4 hours ago
https://magazine.hms.harvard.edu/article...ss-dilemma
EXCERPTS: When treating patients with brain injury, Edlow and other doctors have always faced a conundrum: To infer how conscious a person may or may not be, they rely on what they can observe from the outside. [...] But exams that rely on observable behavior can’t always capture a patient’s subjective experience. That fact came into sharper focus once researchers began employing advanced imaging technologies to glimpse inside the brains of unresponsive patients.
[...] Their study, published in the New England Journal of Medicine in 2024, found that among 241 adults who could not follow bedside commands, 60 (about 25 percent) could follow cognitive tasks in the fMRI scanner or during EEG testing, suggesting that they could think and understand despite being unable to demonstrate it with their bodies. These patients spanned different injury types — from traumatic brain injuries to stroke to cardiac arrest — as well as recovery stages, from acute to chronic. “There was not a subset of patients in which we didn’t find this phenomenon at all,” Bodien says.
[...] While the tests don’t necessarily show the upper limits of a patient’s cognitive capacity, the researchers say that demonstrating those responses to commands on brain scans requires a meaningful level of awareness. “There’s probably a broad spectrum of levels of consciousness that individuals with this diagnosis have, but many of us feel confident that if somebody can do these tasks, their level of consciousness might be quite high,” Edlow says. “The question is, once you identify someone as being covertly conscious, what now?”
[...] The most obvious question decision-makers ask is whether exhibiting covert consciousness means that someone is more likely to recover. The evidence so far is mixed. [...] “The logical next question after you infer that someone is conscious is to say, ‘Well, how do we actually communicate with them?’ And we haven’t been able to answer that question.”
But researchers are trying. Some have attempted using the typical visualization tasks to ask patients questions — for example, by asking them to imagine playing tennis for “yes” and navigating rooms for “no” — but that approach has only worked on rare occasions. [...] Another promising technology is the brain-computer interface. Researchers have had some success enabling communication in patients with “locked-in syndrome” — cognitively normal but paralyzed by conditions like ALS or stroke — by putting microelectrodes on the surface of the brain to turn thoughts into action. Eventually, Edlow says, this technology might progress enough to facilitate communication with patients with disorders of consciousness... (MORE - missing details)
EXCERPTS: When treating patients with brain injury, Edlow and other doctors have always faced a conundrum: To infer how conscious a person may or may not be, they rely on what they can observe from the outside. [...] But exams that rely on observable behavior can’t always capture a patient’s subjective experience. That fact came into sharper focus once researchers began employing advanced imaging technologies to glimpse inside the brains of unresponsive patients.
[...] Their study, published in the New England Journal of Medicine in 2024, found that among 241 adults who could not follow bedside commands, 60 (about 25 percent) could follow cognitive tasks in the fMRI scanner or during EEG testing, suggesting that they could think and understand despite being unable to demonstrate it with their bodies. These patients spanned different injury types — from traumatic brain injuries to stroke to cardiac arrest — as well as recovery stages, from acute to chronic. “There was not a subset of patients in which we didn’t find this phenomenon at all,” Bodien says.
[...] While the tests don’t necessarily show the upper limits of a patient’s cognitive capacity, the researchers say that demonstrating those responses to commands on brain scans requires a meaningful level of awareness. “There’s probably a broad spectrum of levels of consciousness that individuals with this diagnosis have, but many of us feel confident that if somebody can do these tasks, their level of consciousness might be quite high,” Edlow says. “The question is, once you identify someone as being covertly conscious, what now?”
[...] The most obvious question decision-makers ask is whether exhibiting covert consciousness means that someone is more likely to recover. The evidence so far is mixed. [...] “The logical next question after you infer that someone is conscious is to say, ‘Well, how do we actually communicate with them?’ And we haven’t been able to answer that question.”
But researchers are trying. Some have attempted using the typical visualization tasks to ask patients questions — for example, by asking them to imagine playing tennis for “yes” and navigating rooms for “no” — but that approach has only worked on rare occasions. [...] Another promising technology is the brain-computer interface. Researchers have had some success enabling communication in patients with “locked-in syndrome” — cognitively normal but paralyzed by conditions like ALS or stroke — by putting microelectrodes on the surface of the brain to turn thoughts into action. Eventually, Edlow says, this technology might progress enough to facilitate communication with patients with disorders of consciousness... (MORE - missing details)