[Viva] FW: CATIE News - Studying memory provides clues for helping the brain

Thu Feb 17 15:09:19 PST 2011

From: mailing at mercury.catie.ca [mailto:mailing at mercury.catie.ca] 
Sent: February-17-11 12:49 PM
To: cosmictami at shaw.ca
Subject: CATIE News - Studying memory provides clues for helping the brain

CATIE News - Studying memory provides clues for helping the brain

Some studies have suggested that older HIV-positive adults can have mild to
moderate deficits in what brain researchers call "working memory." According
to neuropsychologist and associate professor of psychiatry Steven Woods,
PsyD, who teaches at the University of California at San Diego, a centre for
excellence in neuroAIDS, working memory refers to "the ability to hold,
store and manipulate information in the brain." Deficits in working memory
may play a major role in some of the neurocognitive dysfunction seen in some
HIV-positive adults.

While conducting a cross-sectional study with HIV-positive people, Dr. Woods
and colleagues unexpectedly found that some older HIV-positive adults had
better assessments of working memory than younger HIV-positive adults.
Specifically, it appeared that some older participants had developed
strategies, either deliberately or inadvertently, to help them remember the
locations of a series of visual designs. By comparison, older HIV-positive
individuals who did not use strategies were far more likely than younger
HIV-positive persons to make working memory errors. 

Remembering visual designs might seem trivial to non-scientists, but for
neuropsychologists and other scientists who study the brain, these tests
provide important insight into memory.

Dr. Woods' team was intrigued by how effective spontaneous memory strategy
use was in the older adults and suspected that some older HIV-positive
people somehow gained insight into their memory problems and found ways to
compensate. This suggests that it is possible to help HIV-positive people
who have a mild-to-moderate degree of neurocognitive impairment to overcome
these difficulties.

Ideally it would have been best to have conducted a randomized controlled
clinical trial that recruited both HIV-positive and HIV-negative people for
purposes of comparison. However, the findings by Dr. Woods' colleagues are
exciting because they document that the brains of older HIV-positive people
may be able to develop effective strategies to compensate for some aspects
of HIV-related neurocognitive impairment.

What's next?

Rehabilitation programs for the brains of HIV-negative people who have
suffered traumatic brain injury from accidents or strokes have been
developed. Some of these programs have been found to be successful in
randomized clinical trials.

However, most otherwise-healthy HIV-positive people who take potent anti-HIV
therapy (commonly called ART or HAART) do not have such a serious degree of
cognitive impairment as someone who has injured their head in a car accident
or had a stroke. So existing brain rehabilitation programs need to be
adapted and tested to meet the needs of HIV-positive people.

There are also so-called brain training exercises that have been developed
to help older HIV-negative adults improve and restore their ability to use
language and numbers. In an interview with CATIE News, Dr. Woods notes that
brain training programs have not yet been formally tested with large numbers
of HIV-positive people with mild cognitive impairment. He makes the
following points:

"It is not clear if such exercises can correct or compensate for the
specific effects of HIV infection on the brain. Data are lacking for us to
know if early use of these programs in people without HIV-related cognitive
impairment will delay the onset of these problems."

Until such data do become available, Dr. Woods says that brain training
exercises, crossword puzzles, jigsaw puzzles and numeracy games such as
Sudoku represent "a low-risk investment, as for most HIV-positive people
these exercises will not be harmful."

As more HIV-positive people are aging, they and their doctors are concerned
about the possibility of accelerated decline of the brain. Neuroscientists
are studying memory and higher intellectual functioning to try to find ways
to help HIV-positive people better cope with the effects of aging. Expect to
hear results from these studies in the next several years.

Resources

For additional information about improving brain health in the setting of
HIV, see "A Mind of Her Own" by activist Maggie Atkinson in the winter 2010
issue of CATIE's Positive Side magazine at:

www.positiveside.ca/e/V11I2/Mind_e.htm

-Sean R. Hosein

REFERENCES:

1.     Gongvatana A, Woods SP, Taylor MJ, et al. Semantic clustering
inefficiency in HIV-associated dementia. Journal of Neuropsychiatry and
Clinical Neurosciences. 2007 Winter;19(1):36-42.

2.     Wegesin DJ, Jacobs DM, Zubin NR, et al. Source memory and encoding
strategy in normal aging. Journal of Clinical and Experimental
Neuropsychology. 2000 Aug;22(4):455-64.

3.     Baddeley A. Working memory: looking back and looking forward. Nature
Reviews Neuroscience. 2003 Oct;4(10):829-39.

4.     Redondo RL, Morris RG. Making memories last: the synaptic tagging and
capture hypothesis. Nature Reviews Neuroscience. 2011 Jan;12(1):17-30.

5.     Wang SH, Redondo RL, Morris RG. Relevance of synaptic tagging and
capture to the persistence of long-term potentiation and everyday spatial
memory. Proceedings of the National Academy of Sciences USA. 2010 Nov
9;107(45):19537-42.

6.     Miller GA. The magical number seven, plus or minus two: some limits
on our capacity for processing information. Pschological Review. 1994
Apr;101(2):343-52.

7.     Woods SP, Weber E, Cameron MV, et al. Spontaneous strategy use
protects against visual working memory deficits in older adults infected
with HIV. Archives of Clinical Neuropsychology. 2010 Dec;25(8):724-33.

8.     Heaton RK, Clifford DB, Franklin DR Jr., et al. HIV-associated
neurocognitive disorders persist in the era of potent antiretroviral
therapy: CHARTER Study. Neurology. 2010 Dec 7;75(23):2087-96.

9.     Malaspina L, Woods SP, Moore DJ, et al. Successful cognitive aging in
persons living with HIV infection. Journal of Neurovirology. 2011; in press.

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