Don't Pull that Plug: New Technology Shows that Many in Vegetative State are NOT Brain Dead

Photo Credit: theverge.comFor a patient who sustains devastating brain damage, the outcome is often exceedingly grim: if they don’t show signs of improvement within a few weeks, they’ll be diagnosed as vegetative — unaware of themselves or their environment, and unlikely to ever be again. To their loved ones, these patients are essentially lost, as is the prospect of ever communicating with them again.

Unless, that is, the diagnosis is wrong.

That’s the startling possibility raised by a series of recent studies, which used neuroimaging techniques to evaluate awareness levels among patients diagnosed as being in persistent vegetative states (VS) or in minimally conscious states (wherein patients exhibit fleeting, inconsistent awareness). A small number of patients, these studies found, exhibited brain activity that indicates they were able to focus on a given word, answer a question, or complete a task. “We don’t yet have a full picture of the abilities of these patients,” says Srivas Chennu, PhD, an expert in cognitive and behavioral neuroscience at the University of Cambridge. “And what this research suggests is that there’s much more nuance here than anybody thought.”

Patients in vegetative states can often breathe autonomously, open their eyes, and blink. But despite those abilities, they tend to suffer brain damage so severe that they won’t respond to cues, acknowledge a family member, or react to their own name. For decades, those attributes (combined with extensive bedside tests) led doctors to conclude that the inner workings of these patient’s brains lacked any and all higher function. Patients were awake, in other words, but they weren’t aware.

Several studies in the past decade have questioned that line of reasoning. In 2009, a study on 103 patients found that some of those diagnosed as VS were, in fact, minimally conscious. The research also concluded that some patients diagnosed as minimally conscious actually showed signs of emerging from that state. Other studies, using both EEG and fMRI brain scans, noted that the brains of some vegetative patients engaged with commands similarly to those of healthy control participants.