Post-ictal circulating levels of allopregnanolone in children with partial or generalized seizures

Allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one) is a neurosteroid with a potent modulating activity on the gamma-aminobutyric acid (GABA)(a) receptor complex. It plays a key role in the epileptogenesis of partial seizures. Serum allopregnanolone concentrations significantly increase in the postcritical phase. In the present study we investigated the post-ictal serum allopregnanolone levels in children with partial seizures and generalized seizures, respectively.

Three groups of subjects were included in the study. Group 1 consisted of 18 children affected by complex partial seizures. Group 2 consisted of 11 children presenting with generalized epilepsy. Group 3 consisted of 20 healthy age-matched subjects. Serum allopregnanolone levels were assayed in the inter-ictal phase and within 30 min after an epileptic event.

The data we obtained suggest that circulating allopregnanolone level significantly increases in the post-ictal phase. However, we found no significant differences in the post-ictal serum allopregnanolone concentrations between patients with partial seizures and those with generalized seizures.

Further studies are needed to establish if allopregnanolone is a reliable circulating marker of epileptic seizures. However, our observations seem to indicate that post-ictal circulating allopregnanolone level is not useful in differentiating focal and generalized epilepsy events.