Concordance
Agreement between different diagnostic modalities in identifying the same seizure focus or epileptogenic zone.
Full Definition
Concordance in epilepsy evaluation refers to the alignment of findings across multiple diagnostic investigations, including seizure semiology, EEG localization, neuroimaging abnormalities, and neuropsychological deficits, all pointing to the same brain region as the seizure source. High concordance between modalities strengthens confidence in surgical decision-making and is associated with better postoperative seizure outcomes. Discordant findings may indicate complex epilepsy syndromes, multiple seizure foci, or the need for additional invasive testing. The degree of concordance is often expressed as complete, partial, or discordant, influencing surgical candidacy and approach.
Usage
Usage note: Should not be confused with 'compliance' or 'adherence' when discussing patient medication concordance - in epilepsy medicine, concordance specifically refers to diagnostic agreement.
In Context
- "Excellent concordance was observed between ictal EEG, MRI findings, and neuropsychological testing, all localizing to the left temporal region." — Multidisciplinary team meeting notes
- "The lack of concordance between imaging and electrophysiological data necessitated invasive monitoring with depth electrodes." — Presurgical evaluation summary