Psychogenic Non-Epileptic Seizures (PNES) are a condition where individuals experience seizure-like episodes that resemble epileptic seizures but do not stem from abnormal electrical activity in the brain. Instead, these events have a psychological origin, often linked to stress, trauma, or significant emotional challenges. This article explores the prevalence of PNES, the populations it affects, and the difficulties in accurately determining its occurrence.
Understanding Psychogenic Non-Epileptic Seizures
Psychogenic Non-Epileptic Seizures are characterized by sudden changes in movement, sensation, or awareness that can closely mimic epileptic seizures. Unlike epilepsy, these episodes do not involve chaotic electrical discharges in the brain, a distinction confirmed by tests like electroencephalogram (EEG) monitoring. During a PNES event, a person might exhibit convulsive movements, appear unresponsive, or display thrashing and asynchronous limb movements.
These episodes differ from epileptic seizures in their duration, lasting longer than two minutes, and do not lead to post-seizure confusion or deep sleep. PNES are considered a type of functional neurological disorder, where symptoms arise from changes in brain function rather than structural disease. These seizure-like behaviors are involuntary and not consciously produced, representing a physical manifestation of underlying psychological distress or unresolved emotions.
Prevalence and Incidence of PNES
PNES affects a significant number of individuals. The estimated prevalence ranges from approximately 2 to 33 per 100,000 people in the general population. More recent systematic reviews suggest a higher prevalence, with one estimating around 108.5 per 100,000 people in the United States. This makes PNES as prevalent as other neurological conditions like multiple sclerosis or Parkinson’s disease.
The incidence of PNES is estimated to be between 1.4 and 4.9 per 100,000 individuals per year. A 2021 systematic review reported an incidence of 3.1 per 100,000 per year in the United States, a figure consistent with findings from a population-based study in Norway. PNES is a frequent diagnosis in specialized epilepsy centers, accounting for 20% to 30% of patients referred for seizures that do not respond to medication.
Demographics and Risk Factors for PNES
PNES can affect individuals across all age groups, though it is diagnosed in young to middle adulthood, between the ages of 15 and 35. While cases can occur in children as young as five, the majority of diagnoses are made during adolescence. Research indicates a higher prevalence among females, who constitute approximately 70% of those affected. This gender difference is particularly noticeable in adolescents and young adults.
A history of trauma is a common risk factor, including physical, sexual, or emotional abuse or neglect. Psychological disorders are strongly associated with PNES, including high rates of mood disorders, such as depression (57-85%), and anxiety disorders. Post-traumatic stress disorder (35-49%) and dissociative disorders (22-91%) are commonly reported among individuals with PNES. Other contributing factors can include chronic pain conditions, difficulties in understanding and expressing emotions, and maladaptive responses to stressors.
Challenges in Determining PNES Commonality
Accurately determining the commonality of PNES presents several challenges, primarily due to frequent misdiagnosis. Many individuals with PNES are initially diagnosed with epilepsy, leading to inappropriate treatments and prolonged diagnostic delays, often ranging from 7 to 10 years. Up to 25% of patients previously diagnosed with epilepsy are later found to have PNES. This misidentification can lead to unnecessary medication use and even hospitalizations.
Underreporting and stigma complicate data collection, as PNES is associated with mental health challenges, which can deter individuals from seeking or receiving appropriate diagnosis. The absence of universally standardized diagnostic criteria across all regions also contributes to variability in reported prevalence rates. Despite advancements, distinguishing PNES from epileptic seizures remains complex due to overlapping symptoms and the need for specialized video-EEG monitoring to confirm the absence of abnormal brain activity during an event.