Research Study detects consciousness in unresponsive patients (life support ethics)

[C C]

https://www.eurekalert.org/news-releases/1054335

INTRO: New research co-led by experts at Mass General Brigham found that brain scans can detect consciousness in some patients with brain injury who are unresponsive.

In the study, 241 participants with severe brain injury who do not respond when given a simple instruction were assessed with functional MRI (fMRI), electroencephalography (EEG), or both tests. During these tests, participants heard instructions, such as “imagine opening and closing your hand” followed, 15-30 seconds later by “stop imagining opening and closing your hand.” The fMRI and EEG brain responses showed that 60 (25 percent) of participants repeatedly followed this instruction covertly over minutes.

According to the authors of the study, published August 15 in the New England Journal of Medicine, patients who demonstrate this phenomenon, called cognitive motor dissociation, understand language, remember instructions and can sustain attention, even though they appear unresponsive. For these patients, cognitive (i.e., thinking) abilities exceed, and are therefore dissociated from, motor abilities.

“Some patients with severe brain injury do not appear to be processing their external world. However, when they are assessed with advanced techniques such as task-based fMRI and EEG, we can detect brain activity that suggests otherwise,” said lead study author Yelena Bodien, PhD, an investigator for the Spaulding-Harvard Traumatic Brain Injury Model Systems and Massachusetts General Hospital’s Center for Neurotechnology and Neurorecovery. “These results bring up critical ethical, clinical, and scientific questions – such as how can we harness that unseen cognitive capacity to establish a system of communication and promote further recovery?”

Following a significant brain injury, individuals may have a disorder of consciousness, which can include coma, a vegetative state or minimally conscious state. Since the first study demonstrating cognitive motor dissociation in individuals with disorders of consciousness was published nearly two decades ago, centers around the world have found that this condition occurs in approximately 15 to 20 percent of unresponsive patients.

However, the current study suggests it could be present in 25 percent of patients, or even more. Cognitive motor dissociation was most common in participants assessed with fMRI and EEG, suggesting that multiple tests, using different approaches, may be required to ensure consciousness is not missed... (MORE - details)

[Magical Realist]

"An innovative study into the final moments of BC hospice patients has shown that, even when a dying person has lost all ability to move or communicate, they may still be able to hear and understand their surroundings.

The revelation “lends some credence to the advice that loved ones should keep talking to a dying relative as long as possible,” concludes the study, just published in Nature by Victoria-raised UBC researcher Elizabeth Blundon.

Conducted over two years at a Vancouver-area hospice, the study involved monitoring the brain activity of terminally ill patients in their final days.

Participants, most of whom were dying of cancer, were fitted with an EEG cap; essentially a bathing cap wired with electrodes that record the electrical signals emitted by a human brain. They were then played a series of tone patterns and asked to listen for any tones that sounded out of place.

The sound test was performed twice; once when the patients first entered hospice and were still relatively conscious, and again when they had reached a state researchers referred to as “actively dying.” This latter state was defined as “the hours to days preceding imminent death during which time the patient’s physiologic functions wane.”

On the first test, participants were asked to click a mouse whenever they heard an out-of-place tone pattern. On the second test, the now-unresponsive patient was simply asked to concentrate on the task as much as was possible.

When the dying patient’s EEG data was compared both against their first test and the tests of a healthy control group, they appeared to show a brain that was still functioning and able to concentrate.

For years, it’s been a rule of thumb among healthcare circles that a dying patient will still retain the ability to hear and understand their surroundings even after all other senses have shut down. “Never assume the person is unable to hear you,” advises the British organization Dying Matters. “Talk as if they can hear you, even if they appear to be unconscious or restless.”

https://www.capitaldaily.ca/news/ubc-stu...ring-death