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Experimental Neurology Aug 2024Low-dose (< 2 h/day), acute intermittent hypoxia (AIH) elicits multiple forms of serotonin-dependent phrenic motor plasticity and is emerging as a promising therapeutic...
Low-dose (< 2 h/day), acute intermittent hypoxia (AIH) elicits multiple forms of serotonin-dependent phrenic motor plasticity and is emerging as a promising therapeutic strategy to restore respiratory and non-respiratory motor function after spinal cord injury (SCI). In contrast, high-dose (> 8 h/day), chronic intermittent hypoxia (CIH) undermines some forms of serotonin-dependent phrenic motor plasticity and elicits pathology. CIH is a hallmark of sleep disordered breathing, which is highly prevalent in individuals with cervical SCI. Interestingly, AIH and CIH preconditioning differentially impact phrenic motor plasticity. Although mechanisms of AIH-induced plasticity in the phrenic motor system are well-described in naïve rats, we know little concerning how these mechanisms are affected by chronic SCI or intermittent hypoxia preconditioning. Thus, in a rat model of chronic, incomplete cervical SCI (lateral spinal hemisection at C2 (C2Hx), we assessed serotonin type 2A, 2B and 7 receptor expression in and near phrenic motor neurons and compared: 1) intact vs. chronically injured rats; and 2) the impact of preconditioning with varied "doses" of intermittent hypoxia (IH). While there were no effects of chronic injury or intermittent hypoxia alone, CIH affected multiple receptors in rats with chronic C2Hx. Specifically, CIH preconditioning (8 h/day; 28 days) increased serotonin 2A and 7 receptor expression exclusively in rats with chronic C2Hx. Understanding the complex, context-specific interactions between chronic SCI and CIH and how this ultimately impacts phrenic motor plasticity is important as we leverage AIH-induced motor plasticity to restore breathing and other non-respiratory motor functions in people with chronic SCI.
Topics: Animals; Male; Rats; Cervical Cord; Cervical Vertebrae; Chronic Disease; Hypoxia; Motor Neurons; Neuronal Plasticity; Phrenic Nerve; Rats, Sprague-Dawley; Receptors, Serotonin; Spinal Cord Injuries
PubMed: 38750949
DOI: 10.1016/j.expneurol.2024.114808 -
Annals of Thoracic and Cardiovascular... 2024An 82-year-old male patient underwent a left upper lobectomy with anterolateral thoracotomy for lung cancer. Although a complete left-pericardial defect was observed... (Review)
Review
An 82-year-old male patient underwent a left upper lobectomy with anterolateral thoracotomy for lung cancer. Although a complete left-pericardial defect was observed during surgery, the pericardial repair was not performed because the left lower lobe remained and the heart was considered stable. Postoperative pathological examination revealed primary synchronous double-lung squamous-cell carcinoma (pathological stage pT2a(2)N0M0 stage IB). He was discharged without complications on postoperative day 8. Leftward displacement of the heart and left diaphragmatic elevation, suspected of phrenic-nerve paralysis, were found in the chest X-ray after discharge. However, the patient's overall condition remained unaffected at the 5-month postoperative follow-up. To assess the need for pericardial repair, we compared cases of complete pericardial defects observed during lobectomy or pneumonectomy reported in the literature. Only one of 12 cases occurred postoperative death despite pericardial repair, and that case combined pectus excavatum and pericardial defects. Our assessment indicated that pericardial repair might not be necessary, excluding complex cases.
Topics: Humans; Male; Lung Neoplasms; Pneumonectomy; Incidental Findings; Pericardium; Aged, 80 and over; Treatment Outcome; Carcinoma, Squamous Cell; Thoracotomy; Tomography, X-Ray Computed; Heart Defects, Congenital; Neoplasm Staging
PubMed: 38749719
DOI: 10.5761/atcs.cr.24-00041 -
Cureus Apr 2024Neuralgic amyotrophy (NA) is a multifocal inflammatory neuropathy accompanied by acute pain and muscle atrophy. NA commonly affects the upper extremities, but rarely...
Neuralgic amyotrophy (NA) is a multifocal inflammatory neuropathy accompanied by acute pain and muscle atrophy. NA commonly affects the upper extremities, but rarely affects the phrenic nerve. Here, we report a male with neck pain, orthopnea, difficulty sleeping in the supine position, and inability to slurp. His saturated oxygen level decreased from 97% to 86% in the supine position. His right shoulder showed muscle atrophy. Chest X-ray examination in the supine position and a nerve conduction study showed phrenic palsy. We diagnosed it as bilateral phrenic nerve palsy associated with NA. NA sometimes causes phrenic nerve palsy and may cause slurping difficulty.
PubMed: 38738025
DOI: 10.7759/cureus.58069 -
Head and Neck Pathology May 2024The accurate indication for level IV dissection is crucial for preventing complications such as phrenic nerve damage and chylous fistulas in clinically N0 tongue cancer....
BACKGROUND
The accurate indication for level IV dissection is crucial for preventing complications such as phrenic nerve damage and chylous fistulas in clinically N0 tongue cancer. Although the depth of invasion is an established independent risk factor for occult lymph node metastasis in tongue cancer, its relationship with level IV metastasis has not been evaluated. This study investigated the relationship between the depth of invasion and level IV nodal metastasis in clinically N0 tongue cancer.
METHODS
We retrospectively investigated clinical N0 patients who underwent glossectomy and level I-IV neck dissection. We examined lymph node metastasis, risk factors, and the relationship between depth of invasion and metastasis.
RESULTS
Our study included 58 patients, and no patient had isolated level IV metastasis. Additionally, there was no level IV metastasis in well-differentiated tumors. Tumor size, depth of invasion, differentiation, and perineural invasion were significantly associated with level IV neck metastasis. We found a critical tumor size of 2.5 cm and depth of invasion of 8 mm for level IV neck metastasis.
CONCLUSION
Based on our findings, we recommend that level IV dissection should be considered for poorly differentiated tumors, tumors greater than 2.5 cm in size, and those deeper than 8 mm. This study highlights the importance of depth of invasion as a prognostic factor for predicting level IV metastasis and suggests that our findings can be used to prevent unnecessary level IV dissections that may lead to complications in tongue cancer surgery.
Topics: Humans; Male; Female; Middle Aged; Tongue Neoplasms; Aged; Lymphatic Metastasis; Retrospective Studies; Adult; Neoplasm Invasiveness; Neck Dissection; Aged, 80 and over; Carcinoma, Squamous Cell; Glossectomy
PubMed: 38727801
DOI: 10.1007/s12105-024-01647-0 -
Clinical Case Reports May 2024Forced inspiration during mechanical ventilation risks self-inflicted lung injury. However, controlling it with sedation or paralysis may cause polyneuropathy and...
KEY CLINICAL MESSAGE
Forced inspiration during mechanical ventilation risks self-inflicted lung injury. However, controlling it with sedation or paralysis may cause polyneuropathy and myopathy. We tested bilateral phrenic nerve paralysis with local anesthetic in a patient, showing reduced inspiratory force. This offers an alternative to drug-induced muscle paralysis.
ABSTRACT
Mechanical ventilation, although a life-saving measure, can also pose a risk of causing lung injury known as "ventilator-induced lung injury" or VILI. Patients undergoing mechanical ventilation sometimes exhibit heightened inspiratory efforts, wherein the negative pressure generated by the respiratory muscles adds to the positive pressure generated by the ventilator. This combination of high pressures can lead to a syndrome similar to VILI, referred to as "patient self-inflicted lung injury" or P-SILI. Prevention of P-SILI requires the administration of deep sedation and muscle paralysis to the patients, but both these measures can have undesired effects on their health. In this case report, we demonstrate the effect of a bilateral phrenic nerve block aiming to reduce excessive inspiratory respiratory efforts in a patient suffering from COVID-19 pneumonitis.
PubMed: 38721551
DOI: 10.1002/ccr3.8850 -
Surgery Today May 2024The hemiclamshell (HCS) approach provides a comprehensive view of the anterior mediastinum, whereas the transmanubrial osteomuscular sparing approach (TMA) allows...
PURPOSE
The hemiclamshell (HCS) approach provides a comprehensive view of the anterior mediastinum, whereas the transmanubrial osteomuscular sparing approach (TMA) allows sufficient exposure of the cervico-thoracic transition. We assessed the effectiveness and the outcomes of the combined HCS plus TMA approach to resect thoracic malignant tumors.
METHODS
We reviewed five patients with thoracic malignant tumors invading the thoracic outlet who underwent surgery using an HCS and TMA approach between 2018 and 2021.
RESULTS
The preoperative diagnosis was myxofibrosarcoma, lung cancer, thymic cancer, thymoma, and neurofibromatosis type1 in one patient each, respectively. Cardiovascular reconstruction was done on the aortic arch in two patients, on the descending aorta in one, and on the superior vena cava in one, combined with resection of the vagus nerve in three patients, of the phrenic nerve in two, and of vertebra in one, with overlap in some cases. The TMA was added because all patients required dissection of the periphery of the subclavian artery, and two had tumor extension to the neck. Macroscopic complete resection was achieved in four patients. There was no postoperative mortality.
CONCLUSION
The combination of the HCS and TMA approaches at the same operation provides a comprehensive view of the mediastinum, lung, and cervico-thoracic transition and allows safe access to the thoracic great vessels and subclavian vessels.
PubMed: 38709287
DOI: 10.1007/s00595-024-02838-6 -
Journal of Visualized Experiments : JoVE Apr 2024Loss of ventilatory muscle function is a consequence of motor neuron injury and neurodegeneration (e.g., cervical spinal cord injury and amyotrophic lateral sclerosis,...
Loss of ventilatory muscle function is a consequence of motor neuron injury and neurodegeneration (e.g., cervical spinal cord injury and amyotrophic lateral sclerosis, respectively). Phrenic motor neurons are the final link between the central nervous system and muscle, and their respective motor units (groups of muscle fibers innervated by a single motor neuron) represent the smallest functional unit of the neuromuscular ventilatory system. Compound muscle action potential (CMAP), single motor unit potential (SMUP), and motor unit number estimation (MUNE) are established electrophysiological approaches that enable the longitudinal assessment of motor unit integrity in animal models over time but have mostly been applied to limb muscles. Therefore, the objectives of this study are to describe an approach in preclinical rodent studies that can be used longitudinally to quantify the phrenic MUNE, motor unit size (represented as SMUP), and CMAP, and then to demonstrate the utility of these approaches in a motor neuron loss model. Sensitive, objective, and translationally relevant biomarkers for neuronal injury, degeneration, and regeneration in motor neuron injury and diseases can significantly aid and accelerate experimental research discoveries to clinical testing.
Topics: Animals; Motor Neurons; Rats; Phrenic Nerve; Diaphragm; Biomarkers; Action Potentials; Nerve Degeneration; Rats, Sprague-Dawley
PubMed: 38709037
DOI: 10.3791/66568 -
Europace : European Pacing,... May 2024
PubMed: 38708590
DOI: 10.1093/europace/euae123 -
Anesthesiology Clinics Jun 2024Shoulder surgery introduces important anesthesia considerations. The interscalene nerve block is considered the gold standard regional anesthetic technique and can serve... (Review)
Review
Shoulder surgery introduces important anesthesia considerations. The interscalene nerve block is considered the gold standard regional anesthetic technique and can serve as the primary anesthetic or can be used for postoperative analgesia. Phrenic nerve blockade is a limitation of the interscalene block and various phrenic-sparing strategies and techniques have been described. Patient positioning is another important anesthetic consideration and can be associated with significant hemodynamic effects and position-related injuries.
Topics: Humans; Shoulder; Anesthesia; Nerve Block; Patient Positioning
PubMed: 38705672
DOI: 10.1016/j.anclin.2023.11.007 -
Thoracic Surgery Clinics May 2024An elevated diaphragm may be due to eventration or paralysis. Diaphragm elevation is often asymptomatic and found incidentally on imaging. Fluoroscopic testing can be...
An elevated diaphragm may be due to eventration or paralysis. Diaphragm elevation is often asymptomatic and found incidentally on imaging. Fluoroscopic testing can be used to differentiate eventration (no paradoxic motion) from paralysis (paradoxic motion). Regardless of etiology, a diaphragm plication is indicated in all symptomatic patients with an elevated diaphragm. Plication can be approached either from a thoracic or abdominal approach, though most thoracic surgeons perform minimally invasive thoracoscopic plication. The goal of plication is to improve lung volumes and decrease paradoxic elevation of the hemidiaphragm. Diaphragm plication is safe, has excellent outcomes, and is associated with symptom improvement.
Topics: Humans; Diaphragm; Diaphragmatic Eventration; Respiratory Paralysis
PubMed: 38705666
DOI: 10.1016/j.thorsurg.2024.01.006