Lennox-Gastaut syndrome in south Iran: electro-clinical manifestations

Purpose: Lennox-Gastaut syndrome (LGS) is an uncommon epileptic encephalopathy. In this study, we tried to determine the clinical and EEG characteristics of patients with LGS in south Iran.

Methods: In this retrospective study, all patients with a clinical diagnosis of LGS were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences from 2008 through 2012. Age, gender, age at seizure onset, seizure type(s), epilepsy risk factors, EEG and imaging findings of all patients were registered routinely.

Results: During the study period, 2500 patients with epilepsy were registered at our epilepsy clinic. One-hundred and thirty-five patients (5.4%) were diagnosed as having LGS. Age of onset (mean±standard deviation) was 3.2±3.8 years. In 14 (10.4%) patients, age of onset was above 8 years. Eighty-three patients (61.5%) were male and 52 (38.5%) were female. The most common seizure type was tonic, followed by generalized tonic-clonic and myoclonic seizures. The most common EEG finding was slow spike-wave complexes. The most common abnormal MRI finding was brain atrophy.

Conclusion: LGS is an uncommon epileptic encephalopathy characterized by multiple seizure types, a specific electroencephalographic pattern and psychomotor retardation, beginning in childhood. However, variants of this classical triad including atypical EEG findings, normal psychomotor function, and late-onset disease could be seen in some patients. These atypical findings in a patient with typical history for LGS should not deter from the correct diagnosis. The mainstay for making a correct syndromic diagnosis is a detailed clinical history.