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

PNES Does Not Directly Reduce Lifespan, But Mortality Risk is Significantly Elevated Due to Misdiagnosis and Associated Comorbidities

PNES itself does not cause death through the seizure mechanism, as these episodes lack epileptogenic brain activity and do not produce the life-threatening physiological complications of true epileptic seizures, such as status epilepticus, severe hypoxia, aspiration, or cardiac arrhythmias 1. However, patients with PNES face a significantly elevated mortality risk compared to the general population.

Direct Mortality Risk from PNES Episodes

• PNES episodes do not involve abnormal electrical brain discharge that could cause life-threatening complications 1
• 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 1, 2
• The seizure mechanism itself does not produce the physiological sequelae of true seizures that can be fatal 1

Elevated Mortality Risk: The Real Danger

A national Danish registry study found that mortality was significantly higher in patients with PNES compared to matched controls (Hazard Ratio: 3.21; 95% CI: 1.92-5.34; P < 0.001) 3. This elevated mortality is not from the PNES episodes themselves, but from indirect mechanisms:

Iatrogenic Complications from Misdiagnosis

• 8 out of 10 PNES patients were prescribed anticonvulsants, and 6 received anticonvulsants in the emergency department, with nearly all undergoing invasive procedures and testing 1
• 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
• The challenge is compounded when patients have both true epilepsy (present in 8% of PNES patients) and PNES, making airway management and anticonvulsant decisions complex and potentially life-threatening if the wrong condition is treated 1, 3

Associated Comorbidities Driving Mortality

• Patients with PNES showed increased comorbidities 3 years before and after diagnosis in almost all diagnostic domains 3
• The strongest associations were with other neurological diseases (HR: 38.63; 95% CI: 21.58-69.13), abnormal clinical and laboratory findings (HR: 46.59), other health-related factors (HR: 12.83), and psychiatric comorbidities (HR: 15.45) 3
• Especially frequent comorbidities include overweight, depression, anxiety, dissociative somatoform conditions, reports of pain in multiple organ systems, and minimal traumas to head, trunk, and extremities 3

Quality of Life Impact

While not directly affecting lifespan through the seizure mechanism, PNES profoundly impacts quality of life, which may indirectly contribute to mortality:

• Overall health-related quality of life and scores on 13 of 19 QOLIE-89 subscales were significantly lower in PNES patients compared to epilepsy patients 4
• Depression, anxiety, alexithymia, and dissociation were significantly related to quality of life at diagnosis 5
• Post-traumatic stress disorder, dissociation, and psychiatric comorbidities substantially alter quality of life in PNES patients 5
• Only 37% of patients achieved freedom from PNES at long-term follow-up (mean 5.3 years), with persistent PNES associated with worse psychological functioning and lower quality of life 6

Clinical Approach to Prevent Mortality

Accurate diagnosis through video-EEG monitoring is critical to prevent harmful treatments and identify the true psychiatric nature of the condition 1, 2.

Diagnostic Strategy

• Video-EEG monitoring is the gold standard, capturing typical events with continuous ECG, EEG, and blood pressure monitoring 2
• In PNES, normal EEG during episodes is observed, while true epileptic seizures show epileptiform discharges 2
• Avoid relying on biomarkers such as neuron-specific enolase, prolactin, and creatine kinase, as they are unreliable for differentiating PNES from epilepsy 7, 2

Treatment to Reduce Mortality Risk

• Communicate the diagnosis directly and sympathetically, acknowledging the involuntary nature of episodes, emphasizing they are real and not faked, and that the condition is treatable with psychological interventions 7
• Cognitive behavioral therapy (CBT) is the first-line treatment for PNES 7
• Early psychiatric referral is essential, as 72% of PNES patients showed resolution after psychiatric treatment in follow-up studies 1
• Pharmacotherapy has no demonstrated benefit for PNES itself 7
• Avoid unnecessary anticonvulsants and invasive procedures once PNES is diagnosed, as these interventions carry risks without providing benefit 1, 7
• Mental health care improves quality of life and is linked to positive evolution of quality of life (p = 0.02) 5

Key Pitfall to Avoid

The greatest mortality risk comes from treating PNES as true epileptic seizures, leading to respiratory depression from benzodiazepines, propofol, or barbiturates, and complications from unnecessary anticonvulsants 1. The 3-fold increased mortality risk in PNES patients is driven by comorbidities and iatrogenic complications, not the seizure episodes themselves 3.