Sleep Literature Updates from March 2014

Seasonal Trends in Sleep-Disordered Breathing: Evidence from Internet Search Engine Query Data

In this study, internet search engine query data were retrieved from Google Trends over six years from 2012, from USA and Australia.  Authors found statistically significant seasonal effects were found using cosinor analysis in both USA and Australia for “snoring” (p<0.00001 for both countries). Similarly, seasonal patterns were observed for “sleep apnea” in the USA (p=0.001). Magnitude of seasonal effect raged from 5–50%. This indicates that there are significant trends for both snoring and sleep apnea internet search engine queries, with peaks in winter and early spring. Future studies may examine the mechanisms underlying these findings, and whether there is a clinical correlation or not.

Essential Thalamic Contribution to Slow Waves of Natural Sleep

These results demonstrate that the thalamus finely tunes the frequency of slow waves during non-REM sleep and anesthesia, and thus provide the first conclusive evidence that a dynamic interplay of the neocortical and thalamic oscillators of slow waves is required for the full expression of this key physiological EEG rhythm.

Decreased Connectivity Between the Thalamus and the Neocortex During Human Nonrapid Eye Movement Sleep

Results of this study provide evidence of a functional deafferentation of the neocortex during nonrapid eye movement (NREM) sleep in humans. … suggesting that changes in thalamocortical connectivity may act as a universal “control switch” for changes in consciousness that are observed in coma, general anesthesia, and natural sleep