"Two thirds of all HIV-positive individuals--some 26.6 million individuals--live in the countries of sub-Saharan Africa," said lead study author Matthew Wong of McMaster University in Ontario. "Despite these large numbers, the frequency of neurological complications of HIV infection in this population is largely unknown." In the United States, dementia is seen in 10-15 percent of HIV-positive patients, and sensory neuropathy in 30 percent.
To determine the corresponding rates in sub-Saharan African populations, Wong and colleagues performed detailed neurological, neuropsychological, and functional assessments on 53 HIV-positive and 31 HIV-negative individuals at an infectious diseases clinic in Uganda. Dementia was present in 11 percent of all HIV-positive patients. Within the subgroup whose CD4 counts were below 200, dementia was present in 50 percent. A CD4 count below 200 is a standard threshold for initiating anti-retroviral therapy.
Painful sensory neuropathy was diagnosed in 51 percent of HIV-positive patients, and neurological signs of aberrant nerve function were seen in 38 percent. HIV-positive patients were also approximately 25 percent more functionally impaired than HIV-negative patients, and showed decreased abilities on tests of verbal recall, psychomotor speed, and motor performance.
"HIV-positive individuals with advanced infection have impaired verbal memory, motor, and functional performance compared to HIV-negative individuals," said Wong. He also suggested that the International HIV Dementia Scale, used in this study, may be a useful rapid screening test for HIV dementia in the developing world, since it can be performed quickly by non-neurologists without special equipment.
The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer's disease, epilepsy, Parkinson's disease, autism and multiple sclerosis.
For more information about the American Academy of Neurology, visit its website at www.aan.com/press/.
Editor's Notes: Dr. Wong will present this research during a scientific session at the 56th Annual Meeting at 1:45 p.m. PT (4:45 p.m. ET) on Thursday, April 29 in Room 310 of the Moscone Convention Center. He will be available for media questions during a briefing at 11:00 a.m. PT (2:00 p.m. ET), Wednesday, April 28 in the on-site Press Interview Room, Room 214.