|
Monday, May 12, 2008 A New Approach to Treating Alzheimer'sElectrodes implanted in the brain show promise in early trials. By Emily Singer
Earlier this year, neurosurgeon Andres Lozano published a startling finding. He was testing deep-brain stimulation, in which electrical current is delivered directly to the brain, as a treatment for obesity. The patient's weight showed little change, but his memory improved significantly. Lozano has now formed a company to commercialize the technique as an Alzheimer's therapy, and he's testing it in six patients in the early stages of the disease. Alzheimer's is sorely in need of new treatment approaches. Five million people suffer from it in the United States, a number expected to rise dramatically as the baby boomers enter their senior years. Finding new treatments has proved extremely difficult: drugs currently on the market have at best only a modest impact on symptoms. And experimental drugs that improve cognitive function in animals have largely failed in human tests. In the past few years, deep-brain stimulation has become a routine treatment for Parkinson's disease: approximately 40,000 patients worldwide have undergone the procedure. Scientists are now testing it as a way to treat a growing number of other disorders, including epilepsy, depression, and obsessive-compulsive disorder. In the procedure, a thin electrode is surgically implanted into part of the brain, stimulating neurons in brain areas affected by disease. The voltage delivered to the brain is controlled by a power pack implanted in the patient's chest and connected to the electrode via wires threaded beneath the skin. The patient whose obesity Lozano was attempting to treat is cognitively normal. Lozano's team found that turning on the electrical stimulation triggered old memories in the patient; the higher the voltage, the more details he recalled. More important, after several months of low-level stimulation, cognitive testing revealed that the man's memory significantly improved. "Verbal working memory went off the scale," says Lozano, who holds a Canada Research Chair in Neuroscience at the University of Toronto, in Canada. "We've shown that the function of memory circuits can be modulated." With Alzheimer's, a neurodegenerative disease that affects brain cells involved in memory, the idea is to boost activity in the memory circuits that patients have left. Lozano's group is targeting the fornix, which he describes as a highway that drives information to and from the brain's memory center, the hippocampus. (The electrode is actually implanted into the neighboring hypothalamus, which was selected for the obesity patient because of its role in controlling appetite. But brain-imaging studies confirm that stimulation triggers activity in the neural circuit that encompasses the fornix and the hippocampus.) Lozano and his collaborators have seen promising results in the six patients in their trial: turning on the stimulation boosts cognitive function. Lozano now aims to begin larger clinical trials. It's not yet clear how the therapy will fare in the long run. While deep-brain stimulation's success in treating Parkinson's, which is also a neurodegenerative disease, provides some encouragement, other human studies of Alzheimer's therapies that yielded promising early results failed to show effectiveness in later tests. The researchers are performing parallel experiments in rats and have found that electrical stimulation can drive production of new memories and boost production of new brain cells, which may also boost memory function. |
Audio »
Share »
Digg this
Add to del.icio.us
Add to Reddit
Add to Facebook
Slashdot It!
Stumble It!
Add to Newsvine
Add to Connotea
Add to CiteUlike
Add to Furl
Googlize this
Add to Rojo
Add to MyWeb
Favorite
Print
E-mail
Detecting Alzheimer's Disease
05/16/2008
Comments
hachi on 05/12/2008 at 5:45 AM
17
winterspan on 05/12/2008 at 7:49 AM
3
On the other hand, deep-brain stimulation (DBS) uses a small battery-powered implant to deliver a continuous, but very mild electrical current to a certain local brain region to modulate it's neural activity, either by positively stimulating it (depression/Alzheimers) or attempting to suppress erratic activity (Parkinsons/Obsessive compulsive disorder).
Honey Bee on 05/13/2008 at 4:57 PM
1
Salty on 05/12/2008 at 12:36 PM
1
I quickly grew to understand that many treatments-- like the one described in the article-- were prescribed because they seem to reduce the symptoms of a disease with no underlying understanding of the reasons, side effects or practicality of usage.
Increasing the memory capacity of an overweight, non-alzheimers patient probably has only a tenuous connection to actually "treating" alzheimers.
Is this treatment really that far removed from primitive, pre-scientific methodologies?
If this researcher were going to market his treatment for improving memory then I'd have no problem. Selling it as a treatment for alzheimers because alzheimers seems to destroy memory functions is like selling a gasoline additive to make an untuned automobile run smoother. It might "work" to some extent but really doesn't address the underlying cause.
Umbrage on 05/12/2008 at 6:33 PM
1
Two comments in reply to yours. First this development is presented as a treatment rather than a cure. The two are fundamentally different and lumping them does a disservice both to the patients in regard to meeting their expectations and the physicians in regard to recognizing the work they have done.
Secondly while I agree this article may be premature in calling deep brain electrical stimulation an approach to treating Alzheimer's when it has not in fact been used to do so(throwing a question mark onto the title would assuage my misgivings), calling the methodology pre-scientific is unfair. The scientific method is the logic by which observation is used to form a hypothesis which researchers then attempt to disprove through experimentation. This article presents a hypothesis (Deep brain stimulation has the potential to help treat Alzeheimer's) which is in the process of going on to be tested through clinical trial. Hopefully it will not be disproven.
geetanjali on 05/13/2008 at 6:26 AM
1
Warmly, Geetanjali
(http://www.copperwiki.org/?utm_source=geetanjali_krishna&utm_medium=email&utm_campaign=invite)