Professor Terence Ryan discusses links between the amygdala and physical symptoms and signs such as psychogenic purpura.
Medical students in 1950 at Oxford listened to Dr John Hunt talking about Indian Fakirs. The injury they could do to themselves without long term harm was fascinating. Since then this author has witnessed and photographed a sharp pointed stick being passed through the neck behind the carotid vessels, and a sword being passed through the skin about four inches into the upper abdomen above the liver and below the diaphragm .Both occurred to public view in a ceremonial event that was partly of religious nature. There was no bleeding ,and no complaint of pain, and no scarring. It was repeated on later occasions by the same practitioners. I also have a DVD of an Indian fakir lying on a bed of flaming sticks with burnt clothing but no skin damage. He said the flames were his friends and it was a performance frequently repeated.
Today positron emission tomography (PET) is used to measure the uptake of oxygen by brain tissue where and when activated. There is a link between the forebrain via neuronal pathways to the amygdala named the emotional centre deep in the midbrain. The pharmaceuticals that this releases influence pain and inflammation and are of the greatest interest to both the medical and veterinary professions for both human and animal therapeutic interventions.
In 1915, Cannon informed us with animal studies of agents such as adrenalin (epinephrine and nor epinephrine) which are released by fright and flight. Hans Selye in 1926 informed us of the release of steroids by stress. Others have shown the effects of testosterone, oestrogen, and progesterone on the sexual drive or libido. Dopamine, serotonin and osteocalcin are other agents released sometimes as a consequence of communication between the cortex and the amygdala. Neuroscience shows us that the mind can use these communication links to order the balance between the sympathetic and parasympathetic system, and the vagal nerve is very influential.
In 2018 the Department of Experimental Psychology in Oxford studied human contact named the science of hugging . They reported that friendship is the single most important factor influencing our health ,well being and happiness. A book for which I got my DM(Oxon) in 1976 included my interest in the psychosomatic. In the early 1970s the department of Dermatology in Oxford was asked by the Archbishop of Portugal to help to explain how a family of dubious saintliness was making great sums of money by attracting an audience to observe an urticarial cross, which later bled, appearing on the forehead of a peasant woman every Friday. Various pathologies such as psychogenic purpura and the power of hypnotism were later discussed and published.
Being a Dermatology department we were interested in reports of the induction and suppression by hypnotism in Japan of the dermatitis of poison ivy. Psychogenic purpura was well described by the Americans Ratnoff and Agle, but in Oxford, while it was recognised that coagulation or fibrinolysis could be triggered by anxiety and the lymphocyte immunosuppressed by bereavement, leading haematologists I worked with (Gwyn Macfarlane, Alan Sharp and Leon Bagatruni) could not explain psychogenic inflammation and bleeding. Sydney Truelove, the gastroenterologist, employed hypnotism; only recently hypnotism has been shown to work through the amygdala.
In the year 2021 a study of a young man in Mexico, who from the age of six had recurrent bleeding tears and sweat, following acute emotional stress suggested new approaches to the study of patients with this disability. The most well known was the German Teresa Neuman, whose images of bleeding can be viewed by Googling her name. This young man’s bleeding produced identical images. The new investigations were genetic studies of the extracellular matrix not available to us 50 years ago. Mutations were found in 2325 genes affecting the integrity of the vessel wall.( Salas-Alanis J C, Salas-Garza M, Golddust M et al Hamatidrosis and haemolacria in a young adult. Clinical and Experimental Dermatology 2021;46:394-396 )
In a Blog to follow this one there will be a discussion of the range of stimuli which can be picked up by the forebrain and directed to the amygdala and suggestions how they can used as therapeutic interventions by both the medical and veterinary professions. The amygdala must be examined to see what agents it could produce in the genetically susceptible which might affect the integrity of the vessel wall in the stigmatics and in other forms of psychogenic purpura.
Professor Terence Ryan is an Emeritus Fellow of Green Templeton College and Emeritus Professor of Dermatology, University of Oxford.