Diagnosis - Brain Function / Coma / Persistant Vegetative State / Locked In Syndrome / Awakenings

Functional MRI Tests Indicate ‘PVS’ Patient Aware (2006)

PVS & Ambien: Several studies are being conducted worldwide on patients thought to be in PVS, using zolpidem (Ambien) which actually wakes up to sixty percent of these patients.

Tests conducted on a 23-year-old, severely brain damaged woman—clinically diagnosed as being in a persistent vegetative state (PVS) as the result of a 2005 car accident—have provided researchers with surprising evidence that she is aware but unable to communicate that awareness.

“I was absolutely stunned,” remarked lead British researcher Dr. Adrian M. Owen from the Medical Research Council Cognition and Brain Sciences Unit in Cambridge. The tests showed that “she is aware,” he said. [LA Times, 9/8/06]

According to the study published in the journal Science, researchers in the U.K. and Belgium conducted functional MRI (fMRI) tests on the woman and compared the scan results with identical tests performed on 34 healthy volunteers.

Unlike ordinary MRI scans which show structural brain damage, the newer, more advanced fMRI tests can measure function in specific regions of the brain.

When researchers gave the woman verbal instructions, the fMRI picked up activity in the same brain areas as seen in scans of the healthy volunteers. When she was told to “imagine playing tennis,” her brain fired in the supplementary motor area that controls motor responses.

In contrast, when she was asked to “imagine visiting all the rooms in your home, starting from the front door,” brain activity was seen in the areas responsible for spacial mental images.

Her test results were indistinguishable from those of the 34 healthy volunteers.

Researchers concluded, “These results confirm that…this patient retained the ability to understand spoken commands and to respond to them through her brain activity, rather than through speech or movement.” [Owen et al., “Detecting Awareness in the Vegetative State,” Science, 9/8/06, p. 1402]

While researchers caution that their study focused on only one patient and their findings cannot be applied to all PVS patients, they also recognize that their protocol is a breakthrough for PVS research.

Dr. Owens said that the type of brain responses the patient had “require the willed, intentional action of the participant.”

Study co-author Dr. Steven Laureys, from the University of Liege in Belgium, agreed. “The activity in her higher-order cognitive areas means, to me, that she was consciously aware of herself and her surroundings,” he said. [Wall Street Journal Online, 9/8/06]

Dr. Laureys also pointed out that the findings could mean “the difference between life and death.”

“From cases in the U.K. and the U.S.,” he said, “we know that end-of-life decisions are of course extremely important and this will definitely change the way we deal with these patients. When you have signs of consciousness, you cannot decide to stop hydration and nutrition.” [The Guardian (London), 9/8/06]

Dartmouth University Medical School neurologist James L. Bernat—a member of the Multi-State Task Force on PVS that, in 1994, codified the diagnosis of PVS—called the study’s findings “a little disturbing.” “This suggests there may be things going on inside people’s minds that we can’t assess by interacting with them at the bedside,” he said. [Washington Post, 9/8/06; Int’l Task Force Update, v.20, n.4]