Poster Session 09 Program Schedule
02/16/2024
03:30 pm - 04:45 pm
Room: Shubert Complex (Posters 1-60)
Poster Session 09: Epilepsy | Oncology | MS | Infectious Disease
Final Abstract #44
Utilizing Shortened Versions of the SIMS to differentiate PNEE and Epilepsy in a Veteran-Based Epilepsy Monitoring Unit
Huda Abu-Suwa, Michael E. DeBakey VA Medical Center, Houston, United States
Jonathan Grabyan, Michael E. DeBakey VA Medical Center, Houston, United States
Holley Yazbeck, Michael E. DeBakey VA Medical Center, Houston, United States
Category: Epilepsy/Seizures
Keyword 1: validity (performance or symptom)
Keyword 2: symptom validity
Objective:
The Structured Inventory of Malingered Symptomatology (SIMS) is a measure of impression management that covers a range of symptomatology through 75 items and five scales, some of which are particularly relevant for cognitive evaluations. The SIMS has been utilized to differentiate PNEE and Epilepsy in Veterans, although the literature has been inconsistent in its effectiveness. Four shortened versions of the SIMS have been identified in the literature for the purposes of improving time efficiency and focusing on targeted areas of feigning, such as feigning of cognitive or mental disorders, or focusing on infrequently endorsed items. Shortened versions may increase clinical utility for specific populations by focusing on relevant symptoms of interest. As such, the purpose of the current study is to evaluate the utility of four shortened versions of the SIMS in terms of their ability to identify PNEE and Epilepsy in an inpatient EMU. It is hypothesized that the SIMS-NS and NS-NI-11 will demonstrate the strongest utility for differentiating PNEE and Epilepsy.
Participants and Methods:
Sample consisted of 197 (131 PNEE; 66 Epilepsy) inpatient veterans on a long-term video electroencephalogram epilepsy monitoring unit (EMU). Participants were diagnosed by epileptologist using EMU, which is considered the gold standard for evaluating epilepsy. Those with inconclusive, mixed, or other seizure disorder diagnoses were excluded from the study. The SIMS was completed with each participant as part of a larger test battery. Shortened versions of the SIMS included the following: Rare Symptoms (SIMS-RS), Symptom Combination (SIMS-SC), Short Form (SIMS-SF), and SIMS for Neuropsychological Settings (SIMS-NS). Additionally, the SIMS-NS consists of two subscales that were examined: Amnestic Disorders (NS-AM-8) and Neurological Impairment (NS-NI-11). These four shortened forms, as well as the two subscales from the SIMS-NS, were evaluated in this study.
Results:
ROC curve analysis revealed an optimal cut-scores for identifying PNEE, maintaining a specificity of at least .85, as follows: SIMS-RS (AUC = .497, p = .942) cut-score ≥ 3; SIMS-SC (AUC = .601, p = .021) cut-score ≥ 4; SIMS-SF (AUC = .634, p = .002) cut-score ≥ 19; SIMS-NS (AUC = .649, p <.001) cut-score ≥ 12; NS-NI-11 (AUC = .661, p <.001) cut-score ≥ 8; and NS-AM-8 (AUC = .593, p = .034) ≥ 6.
Conclusions:
The shortened versions of the SIMS demonstrated a poor ability to discriminate between PNEE and ES in an inpatient EMU, though versions emphasizing neurology symptoms showed the largest AUC. This suggests that creation of a shortened version of the SIMS focusing on symptoms experienced specifically in this population may be warranted in the future.
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