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

Abstract

a b s t r a c t a r t i c l e i n f oObjective: Early and accurate diagnosis of patients with psychogenic nonepileptic seizures (PNES) leads to appropriate treatment and improves long-term seizure prognosis. However, this is complicated by the need to record seizures to make a definitive diagnosis. Suspicion for PNES can be raised through knowledge that patients with PNES have increased somatic sensitivity and report more positive complaints on review-of-systems questionnaires (RoSQs) than patients with epileptic seizures. If the responses on the RoSQ can differentiate PNES from other seizure types, then these forms could be an early screening tool. Methods: Our dataset included all patients admitted from January 2006 to June 2016 for videoelectroencephalography at UCLA. RoSQs prior to May 2015 were acquired through retrospective chart review (n = 405), whereas RoSQs from subsequent patients were acquired prospectively (n = 190). Controlling for sex and number of comorbidities, we used binomial regression to compare the total number of symptoms and the frequency of specific symptoms between five mutually exclusive groups of patients: epileptic seizures (ES), PNES, physiologic nonepileptic seizure-like events (PSLE), mixed PNES plus ES, and inconclusive monitoring. To determine the diagnostic utility of RoSQs to differentiate PNES only from ES only, we used multivariate logistic regression, controlling for sex and the number of medical comorbidities. Results: On average, patients with PNES or mixed PNES and ES reported more than twice as many symptoms than patients with isolated ES or PSLE (p b 0.001). The prospective accuracy to differentiate PNES from ES was not significantly higher than naïve assumption that all patients had ES (76% vs 70%, p N 0.1). Discussion: This analysis of RoSQs confirms that patients with PNES with and without comorbid ES report more symptoms on a population level than patients with epilepsy or PSLE. While these differences help describe the population of patients with PNES, the consistency of RoSQ responses was neither accurate nor specific enough to be used solely as an early screening tool for PNES. Our results suggest that the RoSQ may help differentiate PNES from ES only when, based on other information, the pre-test probability of PNES is at least 50%.

Identifying psychogenic seizures through comorbidities and medication history

“…Contrary to our hypothesis that patients with PNES have more comorbidities, a substantial subpopulation of patients with PNES do not have more medical comorbidities than patients with ES. This is consistent with our recent publication that the many patients with PNES did not have a broadly positive review-of-systems 22 .…”

“…In addition to more review-of-systems complaints 22 , our results suggest that patients with PNES have more symptoms attributed to clinical conditions requiring medication. The absolute number of conditions and medications provided more information than the identity of the specific conditions with a few key exceptions: asthma, chronic pain, migraines, diabetes mellitus and non-metastatic cancer.…”

“…This is consistent with our recent finding that the many patients with PNES did not have a broadly positive review-of-systems. 22 Assessment of other aspects of the patient's history, such as ictal behavior and risk factors of sexual abuse and traumatic brain injury, may raise the specificity by identifying characteristics of patients with PNES who do not have more medical comorbidities. Therefore, our score should be one part of a detailed patient assessment by a health care provider, and not a replacement for the clinical interview and diagnostic testing.…”

“…Patients with PNES report more positive symptoms on review of systems questionnaires 22 and frequently are diagnosed with other medical comorbidities associated with psychiatric disorders including asthma 23 , chronic pain 9 , and fibromyalgia 9 . These comorbidities and other medically unexplained symptoms have an impact upon patients’ quality of life 24–26 .…”

“…20 Most frequently, PNES are a sign of conversion disorder where patients express and cope with psychological stressors through physical symptoms. 1,14,21 Patients with PNES report more positive symptoms on review of systems questionnaires 22 and frequently are diagnosed with other medical comorbidities associated with psychiatric disorders including asthma, 23 chronic pain, 9 and fibromyalgia. 9 These comorbidities and other medically unexplained symptoms have an impact upon patients' quality of life.…”