Tag: cognitive impairment

Categories : CancerTags :

A Clue to Breast Cancer Survivors’ Cognitive Problems

On By ModernMedia
Woman receiving mammogram
Source: National Cancer Institute

Why breast cancer survivors experience troubling cognitive problems is a long-standing mystery, and for which inflammation is one possible culprit. A new long-term study of older breast cancer survivors published in the Journal of Clinical Oncology adds evidence to this link.

Higher levels of the inflammatory marker C-reactive protein (CRP) were related to older breast cancer survivors reporting cognitive problems in the new study.

“Blood tests for CRP are used routinely in the clinic to determine risk of heart disease. Our study suggests this common test for inflammation might also be an indicator of risk for cognitive problems reported by breast cancer survivors,” said study lead author Judith Carroll, an associate professor at UCLA. 

The Thinking and Living with Cancer (TLC) Study is one of the first long-term efforts to examine the potential link between chronic inflammation and cognition in breast cancer survivors 60 and older, who make up a majority of the nearly 4 million breast cancer survivors in the United States. Previous research has focused largely on younger women and women immediately after therapy, making it difficult to draw conclusions about CRP’s role in long-term cognitive problems among older breast cancer survivors.   

In TLC, teams of researchers from around the country talked to, and obtained blood samples from, hundreds of breast cancer survivors and women without cancer up to six times over the course of five years. The study was motivated by hearing from survivors and advocates that cognitive problems are one of their major worries. 

“Cognitive issues affect women’s daily lives years after completing treatment, and their reports of their own ability to complete tasks and remember things was the strongest indicator of problems in this study,” said co-senior study author Dr Jeanne Mandelblatt, a professor of oncology at Georgetown University who is the lead of the TLC study.   

“Being able to test for levels of inflammation at the same time that cognition was being rigorously evaluated gave the TLC team a potential window into the biology underlying cognitive concerns,” said Elizabeth C. Breen, a professor emerita of psychiatry and biobehavioral sciences at the Cousins Center for Psychoneuroimmunology at UCLA, who also served as co-senior study author. 

The women’s cognition was evaluated through a commonly used questionnaire. The study found higher CRP levels among survivors were predictive of lower reported cognitive function among breast cancer survivors. There was no similar relationship between CRP levels and reported cognition in the women without cancer. 

Cognitive performance, as measured by standardised neuropsychological tests, failed to show a link between CRP and cognition. The authors say this may indicate women are more sensitive to differences in their everyday cognitive function, self-reporting changes that other tests miss.

The authors said their study supports the need for research on whether interventions that can lower inflammation – including increased physical activity, better sleep, and anti-inflammatory medications – may prevent or reduce cognitive concerns in older breast cancer survivors. 

Source: EurekAlert!

Categories : COVIDTags :

Long COVID Cognitive Impairment More Widespread than Thought

On By ModernMedia
Photo by Alex Green on Pexels

Scientists following COVID patients up to 12 months after diagnosis have found that mild cognitive impairment is common even after mild to moderate COVID. The study results, currently in preprint on the medRxiv server awaiting peer review, suggest that cognitive impairment, though barely noticeable, may affect large portions of the global population.

The finding comes as the US Centers for Disease Control reported that up to 1 in 5 Americans experienced at least one symptom that could be attributable to Long COVID.

SARS-CoV-2 is believed to cause lasting cognitive impairment in some cases, though the exact nature of it was not clear. Severe COVID cases risk damage through hypoxia, stroke, as well as the immune and inflammatory response to SARS-CoV-2. Mild to moderate COVID cases are still at risk of brain dysfunction, and cognitive deficits, providing a window into the potential mechanisms of brain injury without the confounding role of severe disease and its complications. Given the large numbers of people who had mild to moderate COVID disease, there would be significant implications for public health.

To assess the effects of the disease, the researchers studied 128 SARS-CoV-2 positive patients, assessing cognition and olfaction at set intervals after COVID diagnosis, along with lung capacity and blood biomarkers including the kynurenine pathway (KP).

After correcting for demographics, mild to moderate cognitive impairment was present in 26% on year post diagnosis, respectively. Overall cognitive performance declined mildly, but was statistically significant. KP metabolites quinolinic acid, 3-hydroxyanthranilic acid, and kynurenine were significantly associated with cognitive decline.

“The immune system reacts first with the virus … tries to basically get rid of the virus,” she said to ABC News. “Then it goes a little bit into overdrive and this overdrive does not fully calm down.”

The KP pathway was seen to be disturbed similarly to the way inflammation is caused by viruses such as HIV.

“I think we’re seeing something a bit akin here, where this low level of inflammation is more and more understood as being able to traffic to the brain, or even being within the brain and affecting those regions of the brain where we process information that demand speed, extra attention and extra cognitive demands,” she explained.

Dr Cysique emphasises that the cognitive decline recorded among most participants in the study is mild and they may not even notice it.

The researchers suggested that as a unique biomarker, the KP offers a potential therapeutic target for COVID-related cognitive impairment.

Categories : NeurologyTags :

Body Fat Linked to Risk of Reduced Cognitive Function

On By ModernMedia
Photo by Andres Ayrton from Pexels

A new study published in JAMA Network Open has found that greater body fat is a risk factor for reduced cognitive function, such as processing speed, in adults.

Even when accounting for cardiovascular risk factors or vascular brain injury, the association between body fat and lower cognitive scores persisted. This suggests other, currently unknown, mechanisms linking excess body fat to reduced cognitive function.

For the study, 9166 participants were measured by bioelectrical impedance analysis to assess their total body fat. In addition, 6733 underwent magnetic resonance imaging (MRI) to measure abdominal fat packed around the organs known as visceral fat, and the MRI measured vascular brain injury, including silent brain infarctions and high white matter hyperintensities. Cardiovascular risk factors were measured using health and lifestyle questions and physical measures, and cognitive assessment was measured by the Digital Symbol Substitution Test and the Montreal Cognitive Assessment.

Lead author Sonia Anand, lead author, professor of medicine of McMaster University said: “Our results suggest that strategies to prevent or reduce having too much body fat may preserve cognitive function.”

She added that “the effect of increased body fat persisted even after adjusting for its effect on increasing cardiovascular risk factors like diabetes and high blood pressure, as well as vascular brain injury, which should prompt researchers to investigate which other pathways may link excess fat to reduced cognitive function.”

Co-author Eric Smith, associate professor of clinical neurosciences at the University of Calgary, said that “preserving cognitive function is one of the best ways to prevent dementia in old age. This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining a healthy weight and body fat percentage.”

Participants had no existing cardiovascular diseases, and ranged in age from 30 to 75, with an average age of about 58 and 56% were women. Most were White European origin, with about 16% other ethnic backgrounds. 

Source: McMaster University

Categories : Environmental EffectsTags :

Ozone Linked to Cognitive Impairment with Age

On By ModernMedia
Photo by Kouji Tsuru on Unsplash

A robust link has been established between long-term ozone exposure and an increased risk of cognitive impairment in older adults, according to a large-scale study published in Environment International.

Air pollution has long been considered a major risk factor for an ageing society. Fine airborne particulate matter can lead to dementia and other cognitive disabilities. But beyond airborne particles, little is known about the way in which other pollutants can pose a similar danger.

The researchers chose to focus on ambient ozone, a highly reactive gas that exists in much of smog at ground level. They then observed health outcomes in nearly 10 000 older adults across China and analysed the extent to which long-term ozone exposure may have impacted their cognitive ability over time.

The results, they found, were startling. For every 10 microgram increase of yearly average ozone exposure, the risk for cognitive impairment grew by more than 10%. Through their analysis, the researchers also found that this association held even when they abstracted away individual risk factors such as smoking, drinking and education level. That is, older adults in China who were exposed to high levels of yearly ozone pollution were more likely to develop cognitive disabilities later in life, no matter what other activities they were involved in.

“Our findings suggest potential benefits in delaying the progression of cognitive decline among older adults if ozone levels are reduced below the new WHO Global Air Quality Guideline for ozone pollution,” said Kai Chen, Ph.D., assistant professor at the Yale School of Public Health and the study’s lead author.

The researchers acknowledged limitations such as observational data being unable to establish a causal link. More research is needed into ozone’s destructive mechanism. And since many older adults in China spend more time indoors, their ozone exposure may be different.

Nonetheless, the findings match what other researchers have found in areas across the globe: Over the past several years, studies have traced a similar link in adults in the United States and in Taiwan, and have also found an association between ozone exposure and other neurological diseases.

The study shows that ozone exposure needs to be curbed worldwide to prevent healthcare systems from being overwhelmed as populations age and pollution increases.

Study co-author Professor Robert Dubrow said what makes this issue more urgent is that “ozone pollution is projected to be worsening under climate change.” Reducing this threat could bring significant benefits to public health and improve quality of life.

Source: Yale University

Categories : NeurologyTags :

Impairment Lasts up to 10 Hours After Cannabis

On By ModernMedia

A comprehensive analysis of 80 scientific studies has identified a ‘window of impairment’ of between three and 10 hours caused by moderate to high doses of tetrahydrocannabinol (THC), the cannabis component that causes intoxication. According to the researchers, these results have consequences for drug-driving laws around the world.

How long the impairment lasts depends on the THC dose, whether it is taken orally or inhaled, on the usage habits of the cannabis user and the demands of the task. The psychoactive THC component of cannabis has potential medical applications in treating nausea, sleep apnoea, fibromyalgia and chronic pain, though these applications are controversial and currently difficult to study due to legal issues, though off-label use is common. 
Previous research by Dr Arkell and colleagues has shown that cannabidiol (CBD), one of the medically active components of cannabis, does not cause impairment in driving. CBD has analgesic and anti-inflammatory actions, as well as anxiolytic, antiemetic, antipsychotic, and neuroprotective antioxidant properties

Medical and non-medical legal cannabis use is on the rise worldwide.
THC causes acute impairment in driving and cognitive performance, but there is uncertainty among users about the duration of this impairment and when they can start tasks such as driving after consuming cannabis.
“Our analysis indicates that impairment may last up to 10 hours if high doses of THC are consumed orally,”  said lead author Dr Danielle McCartney, Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney. “A more typical duration of impairment, however, is four hours, when lower doses of THC are consumed via smoking or vaporization and simpler tasks are undertaken (eg, those using cognitive skills such as reaction time, sustained attention and working memory). This impairment may extend up to six or seven hours if higher doses of THC are inhaled and complex tasks, such as driving, are assessed.”

A moderate THC dose is considered about 10 milligrams in this study, but could be higher for a regular user, said the researchers.

Co-author Dr Thomas Arkell, also from the Lambert Initiative, said: “We found that impairment is much more predictable in occasional cannabis users than regular cannabis users. Heavy users show significant tolerance to the effects of cannabis on driving and cognitive function, while typically displaying some impairment.”

Regular cannabis users might consume more to get the same effect, resulting in equivalent impairment, the authors noted.

In the case of oral use as in medical cannabis drops, tablets etc, the impairment takes longer to manifest and has a longer duration than the inhalation route.

The findings have implications for so-called drug-driving laws, the researchers said.

Professor Iain McGregor, Academic Director of the Lambert Initiative, said: “THC can be detected in the body weeks after cannabis consumption while it is clear that impairment lasts for a much shorter period of time. Our legal frameworks probably need to catch up with that and, as with alcohol, focus on the interval when users are more of a risk to themselves and others. Prosecution solely on the basis of the presence of THC in blood or saliva is manifestly unjust.

“Laws should be about safety on the roads, not arbitrary punishment. Given that cannabis is legal in an increasing number of jurisdictions, we need an evidence-based approach to drug-driving laws,” Prof McGregor said.

Source: News-Medical.Net

Journal information: McCartney, D., et al. (2021) Determining the magnitude and duration of acute Δ9-tetrahydrocannabinol (Δ9-THC)-induced driving and cognitive impairment: A systematic and meta-analytic review. Neuroscience & Biobehavioral Reviews. doi.org/10.1016/j.neubiorev.2021.01.003.