Abstracts

Diagnostic Yield of MRI for Focal Cortical Dysplasia in Epilepsy Surgery Patients: A Retrospective Cohort Study

Abstract number : 3.323
Submission category : 5. Neuro Imaging / 5A. Structural Imaging
Year : 2025
Submission ID : 423
Source : www.aesnet.org
Presentation date : 12/8/2025 12:00:00 AM
Published date :

Authors :
Presenting Author: Ahmel Arshad, DO – Northwell

Fred Lado, MD – Zucker School of Medicine at Hofstra/Northwell

Rationale: Focal cortical dysplasia (FCD) is a common etiology of drug-resistant epilepsy and a frequent histopathologic finding in patients undergoing epilepsy surgery. Subtle imaging characteristics may make detection difficult even on epilepsy protocol MRI, leading to potential delays in diagnosis/treatment. We aimed to assess the diagnostic accuracy of MRI in identifying FCD among patients with pathologically confirmed FCD, and to assess trends in time delays from MRI to diagnosis based on initial MRI differentials. 

Methods: We retrospectively reviewed epilepsy surgery patients at [] between [Years]. Patients with a pathological diagnosis of FCD were included. Initial or earliest available pre-surgical MRI reports were categorized as: (1) FCD explicitly diagnosed/listed in the differential; (2) alternative abnormality reported; or (3) normal/unremarkable or explicitly no FCD. FCD location (hemisphere, lobe) was also recorded. 

Results:

Of 40 patients reviewed, 27 (67.5%) had pathologically confirmed FCD. 

  • 3/27 (11%) had MRI reports explicitly diagnosing FCD. 

  • 11/27 (41%) had alternative MRI findings, including gliosis, encephalomalacia, cavernoma, angioma, old infarct, or mesial temporal sclerosis (MTS); 4/11 specifically listed MTS. 

  • 13/27 (48%) had MRIs read as normal or explicitly stated no evidence of FCD. 

  •  

Anatomical distribution of FCD was as follows: 

  • Laterality: 18 left-sided (67%), 9 right-sided (33%) 

  • Lobar: 19 temporal (70%), 4 frontal (15%), 2 parietal (7%), 1 occipital (4%), 1 unspecified (4%) 

 

Among the 27 patients with pathologically confirmed focal cortical dysplasia (FCD), time from initial MRI to final diagnosis varied substantially across MRI interpretation categories.  

  • Patients whose MRIs were explicitly suggestive of FCD experienced the shortest diagnostic delays (median 24.0 months, mean 20.0 months) 

Neuro Imaging