JLE

Epileptic Disorders

MENU

Fear, anger and compulsive behavior during seizure: involvement of large scale fronto-temporal neural networks Volume 4, issue 4, December 2002


   
   Figure 1. Schematic diagram of SEEG electrode mapping represented on a lateral view of the Talairach’s basic referential system. A: electrode exploring the amygdala (medial leads) and the anterior part of the middle temporal gyrus (MTG) (lateral leads); B: electrode exploring the anterior hippocampus (medial leads) and the mid part of the MTG (lateral leads); OP: electrode exploring the frontal opercular region; H: electrode exploring the posterior part of the superior temporal gyrus; O: electrode exploring the fronto-orbital cortex (distal leads) and the dorso-lateral prefrontal cortex (proximal leads); TP: electrode exploring the temporal pole, F electrode exploring the fronto-polar region, G electrode exploring the cingulate gyrus (medial leads) and the premotor region (lateral leads).



   
   Figure 2. Illustration of the periods studied by coherence analysis of signal: the curve represents the evolution of coherence values during one seizure in patient S.B., calculated between bipolar signals from electrodes placed in the amygdala and the orbito-frontal cortex. The figure represents the periods analyzed: (1) is the pre-ictal period (pre-I), (2) the initial ictal period (I), (3) the period of strong emotional behavioural changes (EBC). The duration of each period is 15 seconds. The statistical comparison of coherence values between 2 versus 1 reflects the network involved at the onset of seizure, and between 3 versus 2, the network coinciding with fear and the compulsive behavior.



   
   Figure 3. SEEG recording of a spontaneous seizure. Arrow corresponds to the onset of emotional/behavioral changes (fear, compulsion to bite, screaming). A: amygdala; Hi: anterior hippocampus; Pt: temporal pole; MTG: middle temporal gyrus; STG: superior temporal gyrus; Op: frontal operculum; Of: orbito-frontal cortex.



   
   Figure 4. Schematic representation of the epileptogenic network according to coherence variations. Only significant and consistent coherence changes are represented (arrows): the first network describes the structures involved in the epileptogenic zone (a). The period of intense emotional behavior (b) is characterized by a network in which the discharges are synchronized between the amygdala, the temporal pole and the orbito-frontal cortex. A decrease in the relations between the cingulate region, the dorso-lateral cortex on the one hand and the orbitofrontal and temporo-polar region on the other are also demonstrated. Abbreviations: T2: middle temporal gyrus; OF: orbitofrontal region; DLPFC: dorsolateral prefrontal cortex; A: amygdala; H: hippocampus; TP: temporal pole.