Johns Hopkins researchers are reporting that people with chronic insomnia show more plasticity and activity than good sleepers in the part of the brain that controls movement.
“Insomnia is not a nighttime disorder,” says study leader Rachel Salas, an assistant professor of neurology at the Johns Hopkins Univ. School of Medicine. “It’s a 24-hour brain condition, like a light switch that is always on. Our research adds information about differences in the brain associated with it.”
Salas and her team, reporting in the March issue of the journal Sleep, found that the motor cortex in those with chronic insomnia was more adaptable to change — more plastic — than in a group of good sleepers. They also found more “excitability” among neurons in the same region of the brain among those with chronic insomnia, adding evidence to the notion that insomniacs are in a constant state of heightened information processing that may interfere with sleep.
Researchers say they hope their study opens the door to better diagnosis and treatment of the most common and often intractable sleep disorder that affects an estimated 15 percent of the U.S. population.
To conduct the study, Salas and her colleagues from the Department of Psychiatry and Behavioral Sciences and the Department of Physical Medicine and Rehabilitation used transcranial magnetic stimulation (TMS), which painlessly and noninvasively delivers electromagnetic currents to precise locations in the brain and can temporarily and safely disrupt the function of the targeted area. TMS is approved by the U.S. Food and Drug Administration to treat some patients with depression by stimulating nerve cells in the region of the brain involved in mood control.