Interictal scalp electrode recordings of generalized spikes, maximum in the central regions (Cz>Fz), and invasive electrode recording of bilateral mesio-frontal spikes, maximum in the left anterior cingulate region (le2/le3 and lf1/lf2).
Second-stage bilateral EEG implantation with six orthogonally placed electrodes in the right (A) and left frontal lobe (B).
(A) A 250-Hz high-frequency oscillation pattern was seen over-riding the sharp-wave population arising only from the RB1/RB2 electrodes in the right anterior cingulate region, in the inferior bank of the cingulate sulcus, anterior to the genu of the corpus callosum. (B) An evolving ictal onset high-frequency discharge is seen in the same electrode contacts RB1/RB2. (High-frequency filtre: 600 Hz; time constant: 0.0001 ms).
Post-operative MRI shows right medial frontal resection in saggital T1 (A) and axial T2-weighted (C) images. Second-stage bilateral EEG implantation with six orthogonally placed electrodes in right frontal lobe (B).
NeuN immunohistochemistry demonstrating several heterotopic neurons in deep white matter (200x) (A), normal neurons with disoriented dendrites (200x) (B), and hypertrophic neurons in the cortex, outside layer 5 (100x) (C).