Abstracts

Patient Risk Factors for Technical and Interpretive Limitations in the Intracarotid Amobarbital Procedure (Wada Test)

Abstract number : 2.308
Submission category : 11. Behavior/Neuropsychology/Language / 11A. Adult
Year : 2022
Submission ID : 2204188
Source : www.aesnet.org
Presentation date : 12/4/2022 12:00:00 PM
Published date : Nov 22, 2022, 05:23 AM

Authors :
Jeffrey Portnoy, PhD – Lenox Hill Hospital; Daliah Ross, MA – Yeshiva University; Beril Yaffe, PhD – Neuropsychologist, Neurology, Lenox Hill Hospital; Anna Bank, MD – Neurologist, Neurology, Lenox Hill Hospital

Rationale: The intracarotid amobarbital procedure (IAP, or Wada test) is used to lateralize language and memory in epilepsy surgery candidates, with the goal of reducing postsurgical cognitive decline. However, IAP is invasive, and procedural complications may result in inconclusive findings. Some institutions favor less invasive methods of presurgical assessment, such as functional imaging or magnetoencephalography. Prior research has produced mixed findings in predicting which patients are likely to encounter complications during IAP that affect the tolerability and interpretability of the procedure. The current research aims to determine what factors may predict the likelihood of IAP failing to yield conclusive findings.

Methods: Retrospective chart review was conducted for 22 patients with intractable epilepsy who underwent IAP. Demographic characteristics and neurological, psychiatric, and neuropsychological variables were recorded. Exact test and Mann-Whitney U test assessed the relationship between these factors and IAP interpretability. Receiver operating characteristic (ROC) analysis further described statistically significant predictors of interpretability. Optimized predictive cutoffs were selected using maximum Youden’s J.

Results: Complications during four IAPs (18.2%) resulted in significant interpretive limitations. Demographic characteristics, handedness, seizure focus, benzodiazepine naiveté, emotional factors, motor performance, verbal memory scores, and confrontation naming did not predict IAP interpretability. Estimated premorbid IQ (P = .010), current full-scale IQ (P = .020), phonemic fluency (P = .013), and semantic fluency (P = .040) were significant predictors of IAP interpretability. These factors each produced strong and significant models by ROC analysis (AUC ranging from .864 to .932). Intellect-based cutoffs for increased likelihood of uninterpretable Wada were premorbid IQ < 76 or current full-scale IQ < 75.

Conclusions: Several neuropsychological variables, including low baseline or present intellectual functioning, are associated with likelihood of uninterpretable IAP. In patients whose scores fall below these cutoffs, the greater risk of inconclusive findings should be considered in the clinical decision-making process about whether to perform this procedure.

Funding: No external sources of funding
Behavior