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Harry G. Goshgarian - One of the best experts on this subject based on the ideXlab platform.
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MK-801 Upregulates NR2A Protein Levels and Induces Functional Recovery of the Ipsilateral Hemidiaphragm Following Acute C2 Hemisection in Adult Rats
The journal of spinal cord medicine, 2007Co-Authors: Warren J. Alilain, Harry G. GoshgarianAbstract:BACKGROUND C2 hemisection results in paralysis of the ipsilateral Hemidiaphragm. Recent data indicate that an upregulation of the N-methyl-D-aspartate (NMDA) receptor 2A subunit following chronic C2 hemisection is associated with spontaneous Hemidiaphragmatic recovery following injury. MK-801, an antagonist of the NMDA receptor, upregulates the NR2A subunit in neonatal rats. HYPOTHESIS We hypothesized that administration of MK-801 to adult, acute C2-hemisected rats would result in an increase of NR2A in the spinal cord. Furthermore, we hypothesized that upregulation of NR2A would be associated with recovery of the ipsilateral Hemidiaphragm as in the chronic studies. DESIGN To develop a dose-response curve, adult rats were treated with varying doses of MK-801 and their spinal cords harvested and assessed for NR2A as well as AMPA GluR1 and GluR2 subunit protein levels. In the second part of this study, C2-hemisected animals received MK-801. Following treatment, the animals were assessed for recovery of the Hemidiaphragm through electromyographic recordings and their spinal cords assessed for NR2A, GluR1, and GluR2. RESULTS Treatment with MK-801 leads to an increase of the NR2A subunit in the spinal cords of adult noninjured rats. There were no changes in the expression of GluR1 and GluR2 in these animals. Administration of MK-801 to C2-hemisected rats resulted in recovery of the ipsilateral Hemidiaphragm, an increase of NR2A, and a decrease of GluR2. CONCLUSION Our findings strengthen the evidence that the NR2A subunit plays a substantial role in mediating recovery of the paralyzed Hemidiaphragm following C2 spinal cord hemisection.
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Theophylline-induced recovery in a Hemidiaphragm paralyzed by hemisection in rats: Contribution of adenosine receptors
Neuropharmacology, 1998Co-Authors: Kwaku D. Nantwi, Harry G. GoshgarianAbstract:Abstract Previously, we demonstrated that a single intravenous injection of theophylline can induce recovery in a Hemidiaphragm paralyzed by cervical (C2) spinal cord hemisection for up to 3 h. The present study contrasts the actions of enprofylline and theophylline on inducing Hemidiaphragmatic recovery after cervical spinal cord hemisection. Both drugs are methylxanthines; however, theophylline is an adenosine receptor antagonist while enprofylline is not. To further test the involvement of adenosine receptors, N6 ( l -2-phenylisopropyl) adenosine ( l -PIA), an analogue of adenosine was used in conjunction with theophylline. Following a left C2 spinal cord hemisection, animals were injected with either enprofylline (2.5–20 mg/kg) or theophylline (15 mg/kg) alone or in combination. Theophylline-injected animals demonstrated robust respiratory-related activity in the previously quiescent left phrenic nerve and Hemidiaphragm. No recovery was observed in any of the enprofylline-injected rats. When enprofylline injection was followed later with theophylline, recovery occurred. Prior l -PIA administration blocked theophylline-induced recovery. When given after theophylline, l -PIA attenuated and then blocked the induced activity in both the nerve and Hemidiaphragm ipsilateral to spinal cord hemisection. We conclude that adenosine receptor antagonism is implicated in Hemidiaphragmatic recovery after hemisection and theophylline may be useful in the treatment of spinal cord injured patients with respiratory deficits.
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identification of the axon pathways which mediate functional recovery of a paralyzed Hemidiaphragm following spinal cord hemisection in the adult rat
Experimental Neurology, 1992Co-Authors: Dale E Moreno, Xiao-jun Yu, Harry G. GoshgarianAbstract:Abstract Despite extensive neurophysiological work carried out to characterize the crossed phrenic phenomenon, relatively little is known about the morphological substrate of this reflex which restores function to a Hemidiaphragm paralyzed by spinal cord injury. In the present study WGA-HRP was injected into normal and functionally recovered Hemidiaphragm muscle in rats during the crossed phrenic phenomenon. The retrograde transynaptic transport characteristics of WGA-HRP was utilized to delineate the source of the neurons which mediate the crossed phrenic phenomenon. The results indicated that the neurons which drive phrenic motoneurons in spinal hemisected rats during the crossed phrenic phenomenon are located bilaterally in the rostral ventral respiratory group (rVRG) of the medulla. No transneuronal labeling of propriospinal neurons was noted in either normal or spinal-hemisected rats. Thus, propriospinal neurons do not relay respiratory drive to phrenic motoneurons. The neurons of the rVRG project monosynaptically to phrenic motoneurons. The present results suggest that both crossed and uncrossed bulbospinal pathways from the rVRG collateralize to both the left and right phrenic nucleic and functional recovery of a Hemidiaphragm paralyzed by ipsilateral spinal cord hemisection is mediated by supraspinal neurons from both sides of the brain stem. These results are important to our complete understanding of the mechanisms which govern motor recovery in mammals following spinal cord injury.
André Luis Pereira De Albuquerque - One of the best experts on this subject based on the ideXlab platform.
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BMC pulmonary medicine, 2018Co-Authors: Mayra Caleffi-pereira, Letícia Zumpano Cardenas, Pauliane Vieira Santana, Vinicius Iamonti, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, Renata Pletsch-assuncao, Jeferson George Ferreira, Angelo Fernandez, André Luis Pereira De AlbuquerqueAbstract:Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength. Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm. In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm.
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BMC, 2018Co-Authors: Mayra Caleffi-pereira, Letícia Zumpano Cardenas, Pauliane Vieira Santana, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, Renata Pletsch-assuncao, Jeferson George Ferreira, Angelo Fernandez, Vinícius Carlos Iamonti, André Luis Pereira De AlbuquerqueAbstract:Abstract Background Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength. Methods Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). Results RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm. Conclusions In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm
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The contribution of each Hemidiaphragm to the overall inspiratory strength in healthy subjects and unilateral diaphragmatic paralysis
4.1 Clinical respiratory physiology exercise and functional imaging, 2015Co-Authors: Mayra Caleffi Pereira, Letícia Zumpano Cardenas, Andre Apanavicius, Renata Pletsch, Pauliane Vieira Santana, Vinicius Iamonti, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, André Luis Pereira De AlbuquerqueAbstract:Introduction: Total diaphragmatic strength is the result of the contribution of each Hemidiaphragm. However, it is unclear if this is similar for both diaphragms or there is a disparity. Moreover, this compartmental behavior has not been investigated in patients with Hemidiaphragm paralysis (HDP). Objectives: Evaluate the total diaphragmatic strength and its hemi compartments (right and left) during phrenic twitch stimulation (Tw) in controls and HDP patients. Methods: 9 patients with left diaphragm paralyis (LDP) (7male, 55.7±11.6 y) and 16 healthy volunteers (6 female, 46.9±5.5 y) underwent diaphragm muscle strength assessment by transdiaphragmatic pressure (Pdi)= Gastric Pressure (Pgas) - esophageal Pressure (Pes), through gastric and esophageal balloons during phrenic Tw bilaterally, then right and left. Results: The healthy volunteers present homogeneous Pdi distribution between Pes and Pgas. Unlike, HDP group does not generate Pgas enough to increase the Pdi not only on left side, but also in the diaphragm not paralyzed. CONCLUSION: In healthy people, both Hemidiaphragms have similar contribution to the resulting strength. In patients with LDP, Pdi is reduced in both Hemidiaphragms. This reflects the incapacity of preserved Hemidiaphragm to generate adequate Pgas in face to a lifting mechanism of paralyzed Hemidiaphragm.
Gary C. Sieck - One of the best experts on this subject based on the ideXlab platform.
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TrkB kinase activity is critical for recovery of respiratory function after cervical spinal cord hemisection
Experimental neurology, 2014Co-Authors: Carlos B. Mantilla, Sarah M. Greising, Jessica M. Stowe, Wen Zhi Zhan, Gary C. SieckAbstract:Abstract Neuroplasticity following spinal cord injury contributes to spontaneous recovery over time. Recent studies highlight the important role of brain-derived neurotrophic factor (BDNF) signaling via the high-affinity tropomyosin-related kinase (Trk) receptor subtype B (TrkB) in recovery of rhythmic diaphragm activity following unilateral spinal hemisection at C2 (C2SH). We hypothesized that TrkB kinase activity is necessary for spontaneous recovery of diaphragm activity post-C2SH. A chemical-genetic approach employing adult male TrkBF616A mice (n = 49) was used to determine the impact of inhibiting TrkB kinase activity by the phosphoprotein phosphatase 1 inhibitor derivative 1NMPP1 on recovery of ipsilateral Hemidiaphragm EMG activity. In mice, C2SH was localized primarily to white matter tracts comprising the lateral funiculus. The extent of damaged spinal cord (~ 27%) was similar regardless of the presence of functional recovery, consistent with spontaneous recovery reflecting neuroplasticity primarily of contralateral spared descending pathways to the phrenic motor pools. Ipsilateral Hemidiaphragm EMG activity was verified as absent in all mice at 3 days post-C2SH. By 2 weeks after C2SH, ipsilateral Hemidiaphragm EMG activity was present in 39% of vehicle-treated mice compared to 7% of 1NMPP1-treated mice (P = 0.03). These data support the hypothesis that BDNF/TrkB signaling involving TrkB kinase activity plays a critical role in spontaneous recovery of diaphragm activity following cervical spinal cord injury.
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Diaphragm muscle fiber function and structure in humans with Hemidiaphragm paralysis
American journal of physiology. Lung cellular and molecular physiology, 2011Co-Authors: W. N. Welvaart, Gary C. Sieck, Marinus A. Paul, H.w.h. Van Hees, Ger J.m. Stienen, J. W. M. Niessen, F. S. De Man, Anton Vonk-noordegraaf, Coen A.c. OttenheijmAbstract:Recent studies proposed that mechanical inactivity of the human diaphragm during mechanical ventilation rapidly causes diaphragm atrophy and weakness. However, conclusive evidence for the notion that diaphragm weakness is a direct consequence of mechanical inactivity is lacking. To study the effect of Hemidiaphragm paralysis on diaphragm muscle fiber function and structure in humans, biopsies were obtained from the paralyzed Hemidiaphragm in eight patients with Hemidiaphragm paralysis. All patients had unilateral paralysis of known duration, caused by en bloc resection of the phrenic nerve with a tumor. Furthermore, diaphragm biopsies were obtained from three control subjects. The contractile performance of demembranated muscle fibers was determined, as well as fiber ultrastructure and morphology. Finally, expression of E3 ligases and proteasome activity was determined to evaluate activation of the ubiquitin-proteasome pathway. The force-generating capacity, as well as myofibrillar ultrastructure, of diaphragm muscle fibers was preserved up to 8 wk of paralysis. The cross-sectional area of slow fibers was reduced after 2 wk of paralysis; that of fast fibers was preserved up to 8 wk. The expression of the E3 ligases MAFbx and MuRF-1 and proteasome activity was not significantly upregulated in diaphragm fibers following paralysis, not even after 72 and 88 wk of paralysis, at which time marked atrophy of slow and fast diaphragm fibers had occurred. Diaphragm muscle fiber atrophy and weakness following Hemidiaphragm paralysis develops slowly and takes months to occur.
Mayra Caleffi-pereira - One of the best experts on this subject based on the ideXlab platform.
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BMC pulmonary medicine, 2018Co-Authors: Mayra Caleffi-pereira, Letícia Zumpano Cardenas, Pauliane Vieira Santana, Vinicius Iamonti, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, Renata Pletsch-assuncao, Jeferson George Ferreira, Angelo Fernandez, André Luis Pereira De AlbuquerqueAbstract:Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength. Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm. In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm.
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BMC, 2018Co-Authors: Mayra Caleffi-pereira, Letícia Zumpano Cardenas, Pauliane Vieira Santana, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, Renata Pletsch-assuncao, Jeferson George Ferreira, Angelo Fernandez, Vinícius Carlos Iamonti, André Luis Pereira De AlbuquerqueAbstract:Abstract Background Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength. Methods Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). Results RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm. Conclusions In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm
Carlos Roberto Ribeiro De Carvalho - One of the best experts on this subject based on the ideXlab platform.
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BMC pulmonary medicine, 2018Co-Authors: Mayra Caleffi-pereira, Letícia Zumpano Cardenas, Pauliane Vieira Santana, Vinicius Iamonti, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, Renata Pletsch-assuncao, Jeferson George Ferreira, Angelo Fernandez, André Luis Pereira De AlbuquerqueAbstract:Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength. Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm. In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm.
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BMC, 2018Co-Authors: Mayra Caleffi-pereira, Letícia Zumpano Cardenas, Pauliane Vieira Santana, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, Renata Pletsch-assuncao, Jeferson George Ferreira, Angelo Fernandez, Vinícius Carlos Iamonti, André Luis Pereira De AlbuquerqueAbstract:Abstract Background Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength. Methods Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). Results RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm. Conclusions In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm
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Unilateral diaphragm paralysis: a dysfunction restricted not just to one Hemidiaphragm
BioMed Central, 2018Co-Authors: Pereira, Mayra Caleffi, Carlos Roberto Ribeiro De Carvalho, Assunção, Renata Pletsch, Cardenas, Leticia Zumpano, Santana, Pauliane Vieira, Ferreira, Jeferson George, Iamonti, Vinícius Carlos, Caruso Pedro, Fernandez Angelo, Albuquerque, André Luís PereiraAbstract:Abstract\ud \ud Background\ud Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each Hemidiaphragm separately and its contribution to overall inspiratory strength.\ud \ud \ud Methods\ud Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw).\ud \ud \ud Results\ud RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed Hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left Hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed Hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed Hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed Hemidiaphragm.\ud \ud \ud Conclusions\ud In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed Hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed Hemidiaphragm.This study was supported by São Paulo Research Foundation [Fapesp]. Protocol number: 2011/20979–6. Mayra Callefi-Pereira receives a PhD-bursary from Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPq], Process number 142298/2016-6
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The contribution of each Hemidiaphragm to the overall inspiratory strength in healthy subjects and unilateral diaphragmatic paralysis
4.1 Clinical respiratory physiology exercise and functional imaging, 2015Co-Authors: Mayra Caleffi Pereira, Letícia Zumpano Cardenas, Andre Apanavicius, Renata Pletsch, Pauliane Vieira Santana, Vinicius Iamonti, Carlos Roberto Ribeiro De Carvalho, Pedro Caruso, André Luis Pereira De AlbuquerqueAbstract:Introduction: Total diaphragmatic strength is the result of the contribution of each Hemidiaphragm. However, it is unclear if this is similar for both diaphragms or there is a disparity. Moreover, this compartmental behavior has not been investigated in patients with Hemidiaphragm paralysis (HDP). Objectives: Evaluate the total diaphragmatic strength and its hemi compartments (right and left) during phrenic twitch stimulation (Tw) in controls and HDP patients. Methods: 9 patients with left diaphragm paralyis (LDP) (7male, 55.7±11.6 y) and 16 healthy volunteers (6 female, 46.9±5.5 y) underwent diaphragm muscle strength assessment by transdiaphragmatic pressure (Pdi)= Gastric Pressure (Pgas) - esophageal Pressure (Pes), through gastric and esophageal balloons during phrenic Tw bilaterally, then right and left. Results: The healthy volunteers present homogeneous Pdi distribution between Pes and Pgas. Unlike, HDP group does not generate Pgas enough to increase the Pdi not only on left side, but also in the diaphragm not paralyzed. CONCLUSION: In healthy people, both Hemidiaphragms have similar contribution to the resulting strength. In patients with LDP, Pdi is reduced in both Hemidiaphragms. This reflects the incapacity of preserved Hemidiaphragm to generate adequate Pgas in face to a lifting mechanism of paralyzed Hemidiaphragm.