Hiển thị các bài đăng có nhãn Brain. Hiển thị tất cả bài đăng
Hiển thị các bài đăng có nhãn Brain. Hiển thị tất cả bài đăng

Thứ Sáu, 3 tháng 5, 2013

Brain implant may help predict epilepsy seizures

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A device implanted in the brain may help to predict seizures in epilepsy patients who don't respond to drugs, Med Page Today reported.

The study, published in Lancet Neurology, tested the seizure-advisory device in 15 patients. The system, developed by Neurovista, which also funded the study, used electrodes implanted between the skull and brain to detect any abnormal electrical activity that might be indicative of a seizure.

The electrodes in the brain were connected to a second device, implanted in the chest. Data was transmitted wirelessly to a handheld device, which calculated the probability of a seizure, Med Page Today said. Patients could then monitor seizure risk by looking at a series of lights on the handheld device, which indicate high risk (a red light), moderate risk (white light) or low risk (blue light).

Study participants were between ages 20 to 62 and experienced between two and 12 seizures per month.

Initially, the system was able to correctly predict seizures with a "high warning" sensitivity of greater than 65 percent, and worked to a level better than chance, in 11 of the 15 adults.

In eight of the 11 patients who went on to have the device activated, sensitivity ranged from 56 percent to 100 percent over the next four months.

While some patients experienced adverse events related to the device, researchers said  the procedure-related complication rate was similar to that of other intracranial procedures such as implantable deep-brain stimulators for Parkinson's disease, according to Med Page Today.

"Knowing when a seizure might happen could dramatically improve the quality of life of people with epilepsy by giving them back some independence in their lives. A lot of patients with epilepsy will tell you it's not the seizures themselves, but the fact they don't know when they will happen, that is the worst part of their condition," study author Mark Cook, of St. Vincent's Hospital in Melbourne, Australia said.

While more research needs to be done, study authors said they hoped their work would serve as a basis for more studies into new epilepsy treatments.

Click for more from Med Page Today.


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The fountain of youth? Brain region found to control aging

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For the first time, a brain region has been found that may control aging throughout the whole body, a new study reports.

A signaling pathway in the brain region known as the hypothalamus could speed up or slow down aging in mice. If it applies in humans, the discovery could open up possibilities for slowing age-related diseases and increasing life span.

"There's really not much understanding regarding the mechanism of aging," said senior author Dr. Dongsheng Cai, a molecular pharmacologist at Albert Einstein College of Medicine in New York. [Extending Life: 7 Ways to Live Past 100]

The process of aging could involve chaotic, passive changes in individual tissues or organs, or it could be controlled centrally by a single organ or both, Cai told LiveScience.

The hypothalamus, an almond-size structure deep inside the brain, is known to control important functions, including growth, development, reproduction and metabolism. Now, Cai and his team have found that an immune system pathway in the hypothalamus also has a role in controlling aging. Usually, the immune system is involved in fending off infection or damage, but studies have also linked inflammatory changes with age-related conditions, including cardiovascular disease and neurodegenerative diseases. Still, these changes weren't known to actively trigger aging.

Making mice tick

In the study, Cai and his colleagues probed the hypothalamus's role in aging in mice. The team studied a protein complex called nuclear factor kappa-light-chain-enhancer of activated B cells (NF-B), which plays a central role in inflammatory processes.

The researchers showed that activating the NF-B pathway in the mouse hypothalamus sped up aging, demonstrated by decreased muscle strength and size, skin thickness and learning ability. The activation led to aging throughout the body that shortened the life span of the mice.

In contrast, when the researchers blocked the NF-B pathway, the mice aged more slowly and lived about 20 percent longer than mice that didn't receive the treatment.

Furthermore, activating the NF-B pathway led to a drop in the levels of gonadotropin-releasing hormone (GnRH), a neuron-generating chemical, and a subsequent decrease in the development of new neurons. GnRH is known to regulate reproductive processes, but seems also to be necessary for maintaining youthfulness, Cai said.

When the researchers injected GnRH into the hypothalamuses of mice, it promoted neuron generation and decelerated aging. The team gave daily GnRH injections to old mice over an extended period, finding that the treatment slowed cognitive decline due to aging.

Putting the brakes on aging

GnRH treatment represents a potential means of slowing the progress of aging or age-related diseases, the researchers say. Interfering with the immune response in the hypothalamus could also be a promising approach, Cai said, though he added that the GnRH treatment might be more practical given current technology.

Aging researcher Caleb Finch of University of Southern California Davis School of Gerontology, who was not involved in the work, called it a "brilliant study." Finch has previously argued that the hypothalamus contains "pacemakers" that control the rate of aging. The new study's approach showed a more modest increase in life span than approaches such as calorie restriction (which has been shown to extend life span in mice), Finch said. "Nonetheless, the case is now powerfully made for the role of the neuroendocrine mechanisms as modulators of aging."

Next, the researchers hope to gain a deeper understanding of the molecular function of the hypothalamus in controlling aging and life span. "There are a lot of details we don't know," Cai said, such as the other molecules that are involved. The team is ultimately interested in translating their work into clinical efforts to slow down aging.

The findings were reported online May 1 in the journal Nature.

Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


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Thứ Tư, 17 tháng 4, 2013

Can alcohol damage your baby's brain?

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A new study has shown that light drinking during pregnancy does not cause any adverse behavioral or cognitive outcomes in children

RELATED: Light drinking during pregnancy may not harm children

I’m not going to debate having an occasional glass of wine during pregnancy.  But let’s be perfectly clear: alcohol intoxication and pregnancy don’t mix.  

There is a very well established medical diagnosis labeled fetal alcohol syndrome.  Prior to the early 1970s, fetal alcohol syndrome was not well understood, and many pregnant women did not receive the warning that they should avoid excessive use of alcohol during pregnancy.  Therefore, many babies were born with multiple anomalies.

Subsequent research has clearly shown that alcohol intoxication during different periods of embryonic life leads to cellular damage that harms the unborn child.  The typical side effects of fetal alcohol syndrome include:

- Growth deficiency before and after birth

- Unique facial features, such as small eyes, thin upper lip and a short, upturned nose

- Small head and brain size

- Heart defects

Also, these babies often have severe neurodevelopmental deficiencies, such as delayed development and learning disorders.  This is why I always remind women during pregnancy that an occasional glass of wine may not be a problem, but clearly, regular drinking should not be done – even if you consider yourself to be a moderate user.


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Thứ Năm, 7 tháng 3, 2013

'Brain pacemaker' may help treat patients with severe anorexia

Before Kim Rollins had reached the age of 35, she had suffered a severe heart attack, two strokes, developed osteoporosis and broken up to eight bones in her legs and feet.  

Rollins’ health issues, while seemingly extraordinary, all related to her biggest health issue of all – anorexia nervosa.  Rollins first developed the eating disorder at the age of 15 and struggled with it for the next 20 years of her life, unable to find any type of coping mechanism.  At her lowest point, Rollins weighed as little as 71 pounds.

She tried all the ‘conventional’ therapies, entering herself in nearly 10 treatment facilities.  But Rollins’ symptoms were so severe that she never followed through and always ended up breaking the rules.  Eventually, she became completely isolated from her friends and family, and became even more obsessed with her weight – focusing on eating as little as possible and burning as many calories as she could.

“It continued like that for years and years,” Rollins, 36, of Kitchener, Ontario, told FoxNews.com. “My health got worse and my weight got lower, to the point where I thought I was going to die from this.  My mom has even told me she was planning my funeral a couple of times.”

Then, one of her doctors mentioned a study being conducted, in which researchers were recruiting subjects who suffered from severe anorexia and had exhausted all forms of available treatment.  Figuring she had no other options left, she decided to reach out and sign up for the small clinical trial.

“It came down to a choice between almost certain death or taking a chance on this,” Rollins said. “I thought the worst that could happen was that it didn’t have any effect.”

Not only did the procedure have an effect, but her involvement with the study would completely change her life.

Deep brain stimulation

For the phase I safety trial, researchers from the Krembil Neuroscience Center in Toronto and the University Health Network in Canada were looking to experiment with a technique that has been used to treat various nervous system disorders – deep brain stimulation (DBS).

Fairly well established in the surgical world, DBS – sometimes referred to as a ‘brain pacemaker’ – has been used for nearly 25 years to treat movement disorders such as Parkinson’s disease, tremor and dystonia.  More recently, DBS has been experimented with in regards to treatment for epilepsy, Tourette’s syndrome and even major depression.

Given the treatment’s success when it came to treating depression, the researchers decided to take it one step further.  In the first-ever study to treat anorexia with DBS, the scientists decided to target a specific portion of the patient’s brain – a bundle of white matter below the corpus callosum, which divides the left and right sides of the brain.

“When you do imaging studies of patients with anorexia, this area is directly implicated,” Dr. Nir Lipsman, neurosurgery resident and Ph.D. student at the Krembil Neuroscience Center, told FoxNews.com.  “… It’s also connected to other areas in the brain that are implicated, such as areas controlling body image, reward and awareness of one’s internal environment.”

Lipsman surgically implanted electrodes within the target areas of their subjects’ brains – including that of Rollins.  Once in place, the electrodes were attached to a pacemaker-like device, which is placed underneath the skin of the collar bone.  The device was then activated, and the electrodes began sending electrical impulses to the areas of the brain in an attempt to control the abnormal impulses.

“We know that in patients with depression and anorexia, this area is overactive,” Lipsman said. “Putting a DBS electrode in this area turns down the volume and activity in this area of the brain.”

Rollins and the other five subjects in the study were between the ages of 25 and 57, and had been suffering from anorexia for between four and 37 years.  Ten days after each subject had been implanted with the device, the ‘pacemaker’ was activated, and the researchers continued to follow their progress over the next nine months.

Stunning results

Before surgery, Lipsman and researchers conducted baseline investigations of the subjects’ moods and body mass index.  The researchers also conducted PET (positron emission tomography) scans of the subjects’ brains, which detects what areas are consuming the most and least glucose.

After seeing the subjects every two to three weeks throughout the study, the team conducted all of these baseline tests again six months after surgery – and they were amazed with what they found.  Five or six patients had stabilized or gained weight, and half of the patients experience significant improvements in their moods or had reduced their obsessive-compulsive disorder.

At nine months, the results were even more encouraging, with three patients – Rollins included – maintaining a higher weight than before receiving DBS, which was the longest sustained weight any of the patients had since the start of their illness.

“All these changes allowed them to potentially engage in conventional treatment more effectively,” Lipsman said of the results.  “It wasn’t the case that DBS was directly influencing weight; they didn’t report more hunger or appetite.  It focused on getting the foot in the door of a very serious, chronic illness in order to reduce the obstacles in a way so they could get benefit from conventional therapy.”

As for Rollins, the experience has been nothing short of amazing.  Since the surgery, she has been able to maintain a weight of 112 pounds, and continues to see a dietician and therapist to help sustain her progress.

“I feel like taking care of myself,” Rollins said. “I feel like I like my body, and my body image is pretty good.  I no longer think I’m too fat… I’ve really started concentrating on different areas of my life, like going back to school, getting back in touch with my friends, getting a better job.  Things I really ignored for 20 years are becoming important for me again.  It’s been an incredible experience.”

The study was published online in the medical journal The Lancet.


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Thứ Tư, 27 tháng 2, 2013

Brain cells can outlive the body

Brain cells can live at least twice as long as the organisms in which they reside, according to new research.

The study, published Monday, Feb. 25, in the journal Proceedings of the National Academy of Sciences, found that mouse neurons, or brain cells, implanted into rats can survive with the rats into old age, twice as long as the life span of the original mice. The findings are good news for life extension enthusiasts.

'We are slowly but continuously prolonging the life of humans.'

- Dr. Lorenzo Magrassi, a neurosurgeon at the University of Pavia in Italy

"We are slowly but continuously prolonging the life of humans," said study co-author Dr. Lorenzo Magrassi, a neurosurgeon at the University of Pavia in Italy.

So if the human life span could be stretched to 160 years, "then you are not going to lose your neurons, because your neurons do not have a fixed lifetime."

Long-lived cells
While most of the cells in the human body are being constantly replaced, humans are born with almost all the neurons they will ever have. [10 Odd Facts About the Brain]

Magrassi and his colleagues wanted to know whether neurons could outlive the organisms in which they live (barring degenerative diseases like Alzheimer's).

To do so, the researchers took neurons from mice and implanted them into the brains of about 60 rat fetuses.

The team then let the rats live their entire lives, euthanizing them when they were moribund and unlikely to survive for more than two days, and then inspected their brains. The life span of the mice was only about 18 months, while the rats typically lived twice as long.

The rats were found to be completely normal (though not any smarter), without any signs of neurological problems at the end of their lives.

And the neurons that had been transplanted from mice were still alive when the rats died. That means it's possible the cells could have survived even longer if they were transplanted into a longer-lived species.

Life extension
The findings suggest that our brain cells won't fail before our bodies do.

"Think what a terrible thing it could be if you survive your own brain," Magrassi told LiveScience.

While the findings were done in rats, not humans, they could also have implications for neuronal transplants that could be used for degenerative diseases like Alzheimer's disease or Parkinson's disease, Magrassi said.

But just because brain cells may be able to live indefinitely doesn't mean humans could live forever.

Aging is dependent on more than the life span of all the individual parts in the body, and scientists still don't understand exactly what causes people to age, Magrassi said.

Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


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