Automated frequency analysis of synchronous and diffuse sleep spindles

Background: Sleep spindles have different properties in different localizations in the cortex. Objectives: First main objective was to develop an amplitude- independent multi-channel spindle detection method. Secondly the method was applied to study the anteroposterior frequency differences of pure synchronous ( visible bilaterally, either frontopolarly or centrally) and diffuse ( visible bilaterally both frontopolarly and centrally) sleep spindles. Methods: A previously presented spindle detector based on the fuzzy reasoning principle and a level detector were combined to form a multi-channel spindle detector. Results: The spindle detector had a 76.17% true positive rate and 0.93% false-positive rate. Pure central spindles were faster and pure frontal spindles were slower than diffuse spindles measured simultaneously from both locations. Conclusions: The study of frequency relations of spindles might give new information about thalamocortical sleep spindle generating mechanisms. Copyright (C) 2005 S. Karger AG, Basel.