Ultrasound‐guided needle EMG of the diaphragm: Technique description and case report

Abstract

We describe an ultrasound (US)-guided technique for needle examination of the diaphragm and report a case in which the adjuvant use of diagnostic US in conjunction with electrophysiologic studies provided additional information regarding the motion of the diaphragm in a patient who was a potential candidate for phrenic nerve pacing. US imaging provides excellent direct and real-time visualization of soft tissue, anatomic landmarks, fascial planes, and neurovascular structures. It thereby enhances safety by avoiding accidental needle puncture of vital organs, and it also increases the diagnostic utility of the needle examination.

Sensitivity and specificity of diagnostic ultrasound in the diagnosis of phrenic neuropathy

“…[1][2][3][4][5][6][7][8][9] Ultrasound of the diaphragm is an imaging technique that has recently become more accessible to clinicians, and it can improve the technical quality and safety of phrenic NCS and needle EMG. 10,11 When used in isolation, diagnostic ultrasound can identify atrophy and impaired motion or contractility of the diaphragm. [12][13][14][15][16][17] Normal values for diaphragm muscle thickness and diaphragm thickening ratio imaged with B-mode ultrasound have been published, 11 but limited data assess the diagnostic utility of ultrasound in patients with neuromuscular diaphragm dysfunction, including phrenic neuropathy.…”

“…The diaphragm was identified as a 3-layered structure lying deep to the intercostal muscles and subcutaneous tissue. 10 Imaging was performed by either a neurologist or a technician formally trained in ultrasound of the diaphragm. The ultrasound protocol has been described in detail in an earlier study of healthy patients, with 3 images captured at end-expiration and 3 images captured after the patient is asked to inhale as deeply as possible.…”

“…7,8,[25][26][27] One way to decrease the risk of recording a volumeconducted response (a false-negative) is to directly visualize the diaphragm with ultrasound to observe diaphragm contraction while stimulating the phrenic nerve, and this is a technique that we have adopted recently in our practice. 10,25 One limitation of this study is that only the role of B-mode sonography (and not M-mode sonography) was evaluated in diagnosing diaphragm dysfunction. M-mode sonography is technically more challenging, particularly in patients who are obese or for imaging the left hemidiaphragm; however, it can identify decreased or paradoxical excursion of the diaphragm.…”

B-Mode Ultrasound Assessment of Diaphragm Structure and Function in Patients With COPD

“…[1][2][3] Ultrasound of the diaphragm is a noninvasive, reliable, and relatively inexpensive diagnostic tool that is becoming more readily available with the advent of portable high-resolution machines. We now use it routinely in our EMG laboratory in the workup of patients with shortness of breath, not only to enhance the safety and accuracy of needle EMG of the diaphragm, 4 but also to evaluate for atrophy and lack of motion of the muscle, which are readily apparent on ultrasound in patients with phrenic neuropathy. [5][6][7][8] Sonographic assessment of diaphragm structure and function would be a useful clinical tool in patients with COPD presenting for evaluation of possible coexisting neuromuscular respiratory weakness, particularly because needle EMG is relatively contraindicated in this patient population due to the potential for lung hyperinfl ation and associated diffi culty involved in accurately localizing the muscle.…”

Electrodiagnostic Medicine Consultation in Peripheral Nerve Disorders

“…[14] Risky EMG such as diaphragmatic one could be performed safer under sono guide by real time visualization of diaphragm and lung movements with respiration, which let us accurate estimation and finding optimal needle insertion points and depth . [15] We found that our residents learn nerve, muscle and joints anatomy more accurately with more interest using ultrasonography guide. Selection of muscles for botulinum toxin denervation and tendons for chronic tendinipathies could be done more precisely under sono guide and also injection of these tissue with more confidence.…”