Sunday, April 29, 2012
"What the guidelines do is pinpoint first-line treatments based on evidence and effectiveness," said Mark Green, MD, director of the Headache Center at Mount Sinai School of Medicine, in New York. "If these guidelines are used widely, we will be able to up the odds of reducing headaches by 50 percent."
"Moreover, the stakes may be high if we undertreat migraines," said Dr. Green. "Evidence is building to suggest that if we allow migraines to progress, the frequency of attacks may increase, and they may also become harder to treat." Dr. Green compared it to the hazards linked to issues like under treating high blood pressure and asthma, which can lead to significant problems.
Evidence-Based Preventive Treatments First-line prescription drugs with the strongest evidence for prevention must be taken every day to prevent migraine attacks and reduce the severity of attacks.
The guidelines panel found the following:
• The anti-seizure medications divalproex sodium, sodium valproate, and topiramate, as well as beta blockers metoprolol, propranol, and tumolol, are effective for migraine prevention. The antiseizure drug lamotrigine was not effective in preventing migraine, and should not be used.
• The herbal preparation Petasites, or butterbur, proved effective in prevention.
• Rated "probably effective" were the following over the counter medicines: the nonsteroidal anti-inflammatory drugs fenoprofen, ibuprofen, ketoprofen, naproxen, and naproxen sodium, subcutaneous histamine and complementary treatments magnesium, MIG-99 (feverfew) and riboflavin.
• Dr. Green said that gabapentin ranked near the bottom, rated Level U. Verapamil was also in this category.
Read more here
"It has long been known that autism is an umbrella term for a wide range of disorders that impair social and communication skills," says Amy Kalkbrenner, assistant professor in the University of Wisconsin-Milwaukee's Joseph J. Zilber School of Public Health, lead author of the study. "What we are seeing is that some disorders on the autism spectrum, more than others, may be influenced by a factor such as whether a mother smokes during pregnancy."
The study was published April 25 online by the journal Environmental Health Perspectives.
Smoking during pregnancy is still common in the U.S. despite its known harmful impacts on babies. Kalkbrenner found that 13 percent of mothers whose children were included in the study had smoked during pregnancy.
Kalkbrenner and colleagues' population-based study compared smoking data from birth certificates of thousands of children from 11 states to a database of children diagnosed with autism maintained by the CDC's Autism and Developmental Disabilities Monitoring Network (ADDMN). Of the 633,989 children, born in 1992, 1994, 1996 and 1998, 3,315 were identified as having an autism spectrum disorder at age 8.
"The study doesn't say for certain that smoking is a risk factor for autism," Kalkbrenner says. "But it does say that if there is an association, it's between smoking and certain types of autism," implicating the disorders on the autism spectrum that are less severe and allow children to function at a higher level. That connection, she adds, needs further study.
April is Autism Awareness Month, and several studies of possible links between environmental factors and autism are being published by Environmental Health Perspectives at the same time as Kalkbrenner's study. "The CDC recently released data indicating that 1 in 88 children has an autism spectrum disorder, making such environmental studies even more timely," says Kalkbrenner.
Because autism involves a broad spectrum of conditions and the interplay of genetics and environment is so complex, no one study can explain all the causes of autism, she adds. "The goal of this work is to help provide a piece of the puzzle. And in this we were successful."
Read more here
Friday, April 27, 2012
Perhaps this article may guide research? JR
An editorial published April 25 in the journal Environmental Health Perspectives calls for increased research to identify possible environmental causes of autism and other neurodevelopmental disorders in America's children and presents a list of ten target chemicals including which are considered highly likely to contribute to these conditions.
Wednesday, April 25, 2012
Night-time departures, early morning arrivals, and adjusting to several time zones in a matter of days can rattle circadian rhythms, compromise attention and challenge vigilance. And yet, these are the very conditions many pilots face as they contend with a technically challenging job in which potentially hundreds of lives are at stake.
In an article to be published in a forthcoming issue of Current Directions in Psychological Science, a journal of the Association for Psychological Science, John A Caldwell, a psychologist and senior scientist at Fatigue Science, a Honolulu business focusing on fatigue assessment, examines the problem of sleep deprived pilots by teasing out the complex interplay of inadequate sleep and circadian rhythms. He explains how airline industry solutions miss the point and then suggests other options.
Caldwell points out that "fatigue-related performance problems in aviation have been consistently underestimated and underappreciated, despite the fact that decades of research on pilots and other operational personnel has clearly established that fatigue from insufficient sleep significantly degrades basic cognitive performance, psychological mood, and fundamental piloting skills."
Evidence abounds. In 2004, a corporate airlines flight crashed as it approached Kirksville Regional Airport; in 2008, Honolulu based pilots of Go! Airlines overshot their destination by more than thirty miles because they fell asleep during a trip that was only fifty minutes long. A Northwest Airlines Flight overflew its destination by 150 miles because pilots had dozed off at the controls. In 2009, fifty people were killed when a Continental Connection flight en route from Newark to Buffalo crashed into a house. Pilots failed to respond properly to a stall warning and the flight went out of control.
After examining what went wrong, the NTSB concluded that, "the pilots' performance was likely impaired because of fatigue." Since 1990 the US National Transportation Safety Board has placed pilot fatigue on the Most Wanted List of safety related priorities.
Why? Because as fatigue increases, "accuracy and timing degrade, lower standards of performance are accepted, the ability to integrate information from individual flight instruments into a meaningful and overall pattern declines, and attention narrows. "
In one study, F-117 pilots were deprived of one night of sleep and then were tested on precision instruments. Not only did pilot errors on those instruments double after one night of sleep loss, pilots reported feeling depressed and confused.
Clearly fatigue is fundamentally the result of insufficient sleep, but for pilots the important issue is the consequences of that sleep loss when they are sitting at the control panel. The author suggests that "fatigue related risks increase substantially when (a) the waking period is longer than 16 hours, (b) the preduty sleep period is shorter than 6 hours, or (c) the work period occurs during the pilot's usual sleep hours."
"Regulators, and often the pilots themselves, have tried to address the fatigue problem by focusing on duty hours rather than focusing on the physiological factors that are truly responsible," Caldwell says. "The combination of insufficient sleep and circadian factors is at the heart of the fatigue problem in any operational context."
The two most important variables for alertness are recent sleep and the body's natural circadian rhythm, or "body clock." What that means is that when a pilot reports for duty, he or she should have had from seven to nine hours of good sleep within a reasonable period of time before work and that as often as possible, the work schedule is in some harmony with the pilot's natural daily rhythm.
The amount of time that a pilot is actually working is much less important. But that is the area airlines and regulators have focused on to address the problem. "Hours-of- service" regulations have been instituted to mitigate fatigue, but "that seems to be a function of convenience rather than science." Caldwell writes that in traditional regulatory approaches "one hour of daytime flight in one's home time zone after plenty of sleep is considered to generate the same amount of fatigue as an hour of nighttime flight" that was preceded by a transcontinental transition and sleep outside of a normal sleep cycle. Fortunately, new Federal Aviation Administration regulations better account for the true physiological nature of fatigue, but additional fatigue-management strategies are needed.
Caldwell acknowledges that the very nature of airline travel predisposes pilots to disrupted sleep schedules, but he points out several approaches that can both predict a truly impaired pilot and mitigate the consequences of a lack of sleep. There are some fatigue prediction models that can help determine the impact of work/rest schedules on aviator performance. Crew members should be educated on sleep hygiene so they can snag some restorative rest before duty or during layovers. Onboard cockpit napping should be authorized so that pilots will be able to compensate for a lack of sleep. And new wearable sleep-tracking technologies should be utilized to actually measure the pre-duty and layover sleep of flight crews so that they can better manage and optimize their own sleep.
"As a society, we must come to grips with the fact that the average adult needs 7-9 hours of sleep every single day," he says. "And there is no amount of willpower, professionalism, training, or money that will prevent the performance losses associated with the failure to routinely acquire sufficient sleep."
Read more here
Obstructive sleep apnea (OSA) is a disorder in which there are recurring episodes of upper airway collapse during sleep with ongoing effort to breathe. OSA is estimated to affect 1 in 5 adults in America. The serious nature of the problem was captured in a landmark study which found that middle-age and older men with even mild levels of OSA were in danger of increased risk of stroke and death. While a link between OSA and stroke is clear, OSA's effect on the cerebral (brain) vessels is not. In an effort to shed light on this relationship, researchers in Texas have developed a novel model that mimics OSA in humans. Their model has found that after just 30 days of OSA exposure cerebral vessel function is altered, which could lead to stroke.
The model and its findings are the result of efforts undertaken by Randy F. Crossland, David J. Durgan, Eric E. Lloyd, Sharon C. Phillips, Sean P. Marrelli and Robert M. Bryan, Baylor College of Medicine, Houston, Tex. An abstract of their study entitled, "Cerebrovascular Consequences of Obstructive Sleep Apnea," will be discussed at the meeting Experimental Biology 2012 being held April 21-25 at the San Diego Convention Center. The abstract is sponsored by the American Physiological Society (APS), one of six scientific societies sponsoring the conference which last year attracted some 14,000 attendees.
New Model, New Findings
The most common animal model used to study OSA today is intermittent hypoxia (IH) which relies solely on exposing animals to a decrease in blood oxygen levels. The new model incorporates all physiological consequences involved in OSA by inducing true apnea (closure of the airway). The revised model creates a more complete picture of the apnea process and one that more accurately mimics how OSA unfolds in humans.
Using their model the researchers induced 30 apneas (10 seconds duration) per hour in animals for 8-hours during the sleep cycle for up to one month. After one month of apnea, cerebral vessel dilatory function was reduced by up to 22 percent. This finding correlates with studies that show similar cell dysfunction in arteries and an increased risk of stroke in OSA patients. Damage to the vascular wall in brain arteries could be a factor predisposing an individual with OSA to stroke.
"There are two important findings in these results," according to researcher Randy Crossland. "The first is the model itself. The new model allows us to study the complete disease and better understand how repetitive exposure to apnea affects the body. The second is that only one month of moderate OSA produces altered cerebrovascular function which could result in a stroke. A finding that highlights the detrimental impact OSA can have on the body."
OSA Prevalence Expected to Rise
According to Mr. Crossland, some researchers estimate that up to 85 percent of patients with clinically significant sleep apnea have not been diagnosed. Obesity and aging are strongly associated with OSA. "As the prevalence of obesity is rising, and the population continues aging, we expect the rates of OSA to rise. It should also be noted that non-obese individuals and even children can have OSA," he said. And while OSA is seen more often in men than in women for unknown reasons some researchers believe that the true rate in females has been underestimated.
The common signs and symptoms of OSA include: habitual snoring, daytime sleepiness, enlarged neck size, morning headache, sexual dysfunction, and mood and behavioral changes. "OSA can have a detrimental impact on a person's body and their life. It is a serious, yet treatable, disorder that should not be taken lightly," according to Mr. Crossland.
Read more here
White matter injury on term MRI of very preterm-born infants is predictive of future cognitive impairment, according to a study published in the May issue of Pediatrics. This discovery further supports the benefit of obtaining term MRI for very preterm-born infants, according to the authors.
“Because ultrasound scans are insensitive to most MRI findings, early MRI may help identify a group of very preterm born infants with an increased risk of later cognitive impairment,” wrote Osuke Iwata, MD, of the department of paediatrics and child health at Kurume University School of Medicine in Kurume, Japan, and colleagues. “Such information may provide an important key to improve follow-up strategies and to allow better risk stratification for future clinical trials which enroll very preterm born infants.”
While previous studies have demonstrated associations between white matter injury and cognitive impairment in very preterm-born children, this study is the first longitudinal study comparing term MRI findings, based on an MRI completed at term age, with outcomes at nine years old, according to the authors.
Seventy-six very preterm-born infants were imaged as part of the prospective study. Neurodevelopmental outcomes were assessed at 9 years old in 60 subjects using the Wechsler Intelligence Scale for Children, which tests different IQ indices.
Overall, mildly low intelligence scores (less than 85) were observed in 23.3 percent of the study cohort for verbal IQ, 41.7 percent for performance IQ and 30 percent for full-scale IQ. Moderately low scores (less than 70) were observed in 3.3 percent for verbal IQ and 11.7 percent for both performance IQ and full-scale IQ. Cerebral palsy was diagnosed in 10 percent of the children and 56.7 percent required special assistance at school.
Abnormal white matter appearances on the term MRI were predictive of mildly and moderately low performance and full-scale IQ scores, as well as cerebral palsy and the need for special assistance at school. It was also predictive of mildly low verbal IQs, but not moderately low verbal scores. Abnormal gray matter appearances did not predict any of the outcome measures.
“In very preterm born children, reduced cortical gray matter volume has also been associated with poor cognitive outcome at school age. In our current study, abnormal gray matter appearances at term were associated with the presence of white matter injury but not with any of the outcome measures at nine years old,” wrote Sachiko Iwata, MD, and colleagues. They explained that cortical gray matter lesions may contribute less to later cognitive functioning because neurologic functioning associated with gray matter injury may be affected more by other factors, such as education and family environment.
The authors concluded that term MRI may be able to help screen preterm-born infants and aid in earlier diagnosis of cognitive impairment.
“Additional studies with longer follow-up periods are still required, because neurodevelopmental assessments performed at early childhood period may not reflect cognitive functioning at school age and thereafter, either because of the limited reliability of early assessment tools or because cognitive function itself may significantly alter under the influence of numerous intrinsic/extrinsic factors such as plasticity, compensation, reorganization of injured brain, environment, and education.”
Scientists have developed a new type of drug which is capable of reducing the number of epileptic seizures in sufferers.
Perampanel, the result of trials carried out by researchers at Johns Hopkins University School of Medicine, is even effective in those patients where the condition is resistant to current medication.
Doctors explained that the drug works by inhibiting a glutamate receptor in the brain, which subsequently blocks an excitatory response to cut the seizure rate by more than 50 per cent.
Study leader Gregory Krauss said that these sites had been a target for epilepsy research for years and progress had been "very difficult", but this breakthrough was "good news" for sufferers – especially for the drug-resistant population.
The Brain Research Trust states there around 40 different types of epilepsy and the Johns Hopkins scientists added that Perampanel could reduce the frequency of all types of seizures including limb twitching and whole-body convulsions.
Tuesday, April 24, 2012
Monday, April 23, 2012
"By sequencing the genomes of a group of children with neurodevelopmental abnormalities, including autism, who were also known to have abnormal chromosomes, we identified the precise points where the DNA strands are disrupted and segments exchanged within or between chromosomes," senior study author James Gusella, director of the Massachusetts General Hospital Center for Human Genetic Research, said in a hospital news release. "As a result, we were able to discover a series of genes that have a strong individual impact on these disorders."
"We also found that many of these genes play a role in diverse clinical situations -- from severe intellectual disability to adult-onset schizophrenia -- leading to the conclusion that these genes are very sensitive to even subtle perturbations," Gusella added.
The researchers screened the genomes of 38 people with autism or other neurodevelopmental disorders. A significant number of the genes linked with autism also appear to be associated with schizophrenia and other psychiatric disorders.
"The theory that schizophrenia is a neurodevelopmental disorder has long been hypothesized, but we are just now beginning to uncover specific portions of the genetic underpinnings that may support that theory," study author Michael Talkowski, also of Massachusetts General Hospital, said in the news release.
"We also found that different gene variations -- deletion, duplication or inactivation -- can result in very similar effects, while two similar changes at the same site might have very different neurodevelopmental manifestations," Talkowski said. "We suspected that the genetic causes of autism and other neurodevelopmental abnormalities are complex and likely to involve many genes, and our data support this."
Read more here
More people pull the night shift. Teens text past midnight and stumble to school at sunrise. Travellers pack red-eye flights.
Nodding off behind the wheel isn't the only threat from a lack of shut-eye. There's growing evidence that people who regularly sleep too little and at the wrong time suffer long-lasting consequences that a nap won't cure - an increased risk of diabetes, heart disease and other health problems.
"We have a societal conspiracy for sleep deprivation," says Russell Sanna of Harvard Medical School's sleep medicine division, who attended a TEDMED conference last week where scientists called sleep loss one of healthcare's big challenges.
Studies have long shown that people who sleep fewer than five hours a night have an increased risk of developing Type 2 diabetes, the kind that tends to strike later in life.
Rotating shift work - three or more night shifts a month interspersed with day or evening hours - raises the risk, too, according to a recent report from researchers who analysed years of medical records from the huge Nurses' Health Study.
Diet and physical activity are big factors in Type 2 diabetes. Certainly it's harder to exercise or choose an apple over a doughnut when you're tired, especially at 3am when your body's internal clock knows you should be sleeping.
But a recently published study showed sleep plays a more complex role than that. As sleep drops and normal biological rhythms are disrupted, the body physically changes in ways that can help set the stage for diabetes, reports neuroscientist Orfeu Buxton of Boston's Brigham and Women's Hospital.
Buxton's team had 21 healthy volunteers spend almost six weeks living in a laboratory where their diet, physical activity, sleep and even the light was strictly controlled.
The volunteers started out well rested. But for three of those weeks, they were allowed only about 5 ½ hours of sleep every 24 hours - at varying times of the day or night, to mimic a bad shift rotation or prolonged jet lag. That knocked out of whack the body's "circadian rhythm," a master biological clock that regulates such patterns as when we become sleepy and how body temperature rises and falls.
What happened was startling - blood sugar levels increased after meals, sometimes to pre-diabetic levels, because the pancreas stopped secreting enough insulin, Buxton reported in the journal Science Translational Medicine.
At the same time, the volunteers' metabolic rate slowed by eight per cent. The researchers had them on a diet so they didn't gain weight - but Buxton says typically, a metabolism drop of that size could mean gaining about 5kg pounds over a year.
The results make sense, says Dr Michael Thorpy, sleep centre director at New York's Montefiore Medical Center and a neurology professor at Albert Einstein College of Medicine.
"If we're going to spend a third of our day sleeping, there's got to be a good reason for it," said Dr Thorpy.
Impaired sleep has been linked to high blood pressure, heart disease, obesity, depression, memory impairment and a weakened immune system. Plus, The World Health Organization has classified night shift work as a probable carcinogen, because too much light at night may hamper a hormone involved both with sleep and suppressing tumour cells.
Don't people adjust to the night shift if they're on it long enough? Buxton said rotating shifts could be the biggest worry.In his study, the volunteers' bodies went back to normal after nine nights of sufficient sleep at the right time. No one knows how long it takes before sleep deprivation and an off-kilter biological clock may cause permanent damage.
Dr Thorpy said natural night owls seem to adapt better to night shifts, but people never fully adapt if they swing back to daytime schedules on their days off. About 30 per cent of regular night workers have trouble sleeping during their off hours or are particularly fatigued, he said, something termed "shift work disorder."
For good health:
* The National Institutes of Health in the US says adults need between seven and nine hours of sleep daily for good health.
* If you work nights, go straight to bed when you get home. Avoid too much light along the way. Dr Thorpy says wearing yellow or orange tinted sunglasses on the drive home can block short-wavelength "blue light" that triggers wakefulness.
* Let natural light help keep your biological sleep clock on schedule, advises Harvard's sleep-education website. For most people, sunlight in the morning is key. For the night shift, more bright light in the evening shifts people's internal clock, Buxton explains.
* A sleep-inducing bedroom is one that's dark, quiet and cool. Avoid caffeine, alcohol and stressful situations near bedtime. Electronics right before bed aren't advised, either. Going to bed and waking up at the same time every day also helps.
Read more here