Psychogenic nonepileptic seizure

Background

  • Psychogenic nonepileptic seizure (PNES) characterized disturbances of motor, sensory, autonomic, cognitive, and/or emotional functions that can mimic epileptic seizures.
  • In contrast to epileptic seizures, PNES are not associated with abnormally excessive neuronal activity but are instead derived from psychologic causes.
  • The term pseudoseizures and hysterical seizures are historical terms that are now discouraged.
  • Accurate diagnosis is best achieved via a detailed history, physical examination, selected testing, and neurology and/or psychiatry evaluation.
  • Epidemiology
    • Estimated incidence rate ranges from 1.5 to 5 per 100,000 persons per year.
    • Estimate prevalence 2 to 33 per 100,000 persons.
    • More common in women
  • Etiology
    • There may be a history of sexual abuse, eating disorders, depression, substance abuse, anxiety disorders or personality disorders, and the episode may be preceded by a stressful event
    • Dissociative disorders and conversion disorders are felt to be the underlying cause to most episodes of PNES.
  • Some patients may have both psychogenic nonepileptic seizures and true epileptiform seizures

Clinical Features

  • Symptoms specific to PNES:
    • Duration > 2 minutes
    • Pelvic thrusting
    • Side to side head rocking
    • Crying/shrieking
    • Voluntary eye movements away from the examiner/forceful closing of the eyes
    • Stuttering/stammering
    • ABSENT postictal confusion
    • ABSENT physical injury
  • Symptoms similar to an epileptic seizure:

Differential Diagnosis

Differential diagnosis of seizures

Seizure

Evaluation

  • May be a clinical diagnosis
  • Consider standard seizure workup
    • Always check glucose
    • Lactic acid may be able to differentiate from true generalized tonic-clonic seizure[1]
  • Consider obtaining a drug screen (and a pregnancy test in women)
  • If unsure, an urgent neuro consult with EEG can determine the diagnosis

Management

  • Avoid invasive medical procedures
  • Some patients will improve after they are told the diagnosis in a compassionate, non-judgmental fashion.
  • If new diagnosis or diagnostic uncertainty consider admission for neurology consult and video EEG.
  • Psychiatric intervention is the main treatment modality (e.g. outpatient cognitive behavioral therapy).
    • The purpose of psychiatric consultation is to identify underlying psychiatric conditions that can help direct treatment.
  • In case of significant emotional stress, administer a mild tranquilizing agent (e.g. lorazepam 1-2mg IM/IV; hydroxyzine 50-100mg IM)

Disposition

  • If symptoms improve consider discharge with close neurology and psychiatry follow-up to rule out epilepsy and identify and treat the underlying psychiatric origin of symptoms.
  • If symptoms cannot be controlled or patient/family are not accepting of diagnosis. Consider admission for observation and further evaluation.

Prognosis

  • 25-38 percent of patients achieve "seizure" freedom
  • Children have a better prognosis than adults, with 70-80% achieving remission

See Also

External Links

References

  1. Ebru Apaydın Doğan, Ali Ünal, Aslıhan Ünal, Çağla Erdoğan, Clinical utility of serum lactate levels for differential diagnosis of generalized tonic–clonic seizures from psychogenic nonepileptic seizures and syncope, Epilepsy & Behavior, Volume 75, 2017, Pages 13-17, ISSN 1525-5050, https://doi.org/10.1016/j.yebeh.2017.07.003. (http://www.sciencedirect.com/science/article/pii/S1525505017304821)