Validation of a German version of the Anxiety, Abuse, and Somatization Questionnaire (AASQ) for functional/dissociative seizures.

INTRODUCTION

The 20-item Anxiety, Abuse, and Somatization Questionnaire (AASQ) was developed by Trainor et al. (2020) to differentiate functional/dissociative seizures (FDS) from epilepsy. The objectives of our study were to validate the German version of the AASQ and to evaluate its diagnostic accuracy in distinguishing between FDS and epileptic seizures.

METHODS

We conducted a single-center prospective study from October 2023 to February 2025. Newly admitted patients with suspected epileptic seizures or FDS were included and completed the German version of the AASQ.

RESULTS

The AASQ was distributed to 184 patients. Of these, 138 were successfully included. We classified the patients into four groups according to the final diagnosis as follows: (1) epilepsy (n = 88); (2) FDS (n = 21); (3) epilepsy and FDS (n = 9); and (4) other (patients with diagnoses other than epilepsy or FDS, n = 20). Patients in the FDS group had higher AASQ scores than patients in the epilepsy group (median number of endorsed items [range]; FDS: 8 [1-20], epilepsy: 4 [0-20]). At a threshold of > 2.4, the AASQ mean score showed a high negative predictive value (NPV = 88%, 95% confidence interval [CI]: 83-91%) and a high specificity for FDS (0.97, 95% CI: 0.90-0.99). With this threshold, we achieved a sensitivity of 0.43 and a positive predictive value of 75%. Including the number of anti-seizure medications in the prediction improved the sensitivity to 0.76.

SIGNIFICANCE: The German version of the AASQ serves as a concise screening instrument supporting the differential diagnosis between FDS and epileptic seizures. It shows only moderate sensitivity but high specificity and NPV and thus enables the exclusion of FDS in cases with low scores with high confidence.