case_images: PMC11269090_01
case_images: (A) Scalp EEG demonstrating interictal slow spike-and-wave with an internal frequency of 1.5 Hz and (B) GPFA though with increased amplitude over the right frontal region. (C) Ictal scalp EEG showing evolving low-amplitude fast activity at the onset of the complex motor seizure. (D) Intracranial depth electrode monitoring placement map showing overall implantation strategy as well as locations of mesial-frontal contacts. (E) Ictal stereo-EEG confirming a focal onset at the right cingulate gyrus with the patient's typical seizure, occurring 1 s before broad network involvement. mF1, mesial superior frontal gyrus; PFC ant, anterior prefrontal cortex; CG genu, pregenual cingulate gyrus; rF2, rostral middle frontal gyrus; dmPFC, dorsomedial prefrontal cortex; rCMA, rostral cingulate motor area; cF2, caudal middle frontal gyrus; FEF, frontal eye field; cCMA, caudal cingulate motor area; cF1, caudal superior frontal gyrus.
case_images: fnetp-04-1425329-g001.jpg
case_images: PMC11269090_01_fnetp-04-1425329-g001.jpg
case_images: F1
case_images: Video electroencephalography (VEEG) demonstrated frequent interictal generalized paroxysmal fast activity (GPFA) and generalized slow spike/poly-spike-and-wave discharges but with a consistent right fronto-central predominance (Figure 1). Both ictal recordings and intracranial stimulation confirmed that his seizures were focal and arose from the right cingulate gyrus (Figure 1), characterized by low-voltage fast activity first developing in the right cingulate contacts before spread to the remainder of the frontal networks occurring between 1 and 2 seconds into the seizure.
case_images: PMC11269090_02
case_images: (A) T1 MRI-brain overlaid with FDG-PET demonstrating right mesial superior frontal gyrus hypometabolism. (B) Interictal scalp EEG showing apparent generalized slow spike-and-wave discharges with a right frontal predominance. (C) Ictal scalp EEG during a habitual asymmetric tonic seizure showing evolving low-amplitude fast activity with aftercoming slowing.
case_images: fnetp-04-1425329-g002.jpg
case_images: PMC11269090_02_fnetp-04-1425329-g002.jpg
case_images: F2
case_images: Like Case 1, VEEG demonstrated generalized slow spike-and-wave discharges with a right frontal predominance (Figure 2). FDG-PET demonstrated mild hypometabolism of the right mesial superior frontal gyrus (Figure 2).