Functional neurological symptom disorder (FND) is a challenging condition for clinicians to diagnose and an even more challenging condition for patients to live with. Historically, the diagnosis of FND was made after other diagnoses had been excluded. Currently the diagnosis of FND involves a careful history into the presentation, the many biological and psychosocial risk factors that contribute to the condition, as well as positive findings on physical exam or ancillary evaluations such as video EEG. Although improvements have been made to recognize, accurately diagnose and treat these conditions, the average time between a patient first experiencing symptoms to receiving a diagnosis is seven years.
What is functional neurological symptom disorder?
FND, an umbrella term, is a neuropsychiatric condition that encompasses a wide range of motor, cognitive, perceptual or sensory symptoms. The most frequent forms of FND are associated with functional movement disorders (FMD), cognitive disorders, chronic dizziness and non-epileptic seizures (NES).
Typical FND symptoms include the following:
- FMD-related symptoms
- Dystonia
- Limb weakness
- Tremor
- Gait disorders
- NES-related symptoms
- Epileptic-like seizures
- Eye-closing with resistance to opening
- Prolonged seizures with fluctuating intensity
- Awareness during generalized shaking episodes
Epidemiology and Risk Factors
FND has been seen in patients ranging from 4 to 94 years of age, and occurs more frequently in women than men. The average age for patients to develop FND is in their 20s and 30s.
FND is multifactorial. Patients with a history of psychiatric illness or who have experienced neglect or trauma have a greater risk for developing FND. In fact, it is estimated that around two-thirds of patients who are diagnosed with FND have had a prior psychiatric disorder. In addition, patients who have had depression and/or anxiety are more vulnerable to develop FND. Overall, the prevalence of FND is 20 to 50 per 100,000, roughly the same incidence as multiple sclerosis, and it is the second most common reason patients see a neurologist in an outpatient setting.
Challenges in diagnosis and treatment of FND
There is significant heterogeneity in the presentation of FND. The onset of FND can be very abrupt or protracted; and between the times when the condition occurs, patients can feel normal. Since the patient’s brain structures appear normal on MRI and CT, many providers, especially those in the emergency room, may believe these symptoms to be fake or under the patient’s voluntary control, which has contributed to a stigmatization of the condition within the medical community. Additionally, because the condition involves two disciplines — neurology and psychiatry — patients often toggle between these, which can contribute to a longer time to diagnosis and treatment.
Specific FMD-related challenges
One in five patients with FMD simultaneously have an additional neurological disorder, so it’s important for clinicians to conduct an exhaustive examination to accurately diagnose and treat FND along with other neurologic conditions. Often, functional disability is out of proportion with exam findings. Physical findings can be variable and change during different conditions of the exam and the degree of attention focused on the examined body part.
Specific NES-related challenges
Although patients with FND have dissociative attacks that can resemble epileptic seizures, these events are not the result of excessive abnormal electrical activity. Patients with NES are often misdiagnosed 20% to 30% of the time as having epileptic seizures. Patients with functional seizures usually do not respond to anti-seizure medication treatment.
The Non-epileptic Seizures Treatment (NEST) clinic at RUSH
There is a definite need for multidisciplinary care for the diagnosis and management for NES. A comprehensive, collaborative, team-based approach is rarely available in most outpatient neurology and psychiatric settings. The team at RUSH works with patients and referring providers to confirm the diagnosis of NES (or epilepsy if that’s the case), establish the presence of comorbid conditions, understand the neuropsychological and social aspects of the condition in each individual and offer a plan of treatment.
Treating FND requires a true multidisciplinary approach, incorporating specialists in neurology, psychiatry, social work, neuropsychology and physiatry to provide an individually tailored treatment plan that involves physical, occupational and speech and language therapy, along with mindfulness-based cognitive behavioral therapy, medication management and management of the restrictions related to seizures.
The results from the clinic so far are encouraging. Over 70% of patients report satisfaction with the program and over 50% report significant seizure reduction.
The goal of the program for people with functional seizures is similar to the goals we define for patients with epileptic seizures: fewer seizures, less severe seizures, minimize medication-related side effects and empower our patients to pursue their personal goals without the interference of seizures.
