Short-term trigeminal neuromodulation does not alter sleep latency in healthy subjects: a pilot study.

It has been reported that during and/or after acute trigeminal nerve stimulation (TNS) a state of sedation, decreased attention and vigilance, with a tendency to fall asleep, occurs. Whether these effects are due to a hypnotic action of TNS is yet to be demonstrated. This pilot study investigates whether acute TNS affects the latency of sleep using the Multiple Sleep Latency Test (MSLT) in healthy subjects. MSLT was performed in 14 healthy subjects after 20 min of real- and a sham-TNS, delivered in two different sessions. Mean latency of sleep across the five naps accorded and the latency of sleep for each nap was determined. All subjects reported a state of relaxation or drowsiness after the real-TNS session. Repeated-measures ANOVA showed no significant differences in sleep latency between the real and sham conditions. The sedative effects of acute TNS do not seem associated to a hypnotic effect.