What does the brain of a severely traumatized person look like? Unlike a broken ankle, which swells and turns blue, wounds of the spirit remain secret. Impossible to see them, even by opening the skulls of the victims. To know if a person suffering from post-traumatic disorder is feeling better, if their thoughts are no longer necrotized by painful memories, you must observe their behavior, decipher their fears one by one and gradually trace the thread of their fractured daily life. At least, it had to be.
For the first time, researchers were able to “physically” observe the remission of victims of post-traumatic disorder. To do this, the scientists, a French team led by neurologist Pierre Gagnepain, convinced 34 patients who were victims of attacks to undergo a series of MRIs, at different stages of their medical journey. They were thus able to see, almost with their own eyes, the improvements in their damaged brains.
Such photos have already been taken in the past. But until now, these studies have not made it possible to trace the brain changes associated with remission, nor to characterize them. Published this Wednesday in Science AdvancesPierre Gagnepain’s study has a double specificity: it makes it possible to follow the evolution of the brain from the first months after exposure to the traumatic event and at several weeks interval. And above all, it brings together in a single cohort called “Remember” victims of the same event: the attacks of November 2015, which left 130 dead in Paris.
Traces of attacks in the brain
“This is well-conducted, very interesting work. It sheds light on little-known mechanisms and presents a high level of certainty in the interpretations that can be made, which is difficult to obtain for this type of study. “, comments psychiatrist Wissam El Hage, head of the Val de Loire Regional Psychotrauma Center, who did not participate in the study.
The observations of Pierre Gagnepain’s team are far from being as readable as a damaged ankle: we only see lines and points distributed on graphs, “the imprint left by cerebral activity on the IRM”, translates the researcher, who works at the University of Caen. But these results, as enigmatic as they may be to ordinary people, are no less important. “They open up new perspectives in research on post-traumatic disorders,” continues Wissam El Hage.
These ailments are still poorly understood by doctors and scientists. The studies come up against numerous obstacles: in addition to the difficulty of interpreting brain analyses, there is also the difficulty of convincing patients to take part in these exercises, when they are struggling to lead a decent life. “We thought we were going to try many refusals, but we were surprised to see that some of the victims wanted to help us, precisely to reclaim their experience,” says Pierre Gagnepain.
Post-traumatic disorder, primarily a memory problem
Until now, researchers had mainly focused on remembering the traumatic event. They thus tried to decipher in the brain what made the traumatic memory so frightening in certain patients, why it kept returning to these people, plunging them back into the horror they experienced, when others did not present no particular problems apart from the so-called “normal” suffering linked to what they experienced.
Numerous studies have highlighted damage to the hippocampus, the area responsible for learning and memory. But if trauma patients often have a “shrinked” and overworked hippocampus, researchers don’t know why. Previous weaknesses, genetic, biological, or in the patient’s previous experiences may be the cause. Just like stress, known to harm the proper functioning of the body.
To overcome this dead end, Pierre Gagnepain’s team had the idea of looking at another facet of the problem: “Instead of looking at what was wrong with the memory, we wanted to know why traumatized people could not fight against their defective memories”, explains the scientist. To do this, the researchers asked the patients to perform cognitive exercises during the MRI. “We first made them associate a word with an image, so that it systematically appeared in their mind, like a bad memory. Then, during the exam, we asked them to block this phenomenon, to measure brain activity linked to this action.
Sort through, block painful memories
Patients who showed a greater ability to sort and control their memories during the first examinations suffered less often and for less duration. Conversely, people who were affected the longest had brains with low plasticity and abnormal activity. As if the trauma, or previous fragility, had frozen their gray matter. “These people have difficulty evolving in a stressful environment because they were systematically plunged back into their traumatic memory. We had to send taxis to bring them to the university hospital, and we reserved guest rooms for them in the countryside. Making them sleep in the noise of the city was impossible.
Further research will be needed to know the exact implications of these findings. But they are exciting: “Before, we thought that there were vulnerable people, fragile with regard to the risk of trauma, and the others. Our results tend to show that things are more complicated, and that it there are a certain number of mechanisms involved which prevent the individual exposed to a traumatic situation from returning to normal,” continues Pierre Gagnepain.
The study also changes the situation regarding the response to be provided. Until now, the treatments proposed were paradoxically based on re-exposure to trauma. “To forget the shock, you must first remember it, immerse yourself in the same conditions, then make your brain understand that the danger is no longer there. If you see a spider in your kitchen and you don’t “never go back there again, you will never overcome the associated fear. It will stay there if you go there several times, without anything happening, you will be able to relax”, translates Pierre Gagnepain.
The scientist’s work confirms the importance of working on other mechanisms, in particular those used to “block”, or escape, bad thoughts. “We can more easily imagine programs, training or molecules that could promote remission. We are far from opening the way to new therapies, but we see that working on cerebral plasticity, the manufacturing of new neural circuits allowing inhibiting painful memories could be interesting”, adds Professor Wissam El Hage.
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