[Characteristics of clinical manifestations and EEG of Lennox-Gastaut syndrome].
OBJECTIVE
Lennox-Gastaut syndrome (LGS) is one of the most severe and refractory form of childhood epilepsy. The purpose of this study was to investigate the clinical and EEG characteristics of patients with LGS.


METHODS
Sixty-two patients with LGS, including 37 males and 25 females, were followed-up regularly per three months or per six months, therapy was adjusted according to the changes in seizures and EEG, and the clinical data were analyzed in detail.


RESULTS
The onset occurred between the age of 8 months and 12 years, with the peak at 1-4 years of age, accounting for 61%; a late onset which occurred after 8 years of age, was unusual. Furthermore, one patient who developed LGS at the age of 13 years and remained to have all the features of seizures and EEG at 35 years of age was identified as adult's LGS. Forty-three patients were classified as symptomatic, perinatal events were the predominant factors in this group. The others were cryptogenic. It was noted that 11 cases had a history of West syndrome. A transformation process from West syndrome to LGS was observed in another 7 cases. Every patient had two or more seizure types during the course of the disease; tonic seizure, atypical absence seizure, head drop or sudden falls were the characteristic types. The degree of mental deficit was variable from slight to profound deterioration, but mental and behavioral disturbances existed in every case as a rule. In all cases electroencephalogram (EEG) background was abnormal and consisted of diffuse slow spike-and-waves (1-1.5CPS), predominant in frontal and temporal regions. Twenty-four cases had the polyspike-wave. Bursts of fast rhythms (10-14CPS) were observed in 29 patients during sleep. The choice of antiepileptic drugs (AEDs) was based on the seizure types; routinely, 2 or more kinds of AEDs were used in combination, the classic drugs, valproate and clonazepam were firstly recommended; the other drugs, such as lamotrigine and topiramate that are used as add-on therapy were further consideration. Although the total effect was not satisfactory, the severity and frequency of seizures in almost all cases had lessened to some extent.


CONCLUSION
LGS shows diverse manifestations; comprehensive diagnosis is crucial, active and efficacious treatment can improve the mental and behavioral development and prognosis as a whole.