Epilepsy & Behavior 44 (2015) 258–259
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Letter to the Editor “Chapeau de gendarme” — A frontomesial ictal sign?
To the Editor Seizures with symptomatic zone in the frontal lobe present with a plethora of clinical signs . Recently, “chapeau de gendarme” (CG, ictal pouting) was presented as a sign of frontal origin . In particular, two areas were identiﬁed with respect to accompanying symptoms. Patients with seizures involving the rostral parts of
Brodmann's area 24 and 32 and ventral areas of 32 and 33 (“affective division”) presented with ictal pouting and emotional expression, hypermotor behavior, open eyes, and staring. However, patients with seizures originating in or propagating to the dorsal parts of Brodmann's area 24 and 32 (“cognitive division”) usually show no emotional expression and have their eyes closed . Data were extracted from 11 successfully operated, i.e., seizure-free, patients with ictal pouting out of 79 patients operated for intractable focal frontal lobe epilepsy. Chapeau de gendarme might undergo selection bias in that only cases are reported that fulﬁll the hypothesis of frontal involvement. In general, data generation on this topic is difﬁcult as invasive recording
Fig. 1. The MRI shows the right and left hemispheres (mesial view) with frontomesial electrodes in place (indicated by the letters A, B, and C), above. Epoch of invasive recording (15 s) with all invasive electrodes including frontomesial electrodes (A, B, C). The red arrow indicates the point of time of picture with chapeau gendarme sign.
http://dx.doi.org/10.1016/j.yebeh.2014.12.033 1525-5050/© 2014 Elsevier Inc. All rights reserved.
Letter to the Editor
is indeed very much tailored to individual patients. Implantation of electrodes is guided by the individual's hypothesis of seizure initiation but may fail to demonstrate the symptomatogenic zone because of sampling error or propagation phenomena or when clinical symptoms precede ictal EEG changes. We report a 23-year-old woman with drug-resistant epilepsy whose cerebral MRI showed mild atrophy and malrotation of both hippocampi. This patient underwent intracranial EEG recording for presurgical evaluation. At least one depth electrode was positioned in the mesial frontal area on either side (Fig. 1). Chapeau de gendarme was found in 21 out of 34 seizures, with initial sign in 12 seizures. As the patient was staring, with her eyes open and with emotional facial expression, we assumed the involvement of the “affective division” of the cingulate gyrus. There were no ictal EEG manifestations in the electrodes positioned in the frontomesial cingular cortex. Ictal EEG changes with low amplitude–high frequency activity presented with a delay of several seconds in the insula or amygdala on the right and independently on the left. This patient had electrodes bilateral in the relevant frontomesial parts, which were previously described to elicit CG. As our invasive recordings failed to demonstrate any ictal EEG abnormalities in frontomesial electrodes, we would like to challenge the view that CG is exclusively produced by frontomesial activation. Unfortunately, our data do not support a particular alternative area, as activation in the insula and amygdala occurred many seconds after clinical CG. References  Bonini F, McGonigal A, Trébuchon A, Gavaret M, Bartolomei F, Giusiano B, et al. Frontal lobe seizures: from clinical semiology to localization. Epilepsia 2014;55(2):264–77. http://dx.doi.org/10.1111/epi.12490.  Souirti Z, Landré E, Mellerio C, Devaux B, Chassoux F. Neural network underlying ictal pouting (“chapeau de gendarme”) in frontal lobe epilepsy. Epilepsy Behav 2014;37: 249–57. http://dx.doi.org/10.1016/j.yebeh.2014.07.009.
M. Leitinger J. Höﬂer I. Deak G. Kalss A. Rohracher G. Kuchukhidze Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University Salzburg, Salzburg, Austria E. Trinka Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University Salzburg, Salzburg, Austria Centre for Cognitive Neuroscience, Salzburg, Austria University for Medical Informatics and Health Technology, UMIT, Hall In Tirol, Austria Corresponding author at: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University of Salzburg, Ignaz Harrer Straße 79, A-5020 Salzburg, Austria. Tel.: + 43 6624483 3000; fax: + 43 6624483 3004. E-mail address: [email protected]
20 December 2014