The medical team looked at Maria as she did nothing. He was admitted to the New York–Presbyterian Hospital at Columbia University on a hot July day. She fell unconscious at home a few days ago. The bleeding area of her brain was putting pressure on the critical brain regions. The team of nurses and physicians were looking for a sign that the doctor could hear them. Her vital signs were stable and she was on a mechanical ventilator. She didn't show any signs of consciousness.
The parents asked if they could speak to their daughter. Does she know what we're talking about? She didn't seem to know what was going on. When he asked her to open her eyes, hold up her fingers or wiggle her toes, she remained motionless. Her eyes did not focus on what she was seeing. Her family still believed she was in there.
She was, indeed. The medical team gave her an instrument to measure her brain electrical activity, and asked her to keep her hand closed. They asked her to stop using her right hand. Her brain's activity patterns differed between the two commands. She was aware of the requests and that they were different. Her body followed her brain for about a week. Slowly, with small responses, he began to wake up. Within a year she was back to her former self. She is working in a pharmacy.
The brain responds to the outside world with some comprehension, but the body does not. Up to 20% of patients who appear to be in a coma or unresponsive state show some kind of awareness when evaluated with advanced brain-imaging methods or sophisticated monitoring of electrical activity. Many of the techniques have not been refined yet. These methods are making us understand coma and other disorders of consciousness. Our studies at Columbia University show that people with covert consciousness have a better chance of recovery. These discoveries show how important it is to recognize this hidden conscious state and develop ways to communicate with people who are in it.
A comatose patient is someone who is unconscious, can't be woken, and has no signs of awareness or interaction with the environment. Most comatose patients cannot breathe on their own and need a tube inserted into their airway in order to stay alive.
People think that comas are easy to recover from. Both are failures. It's possible that popular depictions in movies and other places are to blame. The Bride in Kill Bill: Volume 1 awakens abruptly from a comatose state and regains her strength within hours. A long road of small steps forward with many steps back is what the reality is like. Patients who survive coma after a severe brain injury usually need feeding tubes and tracheostomies for weeks to months of rehabilitation. Recovery can be variable in those who return to independence. People may think that all coma patients are destined to die without emerging from their coma or live with severe disability, which is incorrect. Even after a long time, some patients can recover consciousness, communication and functional independence.
Over time, the views about coma and consciousness have changed. Some comatose patients opened their eyes but did not interact with the environment. Many of these people remained in this state until they died, leading some clinicians to believe that consciousness could not be recovered.
Reports of patients in a "permanent" vegetative state who returned to consciousness began to surface in the 1990s. People in a coma can open and close their eyes, but they don't react in a deliberate way. The minimally conscious state was developed as a result of the reports of recovery from this condition. Non verbal responses are when patients track objects with their eyes. The states were related to a patient's progess. Someone who moved from a coma to a minimally conscious state had a better chance of recovering.
It is important to detect and predict recovery of consciousness in the intensive care unit. The time when surgical procedures become necessary to support longer-term breathing and feeding is known as the 10 to 14 day period. Clinical decisions about goals of care, pain management, bedside behavior of clinicians and family members, and management of depression and anxiety can be affected by a diagnosis of covert consciousness.
What do clinicians and the patient's family think about covert consciousness? People with locked-in syndrome can have normal or near-normal cognitive abilities, but can't control most motor movements. The limitations of judging awareness, thinking abilities, and emotions are illustrated by locked-in patients. The diagnosis of Stupor and Coma was the basis for the termlocked in. They refer to the description of M. Noirtier De Villefort as a corpse with living eyes. Many locked-in patients can move their eyes up and down in response to commands, even though they don't move their limbs. Some can blink.
The experience of living in a locked-in state was illustrated by Jean-Dominique Bauby who, in 1995, suffered a stroke that blocked signals from the motor cortex in his brain. He wrote a memoir, The Diving Bell and the Butterfly, after he was unable to speak or move his limbs. The fear, frustration and hope of individuals with locked-in syndrome were captured in this book. Some people in locked-in states report a good quality of life.
The lack of outward movement is complete with covert consciousness. This does not mean that there is no life. Adrian M. Owen and his colleagues examined a young woman who had suffered a traumatic brain injury and was thought to be in a vegetative state. She was assessed by the health-care team with a type of brain scans called functional magnetic resonance. The clinicians asked her to imagine playing tennis and walking through the rooms of her home. Owen and his colleagues were surprised by the woman's brain activity. She could change her brain activity by doing the tennis and walking tasks differently.
Patients with different types of brain injuries were identified. It was found in patients who had just been admitted to the intensive care unit at Massachusetts General Hospital with severe brain injuries, indicating that it can happen in people who have recently been injured. In order to diagnose the covert state, clinicians use different behavioral tasks, such as asking the patient to open and close their hands or imagine swimming. Multiple research groups around the world have reproduced these responses. Patients with covert consciousness can make changes to their brain patterns when they are told to do something. They don't seem to follow any prompt in their body movements.
The state of being in which cognitive function exceeds motor expression is poorly understood and both the brain waves and functional magnetic resonance techniques have limitations. Some patients who regain consciousness can't be detected with the methods. The use of sedatives in critically ill patients can be a problem. If unstable patients are moved from the intensive care unit to the magnetic resonance device, they may be at risk. The problem is that theMRI only provides a snapshot of a patient's level of consciousness and can't be repeated. The method of capturing snapshots at different times has its own drawbacks. It can be altered by electrical noise in intensive care rooms, which can cause the test to reflect artifacts instead of reality.
The evidence for their usefulness is strong enough for them to be endorsed for the diagnosis of covert consciousness in clinical guidelines in the U.S. The early detection of covert consciousness, soon after a patient's injury, predicts behavioral recovery of consciousness, long term functional recovery and the speed of that recovery, as shown by the research that our group published in 2019. The goal of the Curing Coma Campaign is to develop new therapies that promote recovery of consciousness, and was launched in 2019.
A test that can identify which patients are likely to be in a state of covert consciousness needs to be developed. Efforts to develop screening methods for covert consciousness have been slow because clinicians don't know what to look for. Recent studies show that brain injuries may cause the thalamus to be disconnected from the cerebral cortex. It is likely that there are different combinations of different types of lesions in different places that could cause motor problems. It's difficult to detect covert consciousness in patients with serious brain injuries. It's possible that a single assessment could miss important signs.
Building on recent discoveries about the presence of covert consciousness, investigators are trying to reestablish contact with patients using brain- computer interface. The brain's electrical activity is recorded when the patient is asked to move a mouse on a computer screen. The computer learns from the signals that correlate with the patient's attempts to move the mouse. The patient's brain patterns allow them to take control of the computer. It can be used by patients to spell out words.
It would be ideal for patients to communicate with the outside world using a brain- computer interface. There are tremendous challenges for acutely brain-injured patients. It is not feasible to train these patients for long. The intensive care environment is loud and chaotic. Even though she had covert consciousness, she was not able to communicate with the health-care team or her family.
It is possible to communicate using functional magnetic resonance. A few years ago, Martin Monti used the method to investigate the presence of covert consciousness in a group of behaviorally unresponsive patients. He wanted to see if he could train them to answer "yes" or "no" in a certain way. The technology needed to analyze the data in real time was enormous. Patients were asked to imagine playing tennis or walking through their apartment. He wanted to see if they understood questions and could answer them. If the answer was yes, he told them to think about tennis and if the answer was no, he told them to walk through their home. Monti identified one patient in the group who reliably communicated with him using this strategy and created a pattern of brain activity for yes and no answers. There are questions about whether this approach can be scaled up for wider use, but his study suggests that it is possible to communicate with patients in a state of covert consciousness.
Reliable tools for identifying patients with covert consciousness need to be at the bedside. Advanced EEG technology can be used in an intensive care unit because it can be integrated into the clinical routine. Adding biological signals, such as heart rate and brain activity, could help improve the accuracy of the brain- computer interface.
Diagnostic and exploration of covert consciousness have the potential to teach us about the human mind. Our consciousness is removed from our behavior in covert consciousness. What is the mental life of a patient who is not in the public eye? Our conceptualization of an individual is affected by detecting covert consciousness. Patients with covert consciousness who recovered the ability to communicate and were interviewed later did not remember the experience of being covertly conscious. Her time in the intensive care unit when she appeared to be in a coma did not come up in her recollection. The experience is mostly unknown.
There is no mystery about the ethical imperative that physicians now have to search for consciousness in patients who appear unresponsive. The Curing Coma Campaign is trying to increase access to technologies and resources for the medical community. We can see a future in which all covertly conscious people are given a way to speak for themselves.
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