Posts tagged cognition

Delirium is widespread among older people but often goes ignored and untreated, according to new research by US and UK researchers including the University of East Anglia.

Published in the September issue of the Journal of Hospital Medicine, the findings show that delirium - or acute confusion – is common among older adults in hospitals and nursing homes. It has a negative impact on cognition and independence, significantly increases the risk of developing dementia, and triples the likelihood of death. Yet this common, acute condition is frequently either undiagnosed or accepted as inevitable.

Led by the Regenstrief Institute and Indiana University, the research team reviewed 45 years of research encompassing 585 studies. They found that one in three cases of delirium were preventable and are calling for delirium to be identified and treated early to prevent poor long-term prognosis.

“As a geriatric psychiatrist I have seen that around 50 per cent or people with dementia in hospital develop delirium,” said co-author Dr Chris Fox, of Norwich Medical School at the University of East Anglia.

“This is because in addition to having dementia, they have multiple risk factors that can predispose and precipitate delirium – including serious illnesses and pre-existing cognitive impairment. In addition, hospital staff commonly label the signs as dementia related and do not pick up the delirium.”

“We need to develop better mechanisms for diagnosing delirium so that prompt treatment regimes can be initiated.”

In general patient groups, more than 60 per cent of delirium cases are not recognised or treated, and significant numbers of elderly patients leave hospital with ongoing delirium which has been missed.

The authors, led by Dr Babar Khan of the Regenstrief Institute and Indiana University School of Medicine, said that delirium could be prevented by eliminating restraints, treating depression, ensuring that patients have access to glasses and hearing aids, and prescribing classes of antipsychotics that do not negatively affect the aging brain. They also noted the need for a more sensitive screening tool for delirium, especially when administered by a non-expert.

“Delirium is extremely common among older adults in intensive care units and is not uncommon in other hospital units and in nursing homes, but too often it is ignored or accepted as inevitable,” said Dr Khan. “Delirium significantly increases risk of developing dementia and triples likelihood of death. It cannot be ignored.”

Co-author Dr Malaz Boustani, of the Regenstrief Institute, Indiana University School of Medicine and Wishard Healthy Aging Brain Center, said: “Having delirium prolongs the length of a hospital stay, increases the risk of post-hospitalization transfer to a nursing home, increases the risk of death and may lead to permanent brain damage.”

(Source: uea.ac.uk)

Looking at a tangled mass of network cables plugged into a crowded router doesn’t yield much insight into the network traffic that runs through the hardware.

Similarly, Lynn H. Matthias Professor of Electrical and Computer Engineering Barry Van Veen says that looking at the three pounds of interwoven neurons that make up the hardware of the human brain doesn’t give the complete picture of the brain activity that supports human cognition and consciousness.

Working with multiple collaborators, Van Veen has applied signal analysis techniques to the electric or magnetic fields measured noninvasively at the scalp through electroencephalography (EEG) or magnetoencephalography (MEG) to develop methods for identifying network models of brain function — essentially, traffic patterns of neural activity present in the human brain.

"It’s analogous to coming up with a new microscope," says Van Veen.

Having a reliable traffic map of normal brain function provides a baseline for comparison for understanding how different disorders, substances and devices affect the brain. “Now that we’ve got the tool ready, the opportunities to try it out on scientifically interesting questions are really blossoming,” says Van Veen.

For instance, network models may provide a better blueprint for how medical devices can interface with the brain. Van Veen recently began working with biomedical engineering Associate Professor Justin Williams to apply his work toward making better brain-machine interfaces.

But the implications of network models go beyond engineering questions. The effect of alcohol on the brain just begs for network analysis, according to Van Veen. The network model could allow researchers to see precisely which parts of the brain are altered by alcohol consumption. It could provide insight into how short-term memory works, help explain the effects of schizophrenia and monitor treatment, help measure the depth and effectiveness of different types of anesthesia, and even help give insight into the brain activity that precedes — or prevents — a miraculous recovery from a coma.

"We’re developing this tool as a significant improvement over what people have had access to before," says Van Veen. "The possibilities for using it to study different aspects of brain function are nearly unlimited."

(Source: news.wisc.edu)

August 11th, 2012
By Laura Sanders

Lifting neural constraints could turn back time, making way for youthful flexibility

Michael Morgenstern

A baby’s brain is a thirsty sponge, slurping up words, figuring out faces and learning which foods are good and bad to eat. Information about the world flooding into a young brain begins to carve out traces, like rushing water over soft limestone. As the outside world sculpts the growing brain, important connections between nerve cells become strong rivers, while smaller unused tributaries quietly disappear.

In time, these brain connections crystallize, forming indelible patterns etched into marble. Impressionable brain systems that allowed a child to easily learn a language, for instance, go away, abandoned for the speed and strength that come with rigidity. In a fully set brain, signals fly around effortlessly, making common­place tasks short work. A master of efficiency, the adult brain loses the exuberance of childhood.

But the adult brain need not remain in this petrified state. In a feat of neural alchemy, the brain can morph from marble back to limestone.

The potential for this metamorphosis has galvanized scientists, who now talk about a mind with the power to remake itself. In the last few years, researchers have found ways to soften the stone, recapturing some of the lost magic of a young brain.

“There’s been a very, very significant change,” says Richard Davidson of the University of Wisconsin–Madison. “I don’t think the import of that basic fact has fully expressed itself.”

Though this research is still in its early stages, studies suggest techniques that dissolve structures that pin brain cells in place, interrupt molecular stop signals and tweak the rush of nerve cell activity can restore the brain’s youthful glow. Scientists are already attempting to reverse brain rigidity, boosting what’s known as “plasticity” in people with a vision disorder once thought to be irreversible in adults.

These efforts are not an exercise in neural vanity. A malleable brain, researchers hope, can heal after a stroke, combat the decline in vision that comes with old age and perhaps even repair a severed spinal cord. An end to childhood — and the prodigal learning that comes with it — does not need to eliminate the brain’s capacity for change. “There are still windows of opportunity out there,” says neuroscientist Daphné Bavelier of the University of Rochester in New York. “It may require a little more work to open them, though.”

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