Computer test accurately detects early Alzheimer's

Last Updated: 2005-03-21 17:00:22 -0400 (Reuters Health)

By Karla Gale

NEW YORK (Reuters Health) - Researchers have developed a more accurate
version of a standard test to detect dementia and cognitive impairment
that takes only about 10 minutes to administer, according to a report in
the Proceedings of the National Academy of Sciences.

The standard scoring method for dementia, known as the "National
Institute of Aging's Consortium to Establish a Registry for Alzheimer's
Disease's 10-word list" (CWL), consists of three immediate-recall trials
of a 10-word list, followed by an interference task, and then a
delayed-recall trial of the word list.

"In the traditional scoring and interpretation, only the total score
from the fourth trial is usually used," lead author Dr. William R.
Shankle explained to Reuters Health. However, much more information can
be gleaned from analyzing the patterns of words recalled based on their
placement in the list.

"The method we describe -- the mental skills test -- uses the individual
responses to every item in all four trials to come up with an answer,"
the researcher added.

The mental skills test takes about 10 minutes to administer online. Once
the answers are submitted, a formula is used to calculate the final
score that within seconds "indicates if a person is impaired or not with
an overall accuracy 97 percent," Shankle said.

Shankle and colleagues at the University of California, Irvine,
evaluated 471 community-dwelling subjects using the interview-based
Clinical Dementia Rating Scale. They then compared results of the
standard CWL test and the mental skills test.

For differentiating mild cognitive impairment from normal aging, the
shorter mental skills test was more sensitive in detecting impaired
subjects than was the longer CWL total delayed-recall test. According to
the authors, their review of the literature showed their procedure to
have a higher reported sensitivity than any other published test results.

"Early detection is absolutely critical because current treatments are
all geared to slow the accumulation of beta amyloid," Shankle noted.
With earlier treatment, "many patients can live out the rest of their
life with no impairment or only minimal impairment."

Just by eliminating the need for institutionalization, he added, the
cost of care can be reduced by $160,000 per patient.

SOURCE: Proceedings of the National Academy of Science, March 29, 2005.