Autonomic and hormonal ictal changes in gelastic seizures from hypothalamic hamartomas

We describe two patients with hypothalamic hamartoma and gelastic seizures.

We performed ictal neurophysiological studies with polygraphic recordings of autonomic parameters and hormonal ictal plasma concentration measurements.

Ictal recordings showed a stereotyped modification of autonomic parameters: increase in blood pressure and heart rate, peripheral vasoconstriction and modification of respiratory activity. At seizure onset, the norepinephrine plasma level was high and epinephrine unchanged, whereas prolactin and adrenocorticotropic hormone were increased in both cases. Growth hormone and cortisol plasma concentrations in each patient showed a different response to seizures.

These data provide evidence that gelastic seizures are accompanied by an abrupt sympathetic system activation, probably due to the direct paroxysmal activation of limbic and paralimbic structures or other autonomic centres of the hypothalamus and medulla.