Regional intravenous guanethidine vs. stellate ganglion block in reflex sympathetic dystrophies: a randomized trial

Regional intravenous guanethidine blocks and stellate ganglion blocks have been compared in a randomized trial. Nineteen patients, randomly allocated to two groups of therapy and exhibiting severe reflex sympathetic dystrophy following peripheral nerve lesions, have been treated. The performance of the intravenous guanethidine block is of longer duration and superior to stellate ganglion block, as regards some early pharmacological effects (skin temperatures and amplitude of plethysmographic waves recorded before blockade and 15 min, 60 min, 24 h, 48 h after institution of the block). In fact the intravenous guanethidine group shows a persistent and significant increase of the skin temperature and of the plethysmographic traces in the blocked side 24 h and 48 h after blockade in comparison with the patients treated with stellate ganglion block. Concerning the therapeutic effects (changes in pain scores and clinical signs--hyperpathia, allodynia, vasomotor disturbances, trophic changes, oedema and limited motion), recorded at the end of treatment and 1 month and 3 months follow-up, an intravenous guanethidine block carried out every 4 days up to a total of 4 blocks is comparable with a stellate ganglion block every day up to a total of 8 blocks. The results of this study show that regional sympathetic block with guanethidine is a good therapeutic tool in the treatment of reflex dystrophies, especially on account of its negligible risks and contraindications.     

Clinical and physiologic evaluation of stellate ganglion blockade for complex regional pain syndrome type I

OBJECTIVE: The efficacy of peripheral sympathetic interruption after stellate ganglion blockade was assessed by a sympathetic function test. Results were compared with clinical signs such as temperature changes, pain reduction, and the development of Horner syndrome to evaluate the correlation with clinical investigations. DESIGN: Stellate ganglion blockade with local anesthetics was carried out via an anterior paratracheal approach in 33 patients suffering from complex regional pain syndrome type I. Patients were examined before and after the procedure. For assessment of sympathetic nervous function, the vasoconstrictor response to sympathetic stimuli was assessed using laser Doppler flowmetry. Clinical parameters like surface temperature changes (thermography), pain relief (visual analogue scale), and Horner syndrome were monitored. RESULTS: Twenty-three (70%) of 33 patients developed an increase in temperature difference between the treated hand and the contralateral hand of more than 1.5 degreesC after the procedure, which is a clinical sign of sympathicolysis. In 48% (n = 11) of these patients, the sympathetic function test showed an undisturbed sympathetic nervous function. In 10 patients, no significant increase in temperature difference was observed. Although these patients presented with a normal sympathetic vasoconstrictor response, 4 felt pain relief of more than 50%, suggesting a placebo effect. Only 7 patients with pain relief revealed both clinical sympathicolysis and extinguished sympathetic nervous function and qualified for sympathetically maintained pain. CONCLUSIONS: Clinical investigation is not reliable in the assessment of stellate ganglion blockade. Proof of sympathetically maintained pain based on pain relief after stellate ganglion blockade is not conclusive.     

Extent of sympathetic blockade after stellate ganglion block with bupivacaine

A study of the extent of sympathetic blockade after stellate ganglion block was assessed using liquid crystal thermography. Two volumes (10 and 20 ml) of bupivacaine 0.5% plain were used. Irrespective of the volume used cranial sympathetic block always occurred and thoracic sympathetic block never occurred. While upper cervical block was present in all patients, lower cervical sympathetic block was present only in the 20-ml group (P less than 0.05). The larger volume was associated with a significant incidence of hoarseness due to spread of local anaesthetic onto adjacent laryngeal nerves.     

Anterior Cervical Approach for Stellate Ganglion and T2 to T3 Sympathetic Blocks: A Novel Technique

Background: Stellate ganglion block is used for the diagnosis and treatment of sympathetically maintained pain syndromes. Multiple anatomic variations and inaccurate sympathetic block may mislead the diagnosis and prevent patients from receiving potentially beneficial interventions. We describe a novel approach to blockade of the sympathetic chain at C7 and at T2 to T3 with a single‐needle injection. Technique: With the patient in supine position, the uncinate process of C7 is identified fluoroscopically as a target for insertion of a catheter through a Touhy needle. The catheter is directed caudally to the junction of T2 and T3. Contrast injection confirms the spread to the appropriate levels before injection of local anesthetic. Conclusion: This novel approach to blockade of the upper extremity sympathetic innervation may enhance diagnostic accuracy and therapeutic benefit as compared with traditional approaches to the stellate ganglion alone. This approach may be expected to decrease the risk of pneumothorax when compared with the posterior approach to T2 to T3.     

Stellate ganglion blockade (SGB) for refractory index finger pain - a case report

ObjectiveTo identify through case study the presentation and possible pathophysiological cause of complex regional pain syndrome and its preferential response to stellate ganglion blockade.SettingComplex regional pain syndrome can occur in an extremity after minor injury, fracture, surgery, peripheral nerve insult or spontaneously and is characterised by spontaneous pain, changes in skin temperature and colour, oedema, and motor disturbances. Pathophysiology is likely to involve peripheral and central components and neurological and inflammatory elements. There is no consistent approach to treatment with a wide variety of specialists involved. Diagnosis can be difficult, with over-diagnosis resulting from undue emphasis placed upon pain disproportionate to an inciting event despite the absence of other symptoms or under-diagnosed when subtle symptoms are not recognised. The International Association for the Study of Pain supports the use of sympathetic blocks to reduce sympathetic nervous system overactivity and relieve complex regional pain symptoms. Educational reviews promote stellate ganglion blockade as beneficial. Three blocks were given at 8, 10 and 13 months after the initial injury under local anaesthesia and sterile conditions. Physiotherapeutic input was delivered under block conditions to maximise joint and tissue mobility and facilitate restoration of function.ConclusionThis case demonstrates the need for practitioners from all disciplines to be able to identify the clinical characteristics of complex regional pain syndrome to instigate immediate treatment and supports the notion that stellate ganglion blockade is preferable to upper limb intravenous regional anaesthetic block for refractory index finger pain associated with complex regional pain syndrome.     

Somatosensory evoked potentials are unchanged by reflex sympathetic dystrophy and by stellate ganglion block.

Median nerve somatosensory evoked potentials (SEPs) were monitored in patients with chronic pain before and after stellate ganglion blockade. A change caused by the syndrome or by the block would suggest that SEPs might be useful in the diagnosis and treatment of chronic pain. We observed 20 subjects. Group I (n = 10) had chronic pain not involving the upper extremity. Group II (n = 8) had reflex sympathetic dystrophy of the arm. All patients underwent unilateral stellate ganglion block using an anterior paratracheal approach. The SEPs were recorded by median nerve stimulation on the blocked (affected) side and unblocked (unaffected) side before and 30 min after the block. Recording sites were ipsilateral brachial plexus, the cervical spinal cord, and the contralateral sensory cortex. There were no between-group differences before or after the block. Paired analysis within each group showed that the SEPs were not different from baseline (unaffected side before block) at any time throughout the study. We conclude that since SEPs are not changed by the reflex sympathetic dystrophy or stellate ganglion block, they would not be useful in the evaluation of pain or in determining the effectiveness of sympathetic block. Both the pain and the block appear to involve alteration of conducting pathways separate from those monitored by median nerve SEPs.     

Interscalene blocks for chronic upper extremity pain.

A study of 25 patients was carried out to determine the efficacy of interscalene block (ISB) for the treatment of chronic upper extremity pain. An RSD score was used to categorize these patients. Seventeen of the 25 patients had less pain after ISB, and 14 also had increased range of motion of the affected limb. Patients with reflex sympathetic dystrophy (RSD)/causalgia, as well as other chronic pain conditions, improved. ISB was compared with stellate ganglion block (SGB) in patients undergoing both treatments. ISB seemed to be at least as effective as SGB for treatment of RSD/causalgia and may have some advantages over SGB. The role of somatic and sympathetic blockade is discussed.     

Cluster headache and the sympathetic nerve

OBJECTIVE: To determine the effect of a sympathetic block at C7 on cluster headache. BACKGROUND: Eleven patients presenting to a pain control unit with cluster headache were included in the study after giving informed consent. METHODS: In all patients, a mixture of 5 mL of 0.5% bupivacaine hydrochloride and 1 cc of methylprednisolone acetate was injected onto the base of the C7 transverse process. RESULTS: The injection was applied during the acute phase of headache in 6 patients and all experienced immediate and complete relief. The other 5 patients received the injection between attacks. Of the 11 patients treated, 8 went into remission by aborting the cluster. In some patients, repeated injections were given before the cluster was aborted. Three patients did not respond to treatment. One patient with chronic paroxysmal hemicrania experienced pain relief of the acute attack after treatment, but the procedure did not abort the subsequent attacks. A surgical sympathectomy removing the stellate ganglion rendered him pain-free for 15 months after which he was lost to follow-up. CONCLUSION: Blocking the sympathetic nerve aborts an acute attack of cluster headache and may play a major role in aborting the cluster. Although only one patient with chronic paroxysmal hemicrania responded to surgical sympathectomy, this procedure may be considered as an alternative if there is poor response to oral medication or a sympathetic block.     

皮肤与内脏相关的神经基础研究

目的在皮内注药治疗遗尿症及内脏痛有效的基础上,研究皮肤与内脏相关的初级神经元和交感神经元分布规律。方法通过家兔静脉注射伊文氏蓝(EvansBlue),胃内注入甲醛致胃伤害性刺激,观察皮肤渗漏斑,找出皮肤牵涉区;在牵涉区皮肤和胃黏膜分别注射辣根过氧化物酶(HRP)和荧光素核黄(NY)用神经逆行追踪法分别观察初级神经元和交感神经元分布规律。结果家兔胃痛的皮肤牵涉区在肩及肩胛区,在牵涉区皮肤和胃黏膜分别注射HRP和NY在C8～T8脊神经节和交感神经节相互重叠。结论胃痛的皮肤牵涉区与胃黏膜初级神经元分布的特点是在脊神经节呈节段性分布且相互重叠,在交感神经节呈弥散性分布,无节段性分布,也相互重叠,这可能是皮内注药治疗内脏痛的神经基础。     

Complex regional pain syndromes: the influence of cutaneous and deep somatic sympathetic innervation on pain

OBJECTIVES: Complex regional pain syndromes (CRPS) can be relieved by sympathetic blockade. Different sympathetic efferent output channels innervate distinct effector organs (ie, cutaneous vasoconstrictor, muscle vasoconstrictor. and sudomotor neurons, as well as neurons innervating deep somatic tissues like bone, joints, and tendons). The aim of the present study was to elucidate in CRPS patients the sympathetically maintained pain (SMP) component that exclusively depends on cutaneous sympathetic activity compared with the SMP depending on the sympathetic innervation of deep somatic tissues. METHODS: The sympathetic outflow to the painful skin was modulated selectively in awake humans. High and low cutaneous vasoconstrictor activity was produced in 12 CRPS type 1 patients by whole-body cooling and warming (thermal suit). Spontaneous pain was quantified during high and low cutaneous vasoconstrictor activity. By comparing the cutaneous SMP component with the change in pain that was achieved by modulation of the entire sympathetic outflow (sympathetic ganglion block), the SMP component originating in deep somatic structures was estimated. RESULTS: The relief of spontaneous pain after sympathetic blockade was more pronounced than changes in spontaneous pain that could be induced by selective sympathetic cutaneous modulation. The entire SMP component (cutaneous and deep) changes considerably over time. It is most prominent in the acute stages of CRPS. CONCLUSIONS: Sympathetic afferent coupling takes place in the skin and in the deep somatic tissues, but especially in the acute stages of CRPS, the pain component that is influenced by the sympathetic innervation of deep somatic structures is more important than the cutaneous activation. The entire sympathetic maintained pain component is not constant in the course of the disease but decreases over time.     

An Unusual Complication of Sinus Arrest Following Right-Sided Stellate Ganglion Block: A Case Report

Abstract:   We present a case of a 29-year-old female patient who had presented to us for the management of her chronic right shoulder–hand pain and developed a sinus arrest following a right-sided stellate ganglion block (RSGB). This patient on receiving a diagnostic RSGB via the anterior paratracheal (C6) approach developed sinus arrest followed by apnea and unconsciousness. On institution of resuscitative measures involving tracheal intubation, positive pressure ventilation, cardiac massage, and intravenous atropine, spontaneous cardiac activity recovered in about 3 minutes. Other signs and symptoms resolved fully in a total of 10 minutes. She had persistent postural hypotension lasting for about 24 hours requiring bed rest and was discharged about 36 hours after the procedure, without any adverse sequelae. As the sinus node is supplied by the right-sided sympathetic chain, its blockade probably resulted in unopposed parasympathetic activity leading to asystole. Available evidence of the role of right stellate ganglion in regulation of cardiac electrophysiology and functioning is also discussed.     

Dual effects of cholecystokinin-octapeptide on duodenal motility of urethane-anesthetized rats

Intravenous administration of cholecystokinin octapeptide (CCK-8) to urethane-anesthetized rats produced both inhibitory and excitatory effects on intestinal motility. The inhibitory effect, evident as a transient relaxation or inhibition of distension-induced reflex contractions, was abolished by adrenoreceptor blockade, guanethidine pretreatment or removal of the celiac ganglion complex, but was hexamethonium-and atropine-insensitive. The excitatory action of CCK-8 was atropine- and hexamethonium-sensitive, while being unaffected by guanethidine pretreatment. Ligation experiments indicated that the excitatory effect of CCK-8 originates from a stimulant action on structures in the upper duodenum/pyloric sphincter from which a propagated contraction travels to the distal duodenum. We conclude that i.v. CCK-8 inhibits small intestinal motility by directly activating sympathetic neurons in the celiac ganglion and initiates a propagated form of intestinal motility by stimulating neural elements in the upper part of the small intestine.     

Effects of xenon irradiation of the stellate ganglion region on fibromyalgia

[Purpose] The aim of the study was to determine the effect of xenon irradiation of the stellate ganglion region on fibromyalgia. [Subjects] The study included 5 men and 22 women (age, 56.4 ± 16.3 years [range, 25–84 years]) who were diagnosed with fibromyalgia according to the modified 2010 criteria of the American College of Rheumatology between July and August 2013. [Methods] Bilateral xenon light irradiation (0.38–1.1 μm) around the stellate ganglion was performed in the supine position by physical therapists using a xenon phototherapy device. We evaluated pain before and after irradiation using the visual analogue scale. [Results] We did not observe a relationship between the change in the visual analogue scale score and duration of fibromyalgia. However, we observed a relationship between the change in the visual analogue scale score and the score for the Japanese version of the Fibromyalgia Impact Questionnaire using the Cochran-Armitage test for trend. [Conclusion] Xenon light irradiation of the stellate ganglion significantly decreased the visual analogue scale score in patients with fibromyalgia having a higher score in the Fibromyalgia Impact Questionnaire, suggesting that a stronger effect could be obtained in patients with more severe fibromyalgia.Key words: Fibromyalgia, Xenon light irradiation, Stellate ganglion     

Depletion of noradrenaline inhibits electrically‐evoked pain in the skin of the human forearm

Guanethidine displaces noradrenaline from sympathetic varicosities, and blocks sympathetic noradrenergic neurotransmission by inhibiting the release of noradrenaline from depleted neural stores. The aim of this study was to determine whether depletion of noradrenaline with guanethidine would oppose thermal hyperalgesia and/or electrically‐evoked pain in mildly‐burnt skin. Guanethidine was transferred by iontophoresis into a small patch of skin on the forearm of 35 healthy human subjects. The heat‐pain threshold to a temperature gradient that increased at 0.5°C/s was then measured at the guanethidine site, a nearby saline‐control iontophoresis site, and in untreated skin. In addition, participants rated pain intensity to a 47°C stimulus that was applied to each site for 7s. Shortly after the iontophoreses, sensitivity to heat was greater at the guanethidine site than the two control sites, suggesting that ejection of noradrenaline from sympathetic varicosities increased sensitivity to heat. One day later, when neural stores of noradrenaline were depleted, sensitivity to heat did not differ between the guanethidine and control sites. The guanethidine pretreatment did not influence thermal hyperalgesia induced by a mild burn, but inhibited pain evoked by electrical stimulation of the skin (0.2mA direct current for 4min). These findings indicate that ongoing sympathetic neural discharge does not normally influence thermal hyperalgesia in inflamed skin, because depleting noradrenergic stores had no effect. However, electrically‐evoked release of noradrenaline may increase nociceptive sensations. Further clarification of this human pain model could provide insights into the mechanism of adrenergic hyperalgesia in certain neuropathic pain syndromes.     

Fibromyalgia as a sympathetically maintained pain syndrome

Abnormal activity of the sympathetic nervous system may be involved in the pathogenesis of chronic pain syndromes. This article reviews the animal studies of sympathetically induced pain behavior, the controversy of sympathetically maintained pain in clinical practice, and the dysautonomic nature of fibromyalgia (FM). FM has neuropathic pain features (stimuli-independent pain state accompanied by allodynia and paresthesias). The proposal of FM as a sympathetically maintained pain syndrome is based on the controlled studies showing that patients with FM display signs of relentless sympathetic hyperactivity and that the pain is submissive to sympathetic blockade and is rekindled by norepinephrine injections. Dysautonomia also may explain the multisystem features of FM.     

星状神经节阻滞与颈横突局部注射疗法对颈源性头痛的疗效评价

目的:探讨星状神经节阻滞疗法和C2横突旁注射疗法对颈源性头痛的疗效.方法:颈源性头痛患者96例分别采用C2横突局部注射36例(A组)、星状神经节阻滞36例(B组)及单纯口服对乙酰氨基酚胶囊24例(C组).治疗前后采用McGill疼痛评分量表评定患者疼痛程度.结果:治疗3周后,A、B组疼痛评分差异无显著性意义,但均优于C组(P＜0.05).结论:C2横突旁局部注射与星状神经节阻滞疗法治疗作用相近,对颈源性头痛均有较好疗效.     

16. Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A–). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).     

A comparison of regional intravenous guanethidine and reserpine in reflex sympathetic dystrophy. A controlled, randomized, double-blind crossover study

Both regional intravenous guanethidine and reserpine have been reported as effective in the treatment of reflex sympathetic dystrophy. Reserpine depletes storage of norepinephrine, and guanethidine interferes with transport of norepinephrine while depleting storage in the sympathetic nerve terminal. The purpose of this study was to compare drug efficacy in double-blind fashion. Twelve patients, 10 of whom had previous stellate or lumbar sympathetic blocks, were entered into this double-blind cross-over study. Each patient successively received 20 mg guanethidine in 50 ml 0.5% lidocaine, 1.25 mg reserpine in 50 ml 0.5% lidocaine, and 50 ml 0.5% lidocaine with a 1-week interval between medications. At the end of the study and before the code was broken, each patient had the option of continuing treatment with any of the three drugs: the patient merely asked for the first, second, or third drug. Pain assessment used verbal ordinal, numeric, and visual analog scales. Follow-up lasted for a minimum of 6 months. Changes in pain intensity for the first 3 days did not differ significantly among guanethidine, reserpine, and control groups. Pain relief from 2 to 14 months was achieved in two patients receiving reserpine, one receiving guanethidine, and none receiving lidocaine. None of the patients experienced permanent relief. No difference was found between reserpine and guanethidine.     

Unterschiede zwischen myofazialen Triggerpunkten und ?tender points��

The article describes and compares the characteristics of myofascial trigger points (MTrPs) of the myofascial pain syndrome and the tender points (TePs) of the fibromyalgia syndrome. Many statements are hypothetical, because not all aspects of the disorders have been clarified in solid studies. Signs and symptoms of MTrPs: (1) palpable nodule, often located close to the muscle belly, (2) often single, (3) allodynia and hyperalgesia at the MTrP, (4) referral of the MTrP pain, (5) normal pain sensitivity outside the MTrPs, (6) local twitch response, (7) local contracture in biopsy material, (8) peripheral mechanism probable. Signs and symptoms of TePs: (1) no palpable nodule, (2) location often close to the muscle attachments, (3) multiple by definition, (4) allodynia and hyperalgesia also outside the TePs, (5) enhanced pain under psychic stress, (6) unspecific histological changes in biopsy material, (7) central nervous mechanism probable. The multitude of differences speak against a common aetiology and pathophysiology.     

Indications and technique of thoracic2 and thoracic3 neurolysis

This article reviews the technique of thoracic (T)₂ and T₃ sympathetic ganglion block and neurolysis. Historic aspects of this technique are described. The concept of radiofrequency thermocoagulation (RFTC) of T₂ and T₃ is discussed and the technique is detailed. This procedure is useful for complex regional pain syndrome (CRPS), vascular compromise, and neuropathic pain syndromes of upper extremities. It is an alternative to stellate ganglion ablation and may be useful for patients with sympathetically maintained pain who have persistent pain after stellate ganglion procedures.