Review of craniofacial pain syndromes involving the greater occipital nerve: relevant anatomy, clinical findings, and interventional management.

Craniofacial pain syndromes exhibit a high prevalence in the general population, with a subset of patients developing chronic pain that significantly impacts their quality of life and results in substantial disabilities. Anatomical and functional assessments of the greater occipital nerve (GON) have unveiled its implication in numerous craniofacial pain syndromes, notably through the trigeminal-cervical convergence complex. The pathophysiological involvement of the greater occipital nerve in craniofacial pain syndromes, coupled with its accessibility, designates it as the primary target for various interventional procedures in managing craniofacial pain syndromes. This educational review aims to describe multiple craniofacial pain syndromes, elucidate the role of GON in their pathophysiology, detail the relevant anatomy of the greater occipital nerve (including specific intervention sites), highlight the role of imaging in diagnosing craniofacial pain syndromes, and discuss various interventional procedures such as nerve infiltration, ablation, neuromodulation techniques, and surgeries. Imaging is essential in managing these patients, whether for diagnostic or therapeutic purposes. The utilization of image guidance has demonstrated an enhancement in reproducibility, as well as technical and clinical outcomes of interventional procedures. Studies have shown that interventional management of craniofacial pain is effective in treating occipital neuralgia, cervicogenic headaches, cluster headaches, trigeminal neuralgia, and chronic migraines, with a reported efficacy of 60-90% over a duration of 1-9 months. Repeated infiltrations, neuromodulation, or ablation may prove effective in selected cases. Therefore, reassessment of treatment response and efficacy during follow-up is imperative to guide further management and explore alternative treatment options. Optimal utilization of imaging, interventional techniques, and a multidisciplinary team, including radiologists, will ensure maximum benefit for these patients.

Bipolar Radiofrequency Ablation of Painful Spinal Bone Metastases Performed under Local Anesthesia: Feasibility Regarding Patient's Experience and Pain Outcome.

Background and objectives: To assess the pain relief of bipolar RFA combined or not with vertebroplasty in patients with painful vertebral metastases and to evaluate the feasibility and tolerance of the RFA procedure performed under local anesthesia. Materials and Methods: 25 patients (18 men, 7 women, mean age: 60.X y.o) with refractory painful vertebral metastasis were consecutively included between 2012 and 2019. A total of 29 radiofrequency ablation (RFA) procedures were performed under CT guidance, local anesthesia and nitrous oxide inhalation, including 16 procedures combined with vertebroplasty for bone consolidation purposes. Pain efficacy was clinically evaluated using the visual analogue scale (VAS) at day 1, 1 month, 3 months, 6 months and 12 months, and the tolerance of the procedure was evaluated. Results: Procedure tolerance was graded as either not painful or tolerable in 97% of cases. Follow-up postprocedure mean VAS score decrease was 74% at day 1: 6.6 (p < 0.001), 79% at 1 month: 6.6 (p < 0.001), 79% at 3 months: 6.5 (p < 0.001), 77% at 6 months, and 79% at 12 months: 6.6 (p < 0.001). Conclusions: Bipolar RFA, with or without combined vertebroplasty, appears to be an effective and reliable technique for the treatment of refractory vertebral metastases in patients in the palliative care setting. It is a feasible procedure under local anesthesia which is well tolerated by patients therefore allowing to broaden the indications of such procedures. Field of study: interventional radiology.

A simplified CT-guided approach for greater occipital nerve infiltration in the management of occipital neuralgia.

OBJECTIVES: To evaluate the efficacy of a simplified CT-guided greater occipital nerve (GON) infiltration approach in the management of occipital neuralgia (ON). METHODS: Local IRB approval was obtained and written informed consent was waived. Thirty three patients suffering from severe refractory ON who underwent a total of 37 CT-guided GON infiltrations were included between 2012 and 2014. GON infiltration was performed at the first bend of the GON, between the inferior obliqus capitis and semispinalis capitis muscles with local anaesthetics and cortivazol. Pain was evaluated via VAS scores. Clinical success was defined by pain relief greater than or equal to 50 % lasting for at least 3 months. RESULTS: The pre-procedure mean pain score was 8/10. Patients suffered from left GON neuralgia in 13 cases, right GON neuralgia in 16 cases and bilateral GON neuralgia in 4 cases. The clinical success rate was 86 %. In case of clinical success, the mean pain relief duration following the procedure was 9.16 months. CONCLUSIONS: Simplified CT-guided infiltration appears to be effective in managing refractory ON. With this technique, infiltration of the GON appears to be faster, technically easier and, therefore, safer compared with other previously described techniques. KEY POINTS: • Occipital neuralgia is a very painful and debilitating condition • GON infiltrations have been successful in the treatment of occipital neuralgia • This simplified technique presents a high efficacy rate with long-lasting pain relief • This infiltration technique does not require contrast media injection for pre-planning • GON infiltration at the first bend appears easier and safer.

Microwave thermal ablation of spinal metastatic bone tumors.

PURPOSE: To assess feasibility, safety, and efficacy of microwave ablation of spinal metastatic bone tumors. MATERIALS AND METHODS: Retrospective study of 17 patients with 20 spinal metastatic tumors treated with microwave ablation under computed tomographic guidance between March 2011 and August 2013 was performed. Ablations were performed under local anesthesia and nitrous oxide ventilation. Lesions were lumbar (n = 10), sacral (n = 7), and thoracic (n = 3) in location. Primary neoplastic sites were lung (n = 9), prostate (n = 4), kidney (n = 6), and uterus (n = 1). Adjunct cementoplasty was performed in nine cases, and a temperature-monitoring device was used in four cases. Procedure effectiveness was evaluated by visual analog scale (VAS) during a 6-month follow-up. Patient medical records were reviewed, and demographic and clinical data, tumor characteristics, and information on pain were assessed. RESULTS: Mean ablation time was 4.4 minutes ± 2.7 (range, 1-8 min), with an average of 3.8 cycles per ablation at 60 W (range, 30-70 W). The preprocedure mean VAS score was 7.4 ± 1.2 (range, 6-9). Pain relief was achieved in all but one patient. Follow-up VAS scores were as follows: day 0, 1.3 ± 1.8 (P < .001); day 7, 1.6 ± 1.7 (P < .001); month 1, 1.9 ± 1.6 (P < .001); month 3, 2.2 ± 1.5 (P < .001); and month 6, 2.3 ± 1.4 (P < .01). No complications were noted. CONCLUSIONS: Microwave ablation appears to be feasible, safe, and an effective treatment of painful refractory spinal metastases and may be considered as a potential alternative percutaneous technique in the management of spinal metastases.

Treatment of painful extraspinal bone metastases with percutaneous bipolar radiofrequency under local anesthesia: feasibility and efficacy in twenty-eight cases.

PURPOSE: To retrospectively assess the feasibility and efficacy of bipolar radiofrequency ablation (RFA) of extraspinal osseous neoplasms performed under local anesthesia. METHODS AND MATERIALS: Twenty-eight patients (21 males, 7 females; mean age, 61.2 years) underwent RFA under local anesthesia between 2005 and 2012. All included patients suffered from painful osseous metastases refractory to previous medication; all presented with end-stage neoplasms. RFA was performed under computed tomography (CT) guidance with bipolar radiofrequency probes. All procedures were performed under local anesthesia (lidocaine-ropivacaine) and nitrous oxide ventilation. Intravenous injection of paracetamol was performed throughout the procedure with or without intravenous injection of nalbuphin. Tolerance of procedure was recorded. Pain efficacy was evaluated on visual anologue scale (VAS) scores at day 7, 1 month, and at 6 months after the procedure. RESULTS: Technical success rate was 100%. The procedure was considered not painful in 4 cases and tolerable in 20 cases. Average procedural time was 23.1 minutes. Mean VAS score prior to RFA was 8.1/10. Significant decrease of pain was noted at day 7 (3.3/10, p<0.001, n=27), 1 month (3.8/10, p<0.001, n=27), and 6 months (4.5/10, p<0.001, n=13). No complications were noted. CONCLUSION: Bipolar RFA of osseous metastases is a safe and effective treatment for refractory bone metastases. Its feasibility under local anesthesia should broaden the indications.

Analgesic effects of microwave ablation of bone and soft tissue tumors under local anesthesia.

OBJECTIVE: To assess the feasibility and efficacy of microwave ablation (MWA) of painful refractory bone and soft tissue tumors performed under local anesthesia. STUDY DESIGN: A retrospective study between 2011 and 2013. SETTING: A single center, Academic Interventional Pain Management Unit. SUBJECTS: Fifteen patients with 25 refractory painful bone (N = 19) or soft tissue (N = 6) tumors treated with MWA were consecutively included. METHOD: Local Institutional Review Board approval was obtained, and written informed consent was waived. Lesions included spinal (N = 3), sacral (N = 4), and extraspinal (N = 18) locations. Pain was measured on a visual analog scale (VAS) from 0 to 10 before and immediately after procedure, at 1 week, and on a monthly basis following procedure. MWA procedures were always performed under computed tomography guidance and local anesthesia along with nitrous oxide inhalation. RESULTS: Mean ablation time was 4.09 minutes (range 1-11) with an average of 4.2 cycles with a mean ablation power of 60 W. Preprocedure mean VAS score was 7.2 ± 0.97 (range 6-9). Follow-up postprocedure VAS scores were as follows: day 0: 1.64 ± 1.86, day 7: 1.82 ± 1.79, month 1: 2.05 ± 2.03 (14/15 patients), month 3: 2.13 ± 1.81, month 6: 2.36 ± 2.17; and were statistically significant (P < 0.001). Mean pain relief was 5.5 months. CONCLUSION: MWA is feasible, safe, and effective in the management of painful refractory bone and soft tissue tumors. It may therefore be considered as a potential alternative to existing percutaneous ablation techniques in the management of bone and soft tissue tumors.

Radiofrequency neurolysis in the management of inguinal neuralgia: preliminary study.

PURPOSE: To evaluate the feasibility and efficacy of computed tomography (CT)-guided radiofrequency (RF) neurolysis (RFN) in the management of refractory inguinal neuralgia. MATERIALS AND METHODS: Local institutional review board approval was obtained and written informed consent was waived. Twelve patients 26-75 years of age with chronic (>6 months) inguinal pain refractory to specific medication were included between 2005 and 2011. Data on patient demographics, clinical history, and pain management history were retrospectively assessed. Pain was measured on a visual analog scale (VAS) from 0 to 10 before and immediately after the procedure and at 1, 3, 6, 9 and 12 months. Diagnosis was always confirmed by a positive nerve block test result. Ambulatory CT-guided RF was the rule. RESULTS: Sixteen RFN procedures were performed. Pain was present for an average of 3.2 years (range: 2-8 years) prior to initial RFN. Mean VAS score before the procedure was 7.75 of 10. Immediate pain relief of 100% was achieved in all patients. Pain reduction at 1-, 3-, 6-, 9-, and 12-month follow-up was statistically significant. Important pain reduction (≥80%) was obtained in 75% of RFN procedures at 6-month follow-up and in 50% of cases at 12 months. The mean duration of pain relief was 11.8 months after RFN, with a maximum average pain reduction of 84.5%. No complications were noted during or after the procedure. CONCLUSION: RFN with CT guidance is an effective technique in the management of refractory inguinal pain with lasting satisfactory pain reduction; it may be considered as an alternative treatment to surgery. These results should be confirmed in a controlled trial with a larger series of patients.