Brain scans using the most recent technologies are challenging the decade-old doctors’ assumption that patients who have been diagnosed as vegetative lack any capacity for conscious thought. Most of these patients are previously healthy people who suffered a traumatic brain injury such as in a car accident, or oxygen deprivation after a heart attack or stroke or perhaps even due to medical malpractice. Although most brain scans show what is wrong with someone’s brain, sophisticated brain scans are showing what parts of the brain are working, with surprising results.
What is lacking in these patients is not necessarily some level of awareness, but rather the ability to communicate their awareness of themselves or their environment. The courts in New York require that in order for a person in a vegetative state to recover an award of damages for conscious pain and suffering, the person must have some level of awareness of his or her condition. McDougald v. Garber, 73 N.Y.2d 246, 538 N.Y.S.2d 937, 536 N.E.2d 372 (1989); Maracle v. Curcio, 24 A.D.3d 1233, 806 N.Y.S.2d 839 (2d Dept. 2005); Weldon v. Beal, 272 A.D.2d 321, 707 N.Y.S.2d 875 (2 Dept. 2000).
Traditionally, proving the requisite level of awareness involves submitting evidence that the person displays some sort of visible, even if slight, response to stimuli. With the advanced brain scans, it is possible to show, through neural response, that stimuli were not reported by the subject but were still processed in the brain.
As stated by a prominent neuroscientist, Adrian Owen, “The thought of coma, vegetative state, and other disorders of consciousness troubles us all, because it awakens the old terror of being buried alive.”
The types of brain scans providing these results are PET scans, which records changes in metabolism and blood flow in the brain, functional MRI (fMRI) scans, which is faster than a PET scanner and captures changes in blood flow in the brain almost as they occur, and diffusion tensor imaging, which assesses the number and health of axons, long fibres that transmit nerve impulses from one brain cell to another.
Estimates from 2006 suggest that there are approximately 35,000 Americans in a vegetative state and another 280,000 in a minimally conscious state – a less severe condition, in which patients show erratic evidence of deliberate behavior, such as responding to a simple command or focussing on a person or an object for a sustained period.
A person in a vegetative state has periods of wakefulness but shows no awareness of her environment and does not make purposeful movements, in contrast to a person in a coma, who appears to be asleep and is unaware of even painful stimulation. These conditions are of course much more serious than a concussion, although concussions may cause more residual and permanent problems than previously recognized.
The neuroscientist Owen’s most ambitious experiment was a test to determine whether vegetative patients who seemed able to comprehend speech could also perform a complex mental task on command be asking them to imagine playing tennis. Owen compared the brain scans of 34 healthy volunteers who were instructed to picture themselves playing tennis for at least 30 seconds to the brain scan of a vegetative woman who had been severely injured in a car accident, and found that she produced a beautiful activation, indistinguishable from those of the group of normal volunteers. The woman’s scan showed the existence of a rich mental life, including auditory language processing and the ability to perform mental imagery tasks.
In another experiment, electrodes were implanted in the thalmus of a 38-year old man who suffered a head injury and had been living in a nursing home for 6 years in order to stimulate the brain tissue. This deep brain stimulation enabled him to regain considerable physical and mental function, such as improved speech, more fluid movements, and the ability to chew and swallow, progress that relapsed when the electrical stimulation was shut off.
The situation of Terry Wallis, a 43-year old truck mechanic who began to speak in 2003, 19 years after he had been injured in a car accident and sustained a severe brain injury and paralysis, has been the subject of national news stories. Not only has he recovered memories from his life before the accident, but he is making new memories. Brain scans suggested that axons in Wallis’s brain were growing and forming new connections- contradicting the long-standing assumption that a damaged brain is incapable of healing after such a lengthy period.
Similarly, the progress made by the aforementioned 38-year old man also shows that deep brain stimulation can promote late functional recovery from severe traumatic brain injury. The existence of late improvement casts some doubt on the appropriateness of insurers’ typical refusal to pay for rehabilitation, on the assumption that such patients are unlikely to improve.