Human assumed central sensitisation (HACS) in patients with chronic low back pain radiating to the leg (CLaSSICO study)

IntroductionPatients with chronic low back pain radiating to the leg (CLBPr) are sometimes referred to a specialised pain clinic for a precise diagnosis based, for example, on a diagnostic selective nerve root block. Possible interventions are therapeutic selective nerve root block or pulsed radiofrequency. Central pain sensitisation is not directly assessable in humans and therefore the term ‘human assumed central sensitisation’ (HACS) is proposed. The possible existence and degree of sensitisation associated with pain mechanisms assumed present in the human central nervous system, its role in the chronification of pain and its interaction with diagnostic and therapeutic interventions are largely unknown in patients with CLBPr. The aim of quantitative sensory testing (QST) is to estimate quantitatively the presence of HACS and accumulating evidence suggest that a subset of patients with CLBPr have facilitated responses to a range of QST tests.The aims of this study are to identify HACS in patients with CLBPr, to determine associations with the effect of selective nerve root blocks and compare outcomes of HACS in patients to healthy volunteers.Methods and analysisA prospective observational study including 50 patients with CLBPr. Measurements are performed before diagnostic and therapeutic nerve root block interventions and at 4 weeks follow-up. Data from patients will be compared with those of 50 sex-matched and age-matched healthy volunteers. The primary study parameters are the outcomes of QST and the Central Sensitisation Inventory. Statistical analyses to be performed will be analysis of variance.Ethics and disseminationThe Medical Research Ethics Committee of the University Medical Center Groningen, Groningen, the Netherlands, approved this study (dossier NL60439.042.17). The results will be disseminated via publications in peer-reviewed journals and at conferences.Trial registration numberNTR NL6765.

Lumbar nerve root blocks using MRI – the effectiveness and safety of ultrasound/MRI fusion image guidance

Objective: To compare the outcome of nerve root injection guided by ultrasound/MRI fusion with radiofrequency needle tracking (eTRAX©) and the same procedure undertaken by fluoroscopic guidance. Methods: This is a retrospective audit of anonymised clinical records from before and after a change in the imaging technique used to perform nerve root blocks. We studied 181 consecutive patients who had undergone a nerve root block, the first 124 guided by fluoroscopic technique and the next 57 guided by ultrasound/MRI fusion with radiofrequency needle guidance. Using pain diaries, we reviewed the outcome scores at 24 h and 2 weeks. We recorded the use of analgesia, the patient’s satisfaction, complications and the duration of the procedures. Results: Completed pain diaries were returned by 61% in the fluoroscopy group and 67% in the fusion imaging group. The visual analogue pain score was reduced at 24 h by 3.29 [standard deviation (SD) 2.35] for the fluoroscopy group and by 3.69 (SD 2.58) in the fusion group (p 0.399). At two weeks the pain reduction was 3.27 (SD 2.57) for the fluoroscopic group and 4.21 (SD 2.95) for the fusion group (p 0.083). There was no statistically significant difference between the groups. The patient’s satisfaction scores were similar for both groups. The procedure by the two guidance methods took a similar time to perform. There were no serious complications in either group. One patient in the fusion-guided nerve root block group experienced paraesthesia in the nerve distribution for 2 h. Conclusion: Ultrasound/MRI fusion imaging with needle tracking is an effective alternative to fluoroscopic image-guided injection. Advances in knowledge: Fusion imaging guidance provides the same outcome as fluoroscopic guidance. Fusion imaging guidance avoids the need for ionising radiation.

Prospective and Observation Study of Selective Nerve Root Block on Patients with PIVD

Introduction: PIVD is the most common cause of lower back pain in old age. The most common site is L4 L5 to L5 S1 in about 95% cases, and about 90% cases are associated with radiculopathy. Methodology: This prospective study was conducted on 150 patients at the Jawahar Lal Nehru Hospital and Research Center between 2019 and 2021. We used 2–3 ml xylocaine and methylprednisolone. Results were assessed through clinical examination. Result: Of the 150 patients, 130 experienced excellent results with no pain for more than six months. Conclusion: We conclude that for mild cases, patients with PIVD have an alternative option of selective nerve root block other than surgery.

Nerve injury following ultrasound-guided nerve root block with 2% lidocaine for shoulder manipulation: a case report

Shoulder manipulation under ultrasound (US)-guided C5 and C6 nerve root block is effective for treating refractory adhesive capsulitis (AC). We herein report the development of cervical nerve root injury following manipulation under anesthesia (MUA) in a patient with AC. A 47-year-old woman underwent shoulder manipulation under US-guided C5 and C6 root block with 2% lidocaine for the management of AC-induced shoulder pain. For the procedure, 3 mL of 2% lidocaine (total of 6 mL) was injected around each C5 and C6 nerve root under US guidance. Seven days after the procedure, the patient visited a university hospital because of severe neuropathic pain (numeric rating scale score of 9) in the right anterior arm, lateral arm, and forearm areas. Sensory deficits in the corresponding C5 and C6 dermatomes and motor weakness of the right shoulder abductor, elbow flexor, and wrist extensor were observed. Electrophysiologic studies demonstrated C5 and C6 nerve root injury. The patient was diagnosed with right C5 and C6 nerve root injury following MUA, and lidocaine toxicity or ischemia was the suspected cause. Clinicians should be mindful of the possibility of this complication.

Selective extraforaminal nerve root block for management of lumbar radiculopathy

Lower back pain with radiculopathy is one of the common complaints that patient presents to an orthopaedician. Study was done to assess effect of extraforaminal Selective Nerve Root Block (SNRB) in management of lumbar radiculopathy in 50 patients between December 2019 and June 2020 at Bapuji Medical College and Chigateri General Hospital, Davanagere, Karnataka, India. Extraforaminal SNRB was performed and Visual Analogue Scale (VAS) scores recorded pre procedure, immediate post procedure, one month and 6 months post procedure. Significant decrease (p<0.001) in VAS scores immediate post procedure by 5 or more points in 25%; by 3-4 points in 44% and 1-2 points in 6% of the patients obtained. One month post procedure showed statistically significant results (p<0.005) owing to change in VAS score by 1-2 points in 84% (42) patients and no change or increase in the VAS scores only in 10%(5) patients. VAS scores at 6th month showed statistically significant results (p<0.005) with reduction of VAS scores in 46.34% (19), retention of VAS score 0 in 31.70% (13) and no change or increase in VAS scores in only 21.95% (9) patients. Our study concludes that extraforaminal SNRB acts as excellent diagnostic tool and therapeutic modality for immediate and long term pain management in lumbar radiculopathy. Increase in the pain scores at 6th month (p=0.2) shows that recurrence of symptoms is a possibility. Further randomized control studies with larger study population, association of patient factors affecting extraforaminal SNRB would give better insight and knowledge of the factual data.

Risk Analysis of Needle Injury to the Long Thoracic Nerve during Ultrasound-Guided C7 Selective Nerve Root Block

Background and Objectives: Ultrasound (US)-guided cervical selective nerve root block (SNRB) is a widely used treatment for upper limb radicular pain. The long thoracic nerve (LTN) passes through the middle scalene muscle (MSM) at the C7 level. The needle trajectory of US-guided C7 SNRB pierces the MSM, therefore indicating a high probability of injury to the LTN. We aimed to identify the LTN and to investigate the risk of needle injury to the nerve during US-guided C7 SNRB. Materials and Methods: This retrospective observational study included 30 patients who underwent US-guided SNRB at the C7 level in a university hospital. We measured the maximal cross-sectional diameter (MCSD) of the LTN and cross-sectional area (CSA) of the C7 nerve root and assessed the injury risk of LTN during US-guided C7 SNRB by simulating the trajectory of the needle in the ultrasound image. Results: The LTN was detectable in all the cases, located inside and outside the MSM in 19 (63.3%) and 11 (36.7%) of cases, respectively. The LTN’s mean MCSD was 2.10 mm (SD 0.13), and the C7 root’s CSA was 10.78 mm2 (SD 1.05). The LTN location was within the simulated risk zone in 86.7% (26/30) of cases. Conclusion: Our findings suggest a high potential for LTN injury during US-guided C7 SNRB. The clear visualization of LTNs in the US images implies that US guidance may help avoid nerve damage and make the procedure safer. When performing US-guided C7 SNRB, physicians should take into consideration the location of the LTN.