Antiretrovirals & Brain Damage
by John Bulloch
365Gay.com Health

Researchers have found significant damage in the brains of HIV-positive
patients whose viral load is effectively suppressed by anti-retroviral
therapy.

In one of the first studies of its kind, researchers from the San
Francisco Veterans Affairs Medical Center (SFVAMC) used a combination of
MRI brain imaging, recording of electrical brain activity, and behavioral
tests to compare the size and function of brains of HIV-positive patients
on
antiretroviral therapy with those of healthy subjects.

Although it is not known whether any or all of the damage occurred before
patients started drug therapy, even minor damage that is present now
should
serve as a warning, says Linda Chao, PhD, the study's lead author and an
assistant adjunct professor with the Magnetic Resonance Unit of the
SFVAMC
and the Departments of Psychiatry and Radiology at University of
California,
San Francisco (UCSF).

"You see people on antiretroviral medications and they seem fine. But the
take-home message of our study is that antiviral medications might not be
stopping brain damage, says Chao.
"When we put patients' brains under closer scrutiny, we saw that they
were
affected."
"The results of our study raise the concern of brain injury in HIV
subjects
who are on treatment, even among those who are virally suppressed," says
the
study's senior investigator, Michael Weiner, PhD, of the Magnetic
Resonance
Unit, SFVAMC, and the Departments of Radiology, Psychiatry, Medicine and
Neurology at UCSF. "What we don't know is whether or not these changes
occurred some time ago, prior to effective treatment, or whether these
changes represent ongoing injury."

HIV can produce neurological abnormalities in any part of the nervous
system, including the brain. Symptoms of HIV brain damage may include
depression, memory loss, a slowing of mental and physical response time
and
sluggishness in limb movement. These symptoms can progress to a severe
disorder known as HIV dementia, an advanced stage of neurological damage
that, before the advent of antiretroviral drug therapy, afflicted some 20
percent of HIV patients. These patients experienced such symptoms as
severe
memory loss and cognitive impairment, tremors, hyperactive reflexes,
immobility, and loss of speech.
Now that antiretroviral drugs have become widely accessible in the U.S.,
the
prevalence of HIV dementia and other neurological problems associated
with
HIV have sharply declined. But the drugs do not eliminate the virus: they
merely suppress it. And while HIV can make its way through the
blood-brain
barrier (the body's natural defense mechanism that prevents many
blood-borne
substances from passing into brain tissue), antiretroviral drugs are
largely
excluded by the barrier.
Taking the first steps to determine how the virus may be affecting the
brains of people taking antiretroviral drugs, Chao and her research team
compared 39 people who tested positive for HIV who had been taking
antiretroviral drugs for at least three months with 39 control subjects
not
infected by the virus. The HIV-positive group was further divided into
two
subgroups: a "virally suppressed" group whose 16 members had no
detectable
virus in blood samples, and a "viremic" group whose 23 members had
substantial virus in blood samples. Whether virally suppressed or
viremic,
all subjects in these groups were healthy with no symptoms of HIV
infection.

C365Gay.com 2005
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