[Lennox-Gastaut syndrome in Spain: a descriptive retrospective epidemiological study]

Lennox-Gastaut syndrome (LGS) is one of the most severe epileptic syndromes in childhood. It is characterised by the presence of several types of seizures, a characteristic electroencephalographic trace and its frequent association with mental retardation. There are no accurate data on the epidemiology of LGS in Spain.

To describe the epidemiological profile of LGS in Spain.

We conducted a retrospective epidemiological study of a series of 331 patients with LGS from 50 Spanish hospitals. Patients were considered to be cases of LGS if they had at least two of the three types of seizures that characterise LGS (axial tonic seizures, atypical absences and atonic seizures) and displayed slow diffuse intercritical spike-wave activity (lower than 3 Hz) in the electroencephalogram in wakefulness.

The mean age of the patients was 18.2 +/- 13.5 years. Of the total sample, 62% were males and 97% had cognitive retardation. And 54% of cases had a symptomatic aetiology. The most frequent types of seizures were axial tonic (89%), followed by the atypical absent type (84%) and atonic seizures (69%). In all, 99% of patients were treated with polytherapy, the most commonly used drugs being valproic acid, lamotrigine and topiramate.

The results of the study are in line with those from previous analyses carried out in populations with similar characteristics. The high percentage of LGS patients with cognitive retardation in this epileptic encephalopathy results in important family and social repercussions.