Reduced Interoception Abilities in Patients with Restless Legs Syndrome

Abstract

Background Restless legs syndrome (RLS) is a complex sensorimotor disorder occurring with a typical circadian fashion. Association with additional features, like alexithymia and nocturnal compulsive behaviors further complicates the framework. Objectives To assess interoception in RLS. Methods A total of 25 RLS patients and 28 controls underwent the heartbeat tracking task (interoceptive accuracy [IAC]). RLS symptoms’ frequency, disturbance and duration, nocturnal behaviors, interoceptive awareness (IAW), alexithymia, depressive and anxiety symptoms were also collected. Results RLS patients showed significant lower IAC (P = 0.0003) and IAW (P = 0.012), and reported more nocturnal eating behaviors (P < 0.001). IAC positively correlated with IAW (R = 0.32), and negatively correlated with age (R = −0.58). Nocturnal eating behavior negatively correlated with IAC (R = −0.44) and IAW (R = −0.50). Conclusions RLS patients presented reduced interoceptive abilities correlating with higher nocturnal eating behaviors. Future studies are needed to explore the role of interoception in RLS pathophysiology, also in relation to other sensorimotor aspects.

Defect of the Endogenous Inhibitory Pain System in Idiopathic Restless Legs Syndrome: A Laser Evoked Potentials Study

“…To that regard only 38% of our patients reported RLS symptoms as painful, and it is well known how RLS have extreme difficulties in describing the quality of their symptoms, showing also lower level of interoception abilities. 45 To further add to this, RLS patients have been reported to have hyperalgesia without allodynia indicating that the central sensitization in the spinal cord is likely because of a different mechanism of other forms of central sensitization seen in chronic pain conditions. In this regard, neuropathic pain has symptoms similar to RLS, but is generally associated with hyperalgesia and allodynia.…”