Pain
-
Complex regional pain syndrome (CRPS) is characterized by inflammation and a failure of multimodal signal integration in the central nervous system (CNS). Central nervous system reorganization might account for sensory deficits, pain, and motor symptoms in CRPS, but it is not clear how motor control is affected by CNS mechanisms. The present study characterized the motor performance and related cortical activity of 16 CRPS patients and 16 control participants during the planning of visually guided unimanual grips, in patients with either the unaffected left or the affected right hand, and investigated resting-state sensorimotor coupling in MRI. ⋯ Fear of movement or individual pain scores contributed only marginally to the observed effects. The study suggests that changes in planning-related sensorimotor CNS regions may explain difficulties with force exertion and motor control in CRPS. Perspective : Functional changes in motor planning-related brain regions might indicate that feedback-enhanced functional motor training may be effective for CRPS rehabilitation.
-
Pain management for patients with dementia is challenging because many experience pain while being unable to communicate their pain. The aim of this study was to describe pain, pain management, and to perform a thorough clinical examination of chronic pain conditions among patients with dementia. Residents (n = 498) from 12 nursing homes were assessed for dementia (Clinical Dementia Rating scale [CDR]) and for pain with the Mobilization-Observation-Behavior-Intensity-Dementia-2 (MOBID-2) assessment form. ⋯ Chronic widespread pain was the most prevalent (14.5%) followed by nonspecific pain from the back (13.4%), whereas the most prevalent chronic secondary pain conditions were chronic pain caused by osteoarthritis (15.4%) and stroke (8.0%). One-fourth received opioids, which was significantly associated with severe pain ( P < 0.001) compared with moderate pain, although no significant association was found between opioid use and the type of pain condition. Although knowledge of the severity and specific types of pain conditions is recommended to direct the choice of treatment, these areas are not sufficiently explored in the nursing home populations with dementia and may hinder a better treatment of pain in this population.
-
The nucleus of the solitary tract (NTS) contains pro-opiomelanocortin (POMC) neurons that are 1 of the 2 major sources of β-endorphin in the brain. The functional role of these NTS POMC neurons in nociceptive and cardiorespiratory function is debated. We have shown that NTS POMC optogenetic activation produces bradycardia and transient apnoea in a working heart-brainstem preparation and chemogenetic activation with an engineered ion channel (PSAM) produced opioidergic analgesia in vivo. ⋯ Inhibiting NTS POMC neurons does not produce any effect on basal nociception but inhibits stress-induced analgesia (unlike inhibition of arcuate POMC neurons). Activation of NTS POMC neuronal populations in conscious mice did not cause respiratory depression, anxiety, or locomotor deficit (in open field) or affective preference. These findings indicate that NTS POMC neurons play a key role in the generation of endorphinergic endogenous analgesia and can also regulate cardiorespiratory function.