Peculiare presentazione clinica della sindrome di Lennox-Gastaut in pazienti con trisomia 21

Lennox-Gastaut syndrome (LGS) has been rarely and incompletely described in subjects with Down syndrome (DS). We retrospectively collected the clinical and EEG data of 13 consecutive patients with LGS and DS referred to 4 epilepsy centres over the last 20 years. The mean age at onset was 9.09 years (range 5-16). There were no patients with seizure onset before the age of 5 years, 5 patients (38%) with seizure onset between 5 and 8 years,while 8 patients (61%) had seizures onset after age 8.Nine patients (69%) had unambiguous reflex seizures mostly precipitated by sudden unexpected sensory stimulations, usually preceding or accompanying the onset of full-blown LGS picture. Interictal and ictal EEG findings were typical for LGS.All patients were drugresistant. Our data suggest that patients with DS may present a peculiar LGS characterized by late onset and high occurrence of reflex seizures.