The effects of unilateral and bilateral ECT on verbal and visual spatial memory

S, Loo CK. A systematic review and computational modelling analysis of unilateral montages in electroconvulsive therapy Objective: To examine the clinical outcomes of ECT unilateral placements compared in prior studies and apply insights from computational modelling to understand differences between placements. Methods: PubMed, Embase, Scopus and PsycINFO and reference lists were systematically searched for studies of depressed patients where two unilateral placements were compared and clinical outcomes were reported. Computational modelling was done to generate electric field maps for each unilateral placement identified in the systematic review. Results: A total of 29 studies met criteria for inclusion. Eight studies reported efficacy outcomes and 23 studies reported cognitive outcomes. Most studies found no significant difference in efficacy between right unilateral (RUL) and left unilateral (LUL) ECT, and no difference was found between temporo-parietal and fronto-temporal ECT. For the majority of studies, RUL placements had better verbal anterograde memory outcomes compared with the LUL placements. There was some evidence suggestive of cognitive advantages for fronto-frontal and fronto-parietal placements relative to temporo-parietal ECT. Conclusions: For efficacy, studies mainly focused on the comparison of right vs. left hemispheric stimulation, with the available evidence suggesting no substantive difference. RUL placements tended to have better verbal anterograde memory outcomes relative to LUL placements, though limited differences were found between the RUL placements.• RUL and LUL ECT were found to be comparable in efficacy in most studies.• RUL tended to have better verbal memory outcomes relative to LUL ECT placements. • Fronto-frontal and fronto-parietal placements may be superior to temporo-parietal placement in cognitive outcomes. Limitations• The included studies were small, and heterogeneous in methodology and the reporting of treatment methods and clinical outcomes.• Insufficient report of unilateral montage details in the included studies may have hindered the accuracy of interpreting the clinical outcomes and computational modelling. 408

Section: Resultsmentioning

confidence: 99%

A systematic review and computational modelling analysis of unilateral montages in electroconvulsive therapy

Martin

Lin

Bai

et al. 2019

“…Most of these assessments were administered within a few minutes to a few days following treatment, and it is therefore unclear to what degree any verbal dysfunction persists. Halliday et al and Cronin et al found that patients receiving LUL ECT were still impaired on tests of verbal memory 4+ weeks post‐treatment; conversely, Jackson found that all verbal decrements had resolved by 10 days post‐treatment, and Chatterjee et al found no difference in memory scores between electrode placement groups after 3 weeks.…”

Section: Discussionmentioning

confidence: 98%

“…Jackson (1978) randomized 46 male right‐handed patients of unspecified diagnoses to BL, RUL, LUL ECT, or a no‐ECT control group. Thirty minutes after the sixth treatment, all ECT groups showed a decline in verbal and nonverbal memory scores compared to the control group.…”

Section: Literature Reviewmentioning

confidence: 99%

A systematic review of left unilateral electroconvulsive therapy

Kellner

Farber

Chen

et al. 2017

Overall, the efficacy of LUL electrode placement for the treatment of depression and psychosis is similar to that of right unilateral (RUL) and bilateral (BL) electrode placements. Patients receiving LUL ECT tend to experience more verbal memory impairment than patients receiving RUL ECT, but less verbal impairment than patients receiving BL ECT. In contrast, patients receiving LUL ECT tended to experience the least visual and nonverbal memory impairment, compared to patients receiving RUL or BL ECT.

“…In seven other studies, either statistically insignificant or small mean differences between bilateral and nondominant unilateral ECT were found using memory tasks that made verbal processing difficult (1,5,10,20,24,27,28). In their study, recognition of common objects was worse following bilateral than nondominant unilateral ECT.…”

Section: Nonverbal Memorymentioning

confidence: 89%

Acute memory impairment following electroconvulsive therapy

1983

The literature concerning acute changes in memory functions following electroconvulsive therapy (ECT) varying in stimulus electrode placement is reviewed. While it is clear that verbal memory deficits are greater following dominant unilateral (or bilateral) ECT than nondominant unilateral ECT, a definitive state ment regarding nonverbal memory and electrode placement cannot be made due to methodological inadequacies of existing studies. The role of time before and after seizure induction is examined in relation to degree of retrograde amnesia, and possible causes o f greater amnesia following bilateral than unilatmal ECT are examined. Practical issues related to the choice of electrode placement are discussed.