Diagnostic Uncertainty in Patients with New Onset Paroxysmal Spells: A Prospective Study

Abstract

Background: Differentiating between a seizure and a non-epileptic spell based on the description of the event can be challenging. An attempt to categorically establish a diagnosis in such cases is prone to errors and such events should be labeled as paroxysmal spells of uncertain nature (PSUN). In this study, we assessed the frequency of PSUN in patients with new onset paroxysmal spells, evaluated the reasons for including patients in this category and calculated the rates of misdiagnoses if the epileptologists were compelled to provide a diagnosis.

Methods: Patients enrolled participated in a prospective study evaluating children and adults with suspected new-onset seizure(s). Two epileptologists classified patients into those with definite diagnoses or PSUN based on the semiology of the spells, and the inter-rater agreement was calculated.

Findings: 255/1880 (13.6%) patients were included in the PSUN group. Patients with PSUN were significantly younger than those with a definite diagnosis. Within the pediatric population, PSUN were significantly more frequent in those with developmental delay compared to children with normal development. The most common reason for including patients in the PSUN group was the inability to categorically discriminate between a seizure and a non-epileptic mimicker. When compelled to provide a diagnosis in the PSUN group, the erroneous diagnoses reached 37.5%.

Interpretation: This is the largest prospective study conducted in patients with new onset paroxysmal spells. In this study we demonstrated that PSUN are not uncommon, are more frequent in the pediatric age group and in children with developmental delay. This diagnostic category should be recognized and used in clinical practice. Acknowledging this uncertainty will result in a lower frequency of erroneous diagnoses.

Funding Statement: Funded in part by grants from the Lebanese National Council for Scientific Research (Grant number: LCR 114110 522214) and the American University of Beirut (Grant number: 1131613 52480 115372099990000).

Declaration of Interests: All authors have nothing to disclose.

Ethics Approval Statement: The Institutional Review Board of the AUBMC approved this study, and all patients or their parents signed an informed consent form. Children between the ages of 7-17 years signed an assent form.