The dyslexic brain struggles to read because even small distractions can throw it off, according to a new model of dyslexia emerging from a group of recent studies.
The studies contradict an influential, 30-year-old theory that blamed dyslexia on a neural deficit in processing the fast sounds of language.
Instead, the studies suggest that children with dyslexia have bad filters for irrelevant data. As a result, they struggle to form solid mental categories for identifying letters and word sounds.
Such children may benefit from intensive training under "noisy" conditions to strengthen their mental templates, said University of Southern California neuroscientist Zhong-Lin Lu. (Originally release by USC and study published in Psychological Science Dec 2006)
Boonzee note: How do you then determine the difference between ADD and dyslexia? We will be watching for further studies and treatment protocols relating to this concept. Let us know if you hear of something interesting as well.
Shire Transdermal Patch for ADHD Treatment
See Shire.com for information about their transdermal patch DAYTRANA. Reported at the American Psychiatric Association (APA) annual meeting in San Diego, the clinical trials proved Daytrana had significant efficacy in reducing the symptoms of ADHD in both male and female children aged 6 to 12.
Boonzee note: this is not a different medication (methylphenidate) but it is a different delivery system and the study proves efficacy of treatment is same between males and females.
ADHD Ritalin and Future Drug Abuse
UPTON, NY (BNL.gov) -- Parents, doctors, and others have wondered whether common treatments for attention-deficit hyperactivity disorder (ADHD) inadvertently predispose adolescents to future drug abuse. The answer may depend on the age at which treatment is started and how long it lasts, say the authors of a new brain-imaging and behavioral study conducted in animals at the U.S. Department of Energy's Brookhaven National Laboratory. The results appear in the June 5, 2007 online issue of the journal Pharmacology, Biochemistry and Behavior.
"Our study shows that the brain's reward pathways are definitely influenced by methylphenidate, one of the stimulant drugs commonly used to treat ADHD," said Brookhaven researcher Panayotis (Peter) Thanos, lead author of the study. "But the brain chemistry changes we observed suggest that the developmental stage at which treatment begins and the duration of treatment are important variables that need further study."
Boonzee note: The long and short of it? Rats treated for only 2 months had less dopamine receptors in the brain and more self-administered cocaine use than rats treated for 8 months. This study confirms changes in brain chemistry but does not tell us what those changes mean (are they even harmful or beneficial or benign?) and why different changes occur depending on age and duration of treatment. The statistical significance of this study will hopefully justify and increase further study.
See Brookhaven National Labs press release for details of the study or the online issue of the journal noted above that publised the study.
New Med for ADHD in the FDA Process
Shire plc (Shire.com) has announced that it has received an approvable letter from the U.S. Food and Drug Administration (FDA) for INTUNIV (guanfacine). Unlike some other ADHD treatments, INTUNIV, a nonstimulant, is not a controlled substance and does not have a known mechanism for potential abuse or dependence. The information requested by the FDA was not unexpected, and Shire is working with the FDA to provide a full and timely response to the agency's request.
"The FDA's approvable letter for INTUNIV is positive news, and Shire will be working closely with the agency to address its questions," said Matthew Emmens, CEO of Shire. "When approved, INTUNIV will be the first medication indicated to treat ADHD symptoms by selectively targeting alpha-2A-receptors in the prefrontal cortex, an area of the brain that is thought to manage executive functioning tasks. Shire is looking forward to further strengthening our broad portfolio of ADHD medications by adding a nonstimulant treatment option with a novel mechanism of action and demonstrated clinical efficacy, which may be ideal for those patients who have not benefited from currently available ADHD medications."
About INTUNIV (guanfacine) Extended Release Tablets
According to a study published in the Archives of General Psychiatry, people who have trouble identifying common smells could be in the early stages of Alzheimer's disease. In the study, participants were asked to identify a dozen common smells and for each scent, they were given a choice of four answers. Over the next five years, the participants took 21 cognitive tests annually. Those who made at least four errors on the smelling test five years previous were 50 percent more likely to develop cognitive problems than those who made no more than one error, even after researchers took into consideration age, gender, education and a history of strokes or smoking. They also had a higher risk of progressing from mild cognitive impairment to Alzheimer's. The Associated Press quotes other experts who said that while a poor sense of smell does not mean a person has Alzheimer's disease, older people who lose their sense of smell should report it to their doctors. (Report from InteliHealth.com Week of July 2, 2007)
