Abstracts

Stereotactic Laser Amygdalohippocampectomy Results in More Favorable Executive Function Outcomes Than Anterior Temporal Lobectomy in Patients with Non-dominant Temporal Lobe Epilepsy

Abstract number : 3.36
Submission category : 11. Behavior/Neuropsychology/Language / 11A. Adult
Year : 2022
Submission ID : 2205014
Source : www.aesnet.org
Presentation date : 12/5/2022 12:00:00 PM
Published date : Nov 22, 2022, 05:27 AM

Authors :
Hyun Jin Kang, BA – University of Washington; Kyle Hulse, BS – University of Washington; Benjamin Grannan, MD – University of Washington; Jeffrey Tsai, MD, PhD – University of Washington; Shahin Hakimian, MD – University of Washington; Jason Hauptman, MD, PhD – University of Washington; Jeffrey Ojemann, MD – University of Washington; Andrew Ko, MD – University of Washington; Michelle Kim, PhD – University of Washington

Rationale: While cognitive outcomes following anterior temporal lobectomy (ATL) and stereotactic laser amygdalohippocampectomy (SLAH) are well-established in the treatment of dominant temporal lobe epilepsy, cognitive impacts in non-dominant epilepsy are not well understood. In this retrospective study, we examined pre- and post-operative cognitive outcomes on a task of executive function in patients who underwent ATL or SLAH.    

Methods: A retrospective review of all ATL and SLAH epilepsy surgeries performed at the University of Washington from 2014 to 2020 identified a total of 26 patients (12 ATL, 14 SLAH) who met the following inclusionary criteria: (1) underwent either functional MRI or WADA testing to determine hemisphere dominance or (2) had both pre- and post-operative neuropsychological evaluation. Performance on the Delis-Kaplan Executive Function System (DKEFS) Color-Word Interference Test (CWIT) Condition 3, a measure of inhibition and mental flexibility was examined. Scaled scores, obtained for completion time on this task were converted to z scores. A paired sample t-test was used to compare pre- and post-operative CWIT Condition 3 performance for patients who underwent ATL and SLAH.

Results: Among the 14 patients who underwent SLAH, 3 were operated on the left and 11 on the right side. All 12 patients had ATL performed on the right side. The average number of months passed since surgery to post-operative neuropsychological evaluation was 14.4 months (SD= 4.67). Compared to ATL patients who demonstrated no significant change on Condition 3 of the CWIT (m pre-op= -0.003, m post-op= 0.18, p=0.73, n =10), there was a significant increase in those with SLAH (m pre-op= -0.21, m post-op=0.52, p=0.019, n = 5). There was no significant difference between pre-operative starting values between the two groups (p=0.62). This finding was even greater when we used the executive functioning composite score, adding patients to our sample that met inclusionary criteria and were administered a similar task, the Color-Word trial of the Stroop Test (Golden Version) (n=10). Analyses revealed patients with SLAH improved significantly (m pre-op= -0.43, m post-op= 0.43, p=0.004, n=13), while patients with ATL showed no significant difference (m pre-op= 0.12, m post-op=0.33, p=0.66, n=12).

Conclusions: Our findings demonstrated that patients who underwent SLAH showed a mild improvement in executive function performance of inhibition and mental flexibility while those who underwent ATL did not, potentially supporting SLAH’s surgical goal specifically targeting mesial temporal structures involved in seizure onset while preserving white matter tracts that may project to frontal regions. Provided the nature of these repeated evaluations however, the potential impact of practice effects should be considered. Future investigation should consider other potential contributing factors to executive function performance, such as seizure freedom or the effect of antiepileptic drugs. 

Funding: None
Behavior