Sunday, April 17, 2011

Interfacing Your Brain with Computers

What's the Most Recent Development?
Renowned scientist and professor of neurology at Brown University, John Donoghue has made incredible advances in interfacing the human brain with computers, allowing paralyzed people to move objects by simply using their imagination. A small chip implanted in the brain picks up the right neural signals and beams them into a computer where they are translated into moving a cursor or controlling a computer keyboard. "By this means, paralysed people can move a robot arm or drive their own wheelchair, just by thinking about it."
What's the Big Idea?
The implications of a brain-computer interface are formidable, from transferring human consciousness onto a computer—in other words, immortality—to using the technology to read people's minds. Military establishments are interested in Dr. Donoghue's research in order to enhance interrogations methods. Were interrogators able to interface the mind of a prisoner with a computer, perhaps information could be extracted they could use to prevent criminal acts and save lives. It seems the next phase of evolution will be synthetic, rather than purely biological. more read...

Connectomics: Mapping The Brain's Complexity

Connectomics: Mapping The Brain's Complexity


Scientists say they have moved a step closer to developing a computer model of the brain after finding a way to map both the connections and functions of nerve cells in the brain together for the first time.
In a study in the journal Nature on Sunday, researchers from Britain's University College London (UCL) described a technique developed in mice which enabled them to combine information about the function of neurons with details of their connections.
The study is part of an emerging area of neuroscience research known as 'connectomics'. A little like genomics, which maps our genetic make-up, connectomics aims to map the brain's connections, known as synapses.
By untangling and being able to map these connections -- and deciphering how information flows through the brain's circuits -- scientists hope to understand how thoughts and perceptions are generated in the brain and how these functions go wrong in diseases such as Alzheimer's, schizophrenia and stroke.
"We are beginning to untangle the complexity of the brain," said Tom Mrsic-Flogel, who led the study.
"Once we understand the function and connectivity of nerve cells spanning different layers of the brain, we can begin to develop a computer simulation of how this remarkable organ works."
But he said would take many years of work among scientists and huge computer processing power before that could be done.
In a report of his research, Mrsic-Flogel explained how mapping the brain's connections is no small feat: There are an estimated one hundred billion nerve cells, or neurons, in the brain, each connected to thousands of other nerve cells, he said, making an estimated 150 trillion synapses.
"How do we figure out how the brain's neural circuitry works? We first need to understand the function of each neuron and find out to which other brain cells it connects," he said.
In this study, Mrsic-Flogel's team focused on vision and looked into the visual cortex of the mouse brain, which contains thousands of neurons and millions of different connections.
Using high resolution imaging, they were able to detect which of these neurons responded to a particular stimulus.
Taking a slice of the same tissue, the scientists then applied small currents to subsets of neurons to see which other neurons responded and which of them were synaptically connected.
By repeating this technique many times, they were able to trace the function and connectivity of hundreds of nerve cells in visual cortex.
Using this method, the team hopes to begin generating a wiring diagram of a brain area with a particular function, such as the visual cortex. The technique should also help them map the wiring of regions that underpin touch, hearing and movement.
John Williams, head of neuroscience and mental health at the Wellcome Trust medical charity, which helped fund the study, said understanding the brain's inner workings was one of science's "ultimate goals."
"This important study presents neuroscientists with one of the key tools that will help them begin to navigate and survey the landscape of the brain," he said. more read....

Brain boffins in cortex mapping breakthrough

Brain boffins at University College London have made a major breakthrough in the ongoing effort to bridge the gap between man and machine.
The UCL research team has developed a technique for mapping both the connections and functions of nerve cells in the brain, as revealed by UCL News.
"We are beginning to untangle the complexity of the brain," reads a statement from UCL research fellow Tom Mrsic-Flogel. "Once we understand the function and connectivity of nerve cells spanning different layers of the brain, we can begin to develop a computer simulation of how this remarkable organ works."  more read...

State Proclamation Coincides with Brain Health Fair and American Academy of Neurology’s Annual Meeting.

Hawaii Governor Neil Abercrombie has issued a state proclamation declaring the week of April 9-16, 2011, as “Brain Health Awareness Week” in the Aloha state. The proclamation coincides with two large events in Honolulu; the Brain Health Fair Saturday, April 9, and the American Academy of Neurology’s Annual Meeting at the Hawaii Convention Center April 9-16, which is the world’s largest meeting of neurologists with more than 9,000 attendees.
“Brain Health Awareness Week” aims to help the American Academy of Neurology and its Foundation raise awareness about the vital need for more research into the prevention, treatment and cure of brain disorders, which currently affect one in six people worldwide. Common brain disorders include Alzheimer’s disease, stroke, migraine, multiple sclerosis, autism and brain cancer.
“We are thankful for the Governor’s support in raising awareness about the vital need for everyone to have a healthier brain through the support of research into the prevention, treatment and cure of brain disorders,” said Christine E. Phelps, Deputy Executive Director of the American Academy of Neurology Foundation. “Please visit our website,, to learn more about how you can help and honor your family and friends who are living with brain disorders. What makes the American Academy of Neurology Foundation so special is the fact that 100% of your donation will go directly toward research.”
“Brain Health Awareness Week” will kick off at 10:00 a.m. on Saturday, April 9, 2011, with the Brain Health Fair presented by the American Academy of Neurology Foundation at the Hilton Hawaiian Village in Honolulu. The Brain Health Fair is a free event for the public to learn from some of the best and brightest neurologists in the world about the latest advances in managing neurologic disorders as well as how to maintain a healthy brain. Brain health classes will be offered along with a kids zone and an exhibit hall with more than 30 exhibitors. Free registration is open at

Should Patients With Stroke Wear Compression Stockings?

Dr. Sprigg and colleagues note that they “do not believe that low-dose heparin should be used routinely for the prevention of VTE in most patients with stroke.” We agree that low-dose heparin should not be used routinely in patients with ischemic stroke and did not make such a suggestion (1). As Dr. Sprigg and colleagues also note, “Prophylactic low-dose anticoagulation may help to treat patients at high risk for VTE in whom the risk for VTE is likely to outweigh the risk for SICH.”
If CLOTS (Clots in Legs Or sTtockings after Stroke) Trial 1 (2) had found that graduated compression stockings were very effective at preventing VTE, we would recommend this intervention over low-dose heparin in all patients with stroke, including those at highest risk for VTE. However, it found that graduated compression stockings did not work (2), and therefore, an effective alternative to low-dose anticoagulation to prevent VTE in patients with ischemic stroke does not currently exist. Lack of an alternative to prevent VTE does not mean that low-dose anticoagulation should be used routinely but does strengthen the argument for, as we suggested, “the cautious use of these agents” in patients with acute ischemic stroke and immobility without additional contraindications to anticoagulant therapy.
We propose that the findings of the IST (3) and TAIST (4) are mostly of indirect relevance to this discussion and, indeed, are consistent with our position. TAIST compared high- and intermediate-dose tinzaparin with aspirin in the acute treatment of ischemic stroke (4). This trial did not evaluate whether low-dose tinzaparin, as used to prevent VTE, was beneficial.
The IST compared high-dose unfractionated heparin (12 500 U twice daily) and low-dose unfractionated heparin (5000 U twice daily) with no anticoagulation (3). High-dose therapy was associated with greater harm than benefit. Low-dose therapy was associated with greater benefit than harm; however, we agree that the findings of this subgroup analysis are not definitive. An additional consideration is that if the IST had enrolled only participants with stroke and immobility—that is, persons with a high risk for VTE, a population group similar to those who are the focus of this discussion and that were enrolled in the CLOT Trials—the balance of benefit (reduction in VTE) to harm (increased intracranial bleeding) may have further favored low-dose heparin.
Finally, both of these trials evaluated the use of heparin in the acute phase of stroke (within 48 hours of onset), when the risk for hemorrhagic transformation is greatest. In patients at increased risk for intracerebral hemorrhage, delayed introduction of low-dose heparin may further alter the balance of benefit to harm. It is hoped that the ongoing CLOTS Trial 3, which is comparing intermittent pneumatic compression with a control group, will identify an effective way to prevent VTE in patients with acute stroke and immobility without increasing the risk for bleeding. more read....

Lacunar stroke is small but significant

Lacunar stroke is small but significant

DEAR DR. DONOHUE: I am a 66-year-old man who thought he was in good shape except for a touch of high blood pressure. About a week ago, I suddenly noticed that my left arm and left leg had gone limp. I had to be careful how I walked, and I couldn't hold on to anything. My wife said the left side of my face looked funny, too. The next day, everything was back to normal. My wife insisted that I see the doctor, and he insisted that I have a brain scan. The report said, "Compatible with a lacunar stroke." What is that? The doctor has me taking aspirin and has changed my blood pressure medicine. How serious is this?
— L.R.
The Latin word "lacuna" is "a small cavity or a hole." A lacunar stroke is one due to occlusion of a tiny brain artery that causes a similarly tiny hole in brain tissue. Blood supply to that part of the brain has been cut off.
Yours is the typical story told by those who have had such a stroke. Up to 60 percent of such patients complain of the sudden onset of arm and leg weakness on one side. The face on that side is weakened, too, and looks odd. People who have this kind of stroke never have trouble expressing themselves, as do people who suffer the more common and larger strokes.
Lacunar strokes don't leaving a lasting deficit. People regain what they lost, and usually do so in quick order.
MRI brain scans shows lacunar strokes clearly. A CT brain scan also can spot them.
Almost always, high blood pressure is involved. Just how high is "a touch of high blood pressure"? You have to take blood pressure control most seriously. Get a home blood pressure kit and take your pressure twice a day. You must take the same preventive steps that people who have had a major stroke take: weight reduction if that applies, limitation of salt, daily exercise within the limits prescribed by your doctor and a diet change to include much more fruits, vegetables and grains and much less meat and fats.
DEAR DR. DONOHUE: I am a female in my 80s and have had one child.
I have hair growing on the small of my back, just above the buttocks in the middle. All these years, a doctor has never explained why this is, and I have been too shy to ask. Can you enlighten me on this?
— Anon.
One possible explanation is spina bifida occulta, a malformation of one or two of the lower backbones.
During fetal development, those bones grow from their sides and form an arch over the spinal cord. In spina bifida occulta, there's a gap at the top of the arch. A sign that this has happened is hair growing on the lower back in the place where you indicate. For most with this defect, no symptoms arise. It causes no trouble to the spine or nerves.
If I am right about this, you're an example of one who hasn't suffered any disturbance from this slight abnormality that has been present all your life. The only way to know for sure is to have an X-ray. I don't recommend you do that.
DEAR DR. DONOHUE: Quite often, I go to bed with my hair up in rollers and fasten them with metal clips. Is this harmful in any way? Could it cause ringing in the ears upon arising from sleep? I'd appreciate your thoughts on the above.
— A.F.
It sounds painful to me. Don't the rollers dig into your scalp? If they don't hurt and they aren't cutting you, I can't see how this does you any harm.
It is not the cause of ringing in your ears.
Readers may write to Dr. Donohue or request an order form of available health newsletters at P.O. Box 536475, Orlando FL 32853-6475.

Angioplasty Trial for Stroke Prevention Halted

A higher rate of adverse events in the angioplasty/stenting arm of the randomized SAMMPRIS trial forced an early halt to the stroke prevention study, according to trial sponsor, the National Institute of Neurological Diseases and Stroke.
With just over half of the planned number of patients enrolled, 14% of those who underwent angioplasty had suffered a stroke or died within the first 30 days, compared with 5.8% of those treated with aggressive medical therapy alone, the NINDS said in a statement.
"The SAMMPRIS Executive Committee is in agreement with NINDS and the data safety and monitoring board that enrollment in the study should be stopped and that the trial data currently available indicate that aggressive medical management alone is superior to angioplasty combined with stenting in patients with recent symptoms and high grade intracranial arterial stenosis," the statement said.
The difference in event rates was "highly significant," according to the statement, which pointed out another surprise: The event rate in the medical-therapy arm was about half what has been observed in earlier studies.
According to NINDS, in historical controls the rate of strokes or death with aggressive medical therapy was 10.7%.
SAMMPRIS -- an acronym for Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis -- began enrolling patients in November 2008. It was halted last week after an interim review by the data safety and monitoring board.
A total of 451 of the planned 764 patients had been treated in the study, the first randomized trial to compare aggressive medical therapy alone with angioplasty and stenting plus aggressive medical management.
The medical therapy in both arms included aspirin at 325 mg/day for the entire follow-up; clopidogrel (Plavix) at 75mg/day for 90 days after enrollment; intensive management of vascular risk factors, including a systolic blood pressure target of less than 140 mm Hg and LDL cholesterol less than 70 mg/dL; and a lifestyle modification program.
The angioplasty arm used the Gateway-Wingspan system, according to NINDS.
Stroke physicians contacted by MedPage Today and ABC News expressed disappointment that the angioplasty-based treatment apparently failed so dismally.
"Obviously, this is not what the investigators or the stroke community at large was hoping for because medical management of this condition has not been very effective in the past," said Stanley Tuhrim, MD, of Mount Sinai Stroke Center in New York City, in an email.
Pierre Fayad, MD, of the University of Nebraska in Omaha, sounded a similar note. "This is, of course, a major disappointment for a novel treatment to improve the care of patients at risk for stroke with narrowing in the brain blood vessels inside the skull," he said in an email.
"At the same time, it is a relief and reassurance that with good medical treatment alone, patients with such disease can do okay," he added.
Joe Broderick, MD, of the University of Cincinnati, suggested that the findings "will change practice."
In an email, Broderick said the truncated trial had two important messages. One was that better outcomes in the control arm "likely reflects that aggressive medical therapy of current standards is an improvement over the past," he wrote.
The other, he said, was that the event rate with stenting was higher than previously reported in registries -- "not surprising [because] registries don't have the rigor of clinical trials."
"These two factors will result in intracranial stenting being used in very, very limited settings (patients with high grade stenoses who literally cannot sit up without becoming symptomatic and who have failed medical therapy)," Broderick wrote.
But Tuhrim suggested that the SAMMPRIS results may not tell the whole story. He pointed out that patients on medical therapy tend "to fall off the wagon over time," in which case the benefit would not be sustained.
"Stents, on the other hand, seem to be durable (and the argument [is] that the stents and the operators will get better over time), at least so far," Tuhrim wrote in the email.
"It remains an open question whether a study of longer duration would produce similar results or if a turning point would be reached down the road." more read...

Saturday, April 9, 2011

Who Can Drive After a Stroke? Tests Can Help Decide

The research analyzed all of the available studies on driving a . In all of the studies, participants' driving skills were tested in an on-road evaluation.
A total of 30 studies were analyzed. There were 1,728 participants with an average age of 61 in the studies. Of those, 938, or 54 percent, passed the on-road evaluation. The average amount of time between the stroke occurring and the on-road evaluation was about nine months.
Three can be used to identify those people who are most at risk of failing the on-road driving test.
"These are simple tests that can be done in the doctor's office, which is important because on-road tests are time-consuming and expensive," said study author Hannes Devos, MSc, of Catholic University of Leuven in Belgium. "These tests are readily available and can be administered within 15 minutes."
The tests are a Road Sign Recognition test that assesses traffic knowledge and visual comprehension, a Compass task that examines visual-perceptual and visual-spatial abilities and mental speed, and the Trail Making Test B, which measures visual-motor tracking and visual scanning abilities.
People who score below 8.5 out of 12 on the road sign test, below 25 out of 32 on the compass test and take more than 90 seconds to finish the trail making test are more likely to fail the on-road evaluation. The tests correctly classified 80 to 85 percent of the unsafe drivers.
The results also showed that participants' fitness to could not be predicted by their motor symptoms. "This is not surprising considering the wide range of adaptive devices that are available, such as steering knobs that can be operated by one hand and left-foot accelerator pedals for people with limited use of the right leg," Devos said.
In addition, the analysis found that three out of four studies showed no increased risk of accidents for people cleared to drive after a stroke.