How does the brain when a panic disorder?

Functional magnetic resonance imaging (fMRI) provides insights

Patients with panic disorder experience no apparent trigger repeatedly states massive anxiety that are often accompanied by heart palpitations, shortness of breath and nausea. In fact, these sensations are caused by failures of the brain. Scientists at the Max Planck Institute of Psychiatry have now examined using functional magnetic resonance imaging (fMRI) brain regions that are involved in the processing of emotional information. Compared to healthy subjects, patients with remitted panic disorder an increased activation of the amygdala, a brain region that plays a key role for triggering a fear response. Interestingly, this hyperactivity occurs parallel to a reduced activation of the cingulate and prefrontal cortex. Panic attacks are apparently the fact that this higher tax regions their controlling function can not perform adequately in the risk assessment. (PLoS ONE, online advance publication 20. 2009 May)

When panic disorder it causes an abrupt onset of intense anxiety, without an objective risk can be seen. The fear may rise to fear of death and be accompanied by numerous physical symptoms such as palpitations, shortness of breath, sweating or nausea. The disease occurs in one to four percent of the population, the outbreak is mostly between 20 and 40 years. Patients are often severely impaired. The symptoms of panic disorder often occur avoidance responses as agoraphobia - added with withdrawal behavior and depressive reactions - fear of open spaces. In extreme cases, patients are no longer able to leave their homes.

To date, the actual causes of the panic disorder are largely unknown. Because of the strong vegetative physical reactions during the panic attack, a focus has so far been on a neuronal network in the brain, which is responsible for recognizing the emotional importance of a stimulus and the development of an excited state. This network primarily includes the almond kernel and the anterior zingular cortex.

In the current study, Dr. With the help of fMRI, sower and his employees determine to what extent the processing of emotional stimuli differs from healthy control persons in patients with panic disorder. It was important to ensure that the patients were free from panic attacks in the period before the examination.

During the approximately 20-minute examination, images of faces were shown that were either combined with a suitable or inappropriate term (see Figure 1). The test subjects should indicate at the push of a button whether the text and the image matched or not. They were instructed to pay attention primarily to the facial expression and to ignore the word content as far as possible.

A slight irritation from contradicting picture / word pairs is a well-known phenomenon in such experiments, which is reflected in a slow response. However, patients show this phenomenon more than healthy people. In addition, there are clear differences in brain activation in patients: They then reduced the activity of the control regions in the prefrontal cortex and reacted with an overactivation of the tonsil kernel if a contradicting picture / word pair preceded it. The greater the overactivation, the more the patient's response was delayed - one of several indications that this excitation of the brain is not a successful compensation, but rather a failure. Interestingly, the patient showed an opposite picture when a matching picture / word pair preceded. Then the activity of the control regions was rather stronger than in healthy people.

These changes in activation patterns indicate an unstable response in those regions of the brain that normally regulate the fear system's response to emotional stimuli. The new findings help to explain why pharmacological substances, which affect the reaction of limbic and prefrontal brain regions in the medium term, such as serotonin reuptake inhibitors, have a successful effect on panic disorder.

Original work:

Natalya Chechko, Renate Wehrle, Angelika Erhardt, Florian Holsboer, Michael Czisch, Philipp G. Sämann Unstable prefrontal response to emotional conflict and activation of lower limbic structures and brainstem in remitted panic disorder PLoS ONE (2009), 1-15, online pre-publication May 20, 2009

Note:

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Source: Munich [mpipsykl]