It can be associated to a wide range of disorders, and although it usually is an innocuous condition, it should prompt a search for the underlying aetiology, since some of its causes impose an urgent treatment.
Although it was formerly believed to be an innocuous condition, it is now considered to be a variant of atherosclerosis with predominance of calcification and a small inflammatory component [89].
But what about the seemingly innocuous condition of sleep apnea?
Fish held in isolation were conditioned over a 10-day period by pairing an innocuous signal (conditioned stimulus, CS: a water jet played on the surface of the tank water) with a mild stressor (unconditioned stimulus, US: 30 min of confinement).
All tested conditions (innocuous cold, noxious cold and cold allodynia) led to significant activations of bilateral insular cortices, bilateral frontal cortices and the anterior cingulate cortex.
Mechanical allodynia [cutaneous hypersensitivity to a mechanical stimulus that is otherwise innocuous under normal conditions] is a pain response common in patients with migraine, and has also been reported in patients with post-traumatic headache [26 28].
Using in vivo electrophysiological recordings, we show that in this condition innocuous mechanical stimuli could activate superficial dorsal horn nociceptive specific neurons.
A factorial design permitted categorical and covariation analysis of four conditions, namely innocuous and noxious heat; with and without distraction.
These overcrowded conditions, seemingly innocuous to policy makers, contributed additional negative consequences to an already unforgiving setting, where prisoners are forced to conform to the "Iron Law of Corrections" ideal to avoid further punishment from guards, and where attitudes and behaviors between inmates themselves often times lead to adverse and even lethal consequences.
We found that in this condition, unmasking innocuous input to superficial dorsal horn NS neurons, as opposed to facilitation of WDR neurons, was mainly responsible for the strychnine-induced allodynia.
