Keeping you up to date on recent headlines in neurology
Study links PET-PIB imaging and brain circuits . . . In a new study published in the journal Biological Psychiatry, researchers have related the findings that are emerging from PET-PIB imaging to changes in the function of brain circuits. The emergence of multiple new brain imaging technologies and the combined application of these new approaches is helping to create new insights into aging and Alzheimer's disease (AD). One of the hallmarks of AD is the deposition of amyloid beta protein in clumps or plaques within the brain. These plaques can be measured in humans with PET scans that use a chemical marker or radiotracer called 11C-PIB. It was long thought that the formation of plaques injured and perhaps even caused the death of nerve cells in the brain. Recent studies, however, suggest that a form of the amyloid beta protein that is soluble rather than the form that is deposited in plaques mediates most of the destructive impact of this protein. In this study, researchers have related the findings that are emerging from PET-PIB imaging to changes in the function of brain circuits. Yvette Sheline, professor of psychiatry and radiology at Washington University (St. Louis) and colleagues examined AD patients and cognitively normal, healthy individuals who were then divided into those with or without brain amyloid plaques. Using functional connectivity brain mapping, they found that amyloid plaques are present in the brains of people with AD as well as some healthy elderly people who do not show behavioral evidence of AD. However, they found that the healthy participants with brain amyloid deposits were associated with compromise of the connections between important brain regions involved in learning and memory even though their memory functions were not markedly impaired. Similar disruptions in brain connections were found in individuals with AD.
SANTE trial results published . . . Medtronic (Minneapolis) reported publication of results from the pivotal study for Medtronic Deep Brain Stimulation (DBS) therapy for epilepsy, known as SANTE (Stimulation of the Anterior Nucleus of the Thalamus in Epilepsy), in the medical journal, Epilepsia. Medtronic claims the SANTE study is the largest clinical study of DBS therapy for epilepsy in adults with medically refractory epilepsy with partial-onset seizures. “The SANTE trial was a rigorous, well-designed, blinded trial with long-term follow up in an open-label phase. Based on the outcome of the study, DBS therapy holds promise for patients with epilepsy who are severely affected and have not had success with other treatments,“ said Robert Fisher, MD, professor of neurology and director of Stanford Epilepsy Center (Stanford, California), principal investigator for the SANTE study. Medtronic DBS Therapy is currently approved by the FDA for the treatment of the disabling symptoms of essential tremor and advanced Parkinson's disease. The therapy is approved under a humanitarian device exemption for the treatment of dystonia, and chronic, severe, treatment-resistant obsessive-compulsive disorder. The therapy is reversible and can be programmed and adjusted non-invasively (without surgery) by a trained clinician to find the most appropriate type and amount of stimulation for each patient to maximize symptom control and minimize side effects.
Research agreement reached to develop new AD drugs . . . The University of Pennsylvania (Philadelphia) and AstraZeneca (London) reported a new collaborative research agreement that will focus on generating new Alzheimer's disease (AD) drug candidates for the clinical development pipeline. In AD, the formation of amyloid plaques and neurofibrillary tangles are thought to contribute to the destruction of nerve cells in the brain, leading to subsequent symptoms of the disease. In this collaboration, researchers will focus on the protein tau, which is the key component of tangles in AD. Penn Medicine's Center for Neurodegenerative Disease Research (CNDR) will provide rapid access to drug compound screening assays and knowledge of the biology of tau – first characterized for its role in dementias by Penn Medicine's Virginia M.-Y. Lee, PhD, MBA, director of CNDR, and John Trojanowski, MD, PhD, director of the Institute on Aging (San Francisco). AstraZeneca scientists will supply basic research with access to the technologies and skills required to discover and develop new drug molecules. “We are excited about the collaborative drug discovery relationship that CNDR has formed with AstraZeneca, as it builds on the exceptional translational research strengths of the Penn CNDR team in elucidating mechanisms of tau-mediated neurodegeneration in AD,“ said Lee, who along with Trojanowski and Kurt Brunden, PhD, Director of CNDR Drug Discovery, will lead the CNDR component of this new alliance at Penn.
ViewSite advances neurosurgical retraction . . . Vycor Medical (Bohemia, New York), a designer of neurosurgery retraction devices, said its ViewSite Brain Access System (VBAS) medical retraction device continues to gain ground. The company said the device has the potential to impact several hundreds of thousands of patients and throngs of surgeons and medical facilities worldwide. it's among a new breed of cost-reducing surgical devices designed to enhance performance, quality of life and surgical results. “Most are shocked to learn that neurosurgical retraction technology has not significantly changed in nearly a century,“ said Heather Vinas, president of Vycor Medical. “Where other forms of diagnostic and operative procedures have evolved by leaps and bounds, this crucial area of surgery has remained virtually unchanged to the detriment of patients, physicians and surgical facilities, alike. Vycor has single-handedly changed all that with a NeuroTech advancement that's also fiscally sound.“ Vycor claims its VBAS offers a less invasive way to access surgical locations and perform critical procedures with minimal damage to surrounding brain tissue, thus minimizing collateral trauma and accelerating post-operative recovery.
BrainPort helps blinded soldier see with tongue . . . A British soldier who was blinded by a grenade in Iraq three years ago said his life has been transformed since he was fitted with a prototype BrainPort (Middleton, Wisconsin) device that allows him to “see“ with his tongue. Lance Corporal Craig Lundberg from Walton in Liverpool, UK, told BBC News that while the device is only a prototype, it has a lot of potential to advance things for blind people: “The potential to change my life is massive,“ he said. The BrainPort device looks like a square plastic lollipop that connects via a wire to a tiny video camera mounted on sunglasses worn by the user. When users want to see their environment, they put the lollipop in their mouth and the video camera images are converted to electrical impulses that users sense with their tongue when it makes contact with the lollipop. “One of the things it has enabled me to do is pick up objects straight away, I can reach out and pick them up when before I would be fumbling around to feel for them,“ said Lundberg. The technology behind the visual aid version of BrainPort, which started life as a device that helps people with vestibular disorders keep their balance, is similar to the way a cochlear implant works. “The camera sends signals down onto the lollipop and onto your tongue, you can then determine what they mean and transfer it to shapes. You get lines and shapes of things, it sees in black and white so you get a 2-D image on your tongue, it's a bit like a pins and needles sensation,“ Lundberg said. The device currently has 400 points of contact with the tongue. The next version will probably have 4,000 points, delivering much clearer, higher resolution images to the user, the company said. (Editor's note: to read a related story about this product and a blind mountain climber, please see Medical Device Daily, Sept. 11, 2009).
— Compiled by Rob Kimball, MDD