Abstracts

Ictal SPECT is routinely used to locate the areas involved in generation of seizures in epileptic patients. Here, we studied patterns of ictal local cerebral blood flow (LCBF) during mild partial seizures in amygdala partially kindled rats. LCBF rates were measured by means of the quantitative autoradiographic [¹⁴C]iodoantipyrine technique at two different times and the two first stages of the kindling (3 rats per groups and 7 controls). The [¹⁴C]IAP infusion was started either at 15 s before the stimulation (early ictal) or simultaneously with the application of the stimulation (ictal). Six animals reached stage 0 seizure and six rats reached stage 1 during the LCBF experiment. LCBF values were determined bilaterally in 30 structures and underwent an analysis of variance and the Dunnett[apos]s t-test. In stage 0 seizures, no significant changes in LCBF rates were observed. In the early ictal stage 1 group, LCBF rates increased ipsilaterally in the cingulate cortex and nucleus accumbens and bilaterally in the caudate nucleus. In the ictal stage 1 group, increases in LCBF rates occurred ipsilaterally in the piriform cortex, basolateral and central amygdala, dorsomedian thalamus, caudate nucleus and substantia nigra pars reticulata, bilaterally in nucleus accumbens, lateral septum, medial amygdala, and all hypothalamic nuclei. LCBF mapping of limited motionless seizures (stage 0) can be falsely negative. In return, mild seizures with oroalimentary automatisms can induce significant hyperperfusion in the epileptogenic zone as well as in distant structures potentially involved in the spreading and/or remote control of ictal discharges.