One of the biggest challenges in sleep medicine and primary care is managing the patient with insomnia. A good provider should assist without prescribing hypnotics, if possible. Some adverse safety issues associated with hypnotics include falls, sleep eating, rebound insomnia, and performing activities during the night without recollection. Watchful follow up is important, as the patient can develop tolerance and dependence on sleep aids. More effective treatments would be beneficial, but studies are limited. However, sleep researchers have currently identified a novel alternative.
Hyperarousal is common in patients with insomnia. These patients will often say to a clinician, “I just can’t turn my brain off”. Increased activity in the frontal cortex has been identified in previous research as a culprit. Cooling the forehead decreases the brain temperature and reduces frontal cerebral metabolism, which helps promote sleep in insomnia patients. Cooling the brain to alter frontal cortex metabolism has demonstrated effectiveness in other areas of medicine including neurosurgery, emergency medicine, and anesthesiology.
In a double-blind, randomized controlled trial, polysomnographic studies showed that cooling the brain indeed helped patients with insomnia fall asleep faster. Participants received either the cooling device or a sham vestibular stimulation device. A thermoelectric cooling unit transported thermal fluid to a urethane forehead bladder. Temperatures ranged between 57 to 61 degrees Fahrenheit. The device was worn throughout the night and was placed on the forehead 60 minutes before lights were turned out.
The cooling device increased the total minutes of sleep in the first hour of the night. It also shortened sleep latency to NREM stage I, NREM stage 2, and NREM stage 3 sleep. It was not clear whether the device increased sleep maintenance. Of importance, a large sham effect was noted. A psychological expectation may have caused this unexpected finding.
Longer term trials would be helpful as this study was done over a two-night period with a limited sample. The significance is that sleep latency was comparable to patients who take hypnotics.
Given this, therapeutics to cool the brain may someday be a safer alternative to hypnotics.
Roth, Tomas, et al. “A novel forehead temperature-regulating device for insomnia: a randomized clinic trial.” Sleep. 2018.