JLE

Epileptic Disorders

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MRI-negative frontal lobe epilepsy with ipsilateral akinesia and reflex activation Volume 10, numéro 4, December 2008

Figure 1 Interictal sleep EEG recording at age 17 years showing frequent, epileptiform sharp and sharp-slow wave discharges over the right frontocentral region, with wide right hemisphere and midline electrode field.

Figure 2 Ictal scalp EEG during a scalp-recorded, habitual seizure. Burst of high voltage fast activity is noted over the right frontocentral area having a wide field but with midline emphasis, followed by late rhythmic theta frequencies in the same location and occurring until the end of the electrographic sequence. Clinical onset corresponded to electrical onset (see video sequence 1).

Figure 3 Ictal SPECT (Tc-HMPAO) performed during a typical seizure. Injection took place 15 seconds after seizure-onset. Hyperperfusion is noted in the right frontal convexity.

Figure 4 Flumazemil PET imaging demonstrating asymmetric metabolism in the left inferior frontal region. FDG PET performed the day prior revealed an additional region of hypometabolism in the left mesial temporal region. Scans were performed after seizure clusters.

Figure 5 Supero-lateral view of implanted electrodes: 48 contacts over the right frontal region, with 8 contact electrode (blue) in the right interhemispheric area. A 16-contact grid was placed epidurally over left frontal lobe, overlapping the central area posteriorly.

Figure 6 Interictal invasive EEG recording. Subdural contacts G1-48 (right convexity), Epidural contacts G49-64 (left frontocentral convexity). Subdural contacts IH 1-8 (right interhemispheric). Continuous epileptiform spike-slow wave discharges emanating from the superior frontal contacts, with wide propagation over inferior dorsolateral contacts, and less frequent epileptiform activity in the right interhemispheric region. Bipolar montage.Epidural contact sensitivity (50 μV/mm) increased to approximate amplitude from the subdural electrodes (150 μV/mm).

Figure 7 Interictal invasive EEG recording in sleep with continuous epileptiform activity seen over the right high frontal convexity contacts. Independent epileptiform activity is noted over the left frontal convexity, maximal anteriorly (contacts 55-56). Referential montage. (Epidural contacts 50 μV/mm; subdural contact 150 μV/mm).

Figure 8 Subdural seizure-onset during habitual seizures. Initial fast activity and attenuation over the superior convexity is followed by rapid involvement of interhemispheric region (see video sequence 2).

Figure 9 Overlay of motor cortex as defined by functional mapping (green), ictal onset zone (blue), SPECT hyperperfusion (orange), and final resection (dark-bordered region including pink).