Study objective: This study was designed to assess the efficacy of using Fz as an additional electrode in screening arousals during polysomnography in children.
Methods: Polysomnograms from 24 children were randomly selected from a sleep-study database of children from different diagnostic categories. Of the children whose polysomnograms selected, 5 were normal, 5 had severe obstructive sleep apnea syndrome, 5 had mild obstructive sleep apnea syndrome, 5 had snoring, and 4 had periodic limb movement disorder. American Academy of Sleep Medicine criteria for arousal were applied to Fz only, C3/C4 only, or both electrode sites combined.
Results: C3/C4 electrode sites picked up 96.33% of arousals in the polysomnograms of children, compared with 87.46% arousals identified at Fz. An additional 3.3% of arousals were identified at Fz that were not detected at C3/C4. The average median number of arousals per subject, accompanied by the interquartile range, was 29 (19.2-39.7) at C3/C4 and 27.5 (19.2-33.7) at FZ, reflecting a significant difference between the two (p = .005). The use of both electrodes sites resulted in the detection of the highest number of arousals per subject, with a median of 29 (20.2-40.7).
Conclusion: Unlike findings recently reported in adults, our study detected a higher number of arousals from central electrodes rather than frontal, with the maximum number of arousals obtained using a combination of frontal and central electrodes. A possible explanation for differences in the optimal location for detection of arousals between adults and children is discussed.