Posts Tagged ‘cognitive function’

Cognitive Decline Accelerates Years After Stroke

Stroke is associated with acute decline in cognitive function as well as a decline in new learning and memory, according to the first study to monitor cognitive function in a longitudinal manner before and after stroke.

About one-third of stroke patients have significant cognitive impairment within several months of the event.

In addition, silent strokes, experienced by 1 in 10 adults by their early 60s, are harbingers of both future stroke and cognitive dysfunction.

Downward Trajectory

Researchers led by Deborah A. Levine, MD, MPH, of the University of Michigan, Ann Arbor, tracked the trajectories of cognitive decline before and after incident stroke in a prospective study of 23,572 participants age 45 years or older without baseline cognitive impairment.

The participants were part of the Reasons for Geographic and Racial Differences in Stroke cohort.

Over a median follow-up of 6 years, 515 participants survived incident stroke and 23,057 remained stroke free.

All participants underwent cognitive function tests administered by telephone to assess their global cognition annually.

They also underwent a battery of cognitive tests administered twice a year.

The results show stroke was associated with acute decline in global cognition, new learning, and verbal memory.

Faster Decline in Cognition

“Participants with stroke, compared with those without stroke, demonstrated faster declines in global cognition and executive function, but not in new learning and verbal memory, compared with pre-stroke slopes,” they wrote.

Also, cognitive impairment was significantly faster post-stroke compared with pre-stroke.

As an example, the researchers note that for a 70-year-old black woman who had average values at baseline, stroke at year 3 was associated with greater incident cognitive impairment.

The absolute difference was 4% at year 3 and 12.4% at year 6.

The results suggest that stroke survivors should be monitored for years, they note.

In an accompanying editorial, Philip B. Gorelick, MD, MPH, and David Nyenhuis, PhD, from the Michigan State University College of Human Medicine, Grand Rapids, state that “acute cognitive decline was associated with incident stroke and accelerated and persisted over the approximately 6-year follow-up period.”

Tracking Pre-stroke Cognition

They note that a novel feature of the study was that it allowed for pre-stroke cognition to be tracked, allowing the researchers to acquire rates of cognitive change prior to incident stroke.

These results suggest that clinicians may have an opportunity to intervene immediately following stroke to prevent accelerated stroke-related cognitive decline.

They support screening for cognitive impairment over the long term following stroke.

Carotid Narrowing Tied to Cognitive Decline as Well as Stroke

Patients who have blockages in the carotid arteries are at risk not only for stroke but possibly for cognitive impairment as well, according to the results of a new study.

“We have fairly compelling evidence that there is a decline in cognitive function associated with blockages in the carotid arteries in asymptomatic patients (those with no symptoms),” principal investigator Brajesh Lal, MD, Professor of Vascular Surgery at the University of Maryland School of Medicine in Baltimore, said in an interview.

“No one has asked about what happens to the way the brain functions—thinks, processes information, remembers, recollects new information—when blood flow is restricted from stenosis (narrowing).”

A neuropsychologist at the University of Maryland, Moira C. Dux, PhD, presented the details of the study at the American Academy of Neurology annual meeting in Philadelphia.

NARROW CAROTIDS, WORSE MEMORY

The study involved 67 persons with asymptomatic carotid stenosis who had a 50% reduction in the diameter of the artery, and 60 persons with vascular risk factors, including diabetes mellitus, hypertension, hypercholesterolemia, and coronary artery disease, with no stenosis.

The patients underwent extensive testing for overall thinking abilities and for specific aspects of thinking, such as processing speed, learning, memory, decision making, and language.

The stenosis group performed significantly worse on the overall memory and thinking tests, as well as on tests for motor and processing speed, and learning and memory.

Language scores did not differ between the 2 groups.

“We have demonstrated, for the first time, that carotid stenosis without a neurologic deficit is not necessarily ‘asymptomatic’ and is associated with greater cognitive impairment compared to patients with similar risk factors but no stenosis,” said Dr. Lal.

TWO POTENTIAL MECHANISMS

Two potential mechanisms are restriction of blood flow caused by the stenosis and microinfarction from the release of microparticles, Dr. Lal stated.

“Microparticles could lodge in non-expressive areas of the brain, which become infarcted, and then be expressed as cognitive impairment,” he said.

“We are now looking at transcranial flow within the brain, microembolization from plaque, and microinfarction and brain injury in these patients.”

The researchers also plan to monitor these patients, average age 60 years, for at least another 2 years to assess their risk of stroke.

Every patient with carotid stenosis has significant atherosclerosis and should be receiving aspirin and statin therapy, Dr. Lal said.

“HOW HAS YOUR MEMORY BEEN?”

“With these data, I will start asking my carotid stenosis patients, how has your memory been? Do you have trouble thinking? If they have any suggestion of cognitive impairment, I will refer them to a neuropsychologist,” he said, adding “I don’t think I can recommend carotid endarterectomy yet.”

Carotid endarterectomy is a surgical procedure used to reduce the risk of stroke by correcting narrowing in the carotid arteries.

Dr. Lal has preliminary data from a previous study that show using both surgery and stenting for carotid artery stenosis leads to a net improvement in cognitive function.

“From 8 to 15 million US patients have asymptomatic carotid artery stenosis.

I anticipate a large number of follow-up studies searching for causes and the best treatment options for this newly identified morbidity associated with carotid narrowing,” Dr. Lal said.

“Once we identify the mechanism, we potentially can mount a clinical trial comparing cognitive rehabilitation versus revascularization.”

Home-based Training Program Improves Memory Function in Epilepsy

Everyone has moments of memory lapses — you forget someone’s name or telephone number, or to take your medication.

These types of memory problems can be part of the normal aging process.

But about half of those with seizures report more than average memory difficulties.

Now a simple self-management intervention may improve the cognitive performance of patients who have epilepsy, according to the results of a new study.

“About half of the 2 million people in the US living with epilepsy have cognitive problems.

Despite the significant impact cognitive functioning has on quality of life, there are limited treatment modalities with which to intervene.

This program teaches epilepsy patients self-efficacy and strategies on how to manage memory problems.

It also helps ease anxiety about memory problems and enhances the ability to cope with memory deficits,” Tracie Caller, MD, Neurophysiology Fellow at Dartmouth Hitchcock Medical Center in Hanover, New Hampshire, said in an interview before her presentation at the American Academy of Neurology annual meeting in Philadelphia.hobscotch_logo

Epileptic seizures typically interrupt cognitive functioning.

“Small epileptic discharges impair cognition.

Eventually, this interrupts the encoding process for new memories.

Also, many epileptic patients have overlying anxiety and depression, which can affect concentration, which in turn affects memory,” said Dr. Caller.

In addition, certain epilepsy medications, such as topiramate, can cause fatigue and affect memory and concentration.

The underlying brain abnormality that causes seizures, for example, scarring in the temporal lobe, also may affect memory, she said.

Dr. Caller and colleagues conducted a pilot study of a self-management intervention for cognitive impairment in epilepsy.

TEACHING PROBLEM-SOLVING STRATEGIES

HOBSCOTCH (HOme Based Self-management and COgnitive Training CHanges lives) is an 8-week, telephone-based intervention developed to teach problem-solving strategies and compensatory memory strategies.

Dr. Caller reported on the results of 16 adult patients with epilepsy and subjective cognitive complaints who were randomized to receive HOBSCOTCH, HOBSCOTCH+ (which adds working memory training), or usual care.

“We found that the 9 HOBSCOTCH participants had significantly improved quality of life scores as compared to 7 controls, and significant changes in depression, as well as improvement in executive function,” said Dr. Caller.

“As a pleasant surprise, we also found improvement in objective memory function.”

The program is “designed to teach memory strategies, to work around deficits, and improve memory confidence,” Dr. Caller said.

“People with epilepsy often lose confidence in their memory, and this becomes a vicious cycle.”

The structure of the program is similar to problem-solving therapy now used by primary care doctors and applied to depression and chronic diseases, such as heart disease and diabetes.

“We teach patients how to solve their own problems, for example, how to remember to take their medication by setting a reminder alarm on a cell phone or putting the medication next to their tooth brush or coffee machine,” Dr. Caller stated.

She said the program would be easy to implement in a doctor’s office.

“We have nurse practitioners deliver HOBSCOTCH.

A variety of practitioners, including psychologists and social workers, can deliver the intervention,” she said.

So far, the researchers have enrolled 50 of a planned 60 patients with epilepsy in a clinical trial to test the effectiveness of HOBSCOTCH.

The patients in the pilot study “are satisfied with the program.

We have a low drop-out rate compared to similar interventions,” said Dr. Caller.

She thinks the program also would be helpful in other neurological disorders, such as multiple sclerosis, in which patients often have memory difficulties and depression, as well as for chemotherapy patients who suffer so-called “chemobrain” post-therapy.

Cardiovascular Fitness May Help Cognitive Function

Good cardiovascular health may help preserve memory and thinking skills into middle age, according to the results of a new study.

“The brain health of young adults shows benefits from cardio fitness activities.

Interestingly, for those who currently have low fitness, even activities at moderate intensity are likely to be beneficial.

For couch potatoes, it’s just getting moving,” said David R. Jacobs, Jr, PhD, Professor, School of Public Health, Division of Epidemiology & Community Health at the University of Minnesota, MN.

“The brain, like all organs, is highly vascularized,” he said.

“Factors that affect the health of the vascular system are likely to affect the health of the brain.

There is substantial evidence that many cardiovascular disease risk factors also reduce chronic low grade inflammatory conditions.”

The researchers published their results online on April 2, 2014 in the journal Neurology.

TREADMILL AND COGNITIVE TESTS

For the study, more than 2700 healthy persons, average age 25 years, underwent treadmill tests in the first year and then again 20 years later.

Cognitive tests conducted 25 years after the start of the study measured verbal memory, psychomotor speed (the relationship between thinking skills and physical movement), and executive function.

Those who had smaller decreases in their time completed on the treadmill test 20 years later were more likely to perform better on the executive function test than those who had bigger decreases.

“Of course, the executive function, memory skill, and speed of processing that we studied in relation to treadmill test–based fitness are not the same as real life situations,” said Dr. Jacobs.

“However, the standardized testing is useful and can be considered to represent ‘thinking skills.’

Other studies in older individuals have shown that these tests are among the strongest predictors of developing dementia in the future.”

Dr. Jacobs noted that many chronic diseases have their roots many years before clinical manifestation.

“It is logical that people who experience mild losses of cognitive function are at risk for dementia,” he said.

“This has been shown at older ages.

However, we do not know whether the ‘thinking skills’ that we measured will lead to the more severe manifestations that are devastating our elderly population.”

He continued: “It will take further follow-up over another 10 to 20 years to discover empirically whether the cognitive losses that we measured are in fact a risk for dementia.

DIMINISHED ‘THINKING SKILL’ IN MIDDLE AGE

At minimum, I speculate that people who suffer less ‘thinking skill’ in middle age do not function as effectively in society as people who remain sharp.”

The study pointed out how middle age (defined as age 43 to 55 years) and elderly chronic disease in the brain may have roots in lifestyle behaviors during youth.

Dr. Jacobs noted that the current study does not address whether improving fitness would reduce the loss of cognitive function.

“Fitness performance on a symptom-limited treadmill test is dependent on many factors, including vigorous activity, musculoskeletal health, general robustness, smoking, adiposity, and social participation,” he said.

“This is not the same as a group activity that requires exercising or just moving around.

However, encouraging patients to exercise and in general to maintain an active, engaged lifestyle may help forestall cognitive loss, among other benefits.”

Heavy Drinking Hastens Cognitive Decline in Men

Men who are heavy drinkers show a faster cognitive decline compared with men who consume light to moderate amounts of alcohol, according to a new study.

The middle-age men who averaged 3 or more drinks per day showed faster 10-year declines in cognitive function than did lighter drinkers.

“The detrimental effect of heavy alcohol consumption on health is well documented.

This study adds a new argument against heavy drinking, showing that it is also detrimental for cognitive aging, with effects evident as early as age 55 years,” said lead author Séverine Sabia, PhD, from the Department of Epidemiology & Public Health at University College London.

“For example, heavy drinking men aged 60 years old show a decline in memory comparable to men aged 66 years old,” she noted.

The researchers published their results online on January 15, 2014 in the journal Neurology.

Lifestyle Questionnaires Assess Alcohol Consumption

Dr. Sabia and colleagues analyzed data from more than 7000 British civil servants, average age 56 years, who had agreed to complete lifestyle questionnaires and to undergo a physical examination beginning in the 1980s.

About two-thirds of the participants were men.

Alcohol consumption was assessed 3 times in the 10 years preceding the first cognitive assessment in the late 1990s.

Cognitive tests were repeated twice more in the 2000s.

The cognitive test battery included 4 tests that assessed memory and executive function.

The participants were stratified into 6 groups according to drinking status, including complete abstainers; those who stopped drinking entirely at some point during follow-up; “occasional” drinkers (their average daily alcohol consumption was not quantified); and light, moderate, and heavy regular drinkers.

Almost two-thirds of the men were light drinkers, just under 20% were moderate drinkers, and just under 10% were heavy drinkers.

The researchers used the light drinkers as the reference group to analyze drinking and cognitive decline.

Heavy Drinking = Cognitive Declines

Compared with the declines observed in the light drinkers, declines in cognitive scores were statistically higher in the heavy-drinking men but did not differ for the other groups.

The scores on 4 tests of short-term memory and executive function dropped the most in the heaviest male drinkers.

“Although we cannot completely exclude confusing effects from an unhealthy lifestyle, we did take into account fruit and vegetable consumption, physical activity, and smoking in the analyses,” said Dr. Sabia.

“The mechanisms underlying the association between alcohol consumption and cognition are complex.

The main hypothesis focuses on cerebrovascular and cardiovascular pathways, involving effects that play out over an extended period of time.

Heavy alcohol consumption is associated with higher risk of vascular disease which, in turn, may increase the risk of cognitive impairment.”

In addition, Dr. Sabia noted that “heavy alcohol consumption has detrimental short-term and long-term effects on the brain, including direct neurotoxic effects, pro-inflammatory effects, and indirect impact via cerebrovascular disease and vitamin deficiency.”

Dr. Sabia added, “Our findings are in agreement with previous studies showing that moderate alcohol consumption is probably not deleterious for cognitive outcomes, but they also show that heavy alcohol consumption in midlife is likely to be harmful for cognitive aging, at least in men.”

Tai Chi May Delay Onset of Alzheimer’s Disease

As an unprecedented number of Americans approach old age, there is a growing concern about the loss of cognitive function that is often attributed to aging.

By around age 70 1 in 6 people have mild cognitive decline.

Mild cognitive decline is considered an intermediate state between the cognitive changes of aging and the earliest clinical features of dementia, particularly Alzheimer’s disease.

The good news is that due to your brain’s plasticity you may be able to improve your cognitive function and offset age-related decline through exercise, stress reduction, learning new tasks, staying socially active, and learning how to focus better — all integral elements of Tai Chi training.

“A body of studies on Tai Chi and cognitive function lend support to the promise of Tai Chi for your brain and mind’s health,” says Peter Wayne, PhD, Assistant Professor of Medicine, Harvard Medical School Director of Research, Osher Center for Integrative Medicine Brigham and Women’s Hospital and Harvard Medical School, and author of The Harvard Medical School Guide to Tai Chi.

This ancient form of slow, meditative exercise helps to create mental activity, and scientists believe it may be possible to delay the onset of Alzheimer’s disease.

November is National Alzheimer’s Disease Awareness Month, and although there is no cure for the disease, a study published in the June issue of the Journal of Alzheimer’s Disease revealed that elderly people practicing Tai Chi just three times a week can boost brain volume and improve memory and thinking.

Scientists from the University of South Florida and Fudan University in Shanghai found increases in brain volume and improvements on tests of memory and thinking in Chinese seniors who practiced Tai Chi three times a week.

The 8-month randomized controlled trial compared those who practiced Tai Chi to a group who received no intervention.

The same trial showed increases in brain volume and more limited cognitive improvements in a group that participated in lively discussions three times per week over the same time period.

“The ability to reverse this trend with physical exercise and increased mental activity implies that it may be possible to delay the onset of dementia in older persons through interventions that have many physical and mental health benefits,” said lead author Dr. James Mortimer, professor of epidemiology at the University of South Florida College of Public Health.

Dr. Wayne notes that other randomized trials have evaluated Tai Chi in adults diagnosed with moderate levels of dementia.

In one large Chinese trial, a group assigned to Tai Chi showed greater improvements in cognitive performance after five months than a group assigned to a stretching and toning program, and fewer of those in the Tai Chi group progressed to dementia.

In a smaller study at the University of Illinois, a group of adults with dementia showed small increases in mental ability and self-esteem after 20 weeks of a combination of Tai Chi, cognitive behavioral therapies, and a support group as compared to an education group, who had slight losses of mental function.

“Interestingly, a follow-up companion study reported benefits of Tai Chi training to the caregivers of people with dementia,” says Dr. Wayne.

“Tai Chi may offer specific benefits to cognition, but more larger-scale trials that also include longer follow-up periods are needed to make stronger conclusions.”