Concordance between fMRI and Wada test for memory lateralization in temporal lobe epilepsy: A meta-analysis and systematic review

Andreu Massot-Tarrús; Kevin P White; Seyed Reza Mousavi; Susan Hayman-Abello; Brent Hayman-Abello; Seyed M Mirsattari

doi:10.1016/j.yebeh.2020.107065

Concordance between fMRI and Wada test for memory lateralization in temporal lobe epilepsy: A meta-analysis and systematic review

Epilepsy Behav. 2020 Jun:107:107065. doi: 10.1016/j.yebeh.2020.107065. Epub 2020 Apr 7.

Authors

Andreu Massot-Tarrús¹, Kevin P White², Seyed Reza Mousavi³, Susan Hayman-Abello⁴, Brent Hayman-Abello⁴, Seyed M Mirsattari⁵

Affiliations

¹ Department of Neurology, Hospital General Universitario Gregorio Marañón, Madrid, Spain. Electronic address: andreu.massot@salud.madrid.org.
² Science Right Research Consulting, London, Ontario, Canada.
³ Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada; Department of Physiology and Pharmacology, Western University, London, Ontario, Canada.
⁴ Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
⁵ Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; Department of Medical Imaging, Western University, London, Ontario, Canada; Department of Psychology, Western University, London, Ontario, Canada.

PMID: 32276205
DOI: 10.1016/j.yebeh.2020.107065

Abstract

Objective: The Wada test (WT) is increasingly being replaced by functional magnetic resonance imaging (fMRI) to evaluate memory lateralization before temporal lobe epilepsy (TLE) surgery. We aimed to determine, via meta-analysis, agreement between the two tests and identify predictors of disagreement.

Methods: We performed a systematic search for studies comparing WT and fMRI for memory lateralization with individual-patient data. If results were provided as laterality indexes instead of hemispheric lateralization, the cutoff point for memory lateralization was set to the usual ±2 for WT and ±0.20 for fMRI. We also evaluated results at our Epilepsy Center.

Results: Seven published series plus our own were included, comprising 124 patients. Wada test was performed by recognizing objects in half of the studies, and scenes, drawings, and words in the rest. All used scenes or pictures encoding for fMRI. Wada test-fMRI agreement across the studies ranged from 21.1 to 100%, averaging 46.8% (95% confidence interval [CI]: 37.6-56.0%). When cases with bilateral memory in either test were excluded, agreement reached 78.7% (95% CI: 67.6-89.8%), and concordance with contralateral TLE foci 86.4% for the WT and 83.0% for fMRI. Higher agreement was associated with using multiple items during WT (p = 0.001) and higher disagreement with presence of a lesion on MRI (p = 0.024). Binary logistic regression confirmed use of multiple items on WT as the strongest predictor of agreement (odds ratio [OR]: 6.95, 95% CI: 1.84-26.22; p = 0.004) and a bilateral result on the WT or fMRI of disagreement (OR: 0.24, 95% CI: 0.07-0.89 and OR: 0.12, 95% CI: 0.03-0.45; p < 0.05).

Conclusion: Concordance between WT and fMRI for memory lateralization is low in patients with TLE and bilateral memoryl memory distribution or a structural etiology, and it improves with encoding of a varied set of items. Both tests can help to lateralize the TLE foci.

Keywords: Functional MRI; Global amnesia; IAT; Intracarotid amobarbital test; Surgery; Surgical outcome.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Adult
Epilepsy, Temporal Lobe / diagnostic imaging*
Epilepsy, Temporal Lobe / physiopathology
Female
Functional Laterality / physiology*
Humans
Magnetic Resonance Imaging / methods
Magnetic Resonance Imaging / standards*
Male
Memory / physiology*
Middle Aged
Neuropsychological Tests / standards*
Preoperative Care / methods
Preoperative Care / standards
Visual Perception / physiology