When a 39-year-old Belgian wo-man suffered a str-oke and fell into a coma, doctors concluded that she was unlikely to regain consciousness and, after a time, diagnosed her condition as persistent vegetative state (PVS). One of the criteria on which they based their decision was her inability to blink or track a moving object with her eyes. It was only when they discovered that the stroke had damaged a cranial nerve, preventing her from opening her eyes, that they realised their error. If they opened her eyes for her, she followed their instructions. Having regained full consciousness soon after her stroke, she revealed she had overheard all the bedside discussions as to whether it was worth keeping her alive. At no point had she wanted to die.
Others might not be so lucky. Research suggests that many patients left to die after being diagnosed as in PVS might have eventually recovered. They may have been in a twilight condition called minimally conscious state (MCS), which has until now proved difficult to identify. In recent years, MCS has muddied the waters further on what it means to be alive, and confused the debate over when is the right time to pull the plug. Now, thanks to a new test, doctors may finally be able to save those who still have a chance.
Those fleeting glimpses of sentience meant that the medical community now viewed them differently: these patients could conceivably recover. Although they might stick at this point on the spectrum, or slide back into PVS, they might also regain a more consistent level of consciousness that would allow them to communicate. Reports of people â€œemergingâ€™â€™ from vegetative state are, by contrast, extremely rare â€” in medical circles, PVS and futility go hand-in-hand.
Unfortunately for both doctors and patients, MCS is no easier to diagnose than PVS. But a paper published recently in the Archives of Neurology could change all that.
The perception of sound in healthy people involves the coordinated communication of many brain areas and, whereas they saw similar widespread patterns of activation in the MCS and control groups, those patterns were absent in the PVS patients.
If doctors had such a test at their fingertips, it would reduce the risk of misdiagnosis. It would also, he believes, provide evidence to support their decision that a patient might, in the case of MCS, benefit from therapy.
Although the treatment that restores consciousness doesnâ€™t exist, there are intriguing clues that it could, one day. Deep brain stimulation is a popular and effective surgical treatment for Parkinsonâ€™s disease and epilepsy among other disorders, which involves feeding current to electrodes implanted deep in the brain. In the early 1990s, Japanese researchers showed that it could also provoke a strong electrical response in the brains of PVS patients. The patients didnâ€™t show any outward improvement, probably due to the degree of disintegration of their brains.
But there are also fears that PVS patients re-categorised as MCS might be worse off than before, because MCS describes a twilight zone between consciousness and unconsciousness and doctors donâ€™t know how to treat it. In the case of PVS, they can suggest withdrawing a feeding tube, but canâ€™t go ahead without a court declaration.
On one side will be those who argue that patients with no better quality of life than their PVS counterparts are being denied the right to die; on the other, disability rights groups who feel that doctors want to kill patients â€” still alive with a possibility to recover.
â€œStudy after study indicates that medical professionals have a much lower opinion of quality of life of people with disabilities than the general population, including people with disabilities themselves,â€™â€™ says Stephen Drake, a research analyst at the American disability rights organisation Not Dead Yet. He argues, â€œWithout a clear statement from patient, an advance directive or something similar, the presumption should always be that they want to live.
When surveyed, only four of the 300 members of the French Association of Locked-In Syndrome (ALIS) said they would opt for euthanasia. The rest, like the Belgian woman who was misdiagnosed, desperately wanted to live.