Patients who are hospitalized sometimes become severely confused. This confusion, called delirium, usually disappears quickly. But after three months, the connections in their brain network are still weakened. This was discovered by a research team at the UMC Utrecht Brain Center. The worse the connections in the brain were weakened, the worse patients scored on a neuropsychological test.
Hospitalization is a drastic event for everyone, but some people come out of it better than others. Older people are especially likely to be severely confused after hospitalization, especially if they also need surgery. Also, one in three patients admitted with COVID-19 becomes very confused. Such a period of severe confusion is called a “delirium,” and doctors now know a lot about its causes and possible symptoms. In the longer term, people who have had delirium also have a greatly increased chance of developing dementia. But what happens in the brains of these patients was previously unknown.
For this study, Utrecht delirium researchers followed 246 elderly patients undergoing planned major surgery, of whom more than 15% (38 people) eventually developed delirium. They took scans of these patients’ brains using a technique called fMRI. “In this, a special MRI scanner maps which parts of the brain are active by measuring the movement of oxygenated blood,” explains PhD student Fienke Ditzel. The researchers took measurements before surgery and three months afterwards.
The brain scans of patients who experienced delirium appeared to look different from those of patients who did not experience delirium. “In most people, we saw that the brain network had become stronger three months after their surgery,” Fienke said. The opposite was true in patients who became confused after their surgery. In these people, the brain network was actually less strongly connected three months after their surgery than before.
What exactly does this mean? The researchers also had all patients take a neuropsychological test. With the test, they mapped their attention and organizational and initiative taking abilities. In doing so, they saw that patients in whom the brain network became weaker performed worse on the test. “Our findings are an important piece of the puzzle in understanding delirium and the increased risk of developing dementia afterwards,” said professor of intensive care neuropsychiatry Arjen Slooter.Ω
Will delirium be curable in the future? Perhaps so. Professor Slooter and psychiatrist Edwin van Dellen, who also participated in the study, already have an idea for a treatment. “We know from this research that delirium can be associated with permanently impaired communication in the brain. We now want to investigate whether we can restore this communication by stimulating the brain,” Edwin says. “This already happens now, for example, in people who have had a stroke, and we think it could also be effective in delirium.”
The results of the Utrecht study were published in The British Journal of Anaesthesia.
Pictured from left to right: psychiatrist Edwin van Dellen, PhD student Fienke Ditzel and postdoc Simone van Montfort. Simone and Fienke conducted their research under the supervision of Edwin and professor of intensive care neuropsychiatry Arjen Slooter.
