PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “THORACIC NERVES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources

Evoked responses in the diagnosis of thoracic outlet syndrome.

The lack of an objective method for diagnosing thoracic outlet syndrome and monitoring the results of treatment has prevented a clear understanding of its natural history and the indications for surgery. Although one can detect vascular compression, the majority of patients have symptoms that are primarily neurogenic; and neither electromyograms nor studies of nerve conduction velocity has proved consistently helpful in their evaluation. We have studied evoked responses in 22 patients and believe that this technique allows selection of patients with significant neural compression for operative treatment. In this procedure, a bipolar stimulating electrode is placed on the median and ulnar nerves at the wrist; and bipolar recording is performed from active electrodes placed at Erb's point, over the spines of C6 and C2, and over the contralateral parietal scalp, all referenced to a midfrontal electrode. A minicomputer temporally summates the low-amplitude potentials elicited by repetitive electrical stimulation to increase the signal to noise ratio and therefore distinguish the potentials of interest from the background bioelectric activity. Normative values have been determined, allowing detection of changes in conduction of the electrical activity that occur between the sites of stimulation and the sites of recording. Of 19 new patients, 13 had abnormal evoked responses. Nine of these underwent surgical treatment; eight obtained good or excellent results. Abnormalities in evoked responses disappeared after operation in seven of the eight in whom it was measured. Four patients with abnormal responses but no surgery are being evaluated. Two of three long-term patients with recurrent symptoms had abnormal evoked responses that changed after treatment. Longer follow-up is needed to determine if this method is helpful in selecting patients for operative treatment or in monitoring its results.

Adult↗

Video-assisted endoscopic thoracic ganglionectomy.

Sympathetic nerve disorders of the upper extremities can be treated by neurosurgeons using upper thoracic sympathectomy via a posterior approach. Descriptions have been published of alternative endoscopic procedures involving thermocoagulation, laser coagulation, or nonvideo-assisted ganglionectomy using equipment not widely available, with low morbidity and excellent results. The authors describe the use of an endoscopic approach to the thoracic sympathetic ganglia with systems designed for laparoscopic cholecystectomy. Thoracic ganglionectomy is reported in 22 patients with primary palmar hyperhidrosis and eight patients with reflex sympathetic dystrophy. The patients underwent double-lumen endotracheal intubation, after which 11- and 5.5-mm trocars were introduced into the chest cavity. Pneumothorax was produced with CO2 insufflation. Fiberoptic closed-circuit television was used to visualize the structures to be dissected. The parietal pleura over the heads of the first and second ribs was excised using 5-mm blunt and sharp insulated coagulating microscissors. The stellate and upper thoracic ganglia were clearly identified and dissected. The T-2 and T-3 ganglia were grasped with forceps and excised. A No. 16 French chest tube was introduced through a trocar, placed under water seal after the lungs were reinflated, and removed in the recovery room. The average hospital stay was 15.4 hours. There were no intraoperative complications. The average operating time was 30 minutes per side. Five patients had mild pleuritic pain which resolved within 2 weeks after surgery. Six (75%) of the eight patients with reflex sympathetic dystrophy had complete or partial relief of their symptoms (average follow-up period 5 months), and all patients had complete relief of hyperhidrosis (average follow-up period 8 months). Endoscopic ganglionectomy requires readily available and easily used instrumentation and provides a well-tolerated, cost-effective alternative to posterior thoracic sympathectomy for primary palmar hyperhidrosis and reflex sympathetic dystrophy.

Ganglionectomy↗

Vagus nerve stimulation decreases left ventricular contractility in vivo in the human and pig heart.

1. Studies of the effect of vagus nerve stimulation on ventricular myocardial function in mammals are limited, particularly in the human. 2. The present study was designed to determine the effect of direct electrical stimulation of the left vagus nerve on left ventricular contractile state in hearts paced at 10 % above the natural rate, in anaesthetised pigs and anaesthetised human subjects undergoing open chest surgery for coronary artery bypass grafting. 3. Contractility of the left ventricle was determined from a series of pressure-volume loops obtained from a combined pressure and conductance (volume) catheter placed in the left ventricle. From the measurements a regression slope of the end-systolic pressure-volume relationship was determined to give end-systolic elastance (Ees), a load-independent measure of contractility. 4. In six anaesthetised open chest pigs, stimulation of the peripheral cut end of the left cervical vagus nerve induced a significant decrease in Ees of 26 +/- 14 %. 5. In nine patients electrical stimulation of the left thoracic vagus nerve close to its cardiac branch resulted in a significant drop in Ees of 38 +/- 16 %. 6. The effects of vagal stimulation were blocked by the muscarinic antagonist glycopyrronium (5 mg kg(-1)). 7. Administration of the beta-adrenoreceptor antagonist esmolol (1 mg kg(-1)) also attenuated the effect of vagal stimulation, indicating a degree of interaction of vagal and sympathetic influences on contractility. 8. These studies show that in the human and pig heart the left vagus nerve can profoundly decrease the inotropic state of the left ventricular myocardium independent of its bradycardic effect.

Animals↗

[Thermographic assessments of the sympathetic blockade after stellate ganglion block (no. 3)--the block at the base of the 6th cervical transverse process].

We attempted to define effects of stellate ganglion block (SGB) at the base of 6th cervical transverse process by evaluating extent and degree of sympathetic blockade after SGB using the infrared thermography. Ten healthy volunteers (7 females, 3 males, age 26.0 years) were subjects of this study. Two different volumes (5 or 10 ml) of 1% plain mepivacaine were used (B5 group and B10 group). We performed SGB twice using two different volumes in all subjects on different day. Thermography was performed before and 30 minutes after SGB. On thenar and hypothenar, change of skin temperature in the B10 group tended to be higher compared with the B5 group. There were no significant differences in forehead or cheek temperature between the two groups. The thermographic whole hot area pattern on the ipsilateral hand after SGB in B10 group (60%) tended to be more frequent compared with the B5 group (40%). All subjects showed Horner's sign. No severe side-effect occurred in either group, but complaints of dysphagia appeared more frequently in the B10 group (80%) than in B5 group (40%). The change of skin temperature on thenar and hypothenar after B5 was significantly larger than that after the SGB at the top of the anterior tubercle of 6th cervical transverse process (P less than 0.05). In conclusion, B10 had more effect on lower cervical and upper thoracic sympathetic nerves than B5, but it also had a significant incidence of dysphagia feeling. Concerning the effect of the lower cervical and upper thoracic sympathetic block, B5 was superior to the SGB at the top of the anterior tubercle of 6th cervical transverse process.

Adult↗

Congenital primitive neuroectodermal tumor (neuroepithelioma) of the chest wall.

Primitive neuroectodermal tumor (neuroepithelioma) is a relatively common central nervous system tumor in children. Those arising from a peripheral nerve are extremely rare in childhood. There is only one reported case in 6-year-old where the tumor arose from the sciatic nerve. A case of neuroectodermal tumor of the chest wall, arising from the intercostal nerve, in a newborn is presented. The tumor metastasized to the brain. Prominent Homer-Wright rosettes, with central eosinophilic fibrillar substance similar to that seen in neuroepithelioma of the central nervous system, were present in the primary tumor and brain metastases. Ultrastructure, as revealed by transmission electron microscopy, is also described.

Brain Neoplasms↗

Intercostal muscles and purring in the cat: the influence of afferent inputs.

Feline purring has previously been reported as originating in a central oscillator, independent of afferent inputs, and also as not involving expiratory muscles. Here we show, via electromyographic recordings from intercostal muscles, quantified by cross-correlation, that expiratory muscles can be involved and that even if the oscillator is central, reflex components nevertheless play a considerable part in the production of the periodic pattern of muscle activation seen during purring.

Animals↗

Patient outcome following a thoracodorsal to musculocutaneous nerve transfer for reconstruction of elbow flexion.

This study reports patient outcome following a thoracodorsal to musculocutaneous nerve transfer. We retrospectively reviewed the charts of six patients who had undergone transfer of the thoracodorsal nerve to the musculocutaneous nerve for reconstruction of elbow flexion. The mean age was 47 years (standard deviation: 24 years; range: 17-72 years). The mean time from injury to surgery was 3 months (standard deviation: 2 months; range: 1-5 months). In all cases, the biceps muscle was successfully reinnervated; in one case the Medical Research Council (MRC) muscle grade was grade 5, in four cases it was grade 4, and in one case it was grade 2. No patients complained of functional weakness with shoulder adduction and/or internal rotation. In the majority of cases, transfer of the thoracodorsal nerve to the musculocutaneous nerve provides excellent recovery of elbow flexion.

Adolescent↗

The sympathetic nervous system and obstructive sleep apnea: implications for hypertension.

Patients with obstructive sleep apnea experience repetitive apneic events during sleep, with consequent hypoxia and hypercapnia. Hypoxia and hypercapnia, acting via the chemoreflexes, elicit increases in sympathetic nerve activity. The sympathetic responses to hypoxia and hypercapnia are potentiated during apnea, when the sympathetic inhibitory influence of the thoracic afferent nerves is eliminated. As a consequence of the sympathetic vasoconstrictor response to apneic events, patients with obstructive sleep apnea manifest marked increases in blood pressure during sleep, especially evident at the end of the apnea. The increases in sympathetic activity and blood pressure during sleep in these patients appear to carry over into the daytime such that patients with sleep apnea have an increased prevalence of hypertension and high levels of sympathetic nerve activity. Although the mechanism underlying the persistent elevation in sympathetic activity during the daytime is not known, it is likely that the increased sympathetic drive is implicated in the higher daytime blood pressures in these patients. Whereas patients with sleep apnea have an increased prevalence of hypertension, in those patients with sleep apnea who do have hypertension, the sympathetic response to apneic events may be potentiated. This may be secondary to impaired baroreflex sensitivity, since the baroreflexes exert an inhibitory influence on the chemoreflex responses to hypoxia. Treatment with continuous positive airway pressure results in an acute reduction in blood pressure and sympathetic activity during sleep. Prolonged effective treatment of sleep apnea may also reduce daytime blood pressure levels. This review examines the physiology of the chemoreflex responses to hypoxia, hypercapnia and apnea, as well as the physiologic responses to sleep in normal humans. These physiologic responses are compared with the pathophysiologic sympathetic and hemodynamic responses that characterize obstructive sleep apnea. Increases in sympathetic activity and blood pressure in patients with obstructive sleep apnea may play a role in linking sleep apnea to hypertension and cardiac and vascular events.

Baroreflex↗