The symptoms of FND often resemble classical neurological symptoms, such as of a stroke, but no underlying organic cause can be found. Several theories investigate why those symptoms appear, and highlighted the importance of physiological and/or psychological stressors or trauma.
Stress research has advanced in understanding the impact of stress on brain structure and function. For example, cortisol has been shown to play an important role not only in the physical response to stress, but also in modulating brain functions such as emotional processing. In parallel, a certain susceptibility to stress has been shown to be associated with specific gene polymorphisms, which can be related to neurological changes based on gene-environment interactions.
The Biogen study aims at investigating how stress gives rise to a cascade of neurophysiological changes in specific neural circuits, which lead to the appearance of functional symptoms. In addition, the identification of different key players within the stress cascade would shed a light on the neuropathological mechanisms underlying FND.