Does Psychogenic Non-Epileptic Seizures (PNES) reduce lifespan?

PNES Does Not Directly Reduce Lifespan, But Mortality Risk is Significantly Elevated

PNES itself does not cause death through the seizure mechanism, but patients with PNES have a 3-fold higher mortality rate compared to matched controls, primarily due to psychiatric comorbidities, misdiagnosis complications, and associated medical conditions rather than the episodes themselves. 1

Direct Mortality Risk from PNES Episodes: Negligible

The episodes themselves do not reduce lifespan through physiological mechanisms because:

• PNES lacks epileptogenic brain activity, meaning there is no abnormal electrical discharge that could cause life-threatening complications like status epilepticus 2
• Episodes typically last less than 30 seconds, significantly shorter than true epileptic seizures, and patients do not experience prolonged cerebral dysfunction that could lead to death 2, 3
• PNES does not cause the physiological sequelae of true seizures such as severe hypoxia, aspiration, or cardiac arrhythmias that occur during prolonged epileptic activity 2

Indirect Mortality Risk: 3-Fold Increase

A Danish national registry study (1998-2013) of 1,057 PNES patients matched with 2,113 controls found:

• Mortality was significantly higher in PNES patients (Hazard Ratio: 3.21; 95% CI: 1.92-5.34; P < 0.001) 1
• This elevated mortality is not from the seizures themselves but from associated conditions and complications 1

Primary Contributors to Elevated Mortality

Psychiatric comorbidities are the strongest mortality drivers:

• Depression, anxiety, dissociative disorders, and PTSD are highly prevalent in PNES patients 1, 4
• Psychiatric comorbidities showed a Hazard Ratio of 15.45 (95% CI: 9.81-24.33) compared to controls 1
• These conditions independently increase mortality risk through suicide, cardiovascular disease, and poor health behaviors 1

Iatrogenic complications from misdiagnosis pose significant mortality risk:

• 8 of 10 PNES patients were prescribed anticonvulsants unnecessarily 2
• Inappropriate treatment with anticonvulsants and sedatives can cause respiratory depression, cardiac complications, and CNS adverse effects potentially requiring intubation 2
• Aggressive treatment of presumed status epilepticus in PNES patients can lead to respiratory failure from benzodiazepines or propofol, which are standard for true seizures but dangerous and unnecessary in PNES 2

Multiple medical comorbidities compound mortality risk:

• Neurological diseases (HR: 38.63; 95% CI: 21.58-69.13) 1
• Other health-related factors (HR: 12.83; 95% CI: 8.45-19.46) 1
• 8% of PNES patients also have true epilepsy, complicating management 1

Quality of Life Impact Without Mortality

While not directly affecting lifespan through the episodes:

• Quality of life is severely impaired in PNES patients, worse than in true epilepsy patients across 13 of 19 quality-of-life subscales 5
• Depression and medication side effects (from misdiagnosis) primarily explain the lower quality of life 5
• 72% of PNES patients showed resolution after psychiatric treatment in follow-up studies, and quality of life can normalize with PNES cessation 6, 7

Critical Clinical Pitfalls to Avoid

Avoid misdiagnosis-related mortality:

• Use video-EEG monitoring as the gold standard when clinical uncertainty exists to prevent harmful treatments 6, 3
• Never rely on biomarkers (neuron-specific enolase, prolactin, creatine kinase) to differentiate PNES from epilepsy—they are unreliable 6, 3
• Discontinue anticonvulsants once PNES is diagnosed, as they carry risks without benefit 2

Prioritize psychiatric treatment to reduce mortality:

• Early psychiatric referral is essential given the 3-fold mortality increase 2, 1
• Cognitive behavioral therapy is first-line treatment (Class IIb recommendation) 6
• The number of mental health consultations correlates with improved quality of life 4