What are the symptoms and consequences of untreated Psychogenic Non-Epileptic Seizures (PNES) in a 13-year-old patient with a history of depression and anxiety?

Understanding PNES: Definition, Symptoms, and Consequences of Non-Treatment

What is PNES?

Psychogenic Non-Epileptic Seizures (PNES) are episodes involving motor, sensory, mental, or autonomic manifestations that resemble epileptic seizures but are caused by psychological processes rather than abnormal electrical brain activity. 1 These episodes are classified as conversion disorder (functional neurologic symptom disorder) in modern diagnostic frameworks and represent a significant diagnostic challenge in clinical practice. 2

• PNES episodes lack epileptogenic brain activity, meaning there is no abnormal electrical discharge in the brain during these events. 1
• Episodes typically last less than 30 seconds, which is significantly shorter than true epileptic seizures. 1
• Between 10-30% of patients referred to epilepsy centers have PNES rather than true epilepsy, with a mean diagnostic delay of 7 years from symptom onset. 3
• Video-EEG monitoring is the gold standard for diagnosis when clinical uncertainty exists. 4

Clinical Presentation and Symptoms

PNES manifests with seizure-like episodes that can include altered movement, sensation, or experience, often accompanied by eye fluttering, which is more characteristic of PNES than epileptic seizures. 4, 3

• Patients present with vague, poorly described complaints that fluctuate with activity or stress, without physical findings or laboratory abnormalities. 2
• Episodes are involuntary and real—not faked—representing a genuine conversion disorder. 4
• The condition commonly affects young females (65-80% of cases), though a subgroup of older men has been recently described. 3

Psychiatric Comorbidities in PNES

In adolescents with PNES, 72% have comorbid psychological problems at initial presentation, with depression being the most frequent (36%), followed by anxiety, conduct disorder, adjustment disorder, ADHD, schizophrenia, and bipolar disorder. 5

• Depression and anxiety are present in approximately one-third of PNES patients, particularly adolescents. 6
• Predisposing factors include familial distress (40%), social distress (24%), and specific triggering events (20%). 5
• Mental stress increases PNES frequency and severity. 6
• The condition shows high rates of dissociative disorders, post-traumatic stress disorder, and somatoform symptoms. 3, 7

Consequences of Untreated PNES

Direct Clinical Consequences

Without treatment, PNES leads to persistent seizure-like episodes, serious disability, and poor quality of life, with many patients remaining unproductive even years after symptom onset. 3

• Patients experience significant impairment in social, educational, and occupational functioning. 2
• Nearly half of patients who eventually become seizure-free remain unproductive, and many continue to have symptoms of psychopathology including other somatoform, depressive, and anxiety disorders. 3
• Untreated patients often have multiple emergency department visits and hospitalizations. 2

Iatrogenic Harm from Misdiagnosis

The most serious consequence of untreated or misdiagnosed PNES is exposure to unnecessary and potentially life-threatening medical interventions. 1

• 80% of PNES patients are inappropriately prescribed anticonvulsants despite lacking epilepsy. 2, 6
• All identified PNES patients in one study had multiple previous ED visits, 8 of 10 had been prescribed anticonvulsants, and 6 received anticonvulsants in the ED or from prehospital personnel. 2
• Nearly all underwent invasive procedures and testing, including lumbar punctures and radiographic studies with ionizing radiation. 2
• Inappropriate treatment with anticonvulsants and sedatives can cause respiratory depression, cardiac complications, and CNS adverse effects, potentially requiring intubation and mechanical ventilation. 1
• Aggressive treatment of presumed status epilepticus in PNES patients can lead to iatrogenic complications, including respiratory failure from benzodiazepines or propofol. 1

Mortality Risk

Mortality is significantly higher in patients with PNES compared to controls (Hazard Ratio: 3.21), though PNES itself does not directly cause death through physiological mechanisms like true epilepsy. 8

• PNES does not cause the life-threatening physiological sequelae of true seizures, such as severe hypoxia, aspiration, or cardiac arrhythmias. 1
• The increased mortality risk is indirect, stemming from complications of misdiagnosis, inappropriate treatment, and associated psychiatric comorbidities. 1, 8
• Patients show increased comorbidities in almost all diagnostic domains three years before and after diagnosis. 8

Psychosocial Burden

Untreated PNES in adolescents is associated with decreased school performance, poor social functioning, increased physical illness, substance abuse, and increased healthcare costs. 2

• Depression in adolescents (which commonly co-occurs with PNES) increases suicide risk, with 10% of children aged 5-12.9 years and 19% of adolescents aged 13-17.9 years with major depressive disorder attempting suicide. 2
• Generalized anxiety disorder with comorbid depression may convey the greatest risk for suicidal ideation and attempts. 2
• Only 36-44% of children and adolescents with depression receive treatment, suggesting the majority remain undiagnosed and untreated. 2

Prognosis with Treatment

The outcomes of PNES in children and adolescents are significantly better than in adults: 72% of patients showed resolution after psychiatric treatment in follow-up studies, with 80% becoming event-free at mean follow-up of 31.5 months. 2, 4, 5

• Among treated patients, 80% were event-free at follow-up, 12% showed reduced frequency, and only 8% experienced persistent symptoms. 5
• Quality of life can be improved with treatment even when complete seizure freedom is not achieved. 4
• Early psychiatric referral is essential to prevent harmful treatments and identify the true psychiatric nature of the condition. 1

Critical Pitfalls in PNES Management

The challenge is compounded when patients have both true epilepsy and PNES (occurring in 8-20% of cases), making airway management and anticonvulsant decisions complex and potentially life-threatening if the wrong condition is treated. 1, 6, 8

• Biomarkers such as neuron-specific enolase, prolactin, and creatine kinase are not reliable for differentiating PNES from epilepsy. 4, 3
• Sleep deprivation and anxiety triggers that precipitate attacks must be addressed for effective management. 6
• Anticonvulsants provide no benefit for PNES and expose patients to unnecessary medication risks. 6