Functional Neurologic Disorder (FND)

Roya Tompkins
19 hours ago
2 min read

Functional Neurologic Disorder (FND) is a neurological condition caused by changes in how brain networks function, rather than by structural damage or disease within the brain itself. Although imaging and diagnostic tests are often normal, the symptoms experienced by individuals with FND are very real and can significantly interfere with daily life.

Common Symptoms of Functional Neurologic Disorder

Symptoms of FND can vary widely from person to person and may fluctuate over time. Some individuals experience symptoms briefly, while others may struggle with them for many years. Common symptoms include:

Seizure-like episodes
Movement abnormalities
Cognitive difficulties
Dizziness
Speech problems, such as sudden-onset stuttering or difficulty speaking
Vision or hearing disturbances
Pain, including chronic migraine
Fatigue
Numbness or sensory changes

EEG Findings in FND

A typical EEG finding in patients with FND is a normal awake EEG.Despite significant symptoms, imaging and neurological testing—including EEG—are often unremarkable.

However, research has shown that individuals with FND frequently demonstrate increased activity in the limbic system, the part of the brain involved in emotion, behavior, and stress regulation. This altered activity may contribute to difficulties in emotional processing and stress responses, which can play a role in symptom development and persistence.

Main Categories of Functional Neurologic Disorder

FND is generally divided into two primary categories:

Psychogenic Non-Epileptic Seizures (PNES)
Functional Movement Disorders

The Role of Video EEG in Diagnosis

Long-term video EEG monitoring is critical for accurately diagnosing FND, particularly in patients with seizure-like events. Capturing a typical episode during monitoring is essential in distinguishing PNES from epileptic seizures and guiding appropriate treatment.

Although these events may closely resemble epileptic seizures, PNES episodes are not caused by abnormal electrical discharges in the brain.

Common features of PNES episodes may include:

Eye closure during events
Side-to-side head movements
Pelvic thrusting
Prolonged episodes
Hyperventilation
Whole-body shaking with preserved awareness

Treatment and Patient Support

Treatment of Functional Neurologic Disorder requires a multidisciplinary approach. The most effective care plans often include:

Physical therapy, to retrain movement and function
Psychotherapy, to address emotional regulation and stress responses

Medications may also be helpful in managing specific symptoms, depending on the individual patient.

As EEG technologists, we frequently encounter patients with FND in the laboratory setting. Providing reassurance, clear communication, and supportive care is essential to obtaining high-quality recordings and helping patients feel safe and understood during their studies.

Roya Tompkins, MS, REEG/EP T, RPSGT, CLTM