From the Guidelines
Yes, functional neurologic disorder (FND) is a legitimate neurological condition that involves real neurological symptoms such as weakness, abnormal movements, seizures, or sensory changes that aren't caused by structural damage or disease in the nervous system but rather by a problem with how the brain functions. FND is characterized by symptoms of altered voluntary motor or sensory function with clinical findings providing evidence of incompatibility between the symptoms and recognized neurological or medical conditions 1. The brain essentially processes and sends signals incorrectly, creating genuine symptoms that patients cannot voluntarily control.
Key Characteristics of FND
- Symptoms can include weakness, movement disorders (tremor, jerks, and dystonia), sensory symptoms, cognitive deficits, and seizure-like events (commonly known as dissociative seizures or non-epileptic seizures) 1.
- Fatigue and persistent pain are also commonly experienced as part of the disorder.
- Symptoms can present acutely and resolve quickly or can be long-lasting.
Importance of Validation and Early Treatment
Patients with FND require validation that their symptoms are real, even though tests like MRIs may appear normal. Early diagnosis and treatment significantly improve outcomes, with many patients experiencing substantial improvement when properly diagnosed and treated 1.
Multidisciplinary Approach to Treatment
Treatment typically involves a multidisciplinary approach including neurological care, physical therapy, psychological therapy (particularly cognitive behavioral therapy), and sometimes medications to address specific symptoms like pain or anxiety 1. Occupational therapy (OT) is recognized as an integral part of multidisciplinary rehabilitation for people with FND, focusing on education, rehabilitation within functional activity, and the use of taught self-management strategies 1.
Outcome Measurement and Future Research
There is a need for well-validated FND-specific outcome measures to capture key outcome domains and facilitate comparison of treatment effects across FND symptom types and treatment modalities 1. Future work should aim to more rigorously validate outcome measures used in this population and develop a core outcome measure set for FND.
From the Research
Definition and Diagnosis of Functional Neurological Disorder (FND)
- FND is a legitimate neurological condition characterized by neurological symptoms that lack an identifiable organic cause 2, 3, 4, 5.
- The diagnosis of FND is based on clear positive evidence, typically from a combination of physical signs on examination or the nature of seizures 3.
- FND can be diagnosed using validated rule-in examination signs, and the range of therapeutic approaches available to care for patients with FND is expanding 2.
Epidemiology and Clinical Presentation of FND
- FND is a common presentation in emergency and acute medical settings, and it can cause severe disability in some individuals 2, 3.
- The condition can affect young and middle-aged adults, and its symptoms can include motor, sensory, or cognitive disturbances 2, 5.
- FND has been recognized as a distinct clinical entity with various subtypes, including functional seizures, functional movement disorders, persistent perceptual postural dizziness, and functional cognitive disorder 4.
Treatment and Management of FND
- Treatment of FND typically involves a multidisciplinary approach addressing each of the neurological symptoms and underlying psychological factors via a mixture of medical management, psychotherapy, and supportive interventions 2, 3, 5.
- Rehabilitative interventions, such as physical and occupational therapy, are treatments of choice for functional motor symptoms, while psychotherapy is an emerging evidence-based treatment across FND subtypes 2.
- Clear communication of the diagnosis and the involvement of the multidisciplinary team is beneficial in the treatment of FND 3.
Pathophysiology and Etiology of FND
- The pathophysiology of FND includes overactivity of the limbic system, the development of an internal symptom model as part of a predictive coding framework, and dysfunction of brain networks that gives movement the sense of voluntariness 4.
- Psychological stressors are common risk factors for FND, but they are often absent, and the condition's etiology is complex and multifaceted 4, 6.
- The integrated etiological summary model combines research from various fields to represent the current understanding of FND etiology, discussing potential causal mechanisms and informing future research and treatment 6.