Diaphragmatic paralysis evaluated by phrenic nerve stimulation during fluoroscopy or real-time ultrasound.

Radiology ◽  
1984 ◽  
Vol 153 (1) ◽  
pp. 33-36 ◽  
Author(s):  
R G McCauley ◽  
K B Labib
Keyword(s):  
Real Time ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Diaphragmatic Paralysis ◽  
Phrenic Nerve Stimulation

Determinants of diaphragm motion in unilateral diaphragmatic paralysis

2004 ◽  
Vol 96 (1) ◽  
pp. 96-100 ◽  
Author(s):  
Pierre Scillia ◽  
Matteo Cappello ◽  
André De Troyer
Keyword(s):  
Clinical Practice ◽  
Muscle Contraction ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Diaphragmatic Paralysis ◽  
Phrenic Nerve Stimulation ◽  
Anesthetized Dogs ◽  
Diaphragm Motion ◽  
Cardinal Sign ◽  
Stimulation Of

Cranial displacement of a hemidiaphragm during sniffs is a cardinal sign of unilateral diaphragmatic paralysis in clinical practice. However, we have recently observed that isolated stimulation of one phrenic nerve in dogs causes the contralateral (inactive) hemidiaphragm to move caudally. In the present study, therefore, we tested the idea that, in unilateral diaphragmatic paralysis, the pattern of inspiratory muscle contraction plays a major role in determining the motion of the inactive hemidiaphragm. We induced a hemidiaphragmatic paralysis in six anesthetized dogs and assessed the contour of the diaphragm during isolated unilateral phrenic nerve stimulation and during spontaneous inspiratory efforts. Whereas the inactive hemidiaphragm moved caudally in the first instance, it moved cranially in the second. The parasternal intercostal muscles were then severed to reduce the contribution of the rib cage muscles to inspiratory efforts and to enhance the force generated by the intact hemidiaphragm. Although the change in pleural pressure (ΔPpl) was unaltered, the cranial displacement of the paralyzed hemidiaphragm was consistently reduced. A pneumothorax was finally induced to eliminate ΔPpl during unilateral phrenic nerve stimulation, and this enhanced the caudal displacement of the inactive hemidiaphragm. These observations indicate that, in unilateral diaphragmatic paralysis, the motion of the inactive hemidiaphragm is largely determined by the balance between the force related to ΔPpl and the force generated by the intact hemidiaphragm.

scholarly journals Explorations of Unilateral Diaphragmatic Paralysis

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Alexandre Quesnel ◽  
Françoise Beuret Blanquart ◽  
Jean Paul Marie ◽  
Eric Verin
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Esophageal Pressure ◽  
Diagnostic Value ◽  
Diaphragmatic Paralysis ◽  
Inspiratory Pressure ◽  
Maximal Inspiratory Pressure ◽  
Phrenic Nerve Stimulation ◽  
Diaphragmatic Dysfunction ◽  
Chest X Ray

Objective. The aim of the present study was to evaluate sniff test, maximal inspiratory pressure, and presence of paradoxical inspiratory diaphragmatic movements and their diagnostic value in patients referred for suspicion of diaphragmatic dysfunction. Methods. Twenty-two patients (8 men and 14 women, 58±13 years) with suspected diaphragmatic dysfunction were included. Pulmonary function test was evaluated by spirometry. Diaphragm dysfunction was diagnosed with unilateral phrenic nerve stimulation. Esophageal pressure was recorded during sniff test and maximal static inspiratory movements. Detection of paradoxical diaphragmatic movement was performed with anteroposterior projection of chest X-ray fluoroscopic video. Results. Phrenic nerve stimulation enabled diagnosis of diaphragmatic paralysis in 15 of the 22 patients. The remaining 7 patients had normal explorations. Lung volumes were significantly lower in patients with diaphragmatic paralysis than in control subjects, as maximal inspiratory pressure. No patient with normal diaphragmatic exploration had paradoxical inspiratory movement. The combined diagnostic value of reduced esophageal pressure during sniff test, reduced esophageal pressure during maximal static inspiratory movements, and presence of paradoxical inspiratory movement had a sensitivity of 87% and a specificity of 71%. Conclusion. Our results suggest that, in most cases, a combination of sniff test, maximal inspiratory pressure, and paradoxical inspiratory movement could help to diagnose diaphragmatic dysfunction. Nevertheless, phrenic nerve stimulation remains the best test for assessing diaphragmatic dysfunction.

Assessment of neonatal diaphragmatic paralysis using magnetic phrenic nerve stimulation

1999 ◽  
Vol 27 (3) ◽  
pp. 224-226 ◽  
Author(s):  
G.F. Rafferty ◽  
A. Greenough ◽  
G. Dimitriou ◽  
M. I. Polkey ◽  
A. Long ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Diaphragmatic Paralysis ◽  
Phrenic Nerve Stimulation

Botzinger complex region role in phrenic-to-phrenic inhibitory reflex of cat

1989 ◽  
Vol 67 (4) ◽  
pp. 1364-1370 ◽  
Author(s):  
D. F. Speck
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Inhibitory Response ◽  
Phrenic Nerve Stimulation ◽  
Bötzinger Complex ◽  
Before And After ◽  
Pass Through ◽  
Bilateral Lesions ◽  
Decerebrate Cats ◽  
Inhibitory Reflex

Neuronal recordings, microstimulation, and electrolytic and chemical lesions were used to examine the involvement of the Botzinger Complex (BotC) in the bilateral phrenic-to-phrenic inhibitory reflex. Experiments were conducted in decerebrate cats that were paralyzed, ventilated, thoracotomized, and vagotomized. Microelectrode recordings within the BotC region revealed that some neurons were activated by phrenic nerve stimulation (15 of 69 expiratory units, 9 of 67 inspiratory units, and 19 nonrespiratory-modulated units) at average latencies similar to the onset latency of the phrenic-to-phrenic inhibition. In addition, microstimulation within the BotC caused a short latency transient inhibition of phrenic motor activity. In 17 cats phrenic neurogram responses to threshold and supramaximal (15 mA) stimulation of phrenic nerve afferents were recorded before and after electrolytic BotC lesions. In 15 animals the inhibitory reflex was attenuated by bilateral lesions. Because lesion of either BotC neurons or axons of passage could account for this attenuation, in eight experiments the phrenic-to-phrenic inhibitory responses were recorded before and after bilateral injections of 5 microM kainic acid (30–150 nl) into the BotC. After chemical lesions, the inhibitory response to phrenic nerve stimulation remained; however, neuronal activity typical of the BotC could not be located. These results suggest that axons important in producing the phrenic-to-phrenic reflex pass through the region of the BotC, but that BotC neurons themselves are not necessary for this reflex.

Mapping for Acute Transvenous Phrenic Nerve Stimulation Study (MAPS Study)

2017 ◽  
Vol 40 (3) ◽  
pp. 294-300
Author(s):  
LUKAS R.C. DEKKER ◽  
BART GERRITSE ◽  
AVRAM SCHEINER ◽  
LILIAN KORNET
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Phrenic Nerve Stimulation

Excitation of dorsal and ventral respiratory group neurons by phrenic nerve afferents

1987 ◽  
Vol 62 (3) ◽  
pp. 946-951 ◽  
Author(s):  
D. F. Speck ◽  
W. R. Revelette
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Afferent Input ◽  
Neuronal Responses ◽  
Onset Latency ◽  
Phrenic Nerve Stimulation ◽  
Group Iii ◽  
Neuronal Excitation ◽  
Dorsal Columns ◽  
The Difference

The projections of phrenic nerve afferents to neurons in the dorsal (DRG) and ventral (VRG) respiratory group were studied in anesthetized, paralyzed, and vagotomized cats. Extracellular recordings of neuronal responses to vagal nerve and cervical phrenic nerve stimulation (CPNS) indicated that about one-fourth of the DRG respiratory-modulated neurons were excited by phrenic nerve afferents with an onset latency of approximately 20 ms. In addition, non-respiratory-modulated neurons within the DRG were recruited by CPNS. Although some convergence of vagal and phrenic afferent input was observed, most neurons were affected by only one type of afferent. In contrast to the DRG, only 3 out of 28 VRG respiratory-modulated neurons responded to CPNS. A second study determined that most of these neuronal responses were due to activation of diaphragmatic afferents since 90% of the DRG units activated by CPNS were also excited at a longer latency by thoracic phrenic nerve stimulation. The difference in onset latency of neuronal excitation indicates an afferent peripheral conduction velocity of about 10 m/s, which suggests that they are predominately small myelinated fibers (group III) making paucisynaptic connections with DRG neurons. Decerebration, decerebellation, and bilateral transection of the dorsal columns at C2 do not abolish the neuronal responses to cervical PNS.

Effects of unilateral phrenic nerve stimulation on tidal volume

Herz ◽  
2014 ◽  
Vol 39 (1) ◽  
pp. 84-86 ◽  
Author(s):  
O. Oldenburg ◽  
T. Bitter ◽  
H. Fox ◽  
D. Horstkotte ◽  
K.-J. Gutleben
Keyword(s):  
Tidal Volume ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Phrenic Nerve Stimulation
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