[Functional Neurological Disorder for Neurologists]

Functional neurological disorders (FND) are frequently observed in neurological clinics. Recently, the approach to this disorder has shifted from a diagnosis of exclusion to a positive diagnosis using so-called "positive signs," which features various forms of incompatibility. Common risk factors for FND include psychological stressors, which are important for diagnosis. Subtypes of FND are classified according to their symptoms. Four entities-functional seizures, functional movement disorders, persistent perceptual postural dizziness, and functional cognitive disorder-are most recognized by neurologists. These subtypes share similar etiologies and pathophysiologies. Among them, positive signs of functional movement disorders are relatively easy for neurologists to detect. New and effective positive signs, recently reported by Japanese neurologists, should be employed to support a positive diagnosis of FND. Neurologists play a critical role in both the diagnosis and treatment of FND.