Utilizing Longer Intramuscular Needle Pair Electrodes: What are we Missing in Our Intraoperative Muscle Recordings?
April 25, 2019
Faisal R Jahangiri1,2* and Courtney Trausch1,3
1Axis Neuromonitoring LLC, Richardson, TX, USA; 2Global Innervation LLC, Dallas, TX, USA; 3Graduate Student, Department of Applied Cognition and Neuroscience, University of Texas, Richardson, TX, USA.
*Corresponding Author: Faisal R Jahangiri, Axis Neuromonitoring LLC and Global Innervation LLC, Dallas, TX, USA.
Received: February 21, 2019; Published: April 01, 2019
Abstract
Objective: This study illustrates the benefit of utilizing longer 18 mm, 25 mm, 37 mm and 50 mm intramuscular needle pair electrodes for recording Transcranial Electrical Motor Evoked Potentials (TCeMEP) in Rectus Femoris (RF) muscle during various surgeries in obese patients, as opposed to the regularly used 13 mm sub-dermal needle electrodes, which can miss Electromyographic (EMG) muscle activity and TCeMEP due to presence of excess adipose tissue. The 37 mm and 50 mm intramuscular needle pair electrodes have increased accuracy and reliability of TCeMEP recording at lower stimulation thresholds.
Methods: We performed a retrospective review of 13 consecutive spinal neurophysiological monitoring cases at two medical centers. Our recording setup included regular 13 mm subdermal needles and 18, 25, 37 and 50 mm long 90-degree intramuscular needle pair hook electrodes placed in right Rectus Femoris muscle. This setup was in addition to Somatosensory Evoked Potentials (SSEP), TCeMEP and EMG from upper and lower extremities. Train of four (TOF) was used as well for monitoring the level of muscle relaxant. We identified thirteen consecutive cases consisted of ten females and three males with age ranging from 22 to 75 years (median: 47 years). The TCeMEP thresholds ranged from 120 - 280 Volts (median: 160V). TCeMEP responses were recordable in all 11 patients with 37 mm hook recordings and one patient with 50 mm hook electrode recording (92.3%). However, TCeMEP were recordable only in one patient with 13 mm subdermal needle recordings (7.7%).
Conclusion: Our muscle recordings with 37 mm and 50 mm length intramuscular needle pairs were much more reliable than 13 mm subdermal in obese patients. These long intramuscular needle pair electrodes are more secure and allow for lower stimulation intensities reducing the risks of excessive TCeMEP stimulation.
Keywords: Transcranial Electrical Motor Evoked Potentials; TCeMEP; Electromyographic; EMG; Neuropathy; Electrodes; Intraoperative Neurophysiological Monitoring; IONM.
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Citation: Faisal R Jahangiri and Courtney Trausch. “Utilizing Longer Intramuscular Needle Pair Electrodes: What are we Missing in Our Intraoperative Muscle Recordings?”. EC Neurology 11.4 (2019): 288-294.
