No Sleep = More Pain
When it comes to sleep loss, we normally think that pain is the problem. If we simply had less pain during the day, we’d sleep better at night.
Certainly, muscle soreness or chronic pain can keep you awake or prevent you from drifting off into a deeper sleep, but what if the situation were actually the reverse? What if it was a lack of sleep that caused the pain? Researchers are investigating that very idea.
Sleep loss does a lot to us: it makes us lose focus, intensifies stress, and boosts our sensation of pain. The problem is, that very increased experience of pain also leads to further sleep loss.
However, the good news is that if you can get a little extra sleep, your perception of pain is going to change – you won’t notice it as much. And it doesn’t have to be a major difference in your usual schedule; even an hour or so more rest can help.
Krause AJ, Prather AA, Wager TD, Lindquist MA, Walker MP. The Pain of Sleep Loss: A Brain Characterization in Humans. J Neurosci. 2019;39(12):2291‐2300. doi:10.1523/JNEUROSCI.2408-18.2018
Sleep loss increases the experience of pain. However, the brain mechanisms underlying altered pain processing following sleep deprivation are unknown. Moreover, it remains unclear whether ecologically modest night-to-night changes in sleep, within an individual, confer consequential day-to-day changes in experienced pain. Here, we demonstrate that acute sleep deprivation amplifies pain reactivity within human (male and female) primary somatosensory cortex yet blunts pain reactivity in higher-order valuation and decision-making regions of the striatum and insula cortex. Consistent with this altered neural signature, we further show that sleep deprivation expands the temperature range for classifying a stimulus as painful, specifically through a lowering of pain thresholds. Moreover, the degree of amplified reactivity within somatosensory cortex following sleep deprivation significantly predicts this expansion of experienced pain across individuals. Finally, outside of the laboratory setting, we similarly show that even modest nightly changes in sleep quality (increases and decreases) within an individual determine consequential day-to-day changes in experienced pain (decreases and increases, respectively). Together, these data provide a novel framework underlying the impact of sleep loss on pain and, furthermore, establish that the association between sleep and pain is expressed in a night-to-day, bidirectional relationship within a sample of the general population. More broadly, our findings highlight sleep as a novel therapeutic target for pain management within and outside the clinic, including circumstances where sleep is frequently short yet pain is abundant (e.g., the hospital setting). SIGNIFICANCE STATEMENT Are you experiencing pain? Did you have a bad night of sleep? This study provides underlying brain and behavioral mechanisms explaining this common co-occurrence. We show that sleep deprivation enhances pain responsivity within the primary sensing regions of the brain's cortex yet blunts activity in other regions that modulate pain processing, the striatum and insula. We further establish that even subtle night-to-night changes in sleep in a sample of the general population predict consequential day-to-day changes in pain (bidirectionally). Considering the societal rise in chronic pain conditions in lock-step with the decline in sleep time through the industrial world, our data support the hypothesis that these two trends may not simply be co-occurring but are significantly interrelated.