Insomnia is a uniquely vexing medical problem. It is the most common sleep-related issue, thought to affect around 10-40% of the population in the US. So it is a challenge that affects a whole lot of us.

Yet despite its prevalence, treatments for the condition are lackluster at best. Why is this the case? Perhaps because it remains poorly understood. Insomnia has been known and documented for thousands of years, but it has proven to be difficult to study for a number of reasons. It’s hard to develop good animal models for the condition, it’s difficult to objectively define, and symptoms manifest quite differently in individuals.

In order to address a complex disorder like insomnia, we need to get to the root cause. Generally speaking, it seems clear that the origin lies within the brain. This has compelled some very clever researchers to take snapshots inside the heads of patients with insomnia (via positron emission tomography, or PET), and compare them to normal controls. The results of such studies have been enlightening.

And that brings me to our guest for this episode.

In this episode of humanOS Radio, Dan speaks with Eric Nofzinger. Dr. Nofzinger has spent more than 35 years practicing sleep medicine and studying the neurobiology of insomnia at the University of Pittsburgh School of Medicine.

As a researcher at Pittsburgh, Dr. Nofzinger frequently interacted with patients with insomnia. They would often attribute their inability to sleep to a “racing mind.” If you’ve ever had trouble falling asleep due to incessant rumination, that characterization probably sounds pretty relatable. Furthermore, they would often claim to have hardly slept at all, even when polysomnography showed that they had experienced normal sleep.

He, along with other scientists in the field, suspected that there was a biological basis for these commonly reported complaints. To gain meaningful insight into what was going on, he couldn’t just look at sleep patterns - he needed to look inside the brain. To that end, he started conducting functional imaging studies on patients with insomnia to examine patterns of brain activity and metabolism during sleep.

In one such trial, subjects completed regional cerebral glucose metabolic assessments while awake and while asleep using the FDG PET method. These scans were telling. During normal healthy sleep, there are typically substantial reductions in brain activity, particularly in the frontal cortex. But imaging for individuals with insomnia painted a very different picture. Their brains remained comparatively active during sleep, particularly in the frontal cortex, and they exhibited greater cerebral glucose metabolism during sleep and while awake. So, when these people claimed that their minds were racing throughout the night - when their brains should have been resting - that was actually a remarkably accurate assessment.

These kinds of studies demonstrate that insomnia is, in essence, a disorder of hyperarousal of the brain. With this revelation, what can be done to slow down the racing mind?

Cooling it down.

It has been known for some time that application of a cooling stimulus to the head can lower the brain temperature in the underlying cortex, and in turn reduce brain metabolism. This insight led to the development of Ebb, a sleep therapy unlike any other that has yet been invented. Here’s how it works: the device is comprised of a headband attached to a bedside unit. Cold fluid circulates through the forehead pad from the bedside unit, keeping your forehead at a cool temperature throughout the night. In this way, Nofzinger and his colleagues hope to target the root cause of insomnia, calming the mind and body.

To learn more about Ebb and Dr. Nofzinger’s research, check out the interview!