Functional disorders are a bane to clinicians and source of debility for many patients. One problem is the lack of understandable and empirically verifiable concepts of pathophysiologic and psychopathologic mechanisms that may inform diagnosis and treatment. Even the term "functional" is a source of confusion. Is it a euphemism, category of enigmatic conditions, or mechanism of illness? This symposium will trace concepts of functional disorders from their origin in the early 1800's to contemporary research that is knitting data from renewed psychological inquiry, physiologic studies, and neuroimaging investigations into sophisticated models of illness. Talks will cover (1) the history of the term functional and how its original meaning may be informative today, (2) neuroimaging data showing alterations in brain activity related to emotional processing that may be shared among functional syndromes, (3) mechanistic hypotheses derived from differences in functional syndromes in childhood versus adulthood, and (4) cutting-edge research on the functional neurologic disorder persistent postural-perceptual dizziness as an example of identifying unique alterations in psychological and physiological processes and associated brain activity underlying a specific functional disorder.
Talk #1: Might “functional” be a mechanism?
This presentation will cover the concept of functional disorders that emerged in the early 1800’s, morphed into a euphemism for medically unexplained (presumably psychogenic) problems in the 1900’s, and is returning to its original meaning of a "shift in functioning of organ systems" in the current century.
Talk #2: Brain correlates of functional disorders
This talk will present data from neuroimaging studies of multiple functional syndromes (e.g., irritable bowel syndrome, fibromyalgia, etc.) that identified altered activity and connectivity in brain networks integral to emotional processing and suggest a potentially unifying hypothesis of neural mechanisms underlying functional disorders.
Talk #3: Functional disorders in children
This presentation will review the epidemiology and clinical manifestations of functional syndromes in children to show that they are more often transient and self-limited than in adults. That will be followed by a discussion of how this intriguing difference may reflect the development of human abilities to use cognitive/emotional more than somatic/behavioral processes to manage biopsychosocial demands, perhaps related to maturation of brain mechanisms described in Talk #2.
Talk #4: PPPD – Evidence-based model of a functional neurologic disorder
Persistent postural-perceptual dizziness (PPPD) is the first functional neurologic disorder to be recognized as a distinct diagnosis by the World Health Organization. This talk will review 30 years of research that identified the core symptoms of PPPD, its likely pathophysiological and psychopathological mechanisms, and their associated changes in brain functioning.
Panel Discussion: The session will conclude with an interactive panel discussion with the audience about clinical and research strategies that may be needed to more completely unravel the enigmas of functional neurological syndromes.