Posts tagged cognitive reserve

Kessler Foundation scientists have shown that working memory may  be an underlying mechanism of cognitive reserve in multiple sclerosis (MS). This finding informs the relationships between working memory, intellectual enrichment (the proxy measure for cognitive reserve) and long-term memory in this population. “Working memory mediates the relationship between intellectual enrichment and long-term memory in multiple sclerosis: An exploratory analysis of cognitive reserve” was published online ahead of print by the Journal of the International Neuropsychological Society on July 14. The authors are Joshua Sandry, PhD, and research scientist James F. Sumowski, PhD, of Neuropsychological & Neuroscience Research at Kessler Foundation. Dr. Sandry is a postdoctoral fellow funded by a grant from the National MS Society.

Cognitive symptoms, including deficits in long-term memory, are known to affect approximately half of individuals with MS. This study was conducted in 70 patients with MS, who were evaluated for intellectual enrichment, verbal long-term memory, and working memory capacity. “We found that working memory capacity explained the relationship between intellectual enrichment and long-term memory in this population,” said Dr Sandry. “This suggests that interventions targeted at working memory in people with MS may help build cognitive reserve to protect against decline in long-term memory.”

(Source: kesslerfoundation.org)

Multiple sclerosis researchers have found that brain reserve and cognitive reserve confer a long-term protective effect against cognitive decline.

“Our research aims to answer these questions,” explained Dr. DeLuca. “Why do some people with MS experience disabling symptoms of cognitive decline, while others maintain their cognitive abilities despite neuroimaging evidence of significant disease progression? Can the theories of brain reserve and cognitive reserve explain this dichotomy? Can we identify predictors of cognitive decline?”

In this study, memory, cognitive efficiency, vocabulary (a measure of intellectual enrichment/cognitive reserve), brain volume (a measure of brain reserve), and disease progression on MRI, were evaluated in 40 patients with MS at baseline and at 4.5-year followup. After controlling for disease progression, scientists looked at the impact of brain volume and intellectual enrichment on cognitive decline.

Results supported the protective effects of brain reserve and cognitive reserve,” noted Dr. Sumowski. “Patients with greater intellectual enrichment experienced lesser degrees of cognitive decline. Those with greater brain reserve showed a protective effect for cognitive efficiency. This study not only confirms these protective effects of brain and cognitive reserve, it shows that these beneficial effects persist for years.”

(Source: kesslerfoundation.org)

Better-educated people appear to be significantly more likely to recover from a moderate to severe traumatic brain injury (TBI), suggesting that a brain’s “cognitive reserve” may play a role in helping people get back to their previous lives, new Johns Hopkins research shows.

The researchers, reporting in the journal Neurology, found that those with the equivalent of at least a college education are seven times more likely than those who didn’t finish high school to be disability-free one year after a TBI serious enough to warrant inpatient time in a hospital and rehabilitation facility.

The findings, while new among TBI investigators, mirror those in Alzheimer’s disease research, in which higher educational attainment — believed to be an indicator of a more active, or more effective, use of the brain’s “muscles” and therefore its cognitive reserve — has been linked to slower progression of dementia.

“After this type of brain injury, some patients experience lifelong disability, while others with very similar damage achieve a full recovery,” says study leader Eric B. Schneider, Ph.D., an epidemiologist at the Johns Hopkins University School of Medicine’s Center for Surgical Trials and Outcomes Research. “Our work suggests that cognitive reserve ¬— the brain’s ability to be resilient in the face of insult or injury — could account for the difference.”

Schneider conducted the research in conjunction with Robert D. Stevens. M.D., a neuro-intensive care physician with Johns Hopkins’ Department of Anesthesiology and Critical Care Medicine.

For the study, the researchers studied 769 patients enrolled in the TBI Model Systems database, an ongoing multi-center cohort of patients funded by the National Institute on Disability and Rehabilitation Research. The patients had been hospitalized with a moderate to severe TBI and subsequently admitted to a rehabilitation facility.

Of the 769 patients, 219 — or 27.8 percent — were free of any detectable disability one year after their injury. Twenty-three patients who didn’t complete high school — 9.7 percent of those at that education level — recovered, while 136 patients with between 12 and 15 years of schooling — 30.8 percent of those at that educational level — did. Nearly 40 percent of patients — 76 of the 194 — who had 16 or more years of education fully recovered.

Schneider says researchers don’t currently understand the biological mechanisms that might account for the link between years of schooling and improved recovery.

“People with increased cognitive reserve capabilities may actually heal in a different way that allows them to return to their pre–injury function and/or they may be able to better adapt and form new pathways in their brains to compensate for the injury,” Schneider says. “Further studies are needed to not only find out, but also to use that knowledge to help people with less cognitive reserve.”

Meanwhile, he says, “What we learned may point to the potential value of continuing to educate yourself and engage in cognitively intensive activities. Just as we try to keep our bodies strong in order to help us recover when we are ill, we need to keep the brain in the best shape it can be.”

Adds Stevens: “Understanding the underpinnings of cognitive reserve in terms of brain biology could generate ideas on how to enhance recovery from brain injury.”

(Source: hopkinsmedicine.org)

Highly educated individuals with mild cognitive impairment that later progressed to Alzheimer’s disease cope better with the disease than individuals with a lower level of education in the same situation, according to research published in the June issue of The Journal of Nuclear Medicine. In the study “Metabolic Networks Underlying Cognitive Reserve in Prodromal Alzheimer Disease: A European Alzheimer Disease Consortium Project,”neural reserve and neural compensation were both shown to play a role in determining cognitive reserve, as evidenced by positron emission tomography (PET).

Cognitive reserve refers to the hypothesized capacity of an adult brain to cope with brain damage in order to maintain a relatively preserved functional level. Understanding the brain adaptation mechanisms underlying this process remains a critical question, and researchers of this study sought to investigate the metabolic basis of cognitive reserve in individuals with higher (more than 12 years) and lower (less than 12 years) levels of education who had mild cognitive impairment that progressed to Alzheimer’s disease, also known as prodromal Alzheimer’s disease.

“This study provides new insight into the functional mechanisms that mediate the cognitive reserve phenomenon in the early stages of Alzheimer’s disease,” said Silvia Morbelli, MD, lead author of the study.  “A crucial role of the dorso-lateral prefrontal cortex was highlighted by demonstrating that this region is involved in a wide fronto-temporal and limbic functional network in patients with Alzheimer’s disease and high education, but not in poorly educated Alzheimer’s disease patients.”

In the study, 64 patients with prodromal Alzheimer’s disease and 90 control subjects—coming from the brain PET project (chaired by Flavio Nobili, MD, in Genoa, Italy) of the European Alzheimer Disease Consortium—underwentbrain ¹⁸F-FDG PET scans. Individuals were divided into a subgroup with a low level of education (42 controls and 36 prodromal Alzheimer’s disease patients) and a highly educated subgroup (40 controls and 28 prodromal Alzheimer’s disease patients). Brain metabolism was compared between education-matched groups of patients and controls, and then between highly and poorly educated prodromal Alzheimer’s disease patients.

Higher metabolic activity was shown in the dorso-lateral prefrontal cortex for prodromal Alzheimer’s disease patients. More extended and significant correlations of metabolism within the right dorso-lateral prefrontal cortex and other brain regions were found with highly educated than less educated prodromal Alzheimer’s disease patients or even highly educated controls.

This result suggests that neural reserve and neural compensation are activated in highly educated prodromal Alzheimer’s disease patients. Researchers concluded that evaluation of the implication of metabolic connectivity in cognitive reserve further confirms that adding a comprehensive evaluation of resting ¹⁸F-FDG PET brain distribution to standard inspection may allow a more complete comprehension of Alzheimer’s disease pathophysiology and possibly may increase ¹⁸F-FDG PET diagnostic sensitivity.

“This work supports the notion that employing the brain in complex tasks and developing our own education may help in forming stronger ‘defenses’ against cognitive deterioration once Alzheimer knocks at our door,” noted Morbelli.“It’s possible that, in the future, a combined approach evaluating resting metabolic connectivity and cognitive performance can be used on an individual basis to better predict cognitive decline or response to disease-modifying therapy.”

(Source: interactive.snm.org)