JUN 30, 2016

Measuring Pressure Inside the Brain

WRITTEN BY: Brenda Kelley Kim
When there has been a traumatic brain injury (TBI) or there is a tumor or other problem in the brain, doctors need to know how much intracranial pressure there is so they can evaluate the options for treating the patient. The most accurate was to do this is the placement of an intraventricular catheter in the cerebral spinal fluid of the brain’s left ventricle but it involves drilling a hole in the skull of the patient. Other methods involve screws or sensors being used, but again, they are invasive and carry additional risks.
There may be a new way however, that is non-invasive. Scientists in Lithuania say they have developed a way to accurately and safely measure brain pressure without surgery, drilling or placing any instruments into the brain tissue.
 
Professor Arminas Ragauskas of Kaulas University of Technology in Lithuania has led a team developing a device called Vittamed which can use ultrasound instruments to check the pressure inside the brain. In an interview with Reuters, Prof. Ragauskas said, "The device consists of just three parts: first of all it is ultrasonic Doppler blood flow meter, which measures blood flow in ophthalmic artery and of course computer and some mechanical parts to fix ultrasonic transducer on to the face of the patient. It works like a pair of scales: we are comparing intracranial pressure with externally applied pressure to the tissue surrounding the eyeball and ultrasonic Doppler device is used as indicator of the pressure balance."
 
A small amount of pressure is put on the eye externally to match the blood pressure in the central retinal artery located just behind the eye, which leads to the brain. The device then compares this pressure, with that inside the retinal artery and a measure of intracranial pressure is determined. Healthy adults will have a range of 0-10 millimeters of mercury (mmHg). Anything above 20 mmHg is abnormal and pressure above 40 mmHg indicates neurological impairment. Readings above 60 mmHg are almost always deadly. The device has been compared to a sphygmomanometer, or as most people know, an ordinary blood pressure cuff.
 
While it uses the technology of Doppler ultrasound, something commonly in use in many other applications in medicine, the team that developed it stressed that is is a bit more advanced, accurate and sensitive than most Doppler devices because in dealing with brain injuries or tumors, precision matters.
 
It’s also safer than the invasive methods with no need for risky anesthesia or surgery and it reduces recovery time for patients and costs for insurance companies and hospitals. The device has already been used in Europe for various medical needs and even NASA has used it for the measurement of intracranial pressure in astronauts in microgravity environments. Brain swelling can impair vision and that’s a problem for space travel and those astronauts working on the ISS. Ragauskas was named a finalist for a European Inventors Award in May for his work on the device. The video below talks more about the development of this device, check it out.

 
Sources:
 
NIH, Reuters via GMA News Network