Interoception and proprioception in patients with fibromyalgia

Interoception and proprioception, both components of body awareness, fulfil a significant role in motor control and symptom perception. We hypothesized interoceptive and proprioceptive impairments in patients with fibromyalgia (fibromyalgia; n = 28) compared with age and gender matched healthy controls (HC; n = 26). Interoception was divided into three measurable constructs: the respiratory occlusion discrimination (ROD) task was used to measure interoceptive accuracy; the Interoceptive Sensitivity and Attention Questionnaire (ISAQ) and the Three-Domain Interoceptive Sensations Questionnaire (THISQ) were used to measure interoceptive sensibility; and the correspondence between performance on 16 ROD trials and confidence ratings was used to measure interoceptive awareness. Proprioceptive accuracy was assessed using two methods: cervical proprioception was measured with the head repositioning accuracy (HRA) test, while the role of proprioception during postural control was also measured. Data analysis showed no significant differences in interoceptive accuracy, interoceptive awareness nor for proprioception during postural control between patients and HC. However, patients did report higher interoceptive sensibility and had higher mean position errors during the HRA test, indicating an impaired proprioceptive accuracy of the cervical joint.