Ipsilateral Stellate Ganglion Research Articles

Increased Subcutaneous Nerve Activity Is Strongly Associated with the Initiation of Atrial Tachyarrhythmias in Ambulatory Canines

<h3>Background</h3> Increased stellate ganglion nerve activity (SGNA) directly precedes the onset of spontaneous atrial tachyarrhythmias (AT) in ambulatory dogs. However, it is difficult to use SGNA for risk stratification and arrhythmia prediction because access to the stellate ganglion requires open chest surgery. Because subcutaneous sympathetic nerve fibers originate from ipsilateral stellate ganglion, we hypothesize that subcutaneous nerve activity (SCNA) can be used as a surrogate of SGNA to predict the immediate onset of AT in ambulatory dogs. <h3>Methods</h3> We continuously recorded SCNA and ECG in 4 ambulatory dogs using an implanted radiotransmitter with electrodes in the subcutaneous space of the left chest. The dogs were atrially paced at 600 bpm for 6 days. The dogs were also treated with digoxin (0.01 mg/kg daily) and diltiazem CD (6 mg/kg daily) to reduce ventricular rates. ECG, SCNA, and SGNA were reviewed for a 24-hour period before and after 6 days of pacing. SCNA and SGNA were also integrated (iSCNA and iSGNA) at 1-minute intervals for 10 minutes of each hour of the 24 hours reviewed. Episodes of AT were identified as a heart rate >150 bpm for at least 5 seconds. SCNA and SGNA were integrated over the 5 seconds preceding each episode of AT (iSCNAAT and iSGNAAT). Also, SCNA and SGNA were integrated for 5 seconds during random episodes of normal sinus rhythm (iSCNANSR and iSGNANSR, respectively). <h3>Results</h3> There were 14 ± 20 episodes/dog/day of spontaneous AT at baseline and 20 ± 25 episodes/dog/day after rapid atrial pacing (<i>P</i> <.05). We analyzed 118 episodes (41 ± 42 per dog) of AT, including 58 episodes of atrial fibrillation and 60 of regular atrial tachycardia, with an average duration of 12 ± 6 seconds/episode. AT was invariably preceded by SCNA activation within 5 seconds before onset. iSCNAAT was significantly greater than iSCNANSR (31.9 ± 18.7 mv-s vs 6.9 ± 4.45 mv-s, <i>P</i> <.005). <h3>Conclusions</h3> Spontaneous AT in ambulatory dogs was invariably preceded by an increased SCNA. These findings suggest that SCNA is an effective biomarker for predicting the onset of AT in this canine model.

Effect of interscalene brachial plexus block on heart rate variability

BackgroundInterscalene brachial plexus block (ISB) may be followed by cardiovascular instability. Until date, there is no clear picture available about the underlying mechanisms of ISB. In this study, we aimed to determine the changes in heart rate variability (HRV) parameters after ISB and the differences between right- and left-sided ISBs.MethodsWe prospectively studied 24 patients operated for shoulder surgery in sitting position and divided them into two respective groups: R (right-sided block = 14 pts) and L (left-sided block = 10 pts). HRV data were taken before and 30 min after the block. Ropivacaine without ephedrine was used for the ISB through an insulated block needle connected to a nerve stimulator. Statistical analysis implemented chi-square, Student's and t-paired tests. Skewed distributions were analyzed after logarithmic transformation.ResultsAll the studied patients had successful blocks. Horner's syndrome signs were observed in 33.3% of the patients (R = 5/14, L = 3/10; [P = 0.769]). There were no significant differences in pre-block HRV between the groups. The application of ISB had differential effect on HRV variables: R-blocks increased QRS and QTc durations and InPNN50, while a statistical decrease was seen in InLF. L-blocks did not show any significant changes. These changes indicate a reduced sympathetic and an increased parasympathetic influence on the heart's autonomic flow after R-block.ConclusionsBased on the obtained results we conclude that ISB, possibly through extension of block to the ipsilateral stellate ganglion, alters the autonomic outflow to the central circulatory system in a way depending on the block's side.

A Case of Cluster Headache: Repeated Ipsilateral Stellate Ganglion Blocks were Effective

A Case of Cluster Headache: Repeated Ipsilateral Stellate Ganglion Blocks were Effective

Reabilitação funcional e analgesia com uso de toxina botulínica A na síndrome dolorosa regional complexa tipo I do membro superior: relato de casos

Functional inability of the affected limb is often added to alodynia and hyperalgesia in Complex Regional Pain Syndrome (CRPS) type I. Two CRPS cases are reported in which botulinum toxin A as coadjuvant drug has contributed to motor and functional recovery of the affected limb. Two CRPS type I patients were initially evaluated for upper limb pain control. Both were unable to open the hand and referred pain intensity by numeric analog scale (NAS) of 10 at rest or when hand and fingers were passively manipulated. A sequence of 5 weekly ipsilateral stellate ganglion blockade with clonidine and lidocaine was started. Simultaneously, during the third stellate ganglion blockade, 75 Ul botulinum toxin A was administered to flexor muscles of phalanges and wrist joint. One week after botulin toxin A administration patients presented phalanges and wrist relaxation, reported easy passive physical therapy and pain was classified as 2 (NAS) at passive manipulation. At stellate ganglion blockade sequence completion patients were submitted to 3 weekly regional intravenous clonidine, lidocaine and parecoxib. At 8 months evaluation patients presented 70% and 80% motor and functional recovery of the affected limb. Muscular botulin toxin A has resulted in movement improvement of the affected limb and analgesia, favoring functional recovery.

Distribution of sympathetic and afferent neurones innervating the submandibular gland in the sheep.

The distribution of sympathetic and sensory neurones innervating the submandibular gland (SMG) in sheep was studied using retrograde tracing technique. The retrograde tracer Fast Blue (FB) was unilaterally injected into the SMG in five juvenile male sheep under general anaesthesia. After a 4-week survival period, all the animals were reanaesthetized, perfused transcardially with 4% buffered paraformaldehyde and ganglia, which could be considered as a potential sources of sympathetic, and afferent innervation of the gland were bilaterally collected. The FB-labelled sympathetic neurones were found in the ipsilateral superior and middle cervical ganglion. Many labelled neurones were distributed in the ipsilateral jugular and nodose ganglia of the vagus nerve and smaller numbers of the nerve cells were also found in ipsilateral C1-C3 dorsal root ganglia (DRG). No labelled neurones were observed in the ipsilateral stellate ganglion, trigeminal ganglion, C4-C8 DRG and in all contralateral ganglia. The present study revealed that the majority of sympathetic neurones projecting to the sheep SMG are found in the superior cervical ganglion but some of them are also distributed in the middle cervical ganglion. Most of the afferent neurones are located in the jugular and nodose ganglia of vagus nerve but C1-C3 DRG also comprise some of these nerve cells.

Periaqueductal gray matter input to cardiac-related sympathetic premotor neurons

The periaqueductal gray matter (PAG) serves as the midbrain link between forebrain emotional processing systems and motor pathways used in the defense reaction. Part of this response depends upon PAG efferent pathways that modulate cardiovascular-related sympathetic outflow systems, including those that regulate the heart. While it is known that the PAG projects to vagal preganglionic neurons, including possibly cardiovagal motoneurons, no information exists on the PAG circuits that may affect sympathetically mediated cardiac functions and, thus, the purpose of this study was to use neuroanatomical methods to identify these pathways. First, viral transneuronal retrograde tracing experiments were performed in which pseudorabies virus (PRV) was injected into the stellate ganglion of rats. After 4 days survival, five PAG regions contained transynaptically infected neurons; these included the dorsomedial, lateral and ventrolateral PAG columns as well as the Edinger–Westphal and precommissural nuclei. Second, the descending efferent PAG projections were studied with the anterograde axonal marker Phaseolus vulgaris leuco-agglutinin (PHA-L) with a particular focus on determining whether the PAG projects to the intermediolateral cell column (IML). Almost no axonal labeling was found throughout the thoracic IML suggesting that the PAG modulates sympathetic functions by indirect pathways involving synaptic relays through sympathetic premotor cell groups, especially those found in the medulla oblongata. This possibility was examined by a double tracing study. PHA-L was first injected into either the lateral or ventrolateral PAG and after 6 days, PRV was injected into the ipsilateral stellate ganglion. After an additional 4 days survival, a double immunohistochemical procedure for co-visualization of PRV and PHA-L was used to identify the sympathetic premotor regions that receive an input from the PAG. The PAG innervated specific groups of sympathetic premotor neurons in the hypothalamus, pons, and medulla as well as providing reciprocal intercolumnar connections within the PAG itself (Jansen et al., Brain Res. 784 (1998) 329-336). The major route terminates in the ventral medulla, especially within the medial region which contains sympathetic premotor neurons lying within the raphe magnus and gigantocellular reticular nucleus, pars alpha. Both serotonergic and non-serotonergic sympathetic premotor neurons in these two regions receive inputs from the PAG. Weak PAG projections to sympathetic premotor neurons were found in the rostral ventrolateral medulla (including to C1 adrenergic neurons), locus coeruleus, A5 cell group, paraventricular and lateral hypothalamic nuclei. In summary, both the lateral and ventrolateral PAG columns appear to be capable of modulating cardiac sympathetic functions via a series of indirect pathways involving sympathetic premotor neurons found in selected sites in the hypothalamus, midbrain, pons, and medulla oblongata, with the major outflow terminating in bulbospinal regions of the rostral ventromedial medulla.

Ipsilateral Stellate Ganglion Block Effective for Treating Shoulder Pain After Thoracotomy

Recently, Burgess et al. (1) documented the incidence and severity of ipsilateral shoulder pain after thoracotomy, a particularly difficult problem to treat. Although they examined several possible mechanisms for such pain, which included thoracic somatic and visceral as well as phrenic nerve nocice

Functional and anatomical variability of canine cardiac sympathetic efferent pathways: implications for regional denervation of the left ventricle.

To further elucidate the functional anatomy of canine cardiac innervation as well as to assess the feasibility of producing regional left ventricular sympathetic denervation, the chronotropic and (or) regional left ventricular inotropic responses produced by stellate or middle cervical ganglion stimulation were investigated in 22 dogs before and after sectioning of individual major cardiopulmonary or cardiac nerves. Sectioning the right or left subclavian ansae abolished all cardiac responses produced by ipsilateral stellate ganglion stimulation. Sectioning a major sympathetic cardiopulmonary nerve, other than the right interganglionic nerve, usually reduced, but seldom abolished, regional inotropic responses elicited by ipsilateral middle cervical ganglion stimulation. Sectioning the dorsal mediastinal cardiac nerves consistently abolished the left ventricular inotropic responses elicited by right middle cervical ganglion stimulation but minimally affected those elicited by left middle cervical ganglion stimulation. In contrast, cutting the left lateral cardiac nerve decreased the inotropic responses in lateral and posterior left ventricular segments elicited by left middle cervical ganglion stimulation but had little effect on the inotropic responses produced by right middle cervical ganglion stimulation. In addition, the ventral mediastinal cardiac nerve was found to be a significant sympathetic efferent pathway from the left-sided ganglia to the left ventricle. These results indicate that the stellate ganglia project axons to the heart via the subclavian ansae and thus effective sympathetic decentralization can be produced by cutting the subclavian ansae; the right-sided cardiac sympathetic efferent innervation of the left ventricle converges intrapericardially in the dorsal mediastinal cardiac nerves; and the left-sided cardiac sympathetic efferent innervation of the left ventricle diverges to innervate the left ventricle by a number of nerves including the dorsal mediastinal, ventral mediastinal, and left lateral cardiac nerves. Thus consistent denervation of a region of the left ventricle can not be accomplished by sectioning an individual cardiopulmonary or cardiac nerve because of the functional and anatomical variability of the neural components in each nerve, as well as the fact that overlapping regions of the left ventricle are innervated by these different nerves.

Chronotropic, inotropic, and coronary artery blood flow responses to stimulation of specific canine sympathetic nerves and ganglia.

Electrical stimulation of the major sympathetic cardiac nerves and ganglia in chloralose-anesthetized, open-chest dogs elicited specific changes in heart rate, coronary blood flow, regional intramyocardial pressure, or intraventricular pressure. The effects produced by stimulation of a cardiac nerve were similar to, but never greater than those produced by stimulation of the ipsilateral stellate ganglion. Coronary blood flow was increased when neural stimulation increased intramyocardial pressure. In contrast, coronary blood flow was not altered significantly when neural stimulation induced tachycardia without increasing intramyocardial pressure. It is concluded that in the intact heart, electrical stimulation of the sympathetic cardiac nerves or ganglia increases coronary blood flow by augmenting intramyocardial pressure, not chronotropism.

Localization of sympathetic postganglionic and parasympathetic preganglionic neurons which innervate different regions of the dog heart.

The locations of sympathetic postganglionic and parasympathetic preganglionic neurons projecting to the heart have not yet been clearly established. Therefore, aliquots of horseradish peroxidase (HRP) were injected into specific regions of the heart, intraventricular cavity, pericardial sac, aortic arch, and the skin in 27 dogs. Following injections into the heart, aorta, or pericardial sac, retrogradely labeled neurons were present in the greatest numbers in the middle cervical ganglia bilaterally. Labeled neurons were located in the cranial poles of the stellate ganglia bilaterally and occasionally in the superior cervical ganglia. Labeled cells were also found in small ganglia located along cardiopulmonary nerves. Injections of HRP into specific areas of the heart did not result in labeling of cells in specific loci of the thoracic or cervical sympathetic ganglia. When the ansae were cut on one side, no labeled cells were found in the ipsilateral stellate ganglion or upper thoracic chain. Following injections into the skin of the left elbow or left cranial nipple, labeled cells were found in the stellate ganglia and the sympathetic chain and in one case in the middle cervical ganglion as well. These data suggest that postganglionic sympathetic neurons which project efferent axons to a specific cardiac region are not located in a specific region of a sympathetic ganglion or a specific sympathetic ganglion. Rather, neurons in one region of a sympathetic ganglion project axons to widespread areas of the myocardium. Sympathetic postganglionic neurons in the stellate ganglion or sympathetic chain project their axons to the heart via the subclavian ansae or interganglionic nerves, not via nerves arising directly from the sympathetic chain. Small numbers of labeled neurons were found in the medulla oblongata, thus indicating that in comparison to sympathetic postganglionic neurons relatively few preganglionic parasympathetic neurons project directly to the heart. When labeled cells were present in the medulla, the majority were located in the ventrolateral nucleus ambiguus.

Localization of sympathetic postganglionic neurons of physiologically identified cardiac nerves in the dog.

Cardiac nerves were identified physiologically and injected with horseradish peroxidase in 38 dogs. Retrogradely labeled neurons were present in the greatest number in the middle cervical ganglion, whereas fewer labeled neurons were present in the stellate ganglion. Only occasional neurons in the superior cervical ganglion were labeled, and no labelphysiologically and injected with horseradish peroxidase in 38 dogs. Retrogradely labeled neurons were present in the greatest number in the middle cervical ganglion, whereas fewer labeled neurons were present in the stellate ganglion. Only occasional neurons in the superior cervical ganglion were labeled, and no labelphysiologically and injected with horseradish peroxidase in 38 dogs. Retrogradely labeled neurons were present in the greatest number in the middle cervical ganglion, whereas fewer labeled neurons were present in the stellate ganglion. Only occasional neurons in the superior cervical ganglion were labeled, and no labeled cells were found in the T3 to T6 paravertebral ganglia or in the ganglia contralateral to the nerve injected. following injections into specific cardiac nerves, retrograde labeling was widespread within the middle cervical ganglion, and the distributions of labeled neurons from different nerves overlapped considerably. In the middle cervical ganglion there was little or no regional grouping of cells projecting to specific cardiac nerves. within the stellate ganglion, however, te cardiac-sympathetic cells were clustered primarily at the cranial pole near toe origin of the ventral and dorsal ansae. Mediastinal ganglia and ganglia located in cardiac nerves were frequently as heavily labeled as the ipsilateral stellate ganglion. The occurrence of heavy labeling in mediastinal and cardiac nerve ganglia indicates that these hitherto unreported ganglia play a significant role in cardiac neural regulation. These data imply that the organization of sympathetic neurons controlling the heart is much more complex than has previously been considered.

Reversal of serotonin vasodilatation in the dog external carotid bed by sympathetic denervation.

In view of the conflicting reports of both constrictor and dilator effects of serotonin on the external carotid vascular bed of dogs, the influence of intraarterial infusions of the amine on blood flow through this territory was assessed by electromagnetic flowmeter techniques. In anesthetized intact dogs, serotonin produced dose-related increases in flow. These vasodilator responses were markedly diminished after ipsilateral vagotomy and were followed by delayed vasoconstriction, which then became the predominant response. Pretreatment with atropine did not modify dilator responses, while resection of the ipsilateral stellate ganglion reversed them to pure constriction. In the internal carotid, serotonin elicited constriction, and this effect was unaffected by vagotomy. These results were interpreted in terms of the hypothesis relating serotonin reactivity to vascular tone. The amine would elicit dilatation through an effect on tonically constricted small vessels. Removal of this tone by section of the vagosympathetic trunk or stellectomy would unmask the constrictor effect of serotonin on large vessels. Such reversal of responses would not occur in the internal carotid, a territory normally devoid of important sympathetic tone.

Neurogenic ECG changes in critically ill patients: an experimental model.

ECG observations in patients critically ill from various CNS problems suggest that T wave abnormalities in these patients may be neurogenic rather than the result of cardiac ischemia. This phenomenon has been experimentally reproduced in the cat. Right hypothalamic stimulation in this species markedly increases T wave amplitude while left hypothalamic stimulation decreases T wave amplitude. ECG results similar to those following right hypothalamic stimulation were obtained by stimulation of the right stellate ganglion and this was also true with regard to left hypothalamic and left stellate ganglion stimulation. ECG effects of unilateral hypothalamic stimulation could be abolished by removal of the ipsilateral stellate ganglion. These results demonstrate that T wave changes on the ECG may be neurogenic and suggest that the mechanism for their production is a unilateral alteration of sympathetic tone to the heart.

Posthemiplegic reflex sympathetic dystrophy.

Hemiplegia in the six cases here described was followed by a painful syndrome in the affected upper extremity. Progressive changes were observed in soft tissues, joints, and bones. Ipsilateral stellate ganglion blocks afforded prompt but not always permanent relief, and the two patients who submitted to high thoracic sympathectomy obtained lasting benefit. The evidence showed that much of the disability represented inhibition caused by severe pain and trophic changes. The prompt remission of the symptoms after sympathetic block or sympathectomy enabled the patient to utilize powers still latent in the extremity and greatly facilitated the program of rehabilitation.