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.
• Etiology
  • Dissociative disorders and conversion disorders are felt to be the underlying cause to most episodes of PNES.

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.

Differential Diagnosis

Differential diagnosis of seizures

Seizure

• Epileptic seizure
  • First-time seizure
  • Seizure with known seizure disorder
  • Status epilepticus
  • Temporal lobe epilepsy
  • Non-compliance with anti-epileptic medications
  • Hyponatremia
  • INH toxicity
• Non-epileptic seizure
  • Meningitis
  • Encephalitis
  • Brain abscess
  • Intracranial hemorrhage
  • Alcohol withdrawal
  • Benzodiazepine withdrawal
  • Barbiturate withdrawal
  • Baclofen withdrawal
  • Metabolic abnormalities: hyponatremia, hypernatremia, hypocalcemia, hypomagnesemia, hypoglycemia, hyperglycemia, hepatic failure, uremia
  • Eclampsia
  • Neurocysticercosis
  • Posterior reversible encephalopathy syndrome
  • Impact seizure (head trauma)
  • Acute hydrocephalus
  • Arteriovenous malformation
  • Seizure with VP shunt
  • Toxic ingestion (amphetamines, anticholinergics, cocaine, INH, organophosphates, TCA, salicylates, lithium, phenothiazines, bupropion, camphor, clozapine, cyclosporine, fluoroquinolones, imipenem, lead, lidocaine, metronidazole, synthetic cannabinoids, theophylline, Starfruit)
  • Psychogenic nonepileptic seizure (pseudoseizure)
• Intracranial mass
• Syncope
• Hyperventilation syndrome
• Migraine headache
• Movement disorders
• Narcolepsy/cataplexy
• Post-hypoxic myoclonus (Status myoclonicus)

Management

• Avoid invasive medical procedures
• Some patients will improve after they are told the diagnosis in a compassionate, non-jugdemental fashion.
• If new diagnosis or diagnostic uncertainty consider admission for neurology consult and video EEG.
• Psychiatric intervention is the main treatment modality for PNES. (e.g. outpatient cognitive behavioral therapy (CBT)).
  • The purpose of psychiatric consultation is to identify underlying psychiatric conditions that can help direct treatment.

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 to 80 percent achieving seizure remission

References

• Chen DK. Psychogenic Non-epileptic Seizure. Uptodate. Updated May 18, 2018. Accessed June 1, 2018. https://www.uptodate.com/contents/psychogenic-nonepileptic-seizures?search=psychogenic%20nonepileptic%20seizures&source=search_result&selectedTitle=1~31&usage_type=default&display_rank=1