Marijuana Use Among MS Patients Raises Risk for Cognitive, Mood Problems

(HealthDay News) -- Multiple sclerosis patients who smoke marijuana in search of symptom relief are more likely to suffer cognitive shortfalls and mood disorders, new Canadian research suggests.

A slowing down in the ability to process and remember information is one significant side effect, as is a rise in the rate of depression and anxiety.

"This is a small study, so our findings are preliminary, but the bottom line is that multiple sclerosis patients who smoke cannabis appear to be at an increased risk for cognitive issues, particularly with respect to the speed of their thinking," said study author Dr. Anthony Feinstein, a professor of psychiatry with the Sunnybrook Health Sciences Centre's department of psychiatry at the University of Toronto.

Feinstein's observations are published in the Feb. 13 online edition of Neurology and are focused exclusively on the impact of smoking marijuana illegally obtained by patients themselves. Medically prescribed marijuana was not studied.

The authors noted that a "significant minority" of multiple sclerosis patients smoke marijuana to combat the tingling, numbness, blindness and paralysis that can accompany the progressive and often disabling nervous system disease.

However, Feinstein's team stressed that scientists have yet to definitively prove that the psychoactive substance -- long linked to psychosis, anxiety and delirium among healthy users -- provides a measurable benefit to the more than 400,000 Americans and 2.5 million people worldwide who suffer from the disease.

The researchers therefore assessed the experience of 140 Toronto-based MS outpatients, 10 of whom had smoked the drug at least once in the previous month and were considered regular marijuana users.

All the patients -- three-quarters of them women -- underwent cognitive and mental health exams by a neurologist and a neuro-psychiatrist. Interviews were also conducted to assess disease severity and course, medications being used, and current disability.

Feinstein and his team observed that while pot smokers were younger, there were no differences between marijuana users and nonusers in terms of gender, education, or MS disease course or duration.

However, MS patients who used marijuana were found to perform 50 percent slower on tests tracking information-processing speed and were more likely than nonusers to have a mental disability of some kind.

Marijuana use was also associated with a greater risk for being depressed or experiencing anxiety. However, the authors were not able to determine whether the drug had triggered such conditions, or if patients had sought out marijuana to help deal with a preexisting emotional issue.

They nonetheless cautioned that smoking marijuana might further raise the risk for experiencing the kind of neuro-psychological impairment that typically occurs among 40 percent to 65 percent of all MS patients.

Feinstein said that he next hopes to gather a much larger pool of patients, while exploring possible differences in the health impact of street-purchased marijuana versus prescribed cannabis.

Meanwhile, Dr. Marshall Keilson, director of neurology at Maimonides Medical Center in Brooklyn, N.Y., said he thinks it best to proceed on a case-by-case basis.

"There are some MS patients who are emotionally disabled from their disease, and if we can use cannabis to help them feel better about the world or life, we should," he said. "We need to always err on the side of doing what's best for our patients. And I don't necessarily believe there is a permanent damage to the brain, based on occasional marijuana use. If they're smoking 10 times a day, yes, there will be damage done. But this goes for excessive alcohol use, too. So, I think we're going to end up somewhere in the middle with this."

More information
For more on multiple sclerosis, visit the National Multiple Sclerosis Society.

Dementia Diagnosis Typically Means Death Within Five Years

(HealthDay News) -- People with dementia survive an average of four and a half years following their diagnosis, new British research shows.

However, age, sex and any existing disability can alter life expectancy, according to the report in the Jan. 11 online issue of the British Medical Journal.

Common socioeconomic influences, such as marital status, social class and living in a community or residential home, did not appear to have an influence on longevity, the study found.

Researchers analyzed data on more than 13,000 people aged 65 and older who took part in a population-based study in England and Wales and were regularly assessed for dementia between 1991 and 2005.

During the 14-year study period, 438 of the participants developed dementia and 356 (81 percent) of those people died.

Dementia is known to be associated with increased risk of death, but considerable uncertainty exists about what influences survival. Worldwide, the number of people with dementia is estimated to reach 81 million by 2040.

The study found a nearly seven-year difference in survival between the youngest and oldest dementia patients -- 10.7 years for those aged 65 to 69 and 3.8 years for those aged 90 and older.

The average survival time after dementia diagnosis was 4.6 years for women and 4.1 years for men.

People who were the most disabled at the time of diagnosis lived about three years less than those who were the least disabled.

People with more education had a slightly shorter length of survival than those with less education, but researchers said the difference was not statistically significant.

Understanding factors that affect survival time after a dementia diagnosis may help health-care providers, patients, caregivers and policymakers, the study authors said.

More information
The U.S. National Institute of Neurological Disorders and Stroke has more about dementia.

Brain Defect Helps Drive Fragile X Syndrome

(HealthDay News) -- A newly discovered brain defect might be a target for the treatment of the inherited mental disorder known as fragile X syndrome, researchers report.

The discovery in rats provides an understanding of how the gene mutation responsible for the condition changes the way brain cells communicate, according to the report in this week's issue of the Proceedings of the National Academy of Sciences.

"Fragile X syndrome is the most common form of inherited mental retardation," explained co-author Gary J. Bassell, a professor of cell biology at Emory University in Atlanta. "It has strong links to autism and epilepsy."

Fragile X syndrome occurs in approximately one in 4,000 males and one in 8,000 females, Bassell noted.

Working with rat brain cells, the team found that synapses between brain cells in the part of the brain called the hippocampus are defective in animals with fragile X, Bassell said.

"We discovered what the specific underlying defect is," he said. "It is actually a defect in the mGluR5 receptor, which is on the surface of neurons. The defect is that there is excessive signaling."

Children with fragile X have difficulty in processing information, because these receptors allow too much signaling and change the function of other receptors, Bassell theorized.

When his team treated the receptor with an mGluR5 antagonist called MPEP, they were able to reverse the effects of the mutation. "When you quiet down this receptor, it corrects the defects that occur in other receptors as well," he noted.

Bassell stressed that MPEP is not a suitable drug for humans. However, the discovery should help researchers find other drugs that do the same thing safely.

Any drug that targets the receptor will not be a cure for fragile X, Bassell cautioned. "These children have a permanent defect in their DNA," he said. "The goal here is to improve the quality of life for these children. We are going to decrease the severity of episodes to help them focus better on learning tasks and help with the behavior problems and improve their cognitive function," he said.

One expert hailed the finding.

"This is a very important paper," said Dr. Randi Hagerman, a professor of pediatrics and medical director of the M.I.N.D. Institute at the University of California, Davis. "It proves that mGluR5 antagonists will be helpful in kids with fragile X syndrome," she added. "We are looking forward to a new age of treatment in fragile X syndrome."

Hagerman noted that trials with mGluR5 antagonists on adults with fragile X syndrome will be starting this fall. "If things go well with adults, then we will move to pediatric trials," she said.
"This is a very hopeful message," Hagerman said. "This means that there will be very specific treatments that will have an impact in the very near future."

Another expert agreed that the discovery should lead to new treatments for children with fragile X.

"This is a very exciting paper, which is a powerful confirmation of the mGluR theory of fragile X," said Dr. Michael Tranfaglia, medical director of the FRAXA Research Foundation. "Since FRAXA Research Foundation is currently working with several pharmaceutical companies to bring mGluR5 antagonists into clinical trials for fragile X, we are delighted to see this elegant proof of the therapeutic potential of this class of drugs."

More information
For more information on fragile X syndrome, visit the Fragile X Research Foundation.

Gene Mutation Linked to Parkinson's Disease

(HealthDay News) -- People who carry a certain gene mutation appear to have a greater risk for getting Parkinson's disease and for getting it at a relatively early age, new research suggests.

The study authors also found that because Ashkenazi Jews -- those with an Eastern European background-- are more likely to carry this gene mutation, this population may run an even higher risk for the disease. An estimated 90 percent of American Jews are of Ashkenazi lineage.

Study lead author Lorraine N. Clark, a researcher at Columbia University, described her team's findings as "unique and different."

"We specifically compared patients who had an early onset Parkinson's before age 50 with patients who had a later onset after age 50, and also with patients with and without Jewish ancestry," she said. "And we showed that mutations are twice as common among early onset Parkinson's and also that they're more frequent among patients with Jewish ancestry."

Clark serves as an assistant professor in the department of clinical pathology with the Taub Institute for Research on Alzheimer's Disease and the Aging Brain, as well as the Center for Human Genetics, both at Columbia University.

The findings are published in the Sept. 18 issue of the journal Neurology.

Parkinson's disease is a brain disorder that affects 1.5 million Americans, according to National Parkinson Foundation estimates. Approximately 60,000 news cases occur each year, striking men and women equally, usually over the age of 65.

The disease is characterized by widespread damage to dopamine-producing nerve cells, impeding their ability to regulate body movement and muscle control. Key signs of the disease include tremors, stiffness, balance problems, and slowness of movement. Patients may also experience difficulty with speech and depression. There is no known cure.

To explore potential genetic underpinnings to the onset of Parkinson's, Clark and her colleagues decided to focus on the GBA gene. Mutations of this gene have already been identified as the cause of Gaucher disease, a rare fat-storage disorder that disrupts spleen and brain function.

Gaucher's and Parkinson's have some links, the study authors noted. In some cases, Gaucher's patients have a family history of Parkinson's, while others actually develop neurological features of Parkinson's. It is also one of the most prevalent genetic illnesses among Ashkenazi Jews.

For the new study, the researchers conducted a sequencing analysis of the GBA gene among 278 Parkinson's patients, 178 of who were of Jewish ancestry dating back to all four grandparents. A similar analysis was done among 179 men and women without Parkinson's.

Clark and her team found that 14 percent of the Parkinson's patients had GBA mutations, compared to just 5 percent of the healthy patients. And, while GBA mutations were found among 22 percent of Parkinson's patients who were diagnosed with their illness before the age of 50, only 10 percent of patients diagnosed after 50 had such abnormalities.

Teasing out information on Jewish patients, the researchers found that while nearly 17 percent of Jewish Parkinson's patients had GBA mutations, the figure was 8 percent among non-Jewish Parkinson's patients.

Clark called the study findings preliminary, and she cautioned that it remains unclear whether a single GBA mutation is a cause of Parkinson's or merely a part of a larger puzzle.

Still, she believes the findings could prove helpful in opening up new avenues of research into the disease.

"This is a gene we hadn't really thought about before," she said. "And it implicates new pathways that might be important in the pathogenesis of Parkinson's disease which could lead to the development of new treatment strategies. I do think, however, that further studies are needed in larger patient populations before we could use this work in diagnostic testing and counseling."

Robin Elliott, executive director of the Parkinson's Disease Foundation in New York City, called the new research "very interesting and very worthwhile, solid work in one of the most fruitful areas of Parkinson's research.

"Genetics and the study of genetics has been one of the most exciting areas of Parkinson's in the last 10 years," he said. "In 1996, we had not a single gene associated with the disease, and now it's up to 12 or 13. So, this is a very important study that pushes the science even further, and gives us the basis for more work."

More information
To learn more, visit the Parkinson's Disease Foundation.

Saline Reduces Mortality for Brain Injury Patients

(HealthDay News) -- A simple change in the way people with traumatic brain injuries are treated initially might make a big difference in their survival odds, a new Australian study suggests.

The study found that using saline rather than albumin fluid to maintain normal fluid volume levels in people with severe brain injuries resulted in nearly double the survival rate at 24 months after the injury.

"We determined that the 2-year mortality rate was significantly high in those patients who received albumin-based fluids compared to those who received saline, particularly those patients with severe brain injuries who presented with traumatic coma," said the study's lead author, Dr. John Myburgh, director of the division of critical care and trauma at the George Institute for International Health, in Sydney.

"Given the significant difference in mortality that we observed, we recommend that albumin-based fluids be avoided for the acute fluid resuscitation of patients with traumatic brain injury," added Myburgh, who's also a professor of critical care at the University of New South Wales.

Results of the study are published in the Aug. 30 issue of the New England Journal of Medicine.

Traumatic brain injury is caused by a sharp blow to the head that often occurs in falls, motor vehicle crashes or from physical assault, according to the U.S. Centers for Disease Control and Prevention. The CDC estimates that about 1.4 million traumatic brain injuries occur annually in the United States, and about 50,000 of those people die as a result of the injury each year.

Those who survive may have lifelong disabilities.

Some of the most serious damage to the brain occurs at the time of the injury, and soon after, when the brain swells in response to the injury. Because the brain is an enclosed system, if swelling occurs, brain tissue becomes damaged.

Fluid resuscitation is a common part of traumatic brain injury treatment to ensure normal blood circulation in the brain, according to the study. However, there's been some debate as to what type of fluid would most benefit people with traumatic brain injuries -- saline or albumin fluid.

Albumin is the main protein component of human blood.

"Albumin is a very expensive product that has to be purified," explained Dr. Keith Siller, medical director of the Comprehensive Stroke Care Center at New York University Medical Center in New York City. "If they're equally effective, you'd pick the cheaper fluid."

And, in fact, a previous study had compared the two fluids and found no statistically significant difference in the rates of death after 28 days.

But, Myburgh and his colleagues re-analyzed the original data to assess results at 24 months after injury. In the original study, 460 people with traumatic brain injuries were randomly selected to receive either saline or albumin fluid. Slightly more than two-thirds of the participants in each group were classified as having a severe traumatic brain injury.

After two years, the researchers behind the new study found that people with traumatic brain injuries who received albumin had a 63 percent higher risk of dying than those given saline. For those with severe brain injuries, the albumin group had an 88 percent increased risk of death compared to the saline group.

"These are people in very bad shape," said Siller. "If there's anything that can help them have better outcomes, we have to pay attention."

Dr. James Goodrich, director of pediatric neurosurgery at the Children's Hospital at Montefiore in New York City, said, "This is a great study that definitely found a significant difference in the sense of outcomes." But, he added, it just confirms what's already going on in the treatment of people with serious brain injury. "Albumin has pretty much been given up on," he said.

As to why saline might offer some benefit over albumin, Myburgh said the researchers can't explain the difference. "The exact mechanism by which the difference in mortality between saline and albumin remains unclear," he said.

"It's probably one of two things," said Siller. "Either albumin is making the brain swelling worse, or somehow the saline is doing something beneficial that albumin can't."

More information
To learn more about traumatic brain injury, visit the National Institute of Neurological Disorders and Stroke.