Human Studies

Procedures to relieve pain are performed frequently but there are concerns about patient selection, appropriate image-guidance, frequency, and training for physicians. Patients, healthcare providers, policymakers, and licensing bodies seek evidence-based recommendations to use these interventions judiciously. In this review we appraised the methodological quality of recent clinical practice guidelines (CPGs) for interventional pain procedures.

Chronic pain is known to alter the brain's network dynamics. These dynamics are often demonstrated by identifying alterations in the brain network topology. A common approach used for this purpose is graph theory. To date, little is known on how these potentially altered networks in chronic pain relate to the symptoms reported by these patients. Here, we applied a graph theoretical approach to identify network changes in patients suffering from chronic neck pain, a group that is often neglected in chronic pain research. Participants with chronic traumatic and non-traumatic neck pain were compared to healthy pain-free controls. They showed higher levels of self-reported symptoms of sensitization, higher levels of disability and impaired sensorimotor control. The brain suffering from chronic neck pain furthermore showed altered network properties in the posterior cingulate cortex, amygdala and pallidum compared to the healthy pain-free brain. These regions have been identified as brain hubs (i.e. regions that are responsible for orchestrating communication between other brain regions) and are therefore known to be more vulnerable in brain disorders including chronic pain. We were furthermore able to uncover associations between these altered brain network properties and the symptoms reported by patients. Our findings indicate that chronic neck pain patients reflect brain network alterations and that targeting the brain in patients might be of utmost importance.

(250 WORDS): Repetitive transcranial magnetic stimulation (rTMS) is a procedure increasingly used to treat patients with central neuropathic pain (CNP), but its efficacy is still under debate.Patients with medically refractory chronic CNP were included in two randomized phases (active/sham), separated by a wash-out period of 8 weeks. Each phase consisted of 4 consecutive rTMS sessions and a final evaluation session, all separated from one another by 3 weeks. High-frequency (20Hz) rTMS was delivered over the primary motor cortex (M1) contralateral to the patient's pain using a neuronavigated robotic system. Patients and clinicians assessing outcomes were blinded to treatment allocation during the trial. The primary outcome measured the percentage of pain relief (%R) from baseline. Secondary outcomes were VAS score, Neuropathic Pain Symptom Inventory (NPSI), analgesic drug consumption and quality of life (EQ-5D).Thirty-six patients performed the entire study with no adverse effects. The analgesic effect for the main criterion (%R) was significantly higher in the active (33.8% CI: [23.88-43.74]) than in the sham phase (13.02% CI:[6.64-19.76]). This was also the case for the secondary outcome VAS (-19.34% CI: [14.31-25.27] vs. -4.83% CI: [1.96-8.18]). No difference was observed for quality of life or analgesic drug consumption. Seventeen patients (47%) were identified as responders but no significant interaction was found between clinical and technical factors considered here and the analgesic response.These results provide strong evidence that 3-weeks spaced high-frequency rTMS of M1 results in a sustained analgesic effect and support the clinical interest of this stimulation paradigm to treat refractory chronic pain.

Prospective cohort study OBJECTIVE.: The aims of this study were to evaluate the outcome of surgical as well as non-surgical treatment for patients with lumbar herniated disc (LHD) or lumbar spinal stenosis (LSS) after two years and to identify predictors for non-success.