Nonepileptic seizures: an updated review

Abstract

Psychogenic nonepileptic seizures are a Functional Neurological Disorder/ Conversion Disorder subtype, which are neurobehavioral conditions at the interface of Neurology and Psychiatry. Significant advancements over the past decade have been made in the diagnosis, management and neurobiological understanding of PNES. This article reviews published PNES research focusing on semiologic features that distinguish PNES from epileptic seizures, consensus diagnostic criteria, the intersection of PNES and other comorbidities, neurobiological studies, evidence-based treatment interventions and outcome studies. Epidemiology and health care utilization studies highlight a continued unmet medical need in the comprehensive care of PNES. Consensus guidelines for diagnostic certainty are based on clinical history, semiology of witnessed typical event(s), and EEG findings. While certain semiologic features may aid the diagnosis of PNES, the gold standard remains capturing a typical event on video electroencephalography (EEG) showing the absence of epileptiform activity with history and semiology consistent with PNES. Medical-neurologic and psychiatric comorbidities are prevalent in PNES and should be assessed in diagnostic evaluations, and integrated into treatment interventions and prognostic considerations. Several studies, including a pilot multicenter, randomized clinical trial, have now demonstrated that a cognitive behavioral therapy informed psychotherapy is an efficacious treatment for PNES, and additional efforts are necessary to evaluate the utility of pharmacologic and other psychotherapy treatments. Neuroimaging studies, while requiring replication, suggest that PNES may occur in the context of alterations within and across sensorimotor, emotion regulation/processing, cognitive control and multimodal integration brain systems. Future research could investigate similarities and differences between PNES and other somatic symptom disorders.

Diagnostic implications of review-of-systems questionnaires to differentiate epileptic seizures from psychogenic seizures

“…However, patients are unable to determine which symptoms are cause by conversion disorder and which are due to other conditions. Therefore, appropriate treatment of PNES addresses both the seizures and the psychological challenges that may be expressed through other somatic complaints [9, 10, 12]. …”

“…The most effective treatment of PNES is cognitive-behavioral-informed therapy to address the underlying psychological stressors that contribute to their seizures [9, 10]. Diagnosing PNES earlier results in reduced cost and better short and long-term seizure control [2, 4, 5, 11, 12]. Unfortunately, the average delay from first seizure to diagnosis of PNES is over 8 years [8].…”

“…Almost all clinics ask patients to fill out standardized review-of-systems questionnaires (RoSQ) before they speak to a physician; evidence that these are effective in diagnosis of seizures is promising but limited [13, 14]. Patients with PNES experience increased somatic sensitivity, as evidenced by medically unexplained symptoms and reporting more disability for less severe symptoms [1, 12, 13, 15, 16]. Additionally, most frequently, PNES are a component of conversion disorder in which patients convert psychological stressors into somatic symptoms or findings, one of which can be seizures [3, 12, 17].…”

“…Patients with PNES experience increased somatic sensitivity, as evidenced by medically unexplained symptoms and reporting more disability for less severe symptoms [1, 12, 13, 15, 16]. Additionally, most frequently, PNES are a component of conversion disorder in which patients convert psychological stressors into somatic symptoms or findings, one of which can be seizures [3, 12, 17]. However, conversion disorder frequently presents with other positive findings including pain, fatigue, lethargy, myalgias, constipation or diarrhea [3].…”

Diagnostic delay in psychogenic seizures and the association with anti-seizure medication trials

“…Patients who are diagnosed earlier with PNES have an improved long-term seizure prognosis [7-9] and cost reduces substantially after diagnosis [10]. Treatment for ES can involve anti-seizure medications (ASMs), the ketogenic diet, neurostimulators and surgery, whereas standard treatment for PNES without co-morbid ES addresses underlying psychological distress with cognitive behavioral inspired therapy and sometimes psychoactive medications, but not ASMs [11-13]. Approximately 10% of patients with PNES have comorbid ES, although this frequency varies substantially among reports [2, 13, 14].…”