A minority of patients with functional seizures have abnormalities on neuroimaging

Abstract

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Clinical MRI morphological analysis of functional seizures compared to seizure-naïve and psychiatric controls

“…Due to the relative infrequency of psychiatric conditions other than depression, anxiety, and PTSD; the other psychiatric conditions were summarized by a miscellaneous category and counted within a ''number of psychiatric conditions" category. This time period of January 2006 to December 2020 was based on data availability from our prior work including clinical information, EEG, and FDG-PET, with a stopping point based on when this analysis started [5,32].…”

“…We allowed mild abnormalities because such abnormalities may be related to FS in ways yet unknown. A substantial minority of patients with FS have radiologically apparent abnormalities, so exclusion of these patients could cause our sample to be less representative of the broader population of patients with FS [32,36]. Alternatively, abnormalities in FS may be reported at higher rates due to framing bias [32].…”

“…A substantial minority of patients with FS have radiologically apparent abnormalities, so exclusion of these patients could cause our sample to be less representative of the broader population of patients with FS [32,36]. Alternatively, abnormalities in FS may be reported at higher rates due to framing bias [32]. In particular, the high prevalence of temporal lobe epilepsy and additional dedicated sequences focused on temporal lobe morphology in the ''epilepsy protocol" MRI can lead to high detection rates for putative hippocampal sclerosis and atrophy [32].…”

“…Alternatively, abnormalities in FS may be reported at higher rates due to framing bias [32]. In particular, the high prevalence of temporal lobe epilepsy and additional dedicated sequences focused on temporal lobe morphology in the ''epilepsy protocol" MRI can lead to high detection rates for putative hippocampal sclerosis and atrophy [32]. This analysis could delineate if these radiologically reported mesial temporal lobe changes reflected either subjective interpretation or quantitative morphometric differences.…”

“…There is growing evidence that quantitative neuroimaging can demonstrate differences in brain structure as well as structural and functional connectivity associated with FS and, more broadly, with the category of functional neurological disorder (FND) [19,[31][32][33][34][35][36][37][38][39][40][41][42]. Broadly, FND has been associated with above-normal connectivity between affective brain areas and higher order motor control networks, as well as with below-normal connectivity and dysfunction of executive control areas [43].…”