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BMJ Open Gastroenterology Jun 2022Recurrent and persistent bouts of hiccups impact the quality of life by interfering with eating, social interaction and work. Popular home remedies, such as breath...
Recurrent and persistent bouts of hiccups impact the quality of life by interfering with eating, social interaction and work. Popular home remedies, such as breath holding and drinking ice water, target activity in the vagal and phrenic nerves that are thought to trigger these repetitive, myoclonic contractions. However, the pathophysiology of hiccups and the mechanism by which any of these methods work are unclear. Indeed, so little is known that there is no agreement whether the 'Hic' sound is due to the abrupt closure of the epiglottis or the glottis, including the vocal cords.Investigations were performed in a 50-year-old, otherwise healthy male with recurrent hiccups, in whom contractions persisted for up to 4 hours. Hiccups were initiated by drinking carbonated soda. The aerodigestive tract was visualised by video fluoroscopy. Hiccups were terminated by drinking a non-viscous contrast agent through a forced inspiratory suction and swallow tool. This device requires significant suction pressure (-100 mm Hg) to draw fluid into the mouth and is effective in approximately 90% of cases. The images were analysed together with concurrent audio recordings to gain insight into 'what causes the 'hic' in hiccups' and how this commonplace but annoying problem can be treated.
Topics: Hiccup; Humans; Male; Middle Aged; Phrenic Nerve; Quality of Life
PubMed: 35760460
DOI: 10.1136/bmjgast-2022-000918 -
Journal of Visualized Experiments : JoVE Oct 2021Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces can be...
Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces can be sensors, actuators, or both. Traditional methods of peripheral nerve interfacing must either tether to an external system or rely on battery power that limits the time frame for operation. With recent developments of wireless, battery-free, and fully implantable peripheral nerve interfaces, a new class of devices can offer capabilities that match or exceed those of their wired or battery-powered precursors. This paper describes methods to (i) surgically implant and (ii) wirelessly power and control this system in adult rats. The sciatic and phrenic nerve models were selected as examples to highlight the versatility of this approach. The paper shows how the peripheral nerve interface can evoke compound muscle action potentials (CMAPs), deliver a therapeutic electrical stimulation protocol, and incorporate a conduit for the repair of peripheral nerve injury. Such devices offer expanded treatment options for single-dose or repeated dose therapeutic stimulation and can be adapted to a variety of nerve locations.
Topics: Animals; Electric Power Supplies; Electric Stimulation Therapy; Peripheral Nerves; Phrenic Nerve; Prostheses and Implants; Rats; Wireless Technology
PubMed: 34747395
DOI: 10.3791/63085 -
Annals of Anatomy = Anatomischer... Jun 2024The aim of this systematic review is to study the subdiaphragmatic anatomy of the phrenic nerve. (Review)
Review
OBJECTIVE
The aim of this systematic review is to study the subdiaphragmatic anatomy of the phrenic nerve.
MATERIALS AND METHODS
A computerised systematic search of the Web of Science database was conducted. The key terms used were phrenic nerve, subdiaphragmat*, esophag*, liver, stomach, pancre*, duoden*, intestin*, bowel, gangli*, biliar*, Oddi, gallbladder, peritone*, spleen, splenic, hepat*, Glisson, falciform, coronary ligament, kidney, suprarenal, and adrenal. The 'cited-by' articles were also reviewed to ensure that all appropriate studies were included.
RESULTS
A total of one thousand three hundred and thirty articles were found, of which eighteen met the inclusion and exclusion criteria. The Quality Appraisal for Cadaveric Studies scale revealed substantial to excellent methodological quality of human studies, while a modified version of the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool denoted poor methodological quality of animal studies. According to human studies, phrenic supply has been demonstrated for the gastro-esophageal junction, stomach, celiac ganglia, liver and its coronary ligament, inferior vena cava, gallbladder and adrenal glands, with half of the human samples studied presenting phrenic nerve connections with any subdiaphragmatic structure.
CONCLUSIONS
This review provides the first systematic evidence of subdiaphragmatic phrenic nerve supply and connections. This is of interest to professionals who care for people suffering from neck and shoulder pain, as well as patients with peridiaphragmatic disorders or hiccups. However, there are controversies about the autonomic or sensory nature of this supply.
Topics: Phrenic Nerve; Humans; Diaphragm; Animals
PubMed: 38692333
DOI: 10.1016/j.aanat.2024.152269 -
Journal of Ultrasound in Medicine :... Feb 2022The diaphragm, the principle muscle of inspiration, is an under-recognized contributor to respiratory disease. Dysfunction of the diaphragm can occur secondary to lung... (Review)
Review
The diaphragm, the principle muscle of inspiration, is an under-recognized contributor to respiratory disease. Dysfunction of the diaphragm can occur secondary to lung disease, prolonged ventilation, phrenic nerve injury, neuromuscular disease, and central nervous system pathology. In light of the global pandemic of coronavirus disease 2019 (COVID-19), there has been growing interest in the utility of ultrasound for evaluation of respiratory symptoms including lung and diaphragm sonography. Diaphragm ultrasound can be utilized to diagnose diaphragm dysfunction, assess severity of dysfunction, and monitor disease progression. This article reviews diaphragm and phrenic nerve ultrasound and describes clinical applications in the context of COVID-19.
Topics: COVID-19; Diaphragm; Humans; Phrenic Nerve; SARS-CoV-2; Ultrasonography
PubMed: 33772850
DOI: 10.1002/jum.15706 -
Anesthesiology May 2022Strong spontaneous inspiratory efforts can be difficult to control and prohibit protective mechanical ventilation. Instead of using deep sedation and neuromuscular...
BACKGROUND
Strong spontaneous inspiratory efforts can be difficult to control and prohibit protective mechanical ventilation. Instead of using deep sedation and neuromuscular blockade, the authors hypothesized that perineural administration of lidocaine around the phrenic nerve would reduce tidal volume (VT) and peak transpulmonary pressure in spontaneously breathing patients with acute respiratory distress syndrome.
METHODS
An established animal model of acute respiratory distress syndrome with six female pigs was used in a proof-of-concept study. The authors then evaluated this technique in nine mechanically ventilated patients under pressure support exhibiting driving pressure greater than 15 cm H2O or VT greater than 10 ml/kg of predicted body weight. Esophageal and transpulmonary pressures, electrical activity of the diaphragm, and electrical impedance tomography were measured in pigs and patients. Ultrasound imaging and a nerve stimulator were used to identify the phrenic nerve, and perineural lidocaine was administered sequentially around the left and right phrenic nerves.
RESULTS
Results are presented as median [interquartile range, 25th to 75th percentiles]. In pigs, VT decreased from 7.4 ml/kg [7.2 to 8.4] to 5.9 ml/kg [5.5 to 6.6] (P < 0.001), as did peak transpulmonary pressure (25.8 cm H2O [20.2 to 27.2] to 17.7 cm H2O [13.8 to 18.8]; P < 0.001) and driving pressure (28.7 cm H2O [20.4 to 30.8] to 19.4 cm H2O [15.2 to 22.9]; P < 0.001). Ventilation in the most dependent part decreased from 29.3% [26.4 to 29.5] to 20.1% [15.3 to 20.8] (P < 0.001). In patients, VT decreased (8.2 ml/ kg [7.9 to 11.1] to 6.0 ml/ kg [5.7 to 6.7]; P < 0.001), as did driving pressure (24.7 cm H2O [20.4 to 34.5] to 18.4 cm H2O [16.8 to 20.7]; P < 0.001). Esophageal pressure, peak transpulmonary pressure, and electrical activity of the diaphragm also decreased. Dependent ventilation only slightly decreased from 11.5% [8.5 to 12.6] to 7.9% [5.3 to 8.6] (P = 0.005). Respiratory rate did not vary. Variables recovered 1 to 12.7 h [6.7 to 13.7] after phrenic nerve block.
CONCLUSIONS
Phrenic nerve block is feasible, lasts around 12 h, and reduces VT and driving pressure without changing respiratory rate in patients under assisted ventilation.
Topics: Acute Lung Injury; Animals; Critical Illness; Disease Models, Animal; Female; Humans; Lidocaine; Phrenic Nerve; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Mechanics; Swine; Tidal Volume
PubMed: 35348581
DOI: 10.1097/ALN.0000000000004161 -
Europace : European Pacing,... Apr 2023
Topics: Humans; Atrial Fibrillation; Phrenic Nerve; Echocardiography; Pericardium
PubMed: 37061851
DOI: 10.1093/europace/euad054 -
Circulation. Arrhythmia and... Jun 2022Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may...
BACKGROUND
Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may reduce the risk of phrenic nerve injury but has not been well characterized.
METHODS
Accelerometers and continuous pacing were used during PFA deliveries in a porcine model. Acute dose response was established in a first experimental phase with ascending PFA intensity delivered to the phrenic nerve (n=12). In a second phase, nerves were targeted with a single ablation level to observe the effect of repetitive ablations on nerve function (n=4). A third chronic phase characterized assessed histopathology of nerves adjacent to ablated cardiac tissue (n=6).
RESULTS
Acutely, we observed a dose-dependent response in phrenic nerve function including reversible stunning (R=0.965, <0.001). Furthermore, acute results demonstrated that phrenic nerve function responded to varying levels of PFA and catheter proximity placements, resulting in either: no effect, effect, or stunning. In the chronic study phase, successful isolation of superior vena cava at a dose not predicted to cause phrenic nerve dysfunction was associated with normal phrenic nerve function and normal phrenic nerve histopathology at 4 weeks.
CONCLUSIONS
Proximity of the catheter to the phrenic nerve and the PFA dose level were critical for phrenic nerve response. Gross and histopathologic evaluation of phrenic nerves and diaphragms at a chronic time point yielded no injury. These results provide a basis for understanding the susceptibility and recovery of phrenic nerves in response to PFA and a need for appropriate caution in moving beyond animal models.
Topics: Animals; Atrial Fibrillation; Catheter Ablation; Peripheral Nerve Injuries; Phrenic Nerve; Pulmonary Veins; Swine; Vena Cava, Superior
PubMed: 35649121
DOI: 10.1161/CIRCEP.121.010127 -
Journal of Neurophysiology Jan 2023Phrenic motoneurons (PhrMNs) innervate diaphragm myofibers. Located in the ventral gray matter (lamina IX), PhrMNs form a column extending from approximately the third... (Review)
Review
Phrenic motoneurons (PhrMNs) innervate diaphragm myofibers. Located in the ventral gray matter (lamina IX), PhrMNs form a column extending from approximately the third to sixth cervical spinal segment. Phrenic motor output and diaphragm activation are impaired in many neuromuscular diseases, and targeted delivery of drugs and/or genetic material to PhrMNs may have therapeutic application. Studies of phrenic motor control and/or neuroplasticity mechanisms also typically require targeting of PhrMNs with drugs, viral vectors, or tracers. The location of the phrenic motoneuron pool, however, poses a challenge. Selective PhrMN targeting is possible with molecules that move retrogradely upon uptake into phrenic axons subsequent to diaphragm or phrenic nerve delivery. However, nonspecific approaches that use intrathecal or intravenous delivery have considerably advanced the understanding of PhrMN control. New opportunities for targeted PhrMN gene expression may be possible with intersectional genetic methods. This article provides an overview of methods for targeting the phrenic motoneuron pool for studies of PhrMNs in health and disease.
Topics: Rats; Animals; Rats, Sprague-Dawley; Motor Neurons; Gene Transfer Techniques; Diaphragm; Phrenic Nerve
PubMed: 36416447
DOI: 10.1152/jn.00432.2022 -
International Journal of Surgery Case... Feb 2022Peripheral neuronal sheath tumors are rare lesions that can arise from the lining of the neuronal axons of any nerve in the body. Schwannomas are usually solitary and...
INTRODUCTION AND IMPORTANCE
Peripheral neuronal sheath tumors are rare lesions that can arise from the lining of the neuronal axons of any nerve in the body. Schwannomas are usually solitary and encapsulated, slow growing, predominantly benign, with a malignant transformation rate of less than 2% and very low recurrence. The phrenic nerve schwannoma is rare in the neck and usually is asymptomatic.
CASE PRESENTATION
We present a case of a phrenic nerve schwannoma as an incidental intraoperative finding in the study of a patient with a cervical mass of progressive growth on the right side of the neck in contact with the anterior scalene muscle and pain intermittent. Resection of the mass was done with preservation of the endoneurium. Intraoperative stimulation after resection had a proper functionality of the phrenic nerve. In the follow-up, the patient had not any damage of the function of the phrenic nerve.
CLINICAL DISCUSSION
This tumor is generated by a deficiency of merlin with the consequent cell proliferation. The diagnostic imaging (CT or MRI) are the studies of choice. The differential diagnosis of these lesions has an impact on the presence or absence of oncological disease or progression of a previously treated one. The ideal management is surgical and the anatomical and/or functional preservation of the nerve depend of the tumor infiltration.
CONCLUSION
The phrenic nerve schwannoma is rare in the neck. The ideal management is surgical, and this pathology must be considered in patients with masses in the Station IV and supraclavicular fossa of the neck.
PubMed: 35101715
DOI: 10.1016/j.ijscr.2022.106783 -
North American Spine Society Journal Dec 2020Phrenic nerve palsy is a rare complication of cervical spine surgery. There are no previously reported cases of unilateral diaphragmatic paralysis following posterior...
BACKGROUND
Phrenic nerve palsy is a rare complication of cervical spine surgery. There are no previously reported cases of unilateral diaphragmatic paralysis following posterior cervical spine surgery. Here, we present a case of a 69 year-old Caucasian male with severe cervical stenosis with myelopathy who underwent posterior spinal instrumentation and fusion (PSIF) from C2 to T2, with laminectomies at C3-C7.
OUTCOME
The patient developed respiratory distress post-operatively and was found to have an elevated hemidiaphragm secondary to phrenic nerve palsy. He was treated with respiratory support, with significant improvement in dyspnea. He was also noted to have a left C5 palsy affecting his deltoid function and proximal upper extremity sensation which gradually improved.
CONCLUSIONS
This is the first reported case of unilateral diaphragmatic paralysis causing dyspnea due to phrenic nerve palsy following cervical spine surgery. This rare complication should be kept in mind when assessing any patient with respiratory distress following cervical spine surgery.
PubMed: 35141599
DOI: 10.1016/j.xnsj.2020.100022