Hysteria to Functional Neurologic Disorders: A Historical Perspective

Unexplained symptoms in functional neurologic and somatoform disorders have mystified physicians for centuries. The understanding of such phenomena evolved in parallel with advances in medicine, neuroanatomy, and societal views of gender and also had a role in the development of psychoanalysis (1). As theories progressed so did the descriptive terminology—from "hysteria" to Babinski’s "pithiatism" and from Freud’s "conversion neurosis" to DSM-5’s "functional neurological symptom disorder" (1).

The word "hysteria" originated in Greek writings as hysterikos, describing symptoms from a "wandering uterus." This association framed the idea that hysteria was a disease afflicting women. The term "hysteria" persisted in the Middle Ages, often explained by witchcraft or the supernatural (2). Theories moved away from a uterine cause, notably with the influences of English physician Thomas Willis (1621–1675) and French physician Pierre Briquet (1796–1881) (2). A variety of psychological and medical symptoms were encompassed in the syndrome of hysteria, and it was increasingly recognized in men, although more often diagnosed as "hypochondriasis" and generally attributed to medical causes (1).

In the 19th century, general interest in hysteria was renewed through the influence of French neurologist Jean-Martin Charcot (1825–1893), from the Salpêtrière School of Neurology in Paris. His theatrical public demonstrations using hypnotism to reproduce symptoms in patients were criticized for the influence of suggestion. Charcot initially defined hysteria as symptoms such as an organic brain lesion without discoverable anatomic pathology and postulated that these inconsistent symptoms could be due to "dynamic lesions" (3). Later in his career, he noticed psychological aspects of hysteria and wrote about the correlation between past trauma and symptomatology (3).

After Charcot’s death in 1893, his students expanded on his work, notably French neurologist Joseph Babinski (1857–1932), who proposed the term "pithiatism." Although short-lived, the term described symptoms brought on by suggestion and cured with persuasion (4). Babinski’s legacy was in differentiating symptoms of hysteria from those of organic disease, as described in the 1917 book Hysteria-Pithiatism and Reflex Nervous Disorders in the Neurology of War, written in response to increasing symptom presentations during World War I (4). He famously distinguished between hysterical and organic hemiplegia by using neurologic signs, including toe extension, contractures, and tongue deviation.

Austrian neurologist Sigmund Freud (1856–1939) studied under Charcot from 1885 to 1886, marking his career transition from neuroanatomy to the study of hysteria and to psychoanalysis (5). He initially focused on differentiating organicity from hysteria on the basis of neuroanatomy. In a series of patient interviews, he found a correlation between hysteria and childhood sexual abuse (5). Later, noting that he may have "overestimated the frequency of such events," Freud hypothesized that the reports of abuse were instead the patient’s own sexual fantasies (5). This was the start of his foundation of psychoanalysis.

The "hysteria" of prior generations encompassed symptoms that today would be categorized among a variety of diagnoses, including dissociation, anxiety, trauma-related disorders, and personality disorders. Freud used the term "conversion neurosis" to describe the unconscious driving a physical manifestation, and this term progressed into "conversion disorder." DSM-5 introduced the additional term "functional neurological symptom disorder" and removed the need for known psychological conflict from the diagnostic criteria, bridging a diagnostic gap between the fields of neurology and psychiatry. With current research in neuroimaging, neural networks, and treatments, including repetitive transcranial magnetic stimulation, the understanding of functional neurologic disorder continues to evolve.