The "Seizing" Patient Who Isn't: A Critical Care Perspective on Pseudoseizures and Psychogenic Nonepileptic Spells

Dr Neeraj Manikath , claude.ai

Abstract

Background: Psychogenic nonepileptic spells (PNES), commonly termed pseudoseizures, represent a significant diagnostic challenge in critical care settings, accounting for 5-20% of patients referred for suspected status epilepticus. Misdiagnosis leads to inappropriate antiepileptic drug administration, prolonged mechanical ventilation, and increased morbidity.

Objective: To provide critical care practitioners with evidence-based tools for rapid identification and management of PNES, emphasizing bedside clinical assessment techniques and appropriate EEG utilization.

Methods: Comprehensive review of literature from 1990-2024, focusing on diagnostic accuracy studies and critical care-specific management strategies.

Results: Key differentiating features include preserved awareness during episodes, atypical motor patterns (pelvic thrusting, side-to-side head movements), resistance to eye opening, and normal post-ictal neurological examination. Urgent EEG monitoring is indicated when clinical suspicion remains high despite atypical features.

Conclusions: Recognition of PNES requires systematic clinical assessment combined with judicious EEG use. Early identification prevents iatrogenic complications and facilitates appropriate psychiatric intervention.

Keywords: Pseudoseizures, psychogenic nonepileptic spells, status epilepticus, EEG, critical care

Introduction

The critically ill patient presenting with seizure-like activity represents one of emergency medicine's most time-sensitive scenarios. However, not all that convulses is epileptic. Psychogenic nonepileptic spells (PNES), historically termed "pseudoseizures," account for 5-20% of patients presenting to emergency departments with suspected status epilepticus and up to 30% of those referred to specialized epilepsy centers¹. In the critical care environment, where rapid decision-making is paramount, the ability to distinguish between true epileptic seizures and PNES can prevent significant iatrogenic harm and resource misallocation.

The term "pseudoseizure" has fallen out of favor due to its pejorative connotations and implication that symptoms are intentionally fabricated. PNES more accurately describes these involuntary, non-volitional episodes that result from underlying psychological distress rather than abnormal electrical brain activity². This distinction is crucial for both diagnostic accuracy and therapeutic approach.

The stakes of misdiagnosis are particularly high in critical care settings. Inappropriate administration of antiepileptic drugs (AEDs), especially intravenous formulations used in status epilepticus protocols, can lead to respiratory depression, hypotension, and cardiac arrhythmias³. Conversely, missing true seizures can result in permanent neurological injury or death. This review provides critical care practitioners with practical, evidence-based tools for navigating this diagnostic challenge.

Epidemiology and Risk Factors

PNES predominantly affects women (female-to-male ratio 3-4:1) with peak incidence in the second and third decades of life⁴. However, critical care practitioners must remain vigilant across all demographic groups, as PNES can occur at any age and affects approximately 2-33 per 100,000 population⁵.

High-Risk Populations in Critical Care:

Psychiatric comorbidities: Depression (50-60%), anxiety disorders (45%), PTSD (30-50%)
History of trauma: Physical, sexual, or emotional abuse in 70-80% of cases
Conversion disorders: Other unexplained neurological symptoms
Healthcare utilization: Frequent ED visits, multiple hospitalizations
Medication history: Prior psychiatric medications or substance use disorders

Pearl 💎

The "Frequent Flyer" Red Flag: Patients with recurrent admissions for "refractory status epilepticus" that responds poorly to standard AED protocols should raise suspicion for PNES, particularly if episodes occur only when witnessed.

Pathophysiology: Understanding the Mechanism

Unlike epileptic seizures, which result from abnormal synchronized neuronal discharge, PNES represents a conversion disorder where psychological distress manifests as neurological symptoms. Neuroimaging studies reveal distinct patterns of brain activation during PNES episodes, with increased activity in limbic structures (particularly the amygdala and insula) and decreased activation in motor control areas⁶.

This neurobiological understanding helps explain several key clinical features:

Preserved awareness: Cortical areas responsible for consciousness remain unaffected
Variable motor patterns: Lack of stereotyped seizure semiology due to absence of electrical focus
Emotional triggers: Episodes often precipitated by stress, medical procedures, or interpersonal conflict

Oyster ⚠️

The Awareness Trap: Some patients with PNES may appear unresponsive during episodes. This "apparent unconsciousness" differs from true ictal impairment and can be assessed through specific bedside tests.

Clinical Assessment: The Art of Bedside Diagnosis

Semiology: Reading the Movement

The motor manifestations of PNES often provide the most valuable diagnostic clues. Unlike epileptic seizures, which follow predictable patterns based on anatomical seizure foci, PNES exhibits variable, often bizarre movements.

Classic PNES Movement Patterns:

Pelvic Thrusting: Rhythmic anterior-posterior pelvic movements, often prominent and sustained
Side-to-Side Head Movements: Horizontal head thrashing (epileptic seizures typically cause vertical movements)
Asynchronous Limb Movements: Arms and legs moving independently without clear pattern
Opisthotonic Posturing: Dramatic arching of the back (rare in true seizures)
Gradual Onset/Offset: Stuttering start and stop, unlike the abrupt nature of epileptic seizures

Preserved Behaviors During Episodes:

Protective Responses: Avoiding injury during falls, protecting face when falling forward
Environmental Awareness: Eyes tracking movement, responding to threats
Selective Responsiveness: Responding to specific stimuli while appearing unresponsive to others

The Eyelid Resistance Test: A Critical Care Game-Changer

One of the most reliable bedside tests for PNES is the eyelid resistance test, with reported sensitivity of 96% and specificity of 98%⁷.

Technique:

Gently attempt to open the patient's eyelids during the episode
Positive Test (PNES): Active resistance to eye opening, tight squeezing of eyelids
Negative Test (Epileptic): Passive eyelid tone, no active resistance

Additional Eye Signs:

Forced Eye Closure: Tight closure with visible effort (crow's feet wrinkles)
Flutter Sign: Rapid eyelid fluttering when attempting to open eyes
Peek Sign: Brief eye opening when patient believes unobserved

Pearl 💎

The "Drop Test" Modification: When testing eyelid resistance, gently lift the patient's arm above their face and release. In PNES, the arm will typically avoid hitting the face, while in true seizures or coma, protective responses are absent.

Timing and Triggers: Pattern Recognition

Episode Characteristics:

Duration: PNES episodes typically last longer than epileptic seizures (>2 minutes common)
Timing: Often occur during daytime hours, rarely during sleep
Triggers: Medical procedures, emotional stress, presence of family members
Location: Frequently occur in healthcare settings, rarely when alone

Post-Ictal Differences:

Unlike true seizures, PNES rarely produces genuine post-ictal confusion or neurological deficits:

Immediate Alertness: Rapid return to baseline mental status
Selective Amnesia: Memory intact for portions of episode
Absence of Physical Signs: No tongue biting, incontinence less common
Normal Neurological Exam: Reflexes, coordination, and mental status normal

Oyster ⚠️

The Incontinence Misconception: While urinary incontinence is more common in epileptic seizures, it can occur in up to 20% of PNES cases, particularly in episodes lasting >10 minutes⁸.

EEG Monitoring: When and How Urgently?

The decision of when to obtain EEG monitoring represents a critical juncture in PNES evaluation. In critical care settings, the competing demands of resource allocation and diagnostic urgency require structured decision-making.

Stat EEG Indications (Within 30 minutes):

High Clinical Suspicion for Status Epilepticus: Despite atypical features
Hemodynamic Instability: During or following episodes
Altered Mental Status: Persistent confusion >30 minutes post-episode
Prior History: Known epilepsy or brain injury
Toxicology Concerns: Potential toxic ingestion or withdrawal syndromes

Urgent EEG (Within 2-4 hours):

Recurrent Episodes: Multiple events despite initial clinical assessment
Diagnostic Uncertainty: Mixed clinical features
Treatment Response Paradox: Worsening with AED administration

Routine EEG (Within 24 hours):

Strong Clinical PNES Features: Multiple typical signs present
Known PNES History: Prior documented episodes
Stable Patient: No acute medical concerns

Video-EEG: The Gold Standard

When available, video-EEG monitoring provides definitive diagnosis by capturing both clinical semiology and electrical activity. The absence of ictal EEG changes during typical clinical episodes confirms PNES diagnosis with >95% accuracy⁹.

Key EEG Findings:

Normal Background: Preserved posterior dominant rhythm
No Ictal Changes: Absence of rhythmic discharge during clinical episodes
Artifact: Movement artifact obscuring recording during episodes
Post-Ictal Normal: Immediate return to baseline EEG

Pearl 💎

The "EEG Paradox": If EEG shows normal background activity immediately after a witnessed "generalized tonic-clonic seizure," consider PNES. True generalized seizures should produce post-ictal slowing lasting minutes to hours.

Differential Diagnosis: The Mimics

Primary Differentials:

Epileptic Seizures
- Focal with impaired awareness
- Generalized tonic-clonic
- Non-convulsive status epilepticus
Movement Disorders
- Dystonia
- Chorea
- Myoclonus
Metabolic Encephalopathy
- Hypoglycemia
- Electrolyte disturbances
- Uremia
Toxicologic Syndromes
- Stimulant intoxication
- Withdrawal syndromes
- Medication toxicity
Psychiatric Conditions
- Panic attacks
- Catatonia
- Malingering

Oyster ⚠️

The Comorbidity Challenge: Up to 30% of PNES patients also have epilepsy¹⁰. A history of seizures doesn't exclude PNES, and current episodes may be non-epileptic even in known epileptics.

Laboratory and Imaging Considerations

Prolactin Levels: Limited Utility

Serum prolactin elevation (>3x baseline) occurs in 60-70% of generalized tonic-clonic seizures but has significant limitations:

Timing Critical: Must be drawn within 20 minutes post-ictal
False Positives: Stress, medications, medical procedures can elevate levels
False Negatives: Simple partial seizures rarely cause elevation
Limited Specificity: Cannot differentiate seizure types

Pearl 💎

Prolactin Pitfalls: Don't rely on prolactin levels alone. A normal prolactin doesn't rule out seizures, and elevated levels don't confirm them in the ICU setting where stress and medications confound results.

Neuroimaging:

CT Head: Indicated for first-time seizure-like episodes to exclude structural lesions
MRI: Consider in atypical presentations or when clinical suspicion for epilepsy remains high
Functional Imaging: Research tool, not routinely indicated

Laboratory Evaluation:

First-Line Tests:

Blood glucose
Comprehensive metabolic panel
Magnesium, phosphorus
Toxicology screen (if indicated)

Consider in Specific Scenarios:

Ammonia (hepatic encephalopathy)
Thyroid function tests
Antiepileptic drug levels (if applicable)

Management Strategies: The Therapeutic Approach

Acute Management:

Ensure Safety: Prevent injury, maintain airway
Avoid Iatrogenic Harm: Resist impulse to administer AEDs
Minimize Stimulation: Reduce crowd, lower voices
Document Thoroughly: Video recording if possible (with consent)

Therapeutic Communication:

The approach to discussing PNES diagnosis requires sensitivity and skill:

Recommended Framework:

Validate Symptoms: "These episodes are real and distressing"
Explain Mechanism: "Your brain is responding to stress differently"
Avoid Blame: Focus on treatment rather than causation
Provide Hope: Emphasize treatability with appropriate intervention

Language to Avoid:

"Fake" or "not real"
"Psychological" (initially)
"Nothing wrong"
"Just stop doing it"

Pearl 💎

The Bridge Phrase: "What you're experiencing are real symptoms caused by your nervous system responding to stress rather than electrical brain activity. This is actually good news because it means we have effective treatments available."

Pharmacological Considerations

Antiepileptic Drug Withdrawal:

If AEDs were administered before PNES diagnosis:

Phenytoin/Fosphenytoin: Can worsen PNES; consider gradual discontinuation
Benzodiazepines: May provide short-term benefit through anxiolysis
Valproate: Potential mood-stabilizing effects may be helpful

Psychiatric Medications:

While not immediately indicated in the critical care setting:

Antidepressants: SSRIs for underlying depression/anxiety
Anxiolytics: Short-term use for acute stress
Mood Stabilizers: For bipolar comorbidities

Oyster ⚠️

The Paradoxical Response: Some patients with PNES may appear to "respond" to AEDs due to placebo effect or coincidental stress reduction. Don't let apparent improvement prevent appropriate diagnosis.

Long-term Outcomes and Prognosis

Factors Affecting Prognosis:

Favorable Prognostic Indicators:

Early diagnosis and intervention
Absence of significant psychiatric comorbidity
Good social support system
Shorter duration of symptoms before diagnosis

Poor Prognostic Indicators:

Delayed diagnosis (>3 years)
Comorbid personality disorders
Ongoing trauma or stressors
Multiple previous misdiagnoses

Treatment Outcomes:

Seizure-Free Rates: 30-50% at 1-2 years with appropriate treatment
Functional Improvement: 70-80% show some improvement
Quality of Life: Significant improvement possible with integrated care

Special Populations and Considerations

Pediatric PNES:

Incidence: Peak in adolescence (13-18 years)
Presentation: Often more dramatic than adult episodes
Family Dynamics: Consider family stress and dysfunction
School Issues: Academic pressure frequently contributory

Elderly PNES:

Underrecognized: Often attributed to medical comorbidities
Medication Effects: Polypharmacy may complicate diagnosis
Cognitive Assessment: Dementia may coexist or be misdiagnosed

ICU-Specific Considerations:

Delirium: May precipitate or mimic PNES
Sedation Withdrawal: Can trigger episodes
Medical Procedures: Common precipitants
Family Presence: Episodes may increase with visitor stress

Quality Improvement and Systems Approaches

Diagnostic Protocols:

Implementing standardized assessment tools can improve diagnostic accuracy:

PNES Assessment Checklist:

[ ] Eyelid resistance test performed
[ ] Motor pattern documented
[ ] Episode duration recorded
[ ] Post-ictal assessment completed
[ ] Triggers identified
[ ] Prior episode history obtained

Educational Initiatives:

Nursing Education: Recognition of atypical features
Physician Training: Bedside assessment techniques
Interdisciplinary Rounds: Psychiatric consultation protocols

Metrics for Monitoring:

Diagnostic Accuracy: Rate of PNES identification
Time to Diagnosis: Duration of diagnostic uncertainty
Iatrogenic Events: AED-related complications
Length of Stay: Impact of early diagnosis

Pitfalls and Practical Pearls

Common Diagnostic Errors:

The Rush to Treat: Administering AEDs before adequate assessment
The Single Sign Fallacy: Relying on one feature for diagnosis
The Comorbidity Oversight: Missing dual diagnosis (PNES + epilepsy)
The Dismissal Error: Labeling all atypical seizures as "fake"

Practical Pearls for Critical Care:

💎 The "Two-Minute Rule": If a generalized tonic-clonic-appearing seizure lasts >2 minutes with preserved awareness, strongly consider PNES.

💎 The "Audience Effect": Episodes that occur primarily when medical staff are present should raise suspicion.

💎 The "Injection Response": Dramatic improvement with saline "antiepileptic" injection suggests PNES (though this practice is ethically questionable).

💎 The "Recovery Pattern": Immediate post-ictal alertness with normal neurological exam is highly suggestive of PNES.

Oysters to Avoid:

⚠️ The "Normal EEG" Assumption: A normal interictal EEG doesn't rule out epilepsy; ictal recording is needed for definitive diagnosis.

⚠️ The "Injury Exemption": Patients with PNES can sustain injuries during episodes; physical harm doesn't confirm epilepsy.

⚠️ The "Response Fallacy": Apparent response to AEDs may be placebo effect or coincidental stress reduction.

⚠️ The "Single Episode" Error: One atypical episode doesn't establish PNES diagnosis; pattern recognition is crucial.

Future Directions and Research

Emerging Technologies:

Wearable EEG Devices: Continuous monitoring capabilities
Artificial Intelligence: Pattern recognition algorithms
Biomarkers: Novel serum and CSF markers under investigation

Treatment Innovations:

Cognitive Behavioral Therapy: Specialized PNES protocols
Virtual Reality: Stress reduction interventions
Telemedicine: Remote psychiatric consultation

Research Priorities:

Improved diagnostic accuracy tools
Standardized treatment protocols
Long-term outcome predictors
Healthcare utilization patterns

Conclusion

The ability to accurately identify PNES in the critical care setting represents a crucial skill that can prevent significant iatrogenic harm while facilitating appropriate treatment. The combination of systematic clinical assessment, judicious EEG utilization, and compassionate patient communication forms the foundation of optimal care.

Key takeaways for critical care practitioners include:

Clinical Assessment Primacy: Bedside evaluation provides the most immediate diagnostic information
The Eyelid Test: A simple, highly accurate diagnostic maneuver
EEG Timing Strategy: Structured approach to monitoring urgency
Communication Importance: Therapeutic discussion prevents psychiatric morbidity
System Integration: Multidisciplinary approach improves outcomes

Recognition that these episodes represent genuine neurological symptoms caused by psychological distress rather than electrical brain activity allows for appropriate treatment and prevents the cascade of interventions associated with refractory status epilepticus. Early identification and intervention can dramatically improve patient outcomes while reducing healthcare costs and resource utilization.

The "seizing" patient who isn't represents both a diagnostic challenge and an opportunity to provide comprehensive, compassionate care that addresses the full spectrum of neurological and psychological factors contributing to patient symptoms.

References

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Conflict of Interest: The authors declare no conflicts of interest.

Funding: No specific funding was received for this work.

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Friday, August 15, 2025