History of FND

Functional Neurological Disorder (FND) is a condition in which individuals experience genuine neurological symptoms—such as seizures, weakness, movement disorders, sensory changes, or speech difficulties—that are not caused by structural damage to the nervous system. Instead, the problem lies in how the brain and body send and receive signals. FND is now understood as a disorder of nervous system functioning rather than a disease of degeneration or injury.

Historically, FND was described under different names, most notably “hysteria,” a term used as far back as ancient Greece. For centuries, symptoms that could not be explained by visible injury or disease were often attributed to emotional instability, particularly in women. In the late 19th century, neurologists such as Jean-Martin Charcot studied these symptoms systematically, recognizing patterns that resembled neurological illness but lacked structural pathology. Sigmund Freud later framed similar symptoms within early psychoanalytic theory, further reinforcing the idea that they were primarily psychological in origin.

Throughout much of the 20th century, the condition was labeled “conversion disorder,” reflecting the belief that psychological distress was being converted into physical symptoms. While this framework acknowledged that symptoms were real, it often led to stigma, dismissal, and limited treatment options. Advances in neuroscience over the past two decades have significantly reshaped understanding of FND. Modern research using functional MRI and other neuroimaging tools has demonstrated measurable differences in brain network functioning, particularly in areas related to movement, attention, emotion regulation, and sense of agency.

Today, FND is recognized as a common and potentially treatable neurological condition. It is diagnosed based on positive clinical signs rather than by exclusion alone, and multidisciplinary treatment approaches—including specialized physical therapy, psychotherapy, and education—have shown promising outcomes. The evolution of understanding from “hysteria” to a recognized brain-based disorder reflects broader changes in medicine’s approach to mind–body conditions and underscores the importance of continued education, research, and stigma reduction.