Psychogenic Non-Epileptic Seizures (Pseudoseizures)

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Figure 1: Historically, this condition was known under the more colloquial term of “hysterical reaction”, although that term is falling out of favor.
Picture from: brontehoroine.wordpress.com

Introduction

Pseudoseizures (or psychogenic non-epileptic seizures PNES) are episodes that resemble convulsive or non-convulsive seizures, which are not the result of an abnormal neuronal discharge and are often due to an underlying psychiatric disorder

 

Incidence                                     

By the numbers….

  • Occurs in 3 per 100,000 individuals studied in cross-section between 1995 and 1998
  • More common in females
  • Presentation
                   
    • Represent 4% of cases of transient loss of consciousness
    • Make up 20% of referral to specialty epilepsy services
    • 50% of apparent status epilepticus are actually pseudoseizures
  • Make up a large proportion of treatment resistant epilepsy and often patients are treated with multiple anti-epileptic drugs to which they are unresponsive
  • But, in some cases can be concurrent with epileptic disorder in somewhere between 5-56% of patients

 

Risk factors

Pseudoseizures are often a behavioral response to underlying emotional or psychological distress including the following:

  • Early sexual, physical, mental abuse

Patients with pseudoseizures have a higher incidence of the following psychiatric illnesses:

  • Depression
  • Panic disorder
  • History of overdose or addiction
  • History of self harm
  • PTSD
  • Personality disorders
  • Somatoform disorders

In addition to early trauma and psychiatric comorbidity, pseudoseizures are often triggered by emotional crises and often occur in the presence of others (suspected seizure attack in waiting room 75% PPV for PNES).

 

Clinical features

Pseudoseizures differ from epileptic seizures in multiple ways. PNES episodes often have:
         

  • No tonic phase
  • Clonic wild thrashing movements where patient rarely harms self or becomes incontinent, repeated side to side movements of the head, striking out, kicking, hand biting
  • Ictal eye closure
  • Ictal vocalizations 
  • No post ictal confusion
  • No occurrences during sleep

Some features typically seen in adults are often not present in children making the diagnosis more difficult to make

Example #1:  CLICK ON LINK BELOW FOR VIDEO

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Example #2: CLICK ON LINK BELOW FOR VIDEO

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Diagnosis

  • In addition to clinical features, labs, imaging, and testing can help differentiate PNES from epileptic seizures in difficult cases
                 
    • Monitoring
                 
      • Epileptiform activity (or lack of) on EEG. Routine EEG monitoring only lasts 20-30min. Therefore, attacks are likely to be missed.  Video EEG can help correlate attacks with electrical brain activity.  73 to 96% of patients have abnormalities within 48 hours. 
      • Outpatient EEG monitoring can also be used
                            
        • PNES can often be elicited via placebo with higher frequency than epileptic seizures using the following techniques:
                 
          • Applying rubbing alcohol to patient informing them that it elicits seizures or giving normal saline bolus with the same statement                 
          • Photic stimulation
          • Hyperventilation
          • These techniques are not without ethical controversy, although 67-90% of patients have an episode with placebo treatment
      • Labs
                         
        • Prolactin is often elevated after an epileptic seizure and peaks 15-20 min after an attack.  A baseline level should be obtained 6 hours after the attack for comparison
        • Creatine kinase levels are often elevated in epileptic seizures but not in PNES
      • Imaging
                       
        1. Brain MRI if there is reason to believe that there is an organic substrate for the attacks

 

Differential diagnosis

  • Epileptic seizures involving the frontal lobe
  • Chorea secondary to rheumatic fever
  • Sleep disorders
  • Movement disorders
  • Syncope

 

Treatment

In-patient

  • Psychiatric consult
                 
    • Assess for suicidal ideation/homicidal ideation
    • Previous psychiatric history/hospitalizations
  • Neurology consult
        
    • Birth history
      • Congenital infections
  • Ativan PRN for longer episodes while hospitalized
  • Advise pts on their condition, prior to discharge and set up a follow-up appointment with a psychiatrist

Outpatient

  • Cognitive-behavioral therapy (CBT) alone or in combination with sertraline

 

Complications

  • Pseudoseizures are often misdiagnosised leading to inappropriate anti-eplieptic use. 
  • However, if identified and treated leads to remission in 70-80% of patients

 

References

  1. Epilepsy and other seizure disorders. Ropper, AH, Martin AS, Raymond AD, Maurice V. Adams and victor's principles of neurology.10 ed, chapter 16. 2009.
  2. Seizures and syncope.Aminoff, MJ, David AG, Roger PS.  Clinical Neurology.Chapter 12, 2005.
  3. Benbadis SR.A spell in the epilepsy clinic and a history of "chronic pain" or "fibromyalgia" independently predict a diagnosis of psychogenic seizures. Epilepsy Behav. 2005 Mar;6(2):264-5.
  4. Wyllie E, Friedman D, Lüders H, Morris H, Rothner D, Turnbull J. Outcome of psychogenic seizures in children and adolescents compared with adults. Neurology. 1991 May;41(5):742-4.