Abstract
Clinical and electroencephalographic aspects of the Lennox syndrome on eighty subjects were studied.1) Age of onset: It most commonly occurs between one and six years (60 cases 76% in our series). The earliest onset in our group was six months.2) Clinical seizure pattern: All the cases exhibi ted both tonic spasms and atypical absence or either of the two. Twelve out of the eighty patients (15%) also exhibited an additional astatic seizure.3) Underlying disease: Twenty-six patients (32.6%) were idiopathic. The majority w ere found to have various underlying illnesses.4) Mental deficiency: Seventy patients (87.5%) were found to have mental deficiency.5) Electroencephalogram: Diffuse slow spike-waves were observed in all subj ects in interictal period. Desynchornization, rapid synchronization and recruiting rhythm were seen during ictal period. These findings indicate the diencephalon as the origin of pathophysiology.6) Longitudinal follow-up on each case revealed close relationship of this syndrome with infantile spasms. It also revealed that some changed to generalized epilepsy.7) Conclusion: The Lennox syndrome is a form of childho od epilepsy with a strong age dependency. It has a specific seizure pattern and EEG features. Mental deficiency is one of the cardinal features of this syndrome, the majoriy of the patients resisting therapy. Thus, this syndrome should be regarded as an independent clinical entity. Although there are multiple factors considered contributing to the formation of this syndrome, dysmaturity of the brain seems essential as one can see from the age distribution in this syndrome. We conclude, therefore, that the combination of immaturity of the brain and cerebral dysfunction plays the basic role in manifestation of this syndrome.
