OBJECTIVES: Extreme spindles were described by Gibbs and Gibbs in 1962. They are typically observed in children younger than five years, occurring in 0.05% of normal children and in up to 5 to 18% of children with mental retardation or cerebral palsy. In this study we describe the clinical and neurophysiological characteristics of five children with extreme spindles, correlating these findings to neuroimaging data, obtained in magnetic resonance imaging of the brain. PATIENTS AND METHODS: Eight patients from the children epilepsy outpatient clinic at UNIFESP were initially included, who had extreme spindles in at least one electroencephalogram (EEG) examination. Five out of these eight were selected, since they had MRI of the brain available for analysis. RESULTS: The age of the children varied from two to 15 years. The five children had mental retardation, and three presented associated motor deficits. All had epilepsy; in three children seizures were controlled with antiepileptic drugs, but in two they were considered refractory to medical treatment. In one patient only the MRI of the brain was considered normal. In the other cases, the findings were: bilateral pachygiria, diffuse brain atrophy, right occipital lesion, and bilateral frontal atrophy. The frequency of extreme spindles varied form 8.9 to 16 Hz, and amplitude from 67 to 256 µV. In three patients, frontal fast activity was observed along with extreme spindles. CONCLUSIONS: Extreme spindles are seldom observed in normal children, but may be quite frequent among those with mental retardation or cerebral palsy. They are probably not related to epilepsy, though in our series all children had epilepsy as well as mental retardation. Diagnostic investigation of these children with MRI of the brain showed that extreme spindles may occur either in children with defined structural abnormalities or in those with normal neuroimaging examination, suggesting that this specific electroencephalographic pattern is associated to mental retardation but not to specific etiologies.
extreme spindles; magnetic resonance imaging; mental retardation; cerebral palsy; epilepsy
