About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Brain's Shift into Low-Energy, Protective Mode Reflected in EEG Pattern

by Nancy Needhima on February 14, 2012 at 12:19 AM
Font : A-A+

Brain's Shift into Low-Energy, Protective Mode Reflected in EEG Pattern

A unique pattern of brain activity linked with conditions including deep anesthesia, coma and congenital brain disorders seem to signify the brain's shift into a protective, low-activity state in response to reduced metabolic energy. A mathematical model developed by a Massachusetts General Hospital (MGH)-based research team accurately predicts and explains for the first time how the condition called burst suppression is elicited when brain cells' energy supply becomes insufficient. Their report has been released online in PNAS Early Edition.

"The seemingly unrelated brain states that lead to burst suppression - deep anesthesia, coma, hypothermia and some developmental brain disorders - all represent a depressed metabolic state," says Emery Brown, MD, PhD, of the MGH Department of Anesthesia, Critical Care and Pain Medicine, senior author of the report. "We believe we have identified something fundamental about brain neurochemistry, neuroanatomy and neurophysiology that may help us plan better therapies for brain protection and design future anesthetics."

Advertisement

Burst suppression is an electroencephalogram (EEG) pattern in which periods of normal, high brain activity - the bursts - are interrupted by stretches of greatly reduced activity that can last 10 seconds or longer. Burst suppression has been observed in deep general anesthesia, in induced hypothermia - used to protect the brain or other structures from damage caused by trauma or reduced blood flow - in coma, and in infants with serious neurodevelopmental disorders. It also has transiently been observed in some premature infants. Previous investigations of burst suppression focused on characterizing the structure of the EEG patterns and understanding the brain's responsiveness to external stimuli while in this state, not on the underlying mechanism.

Lead author ShiNung Ching, PhD, a postdoctoral fellow in Brown's lab, had been working with Nancy Kopell, PhD, a professor of Mathematics at Boston University and co-author of the PNAS article, to develop mathematical models of different brain states under general anesthesia. In developing a model for burst suppression, they focused on what the associated conditions have in common - a significant reduction in the brain's metabolic state. In order for a signal to pass from one nerve cell to another, the balance between sodium ions outside the cell and potassium ions within the cell needs to be correct. Maintaining that balance requires that structures called ion pumps, fueled by the cellular energy molecule ATP, function correctly. The model developed by Ching and his colleagues revealed that, when brain energy supplies drop too low and cause a deficiency in ATP, potassium leaks from the nerve cells and signal transmission halts.
Advertisement

"It looks like burst suppression shifts the brain into an altered physiologic state to allow for the regeneration of ATP, which is the essential metabolic substrate," Ching explains. "During suppression, the brain is trying to recover enough ATP to restart. If the substrate doesn't regenerate quickly enough, the system will have these brief bursts of activity, stop and then need to recover again. The length of suppression is governed by how quickly ATP regenerates, which matches the observation that the deeper someone is anesthetized, the longer the periods of suppression."

Brown adds, "When we use general anesthesia to place patients with serious neurologic injuries into induced comas to allow their brains to heal, we take them down to a level of burst suppression. But there are a lot of questions regarding how deeply anesthetized an individual patient should be - how often the bursts should occur - and how long we should maintain that state. By elucidating what appears to be a fundamental energy-preserving mechanism within the brain, this model may help us think about using burst suppression to guide induced coma and track recovery from brain injuries. This is also a great example of how studying anesthesia can help us learn something very basic about the brain."

Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Advertisement
News Category
What's New on Medindia
January is the Thyroid Awareness Month in 2022
Menstrual Disorders
Coffee May Help You Fight Endometrial Cancer
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Language Areas in The Brain Electroencephalogram Ways to Improve your Intelligence Quotient (IQ) Video-EEG Monitoring Test 

Recommended Reading
Head Injury
Head injury or traumatic brain injury is a leading cause of disability among children and young ......
Depression
Depression is one of the most common mental disorders affecting approximately 340 million people in ...
Brain Exercises to Improve Memory
An active brain can certainly help in improving memory by strengthening the connections between ......
Amnesia
Amnesia, is profound memory loss caused by a physical injury inflicted on the brain, by an ......
Electroencephalogram
An electroencephalogram (EEG) detects electrical activity in the brain using electrodes attached to ...
Language Areas in The Brain
The mechanism of how human brain processes the language to express and comprehend the verbal, writte...
Video-EEG Monitoring Test
Video-electroencephalography monitoring is a diagnostic technique that records the electrical activi...
Ways to Improve your Intelligence Quotient (IQ)
Intelligence quotient (IQ) is a psychological measure of human intelligence. Regular physical and me...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2022

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use
open close
ASK A DOCTOR ONLINE
I have read and I do accept terms of use - Telemedicine

Advantage Medindia: FREE subscription for 'Personalised Health & Wellness website with consultation' (Value Rs.300/-)