For AIDS Patients, Subtle Thinking Problems Could Signal Later Dementia
Mother recalls impact of AIDS-related dementia
Maine artist Elizabeth Ross Denniston says she has tried to put many of the worst memories of her son's death behind her. Bruce Denniston died of AIDS in 1992 at the age of 28, and his mother was his primary caregiver after he got too sick to take care of himself.
She can't forget the seizures, though, or the gaunt appearance her son had toward the end. And she can't forget the dementia, which began with subtle personality changes in the last year of her son's life, but quickly progressed.
"We were trying to cope with a lot of other problems, so we may not have noticed it at first," she says. "He was an extremely intelligent guy and a computer expert, but he lost interest in all that. Toward the end of his life he began to hallucinate. He developed a terrific fear of birds and other animals, even though he had always loved them. I had gotten him a cat, thinking he would really love a pet, but he was scared to death of it."
HIV-related dementia, a progressive loss of intellectual functions, once common in the last stages of AIDS, is seen far less often these days thanks to the introduction of effective therapies like highly active antiretroviral therapy (HAART), a drug combination used to control the disease. But patients who cannot or will not take the new AIDS drugs or fail them are still at risk for dementia.
"Contrary to popular belief, not all AIDS patients are controlled and treatable," reports neurologist David Clifford, MD. "In real practices, as many as half of patients have ongoing [high levels of the virus] or other problems with the new drugs, and these patients are still at risk for dementia."
Now a study conducted prior to the widespread introduction of HAART suggests HIV-infected patients who show subtle signs of mental impairment may actually have a very early manifestation of AIDS-related dementia. Even relatively minor memory, movement, or speaking problems early in the course of disease can be a sign of later dementia.
Specifically, the study found that patients with a condition known as minor cognitive motor disorder (MCMD), characterized by slight thinking, mood, or neurological problems not serious enough to impact day to day functioning, were found to be at significantly increased risk for dementia.
"Our findings suggest that MCMD is not a separate syndrome at all, but is instead a forerunner to later dementia," says study author Yaakov Stern, PhD, of New York's Columbia University College of Physicians and Surgeons. "Although we can't draw firm conclusions from this one study, we can say that AIDS patients with early thinking deficits or MCMD are certainly more likely to develop dementia."
Clifford, who is a professor of neurology at Washington University in St. Louis, and is principal investigator for the Neurologic AIDS Research Consortium, says about 7% of AIDS patients now develop dementia. Just a few years ago, before the new therapies were widely available, the incidence was far higher -- as high as 60% according to 1998 figures from the CDC.
"One other reason that dementia is still a significant issue is that it is really too early in the HAART era to know whether it is going to be a problem down the line," Clifford says. "It is possible that the brain is the last bastion of this virus, and that ... dementia ... may be a problem."
San Francisco General Hospital chief of neurology Richard W. Price, MD, says he has seen no evidence that patients who do well on the new AIDS therapies are progressing to dementia. He says the AIDS-related dementia cases he generally sees occur in patients with advanced disease who have not been treated or built up a resistance to therapy because of irregular use.
"There is no question that the incidence of AIDS dementia in the current era of treatment is markedly reduced," Price says. "I usually see dementia these days in people who are outside of the treatment system, either because they have elected not to be treated or they have fallen through the cracks. It is a very different group of patients than we saw a few years ago."
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