Converting “nonlesional” imaging occult epilepsy into a focal lesional entity using advanced imaging techniques: illustrative case

Authors

Muhammad Usman Khalid, University of Kentucky
Flavius D. Raslau, University of KentuckyFollow
Valentinos Zachariou, University of KentuckyFollow
David Powell, University of Kentucky
Zachary Winder, Washington University, St. Louis
Ryan Cloyd, Indiana University, Indianapolis
Sarah Helen Thomas, University of KentuckyFollow
John Kuipers, University of Kentucky
Rachel Ward Mitchell, University of Kentucky
Riham H. El Khouli, University of KentuckyFollow
Timothy J. Ainger, University of Kentucky
Sally Mathias, University of Kentucky
Farhan A. Mirza, University of KentuckyFollow

Abstract

BACKGROUND To achieve the best possible outcome in surgical refractory epilepsy, the seizure onset zone must be accurately identified prior to treatment.

OBSERVATIONS A 38-year-old man presented with tonic-clonic and focal seizures 2–3 times per month, refractory to antiseizure medications. Scalp EEG, MRI, PET, ictal SPECT, magnetoencephalography, and stereo-EEG (SEEG) did not provide conclusive seizure onset zone localization. Subsequently, the patient was included in the authors’ ongoing postictal arterial spin labeling (ASL) study and additional postprocessing was performed with a morphometric analysis program (MAP) and texture analysis. Using these results, the authors reexamined the original structural MR images, with attention paid to the patient’s semiology. A subtle focal cortical dysplasia at the junction of the anterior bank of the right precentral gyrus and the precentral sulcus was identified, confirmed with repeat SEEG, and safely resected without functional deficits. The patient is now seizure free at 2 years.

LESSONS Advanced imaging techniques, including ASL, MAP, and texture analysis, can manifest seemingly occult epileptogenic foci. Thorough MRI re-review with updated information and new postprocessing tools may be a necessary step in challenging cases.

Document Type

Article

Publication Date

2025

Notes/Citation Information

© 2025 The authors, CC BY-NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Digital Object Identifier (DOI)

https://doi.org/10.3171/CASE24667

Funding Information

The FINDERS research group is supported by the University of Kentucky College of Medicine through the Alliance Initiative, and the Department of Neurosurgery NEUSTAR awards.

Repository Citation

Khalid, Muhammad Usman; Raslau, Flavius D.; Zachariou, Valentinos; Powell, David; Winder, Zachary; Cloyd, Ryan; Thomas, Sarah Helen; Kuipers, John; Mitchell, Rachel Ward; El Khouli, Riham H.; Ainger, Timothy J.; Mathias, Sally; and Mirza, Farhan A., "Converting “nonlesional” imaging occult epilepsy into a focal lesional entity using advanced imaging techniques: illustrative case" (2025). Neurosurgery Faculty Publications. 17.
https://uknowledge.uky.edu/neurosurgery_facpub/17