A Minority of Patients with Functional Seizures Have Abnormalities on Neuroimaging
Abstract number :
3.24
Submission category :
5. Neuro Imaging / 5A. Structural Imaging
Year :
2021
Submission ID :
1825860
Source :
www.aesnet.org
Presentation date :
12/6/2021 12:00:00 PM
Published date :
Nov 22, 2021, 06:50 AM
Authors :
Wesley Kerr, MD, PhD - University of Michigan; John Lee - University of California, Los Angeles; Amir Karimi - University of California, Los Angeles; Hiroyuki Tatekawa - University of California, Los Angeles; L Brian Hickman - University of California, Los Angeles; Michael Connerney - University of California, Los Angeles; Siddhika Sreenivasan - University of California, Los Angeles; Ishita Dubey - University of California, Los Angeles; Corinne Allas - University of California, Los Angeles; Jena Smith - University of California, Los Angeles; Ivanka Savic - Karolinska Institute of Neurology; Daniel Silverman - University of California, Los Angeles; Lubomir Hadjiiski - University of Michigan; Nicholas Beimer - University of Michigan; William Stacey - University of Michigan; Mark Cohen - University of California, Los Angeles; Jerome Engel - University of California, Los Angeles; Jamie Feusner - University of California, Los Angeles; Noriko Salamon - University of California, Los Angeles; John Stern - University of California, Los Angeles
Rationale: Functional seizures often are managed incorrectly as a diagnosis of exclusion and are considered when epileptic seizures are felt to be unlikely. However, a significant minority of patients with functional seizures may have abnormalities on neuroimaging that typically are associated with epilepsy, leading to diagnostic confusion.
Methods: We studied radiologists’ reports from neuroimages acquired at our comprehensive epilepsy center from a consecutive series of patients diagnosed with functional seizures without comorbid epilepsy from 2006 to 2019. We summarized the MRI, FDG-PET, and CT results into the following categories: within normal limits, incidental findings, unrelated findings, non-specific abnormalities, post-operative study, epilepsy risk factors (ERF), borderline epilepsy-associated findings (EAF), and definitive EAF.
Results: Of the 256 MRIs, 24% demonstrated ERF (5%), borderline EAF (8%), or definitive EAF (10%). The most common EAF was hippocampal sclerosis, with the majority of borderline EAF comprising hippocampal atrophy without T2 hyperintensity or vice versa. Of the 87 FDG-PETs, 26% demonstrated borderline EAF (17%) or definitive EAF (8%). Epilepsy-associated findings primarily included focal hypometabolism, especially of the temporal lobes, with borderline findings including subtle or questionable hypometabolism. Of the 51 CTs, only 2% had definitive EAF.
Conclusions: This large case series provides further evidence that, while uncommon, EAF are seen in patients with functional seizures. A significant portion of these abnormal findings are borderline. The moderately high rate of these abnormalities may represent framing bias from the indication of the study being “seizures,” the relative subtlety of EAF, or effects of antiseizure medications.
Funding: Please list any funding that was received in support of this abstract.: NIH R25 NS065723, T32 GM08042, T90 DA022768, R90 DA022768, R90 DA023422, T32 GM008185, R01 NS033310, & P20 NS080181. William M. Keck Foundation.
Neuro Imaging