Functional Neurology

Functional neurologic symptom disorder (FND) is a common presentation in general and specialty neurology clinics with a prevalence of 20 to 50 per 100,000, which is comparable to other neurologic conditions (eg, multiple sclerosis). FND causes significant disability and elevates health care utilization and costs. Until recently, FND was considered a diagnosis of exclusion with limited options for treatment and little hope for recovery.

Fortunately, this bleak landscape is changing. Renewed interest and research into the presentation and pathophysiology of these complex neuropsychiatric conditions allow patients and physicians to recognize, name, and discuss FND openly, forgoing associated and hurtful stigma. Additionally, the advent of evidence-based multidisciplinary treatment presents new hope for patients affected by FND.

This issue of Practical Neurology highlights the evolution of knowledge regarding FND diagnosis and treatment and provides practical strategies and resources to support patients and clinicians in the quest for symptom relief, quality-of-life improvement, and rehabilitation.

We begin with Drs. Gilmour, Lidstone, and Lang who review The Diagnosis of Functional Movement Disorder, including epidemiology, pathophysiology, and presentation. They provide specific features of the clinical history and physical examination as well as an overview of the electrophysiologic studies supporting the diagnosis of FND. These tools will empower clinicians and patients to make and accept the diagnosis, beginning the pathway to recovery. Drs. Holden and Madera walk us through the multidisciplinary approach to Treatment of Functional Movement Disorder including communication strategies; a multidisciplinary, rehabilitation-forward, evidence-based approach; and treatments, both pharmacologic and unconventional, proven beneficial for this population.

The emergence of social media-related FND phenomena is described by Drs. Olvera and Kirby in Functional Tic Disorder: A Pandemic in a Pandemic. The challenges posed by the COVID-19 pandemic include an environment of unprecedented isolation and simultaneous global connectivity, underscoring multiple factors that inform the presentation of FND, which include somatic predisposition, psychiatric comorbidities, and environmental triggers.

Functional seizures (FS) are a frequent presentation of FND. FS account for approximately one-third of evaluations in epilepsy monitoring units for seizures refractory to medical treatment and are the most frequent condition misdiagnosed as epilepsy. In The Diagnosis of Functional Seizures, Drs. Viswanathan and Benbadis review current controversies regarding the terminology and etiology of FS. Clinical elements that aid in making the diagnosis and the efficacy of neurophysiologic and imaging tools are also covered. Next, in Treatment of Functional Seizures, Drs. Raynor, Gonsalvez, and Baslet help us understand that after a positive diagnosis of FS, multiple and often multidisciplinary treatment approaches have proven beneficial, reducing the frequency of episodes and associated disability, and more importantly, improving quality of life for patients.

To culminate the review of the many factors contributing to FND, Drs. Patron, Rustomji, Yip, and Jenkins discuss Psychiatric Comorbidities in Functional Neurologic Symptom Disorder, highlighting attachment deficits as a strong contributing factor to this complex neuropsych-iatric illness. The epidemiology of other common coexisting psychiatric conditions (eg, depression and anxiety) and the need for treatment within a multidisciplinary approach are also addressed.

Our understanding of FND is at a time of transformational evolution. The authors in this issue provide you with specific clinical elements, links, and other resources to use in your clinic as well as a roadmap to improve communication and treatment. We are only at the beginning of this transformation. Growing interest and research into the neurobiology of and treatment for FND bring an overall sense of hope for patients, who are eager to be heard, validated, and treated. The lessons we will learn along the way promise to deepen our knowledge of neurologic diseases and the personal experiences of people living with them.