For a long time now, an explanation for the development of psychogenic (also known as ‘hysterical’) diseases has seemed impossible. These are diseases that have severe symptoms (such as cramp, or paralysis) but have no physical explanation for their presence. Now, however, research from the University of Cambridge and UCL (University College London) have shown that people suffering from these psychogenic diseases do show signs of abnormal brain functioning.
To find this, researchers looked at participants with psychogenic and organic dystonia; a painful and disabling disease causing muscle contractions that affect the leg. The cause of dystonia in the organic group was a gene mutation (DYT1 gene), however the psychogenic group didn’t show any physical signs that could have caused their illness, even after extensive research.
Participants were then given PET scans, with their leg in three different positions; foot resting, foot moving, and foot in a dystonic position. This was to measure blood flow and brain activity, and used both groups of participants. They even recorded the electrical activity of the leg muscles during the scan in order to determine which muscles were active. The brain activity in participants with psychogenic dystonia was discovered to be not normal, in fact Dr Rowe of UCL said that “what struck me was just how very different the abnormal brain function was in patients with the genetic and the psychogenic dystonia. Even more striking was that the differences were there all the time, whether the patients were resting or trying to move.” This research evidence serves to show how psychological factors can actually cause physical illness, and opens up new doors for research into treatments of diseases like psychogenic dystonia.
Further than this, the scans showed that the prefrontal cortex (previously thought to be a cause of only psychogenic dystonia) was also functioning abnormally in the brains of participants with genetic dystonia. Dr Arpan Mehta, from the University of Cambridge, said “it is interesting that, despite the differences, both types of patient had one thing in common – a problem at the front of the brain. This area controls attention to our movements and although the abnormality is not unique to psychogenic disorders, it is part of the problem.”
As psychogenic illnesses are very common – in fact, one in six patients that see a neurologist has a psychogenic disease (Dr Shrag, UCL) – this is very promising research, helping us to understand psychogenic diseases more. They are just like organic diseases after all, but they have a different cause and need different treatments. With more research showing these kinds of promising results, we will be closer to understanding the cause of psychogenic diseases, and closer to curing them.
Written by: Philippa Berry
Published on: 26th February 2013