Washington -- By combing through dozens of Alzheimer's disease (AD) studies, psychologists have gained a clear picture of cognitive problems in people who will develop the degenerative brain disease. The meta-analysis reveals that people can show early warning signs across several cognitive domains years before they are officially diagnosed, confirming that Alzheimer's causes general deterioration and tends to follow a stable preclinical stage with a sharp drop in function. The findings appear in the July issue of Neuropsychology, which is published by the American Psychological Association.
Researchers at the Karolinska Institute and Stockholm Gerontology Research Center, affiliated also with the Max Planck Institute for Human Development and the University of South Florida, crunched the data from a decade's worth of studies: Published reports that met stringent criteria had records on 1,207 people with preclinical Alzheimer's (they later developed the disease) and 9,097 controls who stayed healthy.
Neuropsychologists are striving to understand the preclinical stage for two reasons: On the theoretical level, understanding the transition from normal aging to dementia is vital to understanding how the disease evolves. On the clinical level, treatment can work best when doctors can identify at-risk individuals as early as possible.
The authors studied 47 peer-reviewed studies published between January 1985 and February 2003. The year 1985 marked the introduction of more systematic and reliable diagnostic criteria for Alzheimer's.
The analysis showed that no matter what kind of study, people at the preclinical stage showed marked preclinical deficits in global cognitive ability, episodic memory, perceptual speed, and executive functioning; along with somewhat smaller deficits in verbal ability, visuospatial skill, and attention. There was no preclinical impairment in primary memory.
The generalized nature of the problPage: 1 2 Related medicine news :1
Contact: Pam Willenz
American Psychological Association
. Early-childhood intervention may improve well-being through young adulthood2
. Early-morning Friday classes may prevent students from getting sloppy on thirsty Thursdays3
. Early education for the health care team -- Bringing nursing and medical students together4
. Early onset of poor bone mineralization revealed in children with cystic fibrosis5
. Early sex may lead teens to delinquency, study shows6
. Early switch to an aromatase inhibitor increases survival7
. Early results indicate radiofreqency ablation useful in treating ovarian cancer metastasis8
. Early statin therapy for patients with acute coronary syndromes reduces death, cardiovascular events9
. Early trial shows H5N1 influenza vaccine safe and effective in humans at low doses10
. Early warning test for Parkinsons receives national recognition11
. Early-onset of diabetes associated with increased risk of kidney disease and death before age 55