REM sleep without atonia in narcolepsy.

OBJECTIVE

While there are a number of observations/quantifications indicating a greater proportion of REM sleep without atonia (RWA) in narcolepsy, the intra-night distribution of this parameter has not been evaluated.

MATERIALS AND

METHODS

Thirty-four patients (15 men and 19 women; mean age 44.9 +/- 18.9) with narcolepsy-cataplexy were included in this retrospective study. The clinical diagnosis was confirmed by MSLT, video-polysomnography and HLA typing. Polysomnographic recordings were scored with particular regard to REM sleep without atonia (RWA) across all the nocturnal REM periods. RWA scoring was done according to a standard method.

RESULTS

The analysis showed a significant increase in the proportion of REM sleep without atonia during successive nocturnal REM periods in narcoleptic patients (p<0.01). No correlation was found between the percentage of RWA and the severity or duration of the disease, no age effect was documented.

CONCLUSION

The study demonstrates for the first time an increasing amount of RWA during the night suggesting enhanced nocturnal REM sleep motor disturbance.