Functional Neurological Disorders and Psychogenic Seizures

Functional neurological disorders (FND) encompass a spectrum of disabling symptoms—such as movement abnormalities, sensory disturbances and episodes resembling epileptic seizures—that arise in the absence of structural neuropathology. Psychogenic non-epileptic seizures (PNES), often termed dissociative seizures, are paroxysmal events characterised by altered consciousness or motor activity without the electroencephalographic changes of epilepsy. Patients with FND and PNES frequently encounter diagnostic delays, stigma and fragmented care, despite mounting evidence for distinct neurobiological mechanisms. Contemporary models posit that FND arises from disordered brain networks integrating sensory, motor and affective information within a predictive coding framework. Dysregulation of limbic circuits and aberrant top-down expectations may give rise to symptoms experienced as involuntary. Positive clinical signs—such as variability in motor performance and preserved reflexes—support diagnosis, while functional imaging and electrophysiology increasingly offer objective biomarkers. Optimal management involves clear communication of diagnosis, combined neurological and psychiatric assessment, and tailored multidisciplinary interventions that address both symptom modulation and underlying psychosocial factors. Advances in understanding neural network dysfunction and structured therapeutic pathways have begun to shift FND from a historical diagnosis of exclusion towards a treatable condition with demonstrable recovery potential.

Research from Nature Portfolio

Resting-state functional MRI studies have revealed that patients with PNES exhibit region-specific and network-level alterations in brain activity. Increased low-frequency fluctuations were observed in prefrontal, parietal and motor regions alongside reduced activity in inferior frontal areas. These local changes correlated with abnormal inter-regional connectivity, notably between motor planning regions and affective hubs, suggesting that skewed synchrony across distributed networks may underpin seizure frequency and semiology. The decoupling of functional and structural connectivity emphasises a network-based pathophysiology, in which impaired integration of sensorimotor and limbic circuits predisposes to episodic dissociative events.

Functional Neurological Disorders and Psychogenic Seizures publication trend

The graph below shows the total number of articles in functional neurological disorders and psychogenic seizures across all publications each year (not limited to Nature Index journals).

Technical terms

Functional Neurological Disorder (FND): A condition in which patients experience neurological symptoms—motor, sensory or cognitive—without underlying structural disease.

Psychogenic Non-Epileptic Seizures (PNES): Episodes resembling epileptic seizures in clinical presentation but lacking abnormal electrical discharges on electroencephalography.

Predictive coding: A theoretical framework in which the brain continually generates and updates internal models to anticipate sensory input, with symptoms arising when top-down expectations override incoming signals.

Functional connectivity: The statistical association of activity between spatially separate brain regions, indicative of network integration or dysregulation.

Dissociative seizures: A subtype of PNES characterised by transient alterations in consciousness, awareness or motor function rooted in psychological processes rather than epileptic pathology.

References

1. Functional neurological disorder: new subtypes and shared mechanisms. The Lancet Neurology (2022).
2. Cognitive behavioural therapy for adults with dissociative seizures (CODES): a pragmatic, multicentre, randomised controlled trial. The Lancet Psychiatry (2020).
3. Altered regional activity and inter-regional functional connectivity in psychogenic non-epileptic seizures. Scientific Reports (2015).
4. Altered Functional and Structural Connectivity Networks in Psychogenic Non-Epileptic Seizures. PLOS ONE (2013).
5. Management of functional neurological disorder. Journal of Neurology (2020).