A new research study gives hope that some patients who seem to be in a coma, or persistent vegetative state, may actually be aware of their surroundings and can communicate on a rudimentary level.
The even better news is that misdiagnosis of these patients, which studies suggest may be common, can be corrected by use of a simple, cheap and widely available brain wave test called the EEG, electroencephalogram.
The study was reported in the online edition of the prestigious British medical journal The Lancet.
Many patients who seem to be completely unaware of their surroundings after a brain injury do not show any response to this new kind of testing. But of the 16 patients tested in the new study, three patients did show a response, indicating that they had been misdiagnosed and should be reclassified as “minimally conscious.”
The researchers gave the seemingly vegetative patients two simple tasks: imagine moving a right finger, and then imagine moving a right toe. The patients who passed the test were able to generate specific, repeatable brain wave responses in the same area of the brain, the pre-motor cortex, as normal healthy control patients could do with the same testing.
Other researchers have found that putting patients like this into MRI machines for functional MRI (f-MRI) testing also can show results that indicate the apparently unresponsive patient actually has a response deep within the brain. The brains of some of these patients light up in specific places on the f-MRI test when they are asked to imagine some specific athletic activity like playing tennis.
The problem with f-MRI testing is it’s expensive and requires the patient to be transported to a radiology center.
Here is the conclusion of the authors of the EEG study:
Despite rigorous clinical assessment, many patients in the vegetative state are misdiagnosed. The EEG method that we developed is cheap, portable, widely available, and objective. It could allow the widespread use of this bedside technique for the rediagnosis of patients who behaviourally seem to be entirely vegetative, but who might have residual cognitive function and conscious awareness.
Brain scientists are excited that if these results hold up, we may have a way to communicate with some of the 25,000 Americans who lie in beds seemingly unaware but actually with something going on inside.
Article first published as New Hope for Communicating with Patients in a “Vegetative State” on Technorati.
