RxPG News Feed for RxPG News

Medical Research Health Special Topics World
  Home
 
   Health
 Aging
 Asian Health
 Events
 Fitness
 Food & Nutrition
 Happiness
 Men's Health
 Mental Health
 Occupational Health
 Parenting
 Public Health
 Sleep Hygiene
 Women's Health
 
   Healthcare
 Africa
 Australia
 Canada Healthcare
 China Healthcare
 India Healthcare
 New Zealand
 South Africa
 UK
 USA
 World Healthcare
 
 Latest Research
 Aging
 Alternative Medicine
 Anaethesia
 Biochemistry
 Biotechnology
 Cancer
 Cardiology
 Clinical Trials
 Cytology
 Dental
 Dermatology
 Embryology
 Endocrinology
 ENT
 Environment
 Epidemiology
 Gastroenterology
 Genetics
 Gynaecology
 Haematology
 Immunology
 Infectious Diseases
 Medicine
 Metabolism
 Microbiology
 Musculoskeletal
 Nephrology
 Neurosciences
 Obstetrics
 Ophthalmology
 Orthopedics
 Paediatrics
 Pathology
 Pharmacology
 Physiology
 Physiotherapy
 Psychiatry
 Radiology
 Rheumatology
 Sports Medicine
 Surgery
 Toxicology
 Urology
 
   Medical News
 Awards & Prizes
 Epidemics
 Launch
 Opinion
 Professionals
 
   Special Topics
 Ethics
 Euthanasia
 Evolution
 Feature
 Odd Medical News
 Climate

Last Updated: Oct 11, 2012 - 10:22:56 PM
Research Article
Latest Research Channel

subscribe to Latest Research newsletter
Latest Research

   EMAIL   |   PRINT
How brain pacemakers erase diseased messages

Jun 1, 2007 - 4:00:00 PM , Reviewed by: Dr. Himanshu Tyagi
In the case of tremor, physicians can alter the setting until they see the symptoms stop. You don't have to know how it's really working.

 
[RxPG] Brain pacemakers that have helped ease symptoms in people with Parkinson's disease and other movement disorders seem to work by drowning out the electrical signals of their diseased brains.

Despite the clinical success of the devices, which have been approved by the Food and Drug Administration and can be found in the heads of about 30,000 Americans, the mechanisms by which deep brain stimulation alleviates disease symptoms aren't well understood.

Biomedical engineers at Duke University's Pratt School of Engineering have found that stimulation administered by rapid-fire electrical pulses deep in the brain produces what they call an informational lesion. By relaying a repetitious and therefore meaningless message, constant pulses overwhelm the erratic bursts of brain activity characteristic of disease.

Periodic bursts in the brains of people with tremor -- which might follow a pattern such as 'pop-pop-pop, silence, pop-pop-pop, silence' -- propagate pathological information within brain circuits, said Warren Grill, the study's lead investigator and an associate professor of biomedical engineering. If you replace that instead with a constant 'pop-pop-pop-pop-pop-pop,' you've erased that pathological information.

Grill said the high-frequency deep brain stimulation acts like a surgical lesion, another acceptable treatment for severe tremor disorders and epilepsies. But the electronic device has the advantage of being adjustable or reversible.

The researchers' report appears in a special June 2007 issue of the journal IEEE Transactions on Neural Systems and Rehabilitation Engineering, edited in part by Grill. The study was conducted by a team that included Alexis Kuncel, a doctoral student in biomedical engineering at Duke, and Scott Cooper, a neurologist at the Cleveland Clinic, with support from the National Institutes of Health.

The FDA approved the use of deep brain stimulation for Parkinson's disease in 1997. The electrical implants are also an approved therapy for other movement disorders and are at various stages of testing for the treatment of epilepsy, depression, obsessive-compulsive disorder and pain, according to Grill.

The complexity of the brain -- in which nerves project in all directions and connect with one another to form multiple, looping networks -- makes studying how deep brain stimulation works a challenge, Grill said.

Grill's team created a mathematical model of a normally functioning brain cell. The researchers then gave the model neuron the pathological pattern of activity seen in people with tremors, assembled a group of these model cells and watched what would happen when the cells were electrically stimulated at various rates and intensities.

In addition to showing how the therapy works, their model of neurons in action also revealed that stimulation delivered at too slow a pace fails to keep bad information at bay. Indeed, slower pulses can actually add to problematic bursts, they showed.

The model's findings closely parallel the clinical responses of patients, who typically experience the greatest relief from symptoms when their devices are tuned by physicians to deliver rapid pulses, Grill said. Patients' symptoms can actually worsen when the devices are dialed to a slower setting.

The intensity of stimulation also plays an important role, the study suggests, by determining the number of brain cells affected by a particular series of pulses.

A better understanding of the processes underlying deep brain stimulation could enable physicians to better fine-tune electrical implants, Grill said. That could be particularly useful for zeroing in on effective settings for implants used to treat diseases, such as epilepsy, in which seizures occur only sporadically, as well as conditions, such as depression, in which symptoms can vary widely from day to day.

In the case of tremor, physicians can alter the setting until they see the symptoms stop, Grill said. You don't have to know how it's really working.

In a condition like epilepsy, however, it's extremely unlikely that a person would have a seizure in the doctor's office, he said. Therefore, it might take months of trial and error to find the optimal setting. Grill's new model promises to streamline the process.




Publication: IEEE Transactions on Neural Systems and Rehabilitation Engineering
On the web: Duke University 

Funding information and declaration of competing interests: National Institutes of Health

Advertise in this space for $10 per month. Contact us today.


Related Latest Research News


Subscribe to Latest Research Newsletter

Enter your email address:


 About Dr. Himanshu Tyagi
This news story has been reviewed by Dr. Himanshu Tyagi before its publication on RxPG News website. Dr. Himanshu Tyagi, MBBS is the founder editor and manager for RxPG News. In this position he is responsible for content development and overall website and editorial management functions. His areas of special interest are psychological therapies and evidence based journalism.
RxPG News is committed to promotion and implementation of Evidence Based Medical Journalism in all channels of mass media including internet.
 Feedback
For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 
Contact us

RxPG Online

Nerve

 

    Full Text RSS

© All rights reserved by RxPG Medical Solutions Private Limited (India)