Computers offer better control of coma patients' brains

It may sound a bit sci-fi, but scientists from MIT have developed a computerized system that not only monitors coma patients' brain activity, but can also automatically adjust and administer drugs to maintain the correct state.

Patients who have suffered a traumatic brain injury are often placed into a drug-induced coma to give swelling the chance to go down and the brain time to heal.

These comas can last for days, and nurses need to monitor the patients' condition closely to ensure they are kept at the correct level of sedation.

Dr. Emery Brown, an anesthesiologist at Massachusetts General Hospital (MGH) and a professor of health sciences and technology at MIT, explains:

"Someone has to be constantly coming back and checking on the patient so that you can hold the brain in a fixed state. Why not build a controller to do that?"

The researchers tested the system on rats but are now planning human trials. They say the findings, published in the journal, PLOS Computational Biology, may also have implications for people suffering severe epileptic seizures.

'Is there an app for that?'

Dr. Brown and colleagues analyzed electrical brain waves associated with different states of activity. They found that each state - awake, asleep, sedated, etc. - had its own distinctive electroencephalogram (EEG) pattern.

In a medically induced coma, patients' brains are quiet for several seconds at a time and then experience a surge of activity. Known as "burst suppression," this pattern allows the brain to save vital energy. Doctors try to control the number of "bursts" - as seen on the EEG screen - and maintain that pattern for hours or days at a time.

Dr. Brown says:

"If ever there were a time to try to build an autopilot, this is the perfect time. Imagine that you're going to fly for two days and I'm going to give you a very specific course to maintain over long periods of time, but I still want you to keep your hand on the stick to fly the plane. It just wouldn't make sense."

So, armed with a computer, an EEG system, a drug-infusion pump and a control algorithm, Dr. Brown and his team set out to build a "brain-machine interface" - a pathway for communication between the brain and an external device helping with cognitive, sensory and motor functions.

In true sci-fi style, the control algorithm interprets the EEG signals, calculates how much anesthetic is in the brain and adjusts the dosage second by second. The program can increase the depth of a coma almost instantly and with an accuracy that medical staff could not achieve.

Dr. Sydney Cash from Harvard Medical School, who was not part of the research team, comments:

"Much of what we do in medicine is making educated guesses as to what's best for the patient at any given time. This approach introduces a methodology where doctors and nurses don't need to guess, but can rely on a computer to figure out - in much more detail and in a time-efficient fashion - how much drug to give."

Dr. Brown and his team think this is the start of something big. They believe their technology can be used to control other brain states, including general anesthesia, as every brain activity has a unique EEG "signature."

"If you can quantitatively analyze each state's signature in real time and you have some notion of how the drug moves through the brain to generate those states, then you can build a controller."

The MIT and MGH team are hoping to test the device on humans.

Medical News Today reported in June this year that even experts have a hard time judging the depth of comaand may have to rely on non-scientific methods.

Written by Belinda Weber

Copyright: Medical News Today
Not to be reproduced without the permission of Medical News Today.

Posted By:

Rajni Jaiswal

Faculty