Invertebrate nerve-muscle systems.
Explore the source record for details and available documents.
SEARCH · PubMed Health
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.
Explore the source record for details and available documents.
The third and fourth intercostal nerves were sutured to the musculocutaneous nerve to restore flexion of the elbow joint in complete (preganglionic) brachial plexus injuries. Seventeen patients were followed on the average for 5 years and 7 months after surgery. The results were evaluated by means of manual muscle tests and electrical diagnostic tests. Good (grade IV), or better, flexion of the elbow joint occurred in 12 patients over 3 years after the operation.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The spread of solutions injected to the intercostal space was studied in 10 healthy volunteers. Up to 20 ml of a 50:50 mixture of local anaesthetic solution and a radiopaque dye was injected through a modified extradural catheter placed in an intercostal space at the posterior angle of the rib. Radiographic films demonstrated spread by an extrapleural route into adjacent intercostal spaces and this was confirmed by the occurrence of analgesia in the corresponding dermatomes. The relevance of these results to clinical practice is discussed.
Anatomical study of the proximal intercostal nerve in cadavers revealed three nerve forms, depending on the relation between the nerve and adjacent ribs. This was found in the classical subcostal position in 16.6%, in the midzone in 73% and in the inferior supracostal position in 10%.
Explore the source record for details and available documents.
The usefulness of leaving lateral strips of the rectus abdominis muscle in place during a transverse rectus abdominis musculocutaneous (TRAM) flap procedure is questioned. Since textbooks do not agree on the course of the intercostal nerves in the rectus fascia and no precise description is given of the exact site of penetration of the nerves in the rectus muscle, six fresh cadavers were dissected. It has been observed that the nerves enter the deep face of the muscle in its middle portion. Lateral parts of the muscle are consequently denervated during a transverse rectus abdominis musculocutaneous flap, which preserves them. This has been confirmed by CT scan of the abdominal wall in 10 patients 2 to 37 months after a transverse rectus abdominis musculocutaneous flap. In these patients, a progressive fibrosis and disappearance of the remaining muscle could be demonstrated. It is concluded that a partial taking of the rectus abdominis muscle does not preserve its muscular function.
Five patients with intercostobrachial nerve entrapment syndrome are reported. The pain in this syndrome has three aspects: somatic stimulus, perceptual surround, and behavioral response. Each must be dealt with appropriately. The distribution of the pain, its anatomic basis, and its treatment are discussed.
STUDY DESIGN: We present a case of a patient with chronic paraplegia with a complete spinal cord gap resulting from a stabbing injury 4 years ago recovering after an innovative surgical strategy. OBJECTIVES: To demonstrate the clinical outcome of surgical repair with sural nerve graft with fibrin glue containing acidic fibroblast growth factor in a patient with chronic spinal cord injury. SUMMARY OF BACKGROUND DATA: Spinal cord injury usually causes permanent disability, and there had been not effective surgical technique to obtain satisfactory functional motor recovery, particularly in chronic patients. Previous studies have revealed that acidic fibroblast growth factor could promote axonal regeneration and reduce neuronal death in adult rats with spinal cord injury. METHODS: The spinal cord gap at T11 level was bridged with 4 sural nerve grafts that redirected specific pathways from white to gray matter. The grafted area was stabilized with fibrin glue containing acidic fibroblast growth factor. RESULTS: Before the operation, the paraplegia was identified as ASIA-C, with a motor score for the right and left legs of 12 and 0, respectively, a pinprick score of 77, and 77 on a light touch of left side limbs. His functional status improved from being wheelchair-bound to being able to ambulate independently with a walker 2-and-a-half years after surgery. At this stage, paraplegia was ASIA-D, with motor scores for the right and left legs of 15 and 12, respectively, 86 for a pinprick, and 86 for a light touch of left side limbs. CONCLUSIONS: This case demonstrated significant motor recovery attained in a patient with chronic paraplegia following a repair surgery with nerve graft and growth factor.
Bilateral blockade of the 5th to 11th intercostal nerves, inclusive, was produced in 14 healthy subjects. In seven, bupivacaine 0.25% was used, and in the other seven, etidocaine 0.5%. The latter has been found to have a stronger motor-blocking action than the former. Before and after the blockade, the vital capacity (VC), peak expiratory flow rate (PEF), tidal volumes, respiratory variations in rib cage and abdominal circumferences and in oesophageal and intragastric pressures were recorded. By transthoracic electrical impedance pneumography, measures indicating changes in the functional residual capacity (FRC) were obtained. Although it was considered that changes in the parameters investigated mainly demonstrated changes in motor function, no differences were found between the drugs. With this form of blockade they seem to have equivalent effects in this respect. Thus, VC decreased by an average of 7% and PEF by 6%. Signs of a reduction of FRC after the blockade were also observed. The blockade had no effect on the partitioning of costal and abdominal breathing at rest. Analysis of the relations between the fractions of costal and abdominal breathing and the corresponding variations in intragastric pressure gave support to the view that in normal individuals both intercostal and abdominal muscles remain passive during respiration at rest. This is thus achieved by the diaphragm alone.
Explore the source record for details and available documents.
Three different techniques for producing multiple intercostal nerve blocks using bupivacaine were compared in volunteers. The techniques used were multiple injections at intercostal nerves 7-11, or a single injection employing a needle or a catheter inserted in the 9th intercostal space. The injections were made at the costal angle. The anatomical spread of a mixture of a local anaesthetic and a radio-opaque fluid following the single injection technique at the ninth intercostal space or at the subcostal space was evaluated by computerized x-ray tomography (CT). The distribution of cutaneous analgesia/hypalgesia following all techniques was evaluated by pin prick. No spread of the local anaesthetic to adjacent intercostal spaces or to the paravertebral space could be shown by CT. The distribution of cutaneous analgesia was limited to three segments or less following a single injection. No difference in blood levels of bupivacaine could be found. It is concluded that the single injection technique of producing multiple intercostal nerve blocks is inferior to the multiple injection technique.
Monosynaptic connexions were sought between bulbospinal inspiratory neurones and inspiratory motoneurones of the C5 phrenic nerve or the intercostal nerves of up to six segments in the anaesthetized cat; they were identified by the presence of narrow peaks in cross-correlation histograms constructed from the spontaneous discharges of these neurones. About half of the bulbospinal neurones tested with the phrenic gave a monosynaptic connexion, as did just under half of those tested with the intercostal nerves. Some neurones gave connexions to both. For pairs of bulbospinal neurones and intercostal nerves, connexions were seen in 50 out of 295 instances (17%). No evidence was found of systematic patterns of connexions to different segments. Some neurones gave connexions to adjacent segments, others up to five segments apart. Bulbospinal neurones were not equipotent at giving connexions to the intercostal motoneurones. If a neurone gave a connexion to one segment, it was more likely to give connexion to another segment than chance would predict. The neurones with strong connexions were concentrated rostral to obex in the ventral respiratory group; neurones in both the caudal part of the ventral group and in the dorsal group gave weaker connexions. Regional variation within the medulla in the proportions of neurones giving connexions to the phrenic motoneurones was not seen, in particular neurones of the dorsal group (eight out of sixteen) and the ventral group (five out of eleven) were equipotent. When the strength of the connexions was assessed by k, the ratio of the peak count in the cross-correlation histogram to the base-line count, the mean strength was similar for the peaks seen for the phrenic (k = 1.113) and the intercostal (k = 1.114) motoneurones. However, because, on a segment-by-segment basis, fewer connexions were seen for the intercostals, the over-all mean value of k (absence of a narrow peak taken as k = 1.0) was stronger for the phrenic (k = 1.055) than for the intercostals (k = 1.019). For the phrenic, the apparent strength of connexion (assessed by k) was considerably stronger for the motoneurones giving large spikes than for those giving small ones. The same result was probably also true for the intercostals. With several assumptions, the total depolarization during inspiration derived monosynaptically in phrenic or intercostal motoneurones was calculated and found to be low, about 1 mV for the intercostals and 3-4 mV for the phrenic.(ABSTRACT TRUNCATED AT 400 WORDS)
Phrenic and external intercostal motoneuron activities were compared during progressive asphyxia induced by the interruption of artificial ventilation in the pentobarbital-urethan-anesthetized, gallamine-paralysed rabbit. The relative augmentation of inspiratory activity of the T1-T4 external intercostal nerves was significantly greater than that of the phrenic nerve during asphyxic hyperpnea. This was associated with a greater recruitment of intercostal than of phrenic motoneurons, particularly late in the hyperpneic phase immediately before the period of asphyxic apnea. However, peak and average discharge frequencies developed by intercostal motoneurons (n = 20) were only approximately 60% of those of the phrenic motoneurons (n = 28). Gasping respiration terminated the apneic period and was associated with a further intense recruitment of intercostal though not of phrenic motoneurons, but discharge frequencies developed by the intercostal motoneurons remained approximately 60% of those of the phrenic motoneurons. The instantaneous frequency profiles generated by the motoneurons often exhibited progressive changes during the terminal stages of hyperpnea (reduction in inspiratory duration and duty cycle and increases in inspiratory slope and discharge frequencies) such that much of the character of gasping respiration became evident before the apnea. Such smooth transitional sequences do not obviate the existence of an "independent gasping center" but do require that such a proposed center at least possess the capacity for interaction with those sites responsible for the generation of eupneic and hyperpneic respiration.
To determine whether the central respiratory drives to costal and crural portions of the diaphragm differ from each other in response to chemical and mechanical feedbacks, activities of costal and crural branches of the phrenic nerve were recorded in decerebrate paralyzed cats, studied either with vagi intact and servo-ventilated in accordance with their phrenic nerve activity or vagotomized and ventilated conventionally. Costal and crural electromyograms (EMGs) were recorded in decerebrate spontaneously breathing cats. Hypercapnia and hypoxia resulted in significant increases in peak integrated costal, crural, and whole phrenic nerve activities when the vagi were either intact or cut. However, there were no consistent differences between costal and crural neural responses. Left crural EMG activity was increased significantly more than left costal EMG activity in response to hypercapnia and hypoxia. These results indicate that the central neural inputs to costal and crural portions of the diaphragm are similar in eupnea and in response to chemical and mechanical feedback in decerebrate paralyzed cats. The observed differences in EMG activities in spontaneously breathing animals must arise from modulation of central respiratory activity by mechanoreceptor feedback from respiratory muscles, likely the diaphragm itself.
Despite technical advances, the ability to restore motor function following a brachial plexus avulsion is limited. Twenty patients who suffered the loss of elbow flexion following a brachial plexus avulsion injury underwent a neurotization procedure in an attempt to restore that lost function. Of 16 patients who underwent intercostal to musculocutaneous nerve anastomosis, seven obtained good elbow flexion. Four patients who no longer had a viable biceps brachialis muscle underwent an anastomosis between transposed intercostal nerves and a free vascularized gracilis muscle grafted to the position of the biceps. Two of these patients obtained good elbow flexion. Although synkinesis between the biceps brachialis and the inspiratory muscles can be demonstrated during coughing and deep inspiration, the patients learn to flex their reinnervated biceps brachialis muscle and maintain flexion independent of respiration.