Ultrasound-guided pulsed radiofrequency treatment of the cervical sympathetic chain for complex regional pain syndrome: A retrospective observational study

Comprehensive Comparison of Therapeutic Efficacy of Radiofrequency Thermocoagulation and Pulsed Radiofrequency in Treatment of Elderly Patients with Thoracic Postherpetic Neuralgia

BACKGROUND We comprehensively compared the therapeutic efficacy of radiofrequency thermocoagulation (RFT) and pulsed radiofrequency (PRF) in the treatment of elderly patients with thoracic postherpetic neuralgia (PHN). MATERIAL AND METHODS We divided 149 elderly patients with thoracic PHN into 2 groups - the RFT group (n=79) and the PRF group (n=70) - based on the radiofrequency mode administered. The Visual Analog Scale (VAS), Athens Insomnia Scale (AIS), Generalized Anxiety Disorder 7 items (GAD-7), and Patient Health Questionnaire 9 items (PHQ-9) were used to analyze the degree of pain, sleep quality, and psychological state of patients before and 1 week, 1 month, 3 months, 6 months, and 12 months after treatment. RESULTS VAS, AIS, GAD-7, and PHQ-9 scores were significantly decreased after RFT and PRF treatment (P<0.001). There was no significant difference in VAS scores between the 2 groups at 1 week and 1 month after treatment (P>0.05). Then, VAS scores in the RFT group were significantly lower than those in the PRF group at 3, 6, and 12 months after treatment (P<0.001). At 1 week after treatment, there were no significant differences in AIS, GAD-7, and PHQ-9 scores between the 2 groups (P>0.05). However, the RFT group had significantly lower AIS, GAD-7, and PHQ-9 scores than the PRF group at 1, 3, 6, and 12 months after treatment (P<0.05). CONCLUSIONS RFT and PRF both effectively reduced pain in the distribution area of thoracic spinal neuropathy and improved the sleep quality and psychological state of elderly patients with thoracic PHN, but RFT had a better long-term effect.

Stellate Ganglion Blocks for Refractory Central Poststroke Pain: A Case Series

Central poststroke pain (CPSP) is a neuropathic pain secondary to cerebrovascular accidents. This is characterized by pain and other sensory abnormalities, which correspond with the area of the injured brain. Despite advancements in therapeutic options, this clinical entity is still challenging to treat. We present 5 patients with CPSP, who were refractory to pharmacotherapy and were successfully managed with stellate ganglion blocks. A significant decrease in pain scores and improvement in functional disabilities were noted in all patients following the intervention.

Stellate ganglion intervention for chronic pain: A review

Stellate ganglion (SG) intervention is currently widely being studied in many kinds of chronic pain. As one of the convenient ways to treat the sympathetic nervous system, the indications for stellate ganglion intervention (SGI) include complex regional pain syndrome, postherpetic neuralgia, cancer pain of different origins, orofacial pain, and so forth. SGI refers to the reversible or irreversible blocking of the cervical sympathetic trunk, cervical sympathetic ganglion, and their innervation range through noninvasive or minimally invasive treatment. Current treatment options include stellate ganglion block (SGB), SG pulsed radiofrequency, continuous radiofrequency treatment, and noninvasive SGB. In particular, SGB continues to be one of the most studied methods in chronic pain management. However, a single SGB usually provides only short-term effects; repeated SGB may result in complications such as hoarseness, light-headedness, and vessel or nerve injury. Meanwhile, the mechanism of SGI is still unclear. This review discusses the research progress of SGI methods, effectiveness, complications, and possible mechanisms in the management of chronic pain.

Effects of Stellate Ganglion Block Through Different Approaches Under Guidance of Ultrasound

Objective

This study aimed to investigate the effects of stellate ganglion block (SGB) through different approaches under guidance of ultrasound.

Methods

A total of 130 patients undergoing SGB in our hospital between February 2019 and February 2020 were enrolled as the research subjects. According to the random number table method, these subjects were divided into two groups: a modified 6th cervical vertebra (C6) group (n = 65) and a 7th cervical vertebra (C7) group (n = 65). Under the guidance of ultrasound, the subjects in the modified C6 group were punctured at the level of the C6 transverse process, and the subjects in the C7 group were punctured at the level of the C7 transverse process. The operation duration, number of puncture angle adjustments, block effects, and adverse reactions for SGB were compared between the two groups.

Results

The modified C6 group showed shorter SGB operation duration and a lower number of puncture angle adjustments than the C7 group, and the differences were statistically significant (P &lt; 0.05). Horner Syndrome occurred in both groups after SGB. The incidence of adverse reactions in the modified C6 group was 4.62%, comprising 1 case of hoarseness and 2 cases of slowed pulse, while that in the C7 group was 6.15%, with 1 case of hoarseness and 3 cases of slowed pulse; the difference between the two groups was not statistically significant (P &gt; 0.05).

Conclusion

The operation duration for modified SGB guided by ultrasound puncturing at the C6 transverse process is shorter and requires fewer puncture angle adjustments than puncturing at the C7 transverse process; however, there is no significant difference between the incidence of adverse reactions or the blocking effects of the two methods.

Pulsed Radiofrequency of Stellate Ganglion for Neuropathic Pain Associated with Recurrent Pleural Leiomyosarcoma - A Case Report

Pleural leiomyosarcomas are rare soft-tissue sarcomas. Neuropathic pain associated with such tumours can be quite debilitating. We present the case of a 62-year-old woman with chronic neuropathic pain refractory to pharmacologic interventions in association with recurrent pleural leiomyosarcoma. Pulsed radio-frequency of the stellate ganglion was performed after due consideration and planning as a palliative measure to provide pain relief. The patient was discharged the same day with pain score 0/10 and followed up for 3 years. The unique features of this case report are: (1) Different approach of the treatment modality and (2) longer follow-up.

Successful treatment of complex regional pain syndrome type 1 of upper limb with cryoneurolysis of the stellate ganglion: A rare case report

Complex regional pain syndrome type I (CRPS I) is a multifactorial condition that is related to neural damage, and leads to chronic neuropathic pain. Due to its multifactorial nature, there are many methods that have been recruited for its management. Most of them limit the symptoms to some degree, but the most effective of them so far seems to be blockade of the sympathetic innervation of the region. We present the case of a 71-year-old woman, with an upper limb fracture which was treated conservatively, and later on developed CRPS type I. Analgesic medications and pregabalin were ineffective in controlling her symptoms. Blockade of the stellate ganglion was performed with local anesthetic and dexamethasone. After the stellate ganglion blockade was marked as successful in relieving her symptoms, cryoneurolysis was performed which was very effective. There are not many cases that have been treated with cryoneurolysis, and this is what makes this case interesting.

Effects of thoracic sympathetic stimulation on palmar perfusion: a preliminary study in pigs

OBJECTIVE

Ablation of the upper thoracic sympathetic ganglia that innervates the hands is the most effective and permanent cure of palmar hyperhidrosis. However, this type of sympathectomy causes irreversible neural damage and may result in severe compensatory hyperhidrosis. This experiment is designed to confirm the hypothesis, in which the stimulation of T2 sympathetic chain leads to increased palmar microcirculation, and thus results in treating hyperhidrosis.

METHODS

In this study, we used electric stimulation to induce reversible blockade of the sympathetic ganglion in pigs and investigated its effect on palmar perfusion. An electrode was inserted to the T2 sympathetic ganglion of the pig through three different approaches: open dorsal, thoracoscopic, and fluoroscopy-guided approaches. Electric stimulation was delivered through the electrode using clinically available pulse generators. Palmar microcirculation was evaluated by laser speckle contrast imaging.

RESULTS

The T2 sympathetic ganglion of the pig was successfully accessed by all the three approaches, as confirmed by changes in palmar microcirculation during electric stimulation. Similar effects were not observed when the electrode was placed on the T4 sympathetic ganglion or off the sympathetic trunk.

CONCLUSION

We established a large animal model to verify the effect of thoracic sympathetic stimulation. Electric stimulation can be used for sympathetic blockade, as confirmed by increased blood perfusion of the palm. Our work suggests that sympathetic stimulation is a potential solution for palmar hyperhidrosis.

Bier block as a successful management of a patient with intractable complex regional pain syndrome (CRPS) type 1: A case report

Bier block was successful in the pain management of complex regional pain syndrome (CRPS) type 1.

Effect of ultrasound-guided pulsed radiofrequency on intercostal neuralgia after lung cancer surgery: A retrospective study

This retrospective study investigated the effect of ultrasound-guided pulsed radiofrequency (UGPRF) on intercostal neuralgia (ICN) after lung cancer surgery (LCS).This retrospective observational study analyzed the outcome data of UGPRF on ICN in 80 patients with LCS. All those patients were allocated into a treatment group (n = 40) and a control group (n = 40). All patient data were collected between January 2018 and November 2019. The primary outcome was pain intensity (measured by numerical rating scale, NRS). The secondary outcomes were sleep quality (measured by Pittsburgh Sleep Quality Index, PSQI), anesthetic consumption, and treatment-related adverse events.After treatment, patients in the treatment group showed better outcomes in NRS (P < .01), PSQI (P < .01), and anesthetic consumption (P < .01), than patients in the control group. No treatment-related adverse events were documented in both groups in this study.The results of this study found that UGPRF may benefit patients for pain relief of ICN after LCS.

Poststroke Pain

Pain is common but often underrecognized after stroke. Poststroke pain (PSP) hinders recovery, impairs quality of life, and is associated with the psychological state of patients with stroke. The most common subtypes of PSP include central PSP, complex regional pain syndrome, shoulder pain, spasticity-related pain, and headache. The pathophysiologies of these PSP subtypes are not yet clearly understood, and PSP is refractory to conventional treatment in many patients. However, recent studies have proposed potential pathophysiologies of PSP subtypes, which may help prioritize therapies that target specific mechanisms.

Interventional Radiofrequency Treatment for the Sympathetic Nervous System: A Review Article

Introduction

Interventional techniques such as radiofrequency (RF) treatment can be used to interrupt pain signals transmitted through the sympathetic nervous system (SNS). RF treatments including the pulsed (PRF) and continuous (CRF) modalities show enhanced control over lesion size and enhanced ability to confirm accurate positioning compared to other interventional methods. PRF also acts to reduce the area of the lesion. In this article, we characterize the currently available evidence supporting the use and efficacy of RF treatments in sympathetically mediated pain (SMP) conditions.

Study Design

A comprehensive literature review.

Methods

A PubMed and Cochrane Library database search was performed for human studies applying RF treatment at sympathetic sites (sphenopalatine ganglion, stellate ganglion, cervical, thoracic, or lumbar sympathetic ganglia, celiac plexus, splanchnic nerves, superior hypogastric plexus, and ganglion impar) between January 1970 to May 2020. Data were extracted, summarized into tables, and qualitatively analyzed.

Results

PRF and CRF both show promise in relieving SMP conditions, such as complex regional pain syndrome (CRPS), pain in the perineal region, headache and facial pain, and oncologic and non-oncologic abdominal pain, in addition to other types of pain, with minimal complications. Furthermore, in most comparative studies, outcomes using RF treatments exceeded other interventional techniques, such as anesthetic block and chemical neurolysis.

Conclusions

RF treatments can be effective in carefully selected patients who are refractory to conservative management. However, further randomized controlled studies are needed prior to implementing it into common practice.

Pulsed radiofrequency inhibits expression of P2X3 receptors and alleviates neuropathic pain induced by chronic constriction injury in rats

Background:

Pulsed radiofrequency (PRF) is a minimally invasive interventional technique that provides a novel and effective treatment strategy for neuropathic pain (NP). PRF is advantageous because it does not damage nerves and avoids sensory loss after treatment. At present, animal studies have demonstrated that PRF is safe and effective for relieving the NP associated with sciatic nerve damage in rats with chronic constriction injury (CCI). However, the mechanism through which this effect occurs is unknown. An increasing body of evidence shows that the expression of the P2X ligand-gated ion channel 3 (P2X₃) receptor is closely related to NP; this study was to investigate whether the expression of this receptor is involved in NP relief due to PRF.

Methods:

A total of 36 healthy adult male Sprague-Dawley (SD) rats were randomly divided into three groups: Sham group, CCI group, and PRF group. The right sciatic nerve was ligated in CCI group and PRF group to establish a CCI model; the right sciatic nerve was separated but not ligated in Sham group. On day 14 after the operation, PRF was administered to the ligated sciatic nerve in PRF group (42°C, 45 V, 2 min). A non-live electrode was placed at the exposed sciatic nerve for the rats in Sham and CCI groups. The hindpaw withdrawal threshold (HWT) and thermal withdrawal latency (TWL) were measured at the right hindpaw at different time points before and after PRF or sham therapy. On day 28 after treatment, the dorsal root ganglion (DRG) and spinal dorsal horn of the right L4–6 were harvested from each group to determine the mRNA and protein levels of the P2X₃ receptor.

Results:

On day 28 after PRF treatment, the HWT (8.33 ± 0.67 g vs. 3.62 ± 0.48 g) and TWL (25.42 ± 1.90 s vs. 15.10 ± 1.71 s) were significantly higher in PRF group as compared to CCI group (P < 0.05). The mRNA expression of the P2X₃ receptor in the DRG in PRF group was 23.7% lower than that in CCI group (P < 0.05), in the spinal dorsal horns in PRF group was 22.7% lower than that in CCI group (P < 0.05). The protein expression of the P2X₃ receptor in the DRG in PRF group was 27.8% lower than that in CCI group (P < 0.05), in the spinal dorsal horns in PRF group was 35.6% lower than that in CCI group (P < 0.05).

Conclusion:

PRF possibly reduces NP in CCI rats by inhibiting the expression of the P2X₃ receptor in the L4–6 DRG and spinal dorsal horns.

CT-Guided Stellate Ganglion Pulsed Radiofrequency Stimulation for Facial and Upper Limb Postherpetic Neuralgia

Objective: Postherpetic neuralgia (PHN) is the most common complication of herpes zoster, manifesting as a persistent, spontaneous, knife-like pain or paroxysmal burning that seriously affects a patient’s quality of life. An effective treatment of PHN is lacking. This retrospective study examined the efficacy and safety of stellate ganglion (SG) pulsed radiofrequency (PRF) on facial and upper limb PHN.

Methods: Eighty-four patients with PHN on the face or upper limbs were enrolled for the study. Patients were randomly divided into two surgical groups according to the order of enrollment; one group underwent SG block (SG-B group, n = 42) and the other underwent SG pulsed radiofrequency (SG-P group, n = 42). After surgery, patients were followed at 1 week, 2 weeks, 1 month, 3 months, and 6 months. Observation at each follow-up included basic patient characteristics, visual analog scale (VAS), quality of life (QOL) using Physical Component Summary (PCS), and Mental Component Summary (MCS) to assess, total effective rate, complications and side effects.

Results: Compared with preoperative values, VAS decreased in both groups after surgery (P < 0.05). In the SG-B group, VAS increased after 1 month, while in the SG-P group, VAS gradually decreased at later follow-up time points. VAS decreased more significantly in the SG-P group after 1 month (P < 0.05). PCS and MCS increased in both groups after the operation, and the difference was significant compared with preoperative values (P < 0.05). The total effective rates of the SG-B and SG-P groups were 64.3 and 83.3%, respectively. The total effective rate of the SG-P group was higher than that of the SG-B group (P < 0.05). The incidence of complications and side effects in the SG-B group was higher than that in the SG-P group (P < 0.05).

Conclusion: SG pulsed radiofrequency treatment of facial and upper limb PHN is safe and effective. It is a treatment method worth promoting.

Clinical effects of pulsed radiofrequency to the thoracic sympathetic ganglion versus the cervical sympathetic chain in patients with upper-extremity complex regional pain syndrome: A retrospective analysis

Pulsed radiofrequency (PRF) to the thoracic sympathetic ganglion (TSG PRF) or to the cervical sympathetic chain (CSC PRF) can be performed to overcome transient effects of single sympathetic blocks in patients with upper-extremity complex regional pain syndrome (CRPS).We retrospectively compared the clinical effects of TSG PRF and CSC PRF. Seven TSG PRF cases and 10 CSC PRF cases were enrolled in the present analysis. We assessed effectiveness with multiple clinical measurements: a numerical rating scale (NRS) of pain before and 1 week after the procedure, postprocedure temperature, effect duration, and a self-described patient satisfaction score.The temperature was significantly higher in TSG PRF cases than in CSC PRF cases. Pain values (according to the NRS) 1 week after the procedure were significantly lower, and the effect duration was significantly longer, after TSG PRF than after CSC PRF.TSG PRF is a more effective procedure than CSC PRF for managing chronic upper-extremity CRPS.

Effect of bipolar pulsed radiofrequency on refractory chronic cervical radicular pain: A report of two cases

RATIONALE

Despite undergoing transforaminal epidural steroid injection (TFESI), many patients complain of persisting cervical radicular pain. For the management of chronic cervical radicular pain, clinicians are widely applying pulsed radiofrequency (PRF) stimulation to dorsal root ganglions (DRGs). To enhance the effect of PRF stimulation, we conducted bipolar PRF stimulation in 2 patients with chronic cervical radicular pain that was refractory to monopolar PRF and repeated TFESIs.

PATIENT CONCERNS

Patients 1 and 2 presented with a numeric rating scale (NRS) score of 7 and 6 for chronic cervical radicular pain, respectively, despite undergoing monopolar PRF and 2 TFESIs.

DIAGNOSES

On cervical magnetic resonance imaging, foraminal stenosis at the right C6-7 and right central to right foraminal disc protrusion on C6-7 were observed in patients 1 and 2, respectively. Two patients showed a positive response on diagnostic right C7 selective nerve root block with 0.5 mL of 1% lidocaine.

INTERVENTIONS

Bipolar PRF stimulation was performed under C-arm fluoroscopy. Two parallel RF cannulas (less than 1 cm apart) were used for DRG stimulation. The PRF treatment was administered at 5 Hz and a 5-ms pulsed width for 360 seconds at 45 V with the constraint that the electrode tip temperature did not exceed 42°C.

OUTCOMES

At the 2-week and 1-month follow-up, after undergoing bipolar PRF, the pain of patient 1 was completely relieved, and at 2, 3, and 6 months, the pain was scored as NRS 2. In patient 2, at the 2-week follow-up after undergoing bipolar PRF, pain severity was reduced from NRS 6 to 2. The effect of bipolar PRF on patient 2 lasted for at least 6 months. No adverse effects were observed in either patient.

LESSONS

Application of bipolar PRF to DRGs seems to be an effective and safe technique for treating refractory chronic cervical radicular pain.