, 59% were male, just under two-thirds had been diagnosed with AIDS, median CD4 cell count was 203 cells/mm³, suggesting a significant degree of immunological damage, and 65% were receiving potent HIV therapy. The investigators note that a significant proportion of antiretroviral-treated patients were taking so-called “d” drugs from the nucleoside analogue (NRTI) class of anti-HIV drugs, with 37% taking either d4T (stavudine, Zerit) or ddI (didanosine, Videx). Both of these drugs have been associated with peripheral neuropathy.Virtually none were taking efavirenz, a drug that may exacerbate depression in people with a previous history.

Neurocognitive impairment was highly prevalent amongst the study population, with 12% assessed as suffering serious neurocognitive impairment. Peripheral neuropathy also occurred with high frequency, with 19% of patients diagnosed as having the condition. In addition, a third of patients were diagnosed with depression.

The investigators then looked to see if any specific risk factors for these conditions could be identified. They found that patients with cognitive impairment were significantly older and had lower CD4 cell counts than patients without cognitive problems (p

Concluding, the investigators draw attention to the high prevalence of cognitive impairment, peripheral neuropathy and depression in Thailand, Indonesia, China and Malaysia and emphasise that these conditions are often undiagnosed.