Tag: neurology

Oleh Hornykiewicz, Who Discovered Parkinson’s Treatment, Dies at 93

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Oleh Hornykiewicz in his Vienna office in 2009 He helped identify low dopamine levels as a cause of Parkinson’s disease, a finding that led to an effective treatment.

Oleh Hornykiewicz, a Polish-born pharmacologist whose breakthrough research on Parkinson’s disease has spared millions of patients the tremors and other physical impairments it can cause, died on May 27 in Vienna. He was 93.

His death was confirmed by his longtime colleague, Professor Stephen J. Kish of the University of Toronto, where Professor Hornykiewicz (pronounced whor-nee-KEE-eh-vitch) taught from 1967 until his retirement in 1992.

Professor Hornykiewicz was among several scientists who were considered instrumental in first identifying a deficiency of the neurotransmitter dopamine as a cause of Parkinson’s disease, and then in perfecting its treatment with L-dopa, an amino acid found in fava beans.

The Nobel laureate Dr. Arvid Carlsson and his colleagues had earlier shown that dopamine played a role in motor function. Drawing on that research, Professor Hornykiewicz and his assistant, Herbert Ehringer, discovered in 1960 that the brains of patients who had died of Parkinson’s had very low levels of dopamine.

He persuaded another one of his collaborators, the neurologist Walther Birkmayer, to inject Parkinson’s patients with L-dopa, the precursor of dopamine, which could cross the barrier between blood vessels and the brain and be converted into dopamine by enzymes in the body, thus replenishing those depleted levels. The treatment alleviated symptoms of the disease, and patients who had been bedridden started walking.

The initial results of this research were published in 1961 and presented at a meeting of the Medical Society of Vienna. The “L-dopa Miracle,” as it was called, inspired Dr. Oliver Sacks’s memoir “Awakenings” (1973) and the fictionalized movie of the same name in 1990.
As a therapy for Parkinson’s, L-dopa was further refined by other scientists, including George C. Cotzias and Melvin D. Yahr. But it was Professor Hornykiewicz, defying colleagues who had argued that post-mortem brain studies were worthless, who is credited with the critical breakthroughs.

His findings spurred the establishment of human brain tissue banks, research into dopamine and treatments of other diseases caused by low levels of neurotransmitters.

“Today, it is generally agreed that the initiation of the treatment of Parkinson’s disease with L-dopa represented one of the triumphs of pharmacology of our time,” Professor Hornykiewicz wrote in “The History of Neuroscience in Autobiography, Volume IV” (2004). “This provided, apart from the benefit to the patients, a stimulus for analogous studies of many other brain disorders, both neurological and psychiatric.”

He received several distinguished awards, including the Wolf Prize in Medicine in 1979 and the Ludwig Wittgenstein Prize of the Austrian Research Foundation in 1993.

In 2000, when Dr. Carlsson, of Sweden, and others were awarded the Nobel Prize in Physiology or Medicine for discovering dopamine and “allowing for the development of drugs for the disease,” as the Nobel committee wrote, more than 200 scientists signed a petition protesting that the prize had not also been awarded to Professor Hornykiewicz.

Oleh Hornykiewicz was born on Nov. 17, 1926, in the village of Sychow, near Lviv, in what was then southeastern Poland and is now western Ukraine. His was a fourth-generation family of Eastern Orthodox Catholic priests. His father, Theophil Hornykiewicz, ministered to the village’s several dozen parishioners and taught religion; his mother, Anna (Sas-Jaworsky) Hornykiewicz, managed the affairs of the village’s 300-year-old wooden church.

When the Soviet Union invaded in 1939, the family fled to Austria, his mother’s ancestral home, with whatever belongings they could carry. Oleh knew no German but learned it by reading Hitler’s “Mein Kampf,” which was readily available in Vienna. He suffered from tuberculosis and, when the war ended, decided to follow his eldest brother and become a doctor.

He received his medical degree from the University of Vienna in 1951 and began his academic and research career in its pharmacology department. He held a British Council Research Scholarship at the University of Oxford from 1956 to 1958. Beginning in 1967, he headed the psychopharmacology department at the Clarke Institute of Psychiatry in Toronto (now the Center for Addiction and Mental Health), where he established the Human Brain Laboratory in 1978.

He was named a full professor of pharmacology and psychiatry at the University of Toronto in 1973 and, in 1976, appointed to head the newly-founded Institute of Biochemical Pharmacology of the University of Vienna. He held both posts concurrently.

He is survived by his daughter, Maria Hentosz; three sons, Nicholas, Stephen and Joseph; six grandchildren; and one great-grandchild. His wife, Christina (Prus-Jablonowski) Hornykiewicz, had died.

“He was a pharmacologist, biochemist and neurologist who wanted to find out how the brain works and how dopamine was involved,” Professor Kish said. “And he wanted to be known also as a philosopher.”

Despite being snubbed by the Nobel committee, Professor Hornykiewicz was philosophical about what he had accomplished and the degree to which it had been credited.

“I am surprised to see that I have achieved everything I could have wished for,” he wrote in 2004. “The support and recognition I received for my work, I have accepted with gratitude, as a charming reminder to do more and better.”

Professor Kish, who heads the Human Brain Laboratory at the University of Toronto’s Centre for Addiction and Mental Health, said L-dopa, or Levodopa, as it is also called, is today “the mainstay treatment for Parkinson’s disease — no drug is more efficacious.”

“Hornykiewicz,” he added, “reminds us that before L-dopa, persons with Parkinson’s disease were bedridden, crowding chronic hospital wards, and the doctors were powerless to do anything. His discovery changed all that —- it was a miracle.”

https://bioreports.net/oleh-hornykiewicz-who-discovered-parkinsons-treatment-dies-at-93/

Electric current to the wrist triggers brain waves that help dampen tics in people with Tourette’s syndrome

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An unusual new treatment for Tourette’s syndrome involves applying an electrical current to the wrist, which travels up nerves to the brain and changes brainwaves. The approach, which moderately reduced the number of tics in volunteers with Tourette’s, suggests the condition is linked with an underactivity in brainwaves that normally keep us still.

People with Tourette’s syndrome make frequent involuntary jerks, facial twitches and noises. Tics usually arise around the age of 6, and while they often fade with time, for some they continue and can be debilitating. “Sometimes children literally break bones because they’re flinging themselves around so much,” says Stephen Jackson at the University of Nottingham in the UK.

In most people, when they are motionless, brainwaves cycle at about 12 times a second in part of the brain called the motor cortex, located at the top of the head. “It’s like the handbrake on a car – it maintains a stable posture,” says Jackson.

Previous research has shown that stimulating brainwaves in this area by using a strong oscillating magnetic field above the head can reduce tics in people with Tourette’s. Jackson wondered if there was a way to get this effect more easily.

His group placed an electrode on the wrist to deliver a mild current with a frequency of 12 times a second; the current was noticeable but not uncomfortable. The idea is that this current travels via nerves to the sensory cortex of the brain and induces oscillations at the same frequency in the neighbouring motor cortex.

When 19 people with Tourette’s tried out the electrode, it reduced the frequency of their tics by a third, compared with when the electrode was turned on for the same length of time but had no regular frequency. Voluntary movements were only slowed a little.

Normally people with Tourette’s feel an urge to tic slowly building until it becomes irresistable. Many of the volunteers reported that when the electrodes were at the right frequency, their urges reduced. Charlie, a 21-year-old with severe tics, said in a statement: “When the electrical pulses on the wrist started to increase, the tic urges decreased, which was a completely shocking experience for me, I was silent and still. I wanted to cry with happiness.”

Jackson’s group is developing a watch-like device that people can turn on to deliver the stimulation when it is needed.

Journal reference: Current Biology, DOI: 10.1016/j.cub.2020.04.044

Read more: https://www.newscientist.com/article/2245275-electric-current-helps-dampen-tics-in-people-with-tourettes-syndrome/#ixzz6OUvidHok

40% of people with severe COVID-19 experience neurological complications

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A patient is moved out of Gateway Care and Rehabilitation Center, a skilled nursing facility in Hayward, Calif., on Thursday.

People with severe COVID-19 may experience neurological symptoms, including confusion, delirium and muscle pain, and could be at higher risk for a stroke, a new study out of Wuhan, China has suggested.

Nearly 40 percent of people with the disease caused by the new coronavirus suffered brain-related complications, according to findings published Friday in JAMA Neurology.

Among those with serious infection as a result of the virus, nearly 6 percent experienced a stroke or stenosis, roughly 15 percent had dementia-like symptoms and roughly 20 percent reported severe muscle pain, researchers in China reported.

“This study indicates that neurological complications are relatively common in people who have COVID-19,” S. Andrew Josephson, professor and chair of the Department of Neurology at the University of California, San Francisco and editor-in-chief of JAMA Neurology, told UPI. Josephson also co-authored a related commentary on the study findings.

“However, the majority of those complications are are also relatively common in people with severe pneumonia and viral infections in hospital intensive care units,” he added.

That includes symptoms such as muscle pain and “confusion or difficulty thinking,” according to Josephson, although he emphasizes that if these neurological issues develop in people who know they have COVID-19 — or have symptoms of the disease and are among those at high risk for serious illness — they should be considered a “red flag like shortness of breath,” he said.

“Somebody who has COVID-19 and is at home and experiences difficulty thinking or confusion or anything that indicates a possible stroke, that is a sign they should come into the hospital for additional care,” Josephson continued. “But a symptom like muscle pain is common in viral infections. People don’t need to come into hospital with that.”

To date, nearly 1.7 million people worldwide have been infected with COVID-19, and nearly 100,000 have died from the disease. Although numbers vary by country and region, it is believed that approximately 20 percent of people infected by the new coronavirus become ill enough to require hospital care, and roughly 5 percent experience life-threatening symptoms, including pneumonia.

Those at highest risk for serious illness are believed to be the elderly, as are people with a history of diabetes, high blood pressure and heart disease. Of course these same people are also at increased risk for cerebrovascular diseases like stroke and stenosis, Josephson noted.

The new study looked at 214 patients with the disease at three Wuhan hospitals, all of whom were hospitalized between Jan. 16 and Feb. 19.

Of the 214 patients, who had mean age of 53, 87 were men and 126, or 59 percent, had severe infection based on respiratory status — with shortness of breath caused by a severe lower respiratory tract infection, like pneumonia.

As in prior studies, those with serious illness were older, had more underlying conditions — particularly high blood pressure — and had fewer typical symptoms of COVID-19, like fever and cough, when compared to patients with mild to moderate infection.

Additionally, 6 percent of patients experienced “taste impairment” and 5 percent had “smell impairment.” What causes people with the virus to experience these neurological complications remains unclear, according to Josephson. Because of the known heart-related complications associated with the virus, it’s possible they are the result of blood clots emanating from the heart, he added.

“As with all of the research coming out about the virus, this study shows we still have a lot more to learn,” Josephson said. “The bottom line is that people should be aware of these neurological symptoms, and seek medical attention if they need it.”

https://www.upi.com/Health_News/2020/04/10/40-of-people-with-severe-COVID-19-experience-neurological-complications/2491586526495/?ur3=1

Rare case offers clues to staving off Alzheimer’s

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Francisco Lopera, a neurologist at the University of Antioquia in Medellin, Colombia, has been painstakingly collecting brains, birth and death records from one sprawling Colombian family to study Alzheimer’s.Credit…Federico Rios Escobar for The New York Times


A woman with lots of beta-amyloid buildup (red) in her brain remained cognitively healthy for decades.

by Kelly Servick

In 2016, a 73-year-old woman from Medellín, Colombia, flew to Boston so researchers could scan her brain, analyze her blood, and pore over her genome. She carried a genetic mutation that had caused many in her family to develop dementia in middle age. But for decades, she had avoided the disease. The researchers now report that another rare mutation—this one in the well-known Alzheimer’s disease risk gene APOE—may have protected her. They can’t prove this mutation alone staved off disease. But the study draws new attention to the possibility of preventing or treating Alzheimer’s by targeting APOE—an idea some researchers say has spent too long on the sidelines.

“This case is very special,” says Yadong Huang, a neuroscientist at the Gladstone Institutes in San Francisco, California, who was not involved with the research. “This may open up a very promising new avenue in both research and therapy.”

APOE, the strongest genetic risk factor for Alzheimer’s, has three common forms. A variant called APOE2 lowers risk of the disease. The most common variant, APOE3, doesn’t influence risk. APOE4 raises risk; roughly half of the people with the disease have at least one copy of this variant.

Researchers have long contemplated targeting APOE with therapies. A team at Cornell University will soon start a clinical trial that infuses the protective APOE2 gene into the cerebrospinal fluid of people with two copies of APOE4.

But mysteries about APOE have kept it from becoming a front-runner among drug targets. “It does so many things that it’s confusing,” says Eric Reiman, a neuroscientist at the Banner Alzheimer’s Institute in Phoenix and a co-author on the new paper. The APOE protein binds and transports fats and is abundant in the brain. And the APOE4 variant seems to encourage the formation of sticky plaques of the protein beta-amyloid, which clog the brain in Alzheimer’s. But powerful amyloid-busting drugs have repeatedly failed to benefit patients in clinical trials. Some researchers saw no reason to try an APOE-targeting therapy that seemed to be “just a poor man’s antiamyloid treatment,” Reiman says.

The Colombian woman’s case suggests other ways APOE could affect Alzheimer’s risk. The woman participated in a study led by researchers at the University of Antioquia in Medellín that has tracked roughly 6000 members of her extended family. About one-fifth of them carried an Alzheimer’s-causing mutation in a gene called presenilin 1; these carriers generally developed dementia in their late 40s. Yet the woman didn’t show the first signs of the disease until her 70s, even though she, too, carried the mutation. “She’s definitely an outlier,” says cell biologist Joseph Arboleda-Velasquez of Harvard Medical school in Boston. (The research team is keeping the woman’s name confidential to protect her privacy.)

In Boston, a positron emission tomography scan of the woman’s brain revealed more amyloid buildup than in any other family member who has been scanned. “It was very striking,” says Yakeel Quiroz, a clinical neuropsychologist at Massachusetts General Hospital and Harvard Medical School. But the team found no signs of major damage to neurons, and minimal buildup of another Alzheimer’s hallmark: the misfolded protein tau. Whatever protection this woman had didn’t depend on keeping the brain amyloid-free. Instead, her case supports the idea that tau has a “critical role … in the clinical manifestations of Alzheimer’s disease,” says Jennifer Yokoyama, a neurogeneticist at the University of California, San Francisco.

Genome sequencing revealed two copies of a rare mutation in the APOE gene, the researchers report this week in Nature Medicine. First discovered in 1987, the mutation, known as Christchurch, occurs in a region separate from those that determine a person’s APOE2, 3, or 4 status. (The woman has the neutral APOE3 variant.) Previous research found that the Christchurch mutation—like the more common protective APOE2 mutation—impairs APOE’s ability to bind to and clear away fats and sometimes leads to cardiovascular disease.

The researchers also found that the mutation prevents APOE from binding strongly to other molecules called heparan sulfate proteoglycans (HSPGs), which coat neurons and other cells “like a carpet,” says Guojun Bu, a neuroscientist at the Mayo Clinic in Jacksonville, Florida, who has studied the interaction between these molecules and APOE.

APOE2 may also impair the protein’s ability to bind HSPGs. But how that could protect against disease isn’t clear. One possible clue: Research by neuroscientist Marc Diamond of the University of Texas Southwestern Medical Center in Dallas and his colleagues suggest the toxic tau protein relies on HSPGs to help it spread between cells. Maybe the less APOE binds to HSPGs, the harder it is for tau to spread.

But, Diamond cautions, “It will require much more study to understand if this relationship exists.” The Christchurch mutation might have protective effects unrelated to HSPGs; it’s also possible that mutations other than Christchurch protected the woman.

If hampering APOE’s normal binding really staved off her Alzheimer’s, future treatments might aim to mimic that effect. An antibody or small molecule could latch onto the APOE protein to interfere with binding, gene editing could change the structure of APOE to imitate the Christchurch variant, or a “gene silencing” approach could reduce production of APOE altogether.

Reiman hopes the new study will rally researchers to pursue treatments related to APOE. He, Quiroz, Arboleda-Velasquez, and other collaborators also posted a preprint on the medRxiv server on 2 November showing that people with two copies of APOE2 have lower Alzheimer’s risk than previously thought—about 99% lower than people with two copies of APOE4. “When it comes to finding a treatment that could have a profound impact on the disease,” Reiman says, “APOE may be among the lowest hanging fruit.”

https://science.sciencemag.org/content/366/6466/674

How we think as children may be linked to our cognitive performance at age 70

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Our thinking skills in childhood could offer a glimpse into how our minds might work at the age of 70, according to a study spanning decades.

The research started in 1946, when 502 8-year-olds, who were born in the U.K. in the same week, took tests to measure their thinking and memory skills. The participants took cognitive tests again between the ages of 69 and 71.

The participants also had scans, including a positron emission tomography (PET) scan that detects amyloid-beta plaques in the brain. These sticky collections of protein are linked to Alzheimer’s disease.

The study, published in the journal Neurology, shows those with the highest test scores in childhood were more likely to have high scores later in life. Kids in the top 25 percent had a greater chance of being in that same quartile at 70.

Educational attainment and socioeconomic status also appeared to make a difference. Those who were college-educated scored around 16 percent better in tests than those who left school before they hit 16. Participants who had a white-collar job were able to remember, on average, 12 details from a short story, versus 11 if they had a manual job. Overall, women did better than men when their memory and thinking speed were tested.

Participants who were found to have amyloid-beta plaques in their brains, meanwhile, scored lower on cognitive tests. In one assessment where participants had to find the missing pieces in five geometric shapes, those with the plaque got 23 out of 32 problems correct, versus 25 for those without the plaques.

Dr. Jonathan M. Schott of University College London commented: “Finding these predictors is important because if we can understand what influences an individual’s cognitive performance in later life, we can determine which aspects might be modifiable by education or lifestyle changes like exercise, diet or sleep, which may, in turn, slow the development of cognitive decline.

“Our study found that small differences in thinking and memory associated with amyloid plaques in the brain are detectable in older adults even at an age when those who are destined to develop dementia are still likely to be many years away from having symptoms.”

Earlier this year, Schott and his team published a separate study in the journal The Lancet Neurology that showed having high blood pressure in a person’s mid-30s was linked to higher levels of blood vessel damage in the brain, as well as shrinkage of the organ.

Professor Tara Spires-Jones from the UK Dementia Research Institute at the University of Edinburgh, who did not work on the new study, told Newsweek the findings add to other studies that suggest our genetics, as well as environmental factors, play a role in how we maintain our thinking skills as we age.

“However, this does not mean that all of your brain power during aging is determined during childhood,” she said. “There is good scientific evidence from this study and many others that keeping your brain and body active are likely to reduce your risk of developing Alzheimer’s disease, even as adults.”

Learning, socializing and exercise can all help, she said.

“One way this works is by building new connections between brain cells, called synapses. Synapses are the building blocks of memory, so building up a robust network of synapses, sometimes called ‘brain reserve’ is thought to be the biology behind the finding that more education is associated with a lower risk of dementia and age-related cognitive decline,” explained Spires-Jones.

Spires-Jones suggested amyloid-beta plaques might be linked with lower tests scores in the study because they build up and damage the connections between brain cells, called synapses, impairing brain function.

“Amyloid plaques are also widely thought to initiate a toxic cascade that leads to dementia in Alzheimer’s disease, including the build-up and spread of another pathology called ‘tangles,'” she said.

She said the study was “very strong” but limited because observational studies can’t explain the links that emerge, and the participants were all white so the results might not relate to other populations.

“It will be important in future work to try and understand the biological underpinnings for the associations between childhood intelligence and better cognitive ability during aging,” she said.

https://www.newsweek.com/dementia-aging-study-brains-tests-1468657

Scientists Now Know How Sleep Cleans Toxins From the Brain

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Laura Lewis and her team of researchers have been putting in late nights in their Boston University lab. Lewis ran tests until around 3:00 in the morning, then ended up sleeping in the next day. It was like she had jet lag, she says, without changing time zones. It’s not that Lewis doesn’t appreciate the merits of a good night’s sleep. She does. But when you’re trying to map what’s happening in a slumbering human’s brain, you end up making some sacrifices. “It’s this great irony of sleep research,” she says. “You’re constrained by when people sleep.”

Her results, published last week in the journal Science, show how our bodies clear toxins out of our brains while we sleep and could open new avenues for treating and preventing neurodegenerative diseases like Alzheimer’s.

When we sleep our brains travel through several phases, from a light slumber to a deep sleep that feels like we’ve fallen unconscious, to rapid eye movement (REM) sleep, when we’re more likely to have dreams. Lewis’ work looks at non-REM sleep, that deep phase which generally happens earlier in the night and which has already been associated with memory retention. One important 2013 study on mice showed that while the rodents slept, toxins like beta amyloid, which can contribute to Alzheimer’s disease, got swept away.

Lewis was curious how those toxins were cleared out and why that process only happened during sleep. She suspected that cerebrospinal fluid, a clear, water-like liquid that flows around the brain, might be involved. But she wasn’t sure what was unique about sleep. So her lab designed a study that measured several different variables at the same time.

Study participants had to lie down and fall asleep inside an MRI machine. To get realistic sleep cycles, the researchers had to run the tests at midnight, and they even asked subjects to stay up late the night before so people would be primed to drift off once the test began.

Lewis outfitted the participants with an EEG cap so she could look at the electrical currents flowing through their brains. Those currents showed her which stage of sleep the person was in. Meanwhile, the MRI measured the blood oxygen levels in their brains and showed how much cerebrospinal fluid was flowing in and out of the brain. “We had a sense each of these metrics was important, but how they change during sleep and how they relate to each other during sleep was uncharted territory for us,” she says.

What she discovered was that during non-REM sleep, large, slow waves of cerebrospinal fluid were washing over the brain. The EEG readings helped show why. During non-REM sleep, neurons start to synchronize, turning on and off at the same time. “First you would see this electrical wave where all the neurons would go quiet,” says Lewis. Because the neurons had all momentarily stopped firing, they didn’t need as much oxygen. That meant less blood would flow to the brain. But Lewis’s team also observed that cerebrospinal fluid would then rush in, filling in the space left behind.

“It’s a fantastic paper,” says Maiken Nedergaard, a neuroscientist at the University of Rochester who led the 2013 study that first described how sleep can clear out toxins in mice. “I don’t think anybody in their wildest fantasy has really shown that the brain’s electrical activity is moving fluid. So that’s really exciting.”

One big contribution of the paper is it helps show that the systems Nedergaard has been studying in mice are present and hugely important for humans too. “It’s telling you sleep is not just to relax,” says Nedergaard. “Sleep is actually a very distinct function.” Neurons don’t all turn off at the same time when we’re awake. So brain blood levels don’t drop enough to allow substantial waves of cerebrospinal fluid to circulate around the brain and clear out all the metabolic byproducts that accumulate, like beta amyloid.

The study also could have clinical applications for treating Alzheimer’s. Recent attempts at developing medications have targeted beta amyloid. But drugs that looked promising at first all failed once they got into clinical trials. “This opens a new avenue,” says Nedergaard. Instead of trying to act on one particular molecule, new interventions might instead focus on increasing the amount of cerebrospinal fluid that washes over the brain.

That would help clear out beta amyloid but also could help with other molecules like tau, a protein that gets tangled in Alzheimer’s patients’ brains and harms the connections between neurons. Finding a way to clear out all of that garbage could be much more powerful than just focusing on one piece of the problem. “Aging is not just about one molecule,” says Nedergaard. “Everything fails.”

These discoveries bring along their own set of questions. Lewis didn’t study what happens during other stages of sleep, and she only looked at healthy young adults. But the methods she used were entirely noninvasive—or as noninvasive as having people sleep in an MRI while hooked up to lots of machines can be. She didn’t even inject any dye. That will make it easier to start studying older participants who may be developing neurodegenerative diseases.

https://www.wired.com/story/scientists-now-know-how-sleep-cleans-toxins-from-the-brain/?bxid=5c48e315fc942d0477abe04c&cndid=50678559&esrc=sign-up-page&source=EDT_WIR_NEWSLETTER_0_DAILY_ZZ&utm_brand=wired&utm_campaign=aud-dev&utm_mailing=WIR_Daily_110119&utm_medium=email&utm_source=nl&utm_term=list1_p4

Trans Fats, Bad for the Heart, May Be Bad for the Brain as Well

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By Nicholas Bakalar

Trans fatty acids, known to increase the risk for heart disease, stroke and diabetes, have now been linked to an increased risk for dementia.

Researchers measured blood levels of elaidic acid, the most common trans fats, in 1,628 men and women 60 and older and free of dementia. Over the following 10 years, 377 developed some type of dementia.

Trans fats, which are added to processed food in the form of partially hydrogenated vegetable oils, increase levels of LDL, or “bad” cholesterol. Meat and dairy products naturally contain small amounts of trans fats, but whether these fats raise bad cholesterol is unknown.

After controlling for other factors, the scientists found that compared with those in the lowest one-quarter in blood levels of elaidic acid, those in the highest were 50 percent more likely to develop any form of dementia and 39 percent more likely to develop Alzheimer’s disease in particular. Elaidic acid levels were not associated with vascular dementia considered alone. The study is in Neurology.

The senior author, Dr. Toshiharu Ninomiya, a professor of public health at Kyushu University in Japan, said the study is observational so cannot prove cause and effect. “It is difficult to avoid trans fats completely, and the risk of a small amount of trans fats is unclear,” he said. “But it would be better to try to avoid them as much as possible.”

Genetic Risk for Alzheimer’s Disease Linked to Highly Active Brains

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Young carriers of the APOE4 allele have brains that are more connected (left, red lines illustrate connections between brain areas) and active (right, yellow indicates activity) than the brains of those without the allele.
KRISHNA SINGH, ELIFE, 8:E36011, 2019.

A growing body of evidence supports the theory that neural hyperactivity and hyperconnectivity precede the pathological changes that lead to neurodegeneration.

DIANA KWON

There are approximately 5.6 million people over the age of 65 living with Alzheimer’s disease in the United States. With the population aging, that number is projected to grow to 7.1 million by 2025. Researchers know that age, a family history of the disease, and carrying a genetic variant known as APOE4 are all associated with a higher chance of developing the condition. But the biological mechanisms leading to Alzheimer’s are still largely a mystery.

Over the last decade, scientists have amassed evidence for a hypothesis that, prior to developing full-blown Alzheimer’s disease, patients experience a period of hyperactivity and hyperconnectivity in the brain. Several functional magnetic resonance imaging studies have reported that people with mild cognitive impairment (MCI), a condition that often precedes Alzheimer’s, appear to have higher brain activity levels than their age-matched counterparts. Researchers have also found signs of such changes in healthy people carrying the APOE4 allele, as well as in presymptomatic stages of Alzheimer’s in rodent models of the disease.

Krishna Singh, a physicist and imaging neuroscientist at the Cardiff University Brain Research Imaging Center (CUBRIC) in the UK, and his colleagues wanted to investigate this theory further. Previous studies of brain activity in young APOE4 carriers were mostly conducted using small sample sizes, according to Singh. But by the mid-2010s, his team had access to neuroimaging data from close to 200 participants studied at CUBRIC as part of an effort to build a massive dataset of healthy brains. So the researchers decided to use the data to search for signs of unusual brain activity and connectivity in people with the APOE4 allele.

Using magnetoencephalography (MEG), a neuroimaging technique that records the magnetic fields generated by electrical activity in the brain, Singh and his colleagues had measured resting-state brain activity in a group of 183 healthy adults, which included 51 individuals who carried at least one copy of APOE4. The average age of the participants was 24 years old, although ages ranged from 18 to 65 years old.

Analysis of the imaging data revealed that, compared with controls, young APOE4 carriers displayed greater activity in several regions in the right side of the brain, including parts of what’s known as the default mode network, which is active when a person is not focused on a specific task. A similar set of brain regions also showed an overall increase in connectivity.

The researchers next compared the results to brain activity and connectivity data from a previous neuro­imaging study they had conducted, which found that elderly people with early-stage Alzheimer’s disease had decreased neuronal activity and connectivity compared with that of age-matched controls. The network of brain areas that displayed increased connectivity in young APOE4 carriers, the team found, partially overlapped with the brain regions that exhibited a decrease in connectivity in people with early-stage Alzheimer’s. These findings are intriguing, Singh says, because they suggest that brain areas that end up getting impaired in Alzheimer’s may be highly active and connected early in life—long before symptoms of the disease appear.

“This study adds further evidence that hyperactivity and hyperconnectivity may play an influential role in Alzheimer’s disease,” says Tal Nuriel, a professor of pathology and cell biology at the Columbia University Medical Center who wasn’t involved in the work. Because this was an observational study, the findings can only establish a correlation between brain activity and Alzheimer’s, Nuriel adds, so it’s still unclear whether the hyperactivity and hyperconnectivity observed during the early stages of the disease are a cause or a consequence of pathological changes that lead to neurodegeneration.

Scientists used to think that increased activity was simply a compensatory effect—the brain trying to make up for a loss of neurons and synapses, says Willem de Haan, a neurologist at the Amsterdam University Medical Center who was not involved in the latest study. “But I think there’s overwhelming evidence that this may actually be pathological hyperactivity.”

Much of that evidence comes from animal experiments conducted over the last decade or so. In rodents, researchers have found that hyperactivity can increase the production and spread of amyloid-ß, the peptide that accumulates into plaques found in the brains of people with Alzheimer’s—and that amyloid-ß can in turn induce neuronal hyperactivity. These findings have led some scientists to speculate that there might be a self-amplifying loop, where a progressive hyperactivity and build-up of amyloid-ß drives pathological changes associated with the neurodegenerative disease.

Research in humans also supports the idea that hyperactivity could play a causal role in Alzheimer’s disease. In 2012, researchers at Johns Hopkins University treated individuals with MCI with the anti-epileptic drug levetiracetam and found that the therapy suppressed activity in the hippocampus and led to improved memory performance. The team is currently testing levetiracetam for MCI in clinical trials. “I think this is one of the most interesting results,” says de Haan. “It seems to show that by correcting hyperactivity we can actually find some improvements in patients that might point to a completely new type of therapy for [Alzheimer’s disease].”

For the current study, Singh’s team also trained a machine-learning algorithm to distinguish APOE4 carriers from non-carriers based on their MEG data and tested whether it would be able to predict cases of Alzheimer’s. They found that while the program was able to perform above chance, the effect was not significant. “In a way, that was kind of encouraging,” Singh says. “Because I don’t think anybody would predict that we could find a signature [for Alzheimer’s] in 20- and 30-year-olds.”

For now, Singh says, his team’s findings simply shed light on what might be going on in the brains of people with the APOE4 allele. There are still a number of unanswered questions—such as when the transition from hyper- to hypoconnectivity and activity happens, what changes occur in the largely understudied middle-aged cohort, and whether there are differences between APOE4 carriers who go on to develop Alzheimer’s and those who don’t. Ultimately, to understand how disruptions in neuronal activity lead to behavioral and cognitive deficits, scientists need to decipher what’s going on inside a healthy brain, Singh says. “[We] require a model of how the brain works—and those are still in their infancy.”

https://www.the-scientist.com/notebook/genetic-risk-for-alzheimers-disease-linked-to-highly-active-brains-66483?utm_campaign=TS_DAILY%20NEWSLETTER_2019&utm_source=hs_email&utm_medium=email&utm_content=78081371&_hsenc=p2ANqtz-98aZf5axxCqtPYITNqfIVWKM6xuk3ni-QSpgTS4gFXzeQcntecrOf6DFFXjrf5qcktWTUz2M3xnAEJlvXTaS7WDQEKNg&_hsmi=78081371

Retinal screening for Alzheimer’s disease

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A technology that originated at the University of Minnesota is well on its way to commercialization thanks to an investment award from Alzheimer’s Drug Discovery Foundation (ADDF).

The investment of up to $500,000 was awarded through the ADDF’s Diagnostics Accelerator initiative. Toronto, Ontario-based RetiSpec licensed through the University of Minnesota’s Technology Commercialization program. The technology harnesses hyperspectral imaging and machine learning.

“We are focused on bringing to market a noninvasive, easy-to-use, screening technology that can change when and how we detect Alzheimer’s disease at its earliest stages including before a patient presents with symptoms,” said Eliav Shaked, CEO of RetiSpec. “Early detection provides an important window of opportunity for timely therapeutic interventions that can slow or even prevent the progression of Alzheimer’s disease. ADDF’s investment represents another point of external validation of the promise of our technology.”

In preclinical studies and a pilot human study, the retinal imaging technology was effective in detecting small changes in biomarkers associated with elevated cerebral amyloid beta levels early in the disease process including before the onset of clinical symptoms.

RetiSpec is currently collaborating with Toronto Memory Program, Canada’s largest Alzheimer’s clinical trial site, to validate the accuracy and usability of the technology in patients.

“We believe that RetiSpec’s retinal scanner stands out and shows promise as a unique diagnostic tool among a range of technologies in development,” said Howard Fillit , MD, founding executive director and chief science officer of ADDF The technology has the potential to facilitate early diagnosis, improve the lives of patients and their loved ones and save the healthcare system money and resources. The technology will also be useful in making clinical trials for Alzheimer’s disease more efficient.”

https://www.mddionline.com/feast-your-eyes-new-technology-early-alzheimers-screening

FDA Approves New Adjunct Treatment for Parkinson Disease

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Nourianz is the first adenosine A2A receptor antagonist approved for use in Parkinson Disease

By Brian Park

The Food and Drug Administration (FDA) has approved Nourianz (istradefylline; Kyowa Kirin) tablets as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson disease (PD) experiencing “off” episodes.

Nourianz is an oral selective adenosine A2A receptor antagonist and non-dopaminergic pharmacologic option. Adenosine A2A receptors are found in the basal ganglia of the brain where degeneration or abnormality is noted in PD; the basal ganglia are involved in motor control.

The approval was based on data from four 12-week, randomized, placebo-controlled clinical trials that evaluated the efficacy and safety of Nourianz in 1143 patients with PD taking a stable dose of levodopa/carbidopa with or without other PD medications.

Results from all 4 studies have demonstrated a statistically significant decrease from baseline in daily “off” time in patients treated with Nourianz compared with placebo. Regarding safety, the most common treatment-emergent adverse reactions were dyskinesia, dizziness, constipation, nausea, hallucination, and insomnia.

“Istradefylline is an Adenosine A2A receptor antagonist, and is a novel non-dopaminergic pharmacologic approach to treating OFF episodes for people living with PD,” said Dr Stuart Isaacson, MD, Parkinson’s Disease and Movement Disorders Center of Boca Raton, Florida. “Based on data from four clinical studies, istradefylline taken as an adjunct to levodopa significantly improved OFF time and demonstrated a well-tolerated safety profile. Istradefylline represents an important new treatment option for patients with Parkinson’s disease who experience ‘OFF’ episodes.”

The FDA had accepted the resubmitted NDA for Nourianz in April 2019 after previously rejecting the submission in 2008 due to concerns over efficacy findings.

For more information visit kyowakirin.com.

FDA Approves New Adjunct Treatment for Parkinson Disease