INTRODUCTION: Sleep spindles, the hallmark of sleep synchronization in stage 2 non-REM sleep, are rhythmic and monomorphic waves, between 10 and 14 Hz, with a maximum amplitude in the vertex (Cz), with bilateral irradiation to central regions (C3 and C4). OBJECTIVE: In this article we present an overview of sleep spindles ranging from well established concepts of morphology, generation mechanisms, maturational features, abnormal patterns and pathological aspects since the knowledge is important to identify the normal and abnormal patterns. CONCLUSION: Centro-parietal and frontal spindle are normal pattern and extreme spindle is abnormal, mostly found in children mentally retarded up to 5 years-old. In this review research boundaries of memory consolidation, synaptic potentiation and brain plasticity were also presented.
sleep spindles; non-REM sleep; EEG
