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Transabdominal Motor Action Potentials (Tamap) for Lateral Approach Neuromonitoring in Spine Surgery: Novel Case Series of 51 Patients in Proof-ofConcept Demonstration

Journal of Neurology & Neurophysiology

ISSN - 2155-9562

Review Article - (2020) Volume 11, Issue 7

Transabdominal Motor Action Potentials (Tamap) for Lateral Approach Neuromonitoring in Spine Surgery: Novel Case Series of 51 Patients in Proof-ofConcept Demonstration

William Taylor*
 
*Correspondence: William Taylor, Department of Neurosurgery, University of California, San Diego Campus Point, CA, USA, Tel: (858) 249-0849, Email:

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Abstract

Background: Risk of nerve injury is well-documented in lateral approach spine surgery. Advanced intraoperative neuromonitoring techniques may improve false positive and false negative rates of traditional methods to decrease complications. Objective: Determine the safety, sensitivity, and methodological validity of transabdominal motor action potentials (TaMAP) recordings in lateral access spine surgery. Methods: Institutional Review Board approval was obtained for the prospective collection of patient data. Cathode and anode leads were placed on the posterior and anterior surfaces of back and abdomen, and motor responses were recorded by subdermal needle electrodes in 6 target muscles. Voltage and stimulation amplitude were measured at preoperative baseline, postoperative, and new baseline time points, and compared for muscle groups relevant to symptoms and operative approach. Results: In a total of 51 cases of lateral approach surgery, stimulation sensitivity was 100% for vastus medialis, anterior tibialis, and adductor magnus, followed by 98% in biceps femoris, 95% in gastrocnemius, and 33% for vastus lateralis measures. Decompression at L5/S1 resulted in a decrease in voltage in right gastrocnemius in 80% of cases, 80% of right vastus medialis (L3/L4), and in 58% of right anterior tibialis recordings (L4/5). No postoperative neurological complications were observed. Conclusions: TaMAP intraoperative monitoring is a safe, reliable, and sensitive MEP measure with ease-of-use that may serve as an alternative resource in neuromonitoring for spinal surgery. Sensitivity was observed to be as high as 100% for 3/6 muscle groups tested and with robust efficacy of decompression across a variety of procedures and pathologies, including degenerative spine disease and spinal tumor.

Keywords

Lateral interbody fusion • Lateral approach • Motor evoked potentials • Intraoperative neuromonitoring • Nerve injury • Trans-abdominal motor action potentials

Introduction

Incorporation of minimally invasive (MIS) procedures has increased across a variety of indications of spine surgery including, discectomy, stenosis, spondylolisthesis, laminectomy, and fusion. MIS lumbar spine surgery is associated with fewer postoperative complications, improved patient reported outcomes, shorter length of stay, and reduced blood loss compared to analogous open approach procedures [1,2]. While a narrow operative window has reduced cerebrospinal fluid (CSF) leak complications, soft tissue distraction, and postoperative recovery duration, one notable drawback is limited anatomical visualization during the procedure that may lead to increased nerve root compression injury and dysesthesia, especially in far lateral approaches [3,4]. Indeed, radiculitis is the most commonly reported complication following MI-transforaminal lumbar interbody fusion (TLIF), in as high as 57% of cases [5,6]. Traversing nerves may be particularly susceptible to distraction injury over the psoas that are not sufficiently avoided in exceedingly small operative fields [7,8].

Intraoperative neurophysiological monitoring (IONM) is used during spinal surgery to assess the integrity of descending motor and ascending sensory pathways to signal spinal cord or nerve compression through transcranial, spinal, and muscle motor evoked potentials [9,10]. However, guidelines for degenerative spine fusion cases highlight trials that have shown limited evidence for the success of traditional monitoring methods to reduce nerve injury or improve responses [11]. Mechanically elicited electromyography (EMG) has not been shown to be responsive to compression in animal studies.4 Even transcranial motor evoked potentials (Tc-MEPs), the most commonly used IONM method [12] and spontaneous EMG may not accurately detect intraoperative cervical palsy [13,14]. False positive and false negative reports of somatosensory evoked potentials (SEP) also challenge the reliability and validity of traditional IONM methods [15,16].

In the present single-center, single-surgeon, prospective study, we introduce transabdominal motor action potentials (TaMAP) that may serve as an alternative intraoperative motor evoked potential (MEP) monitoring technique that offers immediate, quantitative feedback that may signal impending injury or improved nerve functioning. Additionally, in a patient population with preoperative radiculopathy, TaMAP may offer an advantage in quantifying severity of nerve compression in this comorbid surgical cohort.

We prospectively analyzed a series of minimally invasive lumbar procedures using TaMAP technique and traditional neuromonitoring. Baseline, immediate postoperative, and new baseline recordings in the intraoperative and perioperative settings were compared to assess the sensitivity and efficacy of this novel monitoring adaptation. We anticipate that a decrease in voltage represents a lower current necessary to reach threshold because of decompression. Given previous animal studies and translational capability [17] TaMAP monitoring may augment intraoperative decision-making with immediate, reliable feedback of specific nerve roots, resulting in fewer cases of postoperative radiculitis and nerve root injury.

Method

University of California, San Diego Institutional Review Board (IRB) approval was obtained for the prospective collection of data. All cases were performed at University of California, San Diego Health System Jacobs Hospital or Hillcrest Hospital from January 2017 to December 1st, 2018. All cases of lateral approach for lumbar surgery were monitored with TMAP and standard neurologic monitoring that recorded triggered and free run EMG in large muscle groups of the lower extremities. This prospectively collected neuromonitoring data, using TMAP, was reviewed in cases in which an intraoperative decision was made after a change in stimulation thresholds. We evaluated these individual procedures with threshold changes to identify factors or neurological deteriorations that may correlate with these changes. Data retrieved from patient records included preoperative neuro exam, procedure name, surgical approach and laterality, and time of operation.

Intraoperative TaMAP Recordings

Cathode and anode leads were placed on the posterior and anterior surfaces of back and abdomen of human participants, as previously described. Motor responses were monitored and recorded from subdermal needle electrodes in 6 target muscles: adductor magnus, vastus medialis, vastus lateralis, anterior tibialis, biceps femoris, and gastrocnemius intraoperatively. Stimulation of abdominal leads was set at 450 mA and confirmed by evoked potentials measured distinct electrophysiological outputs for specific target muscles. Stimulation amplitude resulting in insufficient recording in distal electrode leads was subsequently increased in linear increments until sufficient mV threshold was reached or deemed to recordable. Baseline measures were recorded prior to operation, and a second recording in all muscles were recorded immediately postoperatively after the decompression and prior to closure. A third and final recording was measured to record a new baseline in the postoperative setting after closure.

Statistical Analysis

Standard measures of mean were calculated to report changes across patients for different levels.

Results

A total of 51 cases of lateral approach surgery were performed from 1/9/2017- 9/25/2018, including 26 lumbar laminectomies, 8 hemilaminectomies, 2 endoscopic hemilaminotomies, 1 endoscopic discectomy, 2 extreme lateral interbody fusions (XLIF) procedures, 1 facetectomy, 1 revision open laminectomy, 1 MIS microdiscectomy, 2 MIS hemilaminotomies and discectomies, 1 transforaminal endoscopic discectomy, 1 facetectomy and resection of tumor, 1 posterior spinal fusion (PSF), and 4 uncategorized decompressions. Across all patients, levels of operation were: 1 case involving L1- 2; 11 cases involving L2-3; 18 cases involving with L3-4; 33 cases involving L4-5; 8 cases involving L5-S1; and 7 cases with unknown levels. Bilateral approaches were used in 22 cases, unilateral right-sided was in 11 cases, and unilateral leftsided approaches in 8 cases. Of the 51 patients, 16 experienced pain only with no signs of radiculopathy while 30 patients had pain with at least intermittent or reproducible radiculopathy in the expected distribution of pathology.

Intraoperative TaMAP Recordings

Of the 6 target muscles, measures were identified in all attempted stimulation trials for vastus medialis, anterior tibialis, and adductor magnus recordings. Recordings failed to elicit a response in 3 of 51 (6%) gastrocnemius (2 left, 1 right) measures, 1 of 51 (2%) biceps femoris (right) measures, and in in 34 of 51 cases (67%) vastus lateralis recordings. An additional 5 patients did not have sufficient data in our records. Unknown subjects were not included in the tallies for muscle groups based on level of operation. For procedures in which a change greater than 100 milliamps (mA) was observed on the operative side in the distribution of the femoral nerve, effort was made to relieve nerve compression by releasing the retractor and/or concluding the surgery. No postoperative neurological complications were observed for all cases.

L1-2 Levels (Vastus medialis, vastus lateralis)

Bilateral

For the single patient who received decompression at L1-L5 for bilateral radiculopathy, increases in immediate postoperative baseline were seen in the left vastus medialis of 9 mV (amplitude change= 0), right vastus medialis of 60 mV (amplitude change= 0), and left vastus lateralis of 15 mV (amplitude change= 0), see Supplementary table 1.

L2-3 Levels (Adductor magnus, vastus medialis, vastus lateralis)

Bilateral

Of the 8 patients who received bilateral decompression at L2/3, recording of the left vastus medialis was observed to decrease by an average of -5 mV (-161-75 mV). Recordings for two of the 8 patients (25%) decreased in voltage by -7mV (49-42 mV, change in amplitude=0) and -161 (437-276, change in amplitude=0). Right vastus medialis saw an average increase of 5 mV (-9-32 mV). Three of the 8 patient recordings (38%) saw a decrease in voltage of -2 mV (decrease in amplitude of 50 mA), -9 mV (no change in amplitude), and -6 mV (no change in amplitude).

Left-Sided

Of the two patients with left-sided symptoms who received left-sided decompression approach, the left vastus medialis observed no change in voltage for one (amplitude change of +100) and an increase of 2 mV in the other (no change in amplitude), for an average of 1 mV (0-2 mV). One patient experienced a recording change for the left adductor magnus, demonstrating an increase in voltage of 43 mV from 113mV to 156mV at postoperative baseline (50 mA higher stimulation than baseline). The right adductor magnus for the same patient increased 44 mV (479-435 mV) at the same stimulation as baseline (500 mA).

L3-4 Levels (Adductor magnus, vastus medialis, vastus lateralis)

Bilateral

Recordings for the left and right adductor magnus were reported for bilateral laminectomy decompression in one of 5 patients receiving operation at bilateral levels. Left adductor magnus increased 16 mV (decrease in amplitude of 50 mA) and right adductor magnus increased 4 mV (decrease in amplitude of 50 mA).

For the left vastus medialis, an average increase of 92 mV (-115-306 mV) was observed. 2 of 5 recordings (40%) decreased at -4 mV (no change in amplitude) and -115 mV (decrease in amplitude of 50 mV). The right vastus medialis saw an average change of -6 mV (-30-33 mV). A total of 4 of 5 (80%) recordings decreased at -30 mV (decrease in amplitude of 50 mV), -11 mV(decrease in amplitude of 100 mV), -14 mV (no change in amplitude), and -8 mV (increase in amplitude of 100 mV).

Left-sided

For the left vastus medialis, an average change of -46 mV (-69- -23mV) was observed after surgical decompression. One value of -69mV (328-397 mV) had no change in amplitude between the recordings while the other at -23 mV (32-55mV) saw a decrease in 100 mA.

Right-sided

Vastus lateralis measures were recorded in one patient receiving a rightsided decompression. The right vastus lateralis recording changed by- 9 mV (amplitude increased 100 mA). Two patients received right-sided decompression for radiculopathy. Right vastus medialis recording changes were 128 mV (no change in amplitude) and -24 mV (decrease in amplitude of 50 mV).

L4-5 Levels (Anterior tibialis)

Bilateral

Bilateral approaches involving the L4/5 level were observed in 19 cases. Left anterior tibialis recordings averaged 88 mV (-74-1164 mV). Decreased voltage was observed in 6 of 19 cases (32%), involving -6 mV (no change in amplitude), -50 mV (decrease in amplitude of -150 mA), and -60 mV (decrease in amplitude of -50 mA), -27 (no change in amplitude), and -74 (no change in amplitude). Right anterior tibialis saw an average change of -63 mV (-1073-81 mV), with 11 of 19 cases (58%) showing a decrease in current postoperatively, including – 9 mV (no change in amplitude), -13 mV (decrease of -100 mA), -14 mV (increase of 50 mA), -34 mV (no change in amplitude), -14 mV (decrease of -50 mV), and -1073 (no change in amplitude).

Left-sided

3 recordings were taken for left-sided approaches at L4-5 for an average increase of 26 mV at left anterior tibialis (-4-56 mV). One of 3 recordings was found to decrease postoperatively with change of -4 mV (no change in amplitude).

Right-sided

5 recordings were observed for the anterior tibialis for an average change of -20mV (-76-42). 3 of the 5 (60%) saw decreases in voltage of -76 mV (decrease in 50 mA), -71 mV (no change in amplitude), and -1 (no change in amplitude).

L5-S1 Levels (Gastrocnemius)

Bilateral

Two patients received bilateral decompression at L5-S1. Left Anterior tibialis saw an increase in current at 24 mV (no change in amplitude) and right gastrocnemius saw a decrease of -14 mV (increase of 50 mA). In the other patient, left anterior tibialis saw an increase in 18 mV (decrease of 150 mA), while right anterior tibialis saw an increase in 70 mA (increase of 100 mA).

Right-sided

Right gastrocnemius recordings were observed in 6 patients who received decompression at L5-S1. Postoperative measurements decreased from baseline in 4 of 5 (80%) for an average of -29.8 mV (-233-83 mV). Decreases were observed to be -5 mV (no change in amplitude), -3 mV (decrease of -100 mA), and -233 mV (no change in amplitude).

Discussion

Risk of nerve injury is as high as four times more likely in minimally invasive procedures of the spine, ranging from naurapraxia to axonotmesis [18]. Intraoperative neuromonitoring reduces the risk of nerve injury with reliable feedback of nerve compression, stretching, or ischemia. Somatosensory evoked potential (SEP) monitoring has been reported to reduce paraplegia in 60% of spinal surgery cases [19]. While SEPs have traditionally been used in spine surgery, motor evoked potentials (MEP) offer a direct assessment of descending motor pathway function and include transcranial motor evoked potentials and spontaneous EMG [20,21].

Sensitivity of SSEP has been reported to be as high as 90%,22 while Tc-MEP is from 78%-91%, and differing upon muscle groups [23,24]. The present study represents a novel paradigm of TaMAP in spine surgery across a host of different pathologies (e.g. spinal stenosis, degenerative disc disease, tumor). Recordings elicited a response in all cases (100%) for 3 of the 6 muscle groups. Cases involving the gastrocnemius (95%) and biceps femoris (98%) were also highly sensitive; however, vastus lateralis was the lowest in successfully eliciting a response in 33% of cases. Given the overlap of the femoral nerve innervation to vastus medialis and vastus lateralis, identification of the higher lumbar nerve roots may be best achieved through recordings of the vastus medialis which achieved response in 100% of cases.

TaMAP recordings represent another form of MEP that do not require an averaging and are immediately available, unlike those of somatosensory evoked potentials that may take minutes to determine latency and amplitude [25]. Additionally, quantitative TaMAP recordings do not involve interpretation of waveform as in other forms of MEP that may have lower inter-rater reliability and require interpretative expertise. Thus, TaMAP may introduce streamlined interpretation that overcomes challenges of traditional SSEP and MEP monitoring methods. Quantitative readings may also give more indication of the type or severity of compression or stretch injury to allow swift adjustments intraoperatively.

Efficacy of decompressive surgery is presumed to result in an increase in voltage from lower or similar stimulation amplitude [26]. We found that decompression at the level of L5/S1 resulted in a decrease in voltage in the recording of right gastrocnemius in 80% of cases. Similarly, postoperative current measures of the right vastus medialis decreased in 80% of bilateral cases for the L3/L4 level, and decreased in 58% of right anterior tibialis recordings bilateral decompression L4/5. These decompressed lumbar nerve roots corresponded to the side of chief complaint, neuro exam findings, and other indications of pathology at level of decompression such as preoperative MRI as anatomically expected. These findings support the argument that a decrease in voltage may underlie successful relief of nerve compression and represent an immediate form of intraoperative feedback. It is often reported that decreased amplitude signifies a compression of the nerve and may correlate with motor deficits postoperatively [27] However, few reports have suggested interpretation of recorded voltage from stimulation. It is possible that a decrease in voltage from a similar stimulation current may indicate lower resistance and successful decompression or reduction in resistance.

Notably, conflicting conclusions exist on interpretation of even established methods of IONM [28] Reliable interpretation of TcMEP thresholds has proven controversial, and may result in false negatives that result in motor deficit despite no discernable changes in recording.14 One explanation for this discrepancy could be due to overlapping innervation. Anesthetic use may further alter the threshold for nerve conduction and synapse transmission [29] and may require higher stimulation amplitude recordings and subsequent physiologic interpretation, especially in myelopathy patients [30]. However, several studies have reported minimal change to IONM recordings related to anesthetic administration [31,32].

TaMAP also offers an ease-of-use, applying two electrodes, and distal electrodes similar to transcranial monitoring, without scalp and facial electrode placement. Reduction in preoperative and postoperative setup is significant, given reduction in number of electrodes. During the stimulation trials, no cases of tissue injury to the patient or operating room personnel were reported. Given the benefit of a multi-modal neuromonitoring (MIOM) platform in complex spinal cases and correction for scoliosis [33]. TaMAP brings unique and unparalleled advantages that may particularly complement the armamentarium of IONM methods in spinal surgery.

Strengths and Limitations

Some recordings may be underestimated by decreased stimulation amplitude to achieve voltage. As shown in previous animal model study, a positive correlation is observed between stimulation amplitude and measured voltage. Certain recordings may therefore not reflect the degree of decompression or restoration of nerve function based on our quantitative measures. Specificity measures may also be pursued for TaMAP in additional analyses. Lack of a control group may also limit the generalizability of our findings and would be beneficial for future studies analyzing TaMAP technique. Future studies may incorporate other surgeons and facilities that may use TaMAP to validate its efficacy, as well as postoperative complication profiles to determine efficacy in reducing neurapraxia and other forms of nerve injury. It may also be beneficial to parse out the use of TaMAP in patients with pacemakers, defibrillators, or pulse generators in the chest, abdomen, or subclavicular locations to determine local stimulation effect on these devices and possible contraindications for cardiac history. TaMAP may also be used in scoliosis surgery separately or as part of a MIOM regimen given the higher risk of complication to the spinal cord and traditional reliance on IONM.

Conclusion

TaMAP intraoperative monitoring is a safe, reliable, and sensitive MEP measure with ease-of-use that may serve as an alternative resource in neuromonitoring for spinal surgery. Sensitivity was observed to be as high as 100% for 3/6 muscle groups tested and with robust efficacy of decompression over a variety of procedures and pathologies, including degenerative spine disease and spinal tumor. Future studies may explore postoperative outcome measures following TaMAP to obtain specificity, comparative analyses to other monitoring techniques, and a broader scope of utilization across surgeons, institutions, and patient populations susceptible to complication.

Conflict of Interests

The authors hereby declare there is no conflict of interests associated with this study or any of the procedures and materials used for the purpose of the study.

References

 Patient Number Procedure Levels Neuro exam Approach TaMAP Baseline TaMAP Postoperatively TaMAP Postoperative Basline
1 Lumbar Laminectomy L1-L2, L3-L4 and  partial L5 Bilateral lower leg symptoms Bilateral Left Gastrocnemius Amp: 700 Left Gastrocnemius Amp: 800  
          Voltage: 62 Voltage: 38 Right Gastrocnemius
              Voltage:118
          Right Gastrocnemius Right Gastrocnemius  
          Amp:650 Amp:650  
          Voltage:183 Voltage:120  
          Left Vastus Medialis Left Vastus Medialis  
          Amp: 400 Amp: 400  
          Voltage:36 Voltage:45  
          Right Vastus Medialis Right Vastus Medialis  
          Amp: 400 Amp: 400  
          Voltage:65 Voltage:125  
          Left Tibialis Anterior Left Tibialis Anterior  
          Amp:650 Amp:650  
          Voltage: 253 Voltage: 451  
          Right Tibialis Anterior Right Tibialis Anterior  
          Amp:700 Amp:750  
          Voltage: 202 Voltage: 80  
          Left Biceps Femoris Left Biceps Femoris  
          Amp:500 Amp:500  
          Voltage:33 Voltage:37  
          Right Biceps Femoris Right Biceps Femoris  
          Amp:550 Amp:650  
          Voltage: 161 Voltage: 85  
          Left Vastus Lateralis Left Vastus Lateralis  
          Amp: 350 Amp: 350  
          Voltage: 80 Voltage: 95  
          Right Vastus Lateralis Right Vastus Lateralis  
          Amp: No response Amp: No response  
          Voltage: No response Voltage: No response  
2 Lumbar Laminectomy L2, L3, L4 Bilateral leg pain Bilateral Left Gast Left Gast Left Gast
          Amp: 500 Amp: 500 Amp: 450
          Voltage: 37 Voltage: 39 Voltage: 38
          Right Gast Right Gast Right Gast
          Amp:750 Amp:600 Amp:600
          Voltage:150 Voltage:43 Voltage:35
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 500 Amp: 500 Amp: 500
          Voltage:33 Voltage:44 Voltage:44
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 400 Amp: 400 Amp: 400
          Voltage:32 Voltage:40 Vol:37
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:700 Amp:800 Amp:800
          Voltage: 188 Voltage: 47 Voltage: 48
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:500 Amp:500 Amp:500
          Voltage: 70 Voltage: 72 Voltage: 70
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:550 Amp:600 Amp:600
          Voltage:61 Voltage:44 Voltage:38
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:750 Amp:500 Amp:500
          Voltage: 66 Voltage: 35 Voltage: 37
3 Lumbar Laminectomy L2-L5 Bilateral leg pain Bilateral Left Gast Left Gast Left Gast
          Amp: 600 Amp: 550 Amp: 900
          Voltage: 40 Voltage: 66 Voltage: 40
          Right Gast Right Gast Right Gast
          Amp:550 Amp:350 Amp:850
          Voltage:179 Voltage:30 Voltage:31
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 350 Amp: 550 Amp: 650
          Voltage:34 Voltage:37 Voltage:42
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 300 Amp: 250 Amp: 350
          Voltage:33 Voltage:31 Voltage:38
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:450 Amp:400 Amp:600
          Voltage: 59 Voltage: 66 Voltage: 45
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:400 Amp:400 Amp:800
          Voltage: 34 Voltage: 39 Voltage: 48
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:450 Amp:450 Amp:800
          Voltage:40 Voltage:37 Voltage:70
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:350 Amp:300 Amp:250
          Voltage: 64 Voltage: 66 Voltage: 35
4 Lumbar Laminectomy L2-L5 Bilateral leg pain Bilateral Left Gast Left Gast  
          Amp: 850 Amp: 800  
          Voltage: 50 Voltage: 31  
          Right Gast Right Gast  
          Amp:850 Amp:850  
          Voltage:46 Voltage:46  
          Left Vast Med Left Vast Med  
          Amp: 650 Amp: 700  
          Voltage:49 Voltage:51  
          Right Vast Med Right Vast Med  
          Amp: 650 Amp: 550  
          Voltage:30 Voltage:39  
          Left Tib Ant Left Tib Ant  
          Amp: 600 Amp:650  
          Voltage: 35 Voltage: 48  
          Right Tib Ant Right Tib Ant  
          Amp:800 Amp:800  
          Voltage: 34 Voltage: 38  
          Left Bicep Fem Left Bicep Fem  
          Amp:550 Amp:800  
          Voltage:35 Voltage:51  
          Right Bicep Fem Right Bicep Fem  
          Amp:550 Amp:800  
          Voltage: 41 Voltage: 75  
5 Lumbar Laminectomy L3-L4, partial L2 and partial L5 L2-L5 Lumbar radiculopathy Bilateral Left Gast Left Gast Left Gast
          Amp: 700 Amp: 1100 Amp: 1100
          Voltage: 46 Voltage: 90 Voltage: 85
          Right Gast Right Gast Right Gast
          Amp:750 Amp:750 Amp:750
          Voltage:87 Voltage:42 Voltage:43
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 550 Amp: 650 Amp: 650
          Voltage:33 Voltage:110 Voltage:108
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 850 Amp: 800 Amp: 850
          Voltage:34 Voltage:31 Voltage:46
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 950 Amp: 950 Amp: 950
          Voltage: 31 Voltage: 74 Voltage: 73
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:950 Amp:950 Amp:950
          Voltage: 80 Voltage: 87 Voltage: 33
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:900 Amp:850 Amp:850
          Voltage:149 Voltage:41 Voltage:62
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:900 Amp:850 Amp:800
          Voltage: 113 Voltage: 129 Voltage: 71
6 Lumbar Laminectomy with partial hemilamiotomy L3     Bilateral Left Gast Left Gast Left Gast
    L2-L3, L4-L5     Amp: Not reported Amp: Not reported Amp: Not reported
      Low back pain radiating to both legs   Voltage: Not Reported Voltage: Not Reported Voltage: Not Reported
          Right Gast Right Gast Right Gast
          Amp:500 Amp:550 Amp:600
          Voltage:512 Voltage:132 Voltage:139
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 700 Amp: 750 Amp: 700
          Voltage:36 Voltage:33 Voltage:68
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 600 Amp: 600 Amp: 600
          Voltage:45 Voltage:33 Voltage:34
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 600 Amp: 600 Amp: 600
          Voltage: 163 Voltage: 163 Voltage: 89
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:550 Amp:550 Amp:600
          Voltage: 1128 Voltage: 58 Voltage: 55
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:750 Amp:750 Amp:800
          Voltage:35 Voltage:45 Voltage:49
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:550 Amp:650 Amp:650
          Voltage: 109 Voltage: 83 Voltage: 38
7 Lumbar Laminectomy L2-L5 Midline lower back pain, no leg pain, numbness and tingling in his feet/toes Unknown Left Gast Left Gast Left Gast
          Amp: 300 Amp: 400 Amp: 400
          Voltage: 60 Voltage: 35 Voltage: 42
          Right Gast Right Gast Right Gast
          Amp:400 Amp:400 Amp:250
          Voltage:34 Voltage:41 Voltage:33
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 350 Amp: 400 Amp: Not reported
          Voltage:33 Voltage:40 Voltage:34
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 350 Amp: 350 Amp: 350
          Voltage:77 Voltage:58 Voltage:71
              Left Tib Ant
          Left Tib Ant Left Tib Ant Amp: 450
          Amp: 500 Amp: 400 Voltage: 30
          Voltage: 33 Voltage: 272  
              Right Tib Ant
          Right Tib Ant Right Tib Ant Amp:450
          Amp:350 Amp:400 Voltage: 44
          Voltage: 31 Voltage: 33  
              Left Bicep Fem
          Left Bicep Fem Left Bicep Fem Amp:250
          Amp:250 Amp:250 Voltage:112
          Voltage:138 Voltage:85   
              Right Bicep Fem
          Right Bicep Fem Right Bicep Fem Amp:550
          Amp:350 Amp:550 Voltage: 38
          Voltage: 31 Voltage: 235  
8 Lumbar Laminectomy L2-S1 Back pain and bilateral radicular pain Bilateral Left Gast Left Gast Left Gast
          Amp: 550 Amp: 500 Amp: 400
          Voltage: 38 Voltage: 47 Voltage: 56
          Right Gast Right Gast Right Gast
          Amp:600 Amp:500 Amp:500
          Voltage:189 Voltage:249 Voltage:259
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 700 Amp: 600 Amp: 600
          Voltage:30 Voltage:36 Voltage:33
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 550 Amp: 550 Amp: 600
          Voltage:32 Voltage:33 Voltage:64
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 500 Amp: 500 Amp: 400
          Voltage: 399 Voltage: 543 Voltage: 501
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:550 Amp:500 Amp:500
          Voltage: 121 Voltage: 121 Voltage: 115
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:850 Amp:700 Amp:650
          Voltage:42  Voltage:82  Voltage:36 
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:600 Amp:500 Amp:500
          Voltage: 41 Voltage: 31 Voltage: 36
9 Transforaminal endoscopic diskectomy L2-L3 Left sided radicular pain Left sided Left Adductor Left Adductor Left Adductor
          Magnus: 550 Magnus Magnus
          Voltage: 113 Amp: 600 Amp: 600
            Voltage: 159 Voltage: 156
          Right Adductor Magnus Right Adductor Magnus Right Adductor Magnus
          Amp: 500 Amp: 500 Amp: 500
          Voltage: 435 Voltage: 461 Voltage: 479
            Left Vast Med Left Vast Med
          Left Vast Med Amp: 450 Amp: 450
          Amp: 350 Voltage:233 Voltage:122
          Voltage:112    
            Right Vast Med Right Vast Med
          Right Vast Med Amp: 300 Amp: 300
          Amp: 300 Voltage:90 Voltage:93
          Voltage:68    
            Left Tib Ant Left Tib Ant
          Left Tib Ant Amp: 400 Amp: 400
          Amp: 400 Voltage: 111 Voltage: 116
          Voltage: 91    
            Right Tib Ant Right Tib Ant
          Right Tib Ant Amp:350 Amp:350
          Amp:300 Voltage: 838 Voltage: 844
          Voltage: 759    
            Left Bicep Fem Left Bicep Fem
          Left Bicep Fem Amp:450 Amp:450
          Amp:500 Voltage:36 Voltage:35
          Voltage:204    
            Right Bicep Fem Right Bicep Fem
          Right Bicep Fem Amp:400 Amp:400
          Amp:600 Voltage: 55 Voltage: 35
          Voltage: 41    
10 Minimally invasive hemilaminotomy and diskectomy L2-L3 Left sided radicular pain Left sided Left Gast Left Gast Left Gast
          Amp: 650 Amp: 600 Amp: 600
          Voltage: 69 Voltage: 32 Voltage: 32
          Right Gast Right Gast Right Gast
          Amp:550 Amp:550 Amp:600
          Voltage:34 Voltage:42 Voltage:39
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 800 Amp: 600 Amp: 800
          Voltage:32 Voltage:31 Voltage:34
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 450 Amp: 450 Amp: 450
          Voltage:34 Voltage:47 Voltage:56
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 600 Amp: 450 Amp: 450
          Voltage: 32 Voltage: 64 Voltage: 67
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:600 Amp:600 Amp:250
          Voltage: 1938 Voltage: 1151 Voltage: 33
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:550 Amp:550 Amp:500
          Voltage: 58 Voltage: 110 Voltage: 34
11 Lumbar Laminectomy and foraminotomy L2-L5 Low back pain and occasional shoowing pains down left leg(3/10) Bilateral Left Gast Left Gast Left Gast
          Amp: 550 Amp: 550 Amp: 500
          Voltage: 46 Voltage: 74 Voltage: 60
          Right Gast Right Gast Right Gast
          Amp:600 Amp:600 Amp:500
          Voltage:38 Voltage:44 Voltage:32
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 200 Amp: 200 Amp: 200
          Voltage:437 Voltage:276 Voltage:276
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 250 Amp: 250 Amp: 250
          Voltage:130 Voltage:135 Voltage:135
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 400 Amp: 400 Amp: 350
          Voltage: 32 Voltage: 31 Voltage: 31
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:400 Amp:350 Amp:350
          Voltage: 48 Voltage: 40 Voltage: 47
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:350 Amp:300 Amp:300
          Voltage: 44 Voltage: 46 Voltage: 44
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:300 Amp:300 Amp:300
          Voltage: 55 Voltage: 57 Voltage: 56
12 Lumbar Lamiectomy L3-L4, L4-L5 Bilateral leg pain Bilateral Left Adductor Magnus Left Adductor Magnus Left Adductor Magnus
          Amp: 300 Amp: 300 Amp: 250
          Voltage: 31 Voltage: 39 Voltage: 47
          Right Adductor Magnus Right Adductor Magnus Right Adductor Magnus
          Amp:400 Amp:350 Amp:350
          Voltage:37 Voltage:39 Voltage:33
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 300 Amp: 300 Amp: 300
          Voltage:45 Voltage:39 Voltage:41
          Right Vast Med Right Vast Med Right Vast Med
          Amp: 300 Amp: 300 Amp: 250
          Voltage:144 Voltage:111 Voltage:114
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 300 Amp: 300 Amp: 350
          Voltage: 54 Voltage: 62 Voltage: 176
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:350 Amp:300 Amp:350
          Voltage: 37 Voltage: 58 Voltage: 50
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp:350 Amp:350 Amp:350
          Voltage:50 Voltage:34 Voltage:46
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:300 Amp:300 Amp:300
          Voltage: 43 Voltage: 45 Voltage: 44
13 Hemilamiotomy L3-L4 Right sided L4 radiculopathy Right Sided Left Vast Med Left Vast Med Not recorded
          Amp: 650 Amp: 600  
          Voltage:50 Voltage:34  
          Right Vast Med Right Vast Med  
          Amp: 300 Amp: 300  
          Voltage:86 Voltage:214  
          Left Vast Lat Left Vast Lat  
          Amp: 350 Amp: 350  
          Voltage: 42 Voltage: 42  
          Right Tib Ant Right Tib Ant  
          Amp:250 Amp:350  
          Voltage: 44 Voltage: 35  
          Left Tib Ant Left Tib Ant  
          Amp: 300 Amp: 300  
          Voltage: 73 Voltage: 79  
          Right Tib Ant Right Tib Ant  
          Amp:450 Amp:500  
          Voltage: 34 Voltage: 33  
14 Lumbar Laminectomy L3-L4, RD L4-L5 Left sided leg pain Bilateral Left Gastroc Left Gastroc Left Gastroc
          Amp: 400 Amp: 350 Amp: 350
          Voltage:56 Voltage:44 Voltage:50
          Right Gstroc Right Gstroc Right Gstroc
          Amp: 250 Amp: 250 Amp: 250
          Voltage:135 Voltage:127 Voltage:146 
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 300 Amp: 300 Amp: 250
          Voltage: 160 Voltage: 143 Voltage: 45
          Right Vast Med Right Vast Med Right Vast Med
          Amp:400 Amp:400 Amp:300
          Voltage: 70 Voltage: 70 Voltage: 59
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 450 Amp: 400 Amp: 400
          Voltage: 216 Voltage: 134 Voltage: 189
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:350 Amp:300 Amp:300
          Voltage: 87 Voltage: 96 Voltage: 74
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 350 Amp: 350 Amp: 350
          Voltage: 62 Voltage: 57 Voltage: 90
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:350 Amp:300 Amp:300
          Voltage: 59 Voltage: 47 Voltage: 47
15 Lumbar Laminectomy L3-L4 Bilateral leg pain in L3-4 region Bilateral Left Gastroc Left Gastroc Left Gastroc
          Amp: 500 Amp: 500 Amp: 450
          Voltage:77 Voltage:70 Voltage:72
          Right Gstroc Right Gstroc Right Gstroc
          Amp: 700 Amp: 700 Amp: 700
          Voltage:52 Voltage:36 Voltage:46
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 300 Amp: 300 Amp: 350
          Voltage: 34 Voltage: 327 Voltage: 340
          Right Vast Med Right Vast Med Right Vast Med
          Amp:650 Amp:750 Amp:650
          Voltage: 46 Voltage: 120 Voltage: 32
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp: 700 Amp: 700 Amp: 700
          Voltage: 58 Voltage: 44 Voltage: 42
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:650 Amp:650 Amp:550
          Voltage: 910 Voltage: 687 Voltage: 695
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 650 Amp: 650 Amp: 650
          Voltage: 32 Voltage: 31 Voltage: 31
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:300 Amp:350 Amp:350
          Voltage: 48 Voltage: 56 Voltage: 60
16 RD hemilaminotomy, foraminotomy and diskectomy L5-S1. Minimally invasive L3-4 and L4-5 hemilaminotomy, foraminotomy and diskectomy at L4-5. Hemilaminotomy, foraminotomy and medial factectomy at L3-4 L3-S1 Right sided radiular pain Right Left Gastroc Left Gastroc Left Gastroc
          Amp: 450 Amp: 400 Amp: 400
          Voltage:281 Voltage:319 Voltage:338
          Right Gstroc Right Gstroc Right Gstroc
          Amp: 500 Amp: 500 Amp: 500
          Voltage:435 Voltage:244 Voltage:202
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 250 Amp: 250 Amp: 250
          Voltage: 1902 Voltage: 1509 Voltage: 1509
          Right Vast Med Right Vast Med Right Vast Med
          Amp:300 Amp:250 Amp:250
          Voltage: 75 Voltage: 53 Voltage: 51
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:250 Amp:250 Amp:350
          Voltage: 31 Voltage: 156 Voltage: 171
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:400 Amp:400 Amp:400
          Voltage: 100 Voltage: 108 Voltage: 99
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 300 Amp: 250 Amp: 250
          Voltage: 146 Voltage: 35 Voltage: 35
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:500 Amp:550 Amp:500
          Voltage: 34 Voltage: 38 Voltage: 32
17 Lumbar Laminectomy L3, L4, L5 Bilateral radicular pain Bilateral Left Gastroc Left Gastroc Left Gastroc
          Amp: 550 Amp: 550 Amp: 450
          Voltage:37 Voltage:38 Voltage:34
          Right Gstroc Right Gstroc Right Gstroc
          Amp: 400 Amp: 500 Amp: 500
          Voltage:56 Voltage:42 Voltage:31
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 500 Amp: 500 Amp: 550
          Voltage: 33 Voltage: 35 Voltage: 58
          Right Vast Med Right Vast Med Right Vast Med
          Amp:350 Amp:400 Amp:400
          Voltage: 32 Voltage: 62 Voltage: 65
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:450 Amp:550 Amp:450
          Voltage: 61 Voltage: 203 Voltage: 173
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:450 Amp:500 Amp:450
          Voltage: 61 Voltage: 67 Voltage: 62
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 550 Amp: 550 Amp: 600
          Voltage: 44 Voltage: 31 Voltage: 59
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:550 Amp:600 Amp:600
          Voltage: 87 Voltage: 45 Voltage: 56
18 L3, L4, L5 lumbar laminectomiesm, L3/4 and L4/5 bilateral foraminotomies L3-L4, L4-L5 Lower back pain Unknown Left Gastroc Left Gastroc Left Gastroc
          Amp: 500 Amp: 500 Amp: 500
          Voltage:83 Voltage:228 Voltage:178
          Right Gstroc Right Gstroc Right Gstroc
          Amp: no response Amp: no response Amp: no response
          Voltage: no response Voltage: no response Voltage: no response
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 500 Amp: 500 Amp: 500
          Voltage: 38 Voltage: 41 Voltage: 38
          Right Vast Med Right Vast Med Right Vast Med
          Amp:550 Amp:500 Amp:400
          Voltage: 47 Voltage: 55 Voltage: 33
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:300 Amp:300 Amp:300
          Voltage: 43 Voltage: 46 Voltage: 41
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:550 Amp:500 Amp:500
          Voltage: 59 Voltage: 43 Voltage: 40
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 550 Amp: 500 Amp: 350
          Voltage: 41 Voltage: 46 Voltage: 31
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:500 Amp:500 Amp:500
          Voltage: 37 Voltage: 30 Voltage: 39
19 Lumbar Laminectomy L3, L4, L5 Bilateral radicular pain, left greater than right Bilateral Left Gastroc Left Gastroc Left Gastroc
          Amp: 650 Amp: 650 Amp: 650
          Voltage:35 Voltage:83 Voltage:86
          Right Gastroc Right Gastroc Right Gstroc
          Amp: 550 Amp: 550 Amp: 450
          Voltage: 52 Voltage: 104 Voltage: 106
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 250 Amp: 250 Amp: 350
          Voltage: 124 Voltage: 368 Voltage: 371
          Right Vast Med Right Vast Med Right Vast Med
          Amp:350 Amp:350 Amp:300
          Voltage: 44 Voltage: 55 Voltage: 36
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:650 Amp:550 Amp:500
          Voltage: 31 Voltage: 104 Voltage: 103
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:350 Amp:350 Amp:350
          Voltage: 294 Voltage: 376 Voltage: 375
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 400 Amp: 400 Amp: 400
          Voltage: 44 Voltage: 75 Voltage: 77
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:350 Amp:350 Amp:350
          Voltage: 60 Voltage: 45 Voltage: 44
20 Facetectomy, decompression of nerve root and resection of tumor L3-4 Worsening back pain and numbness in L3 distrubtion Left sided Left Gastroc Left Gastroc Left Gastroc
          Amp: 500 Amp: 550 Amp: 500
          Voltage:127 Voltage:54 Voltage:92
          Right Gstroc Right Gstroc Right Gstroc
          Amp: 450 Amp: 450 Amp: 450
          Voltage: 93 Voltage: 75 Voltage: 67
          Left Vast Med Left Vast Med Left Vast Med
          Amp: 200 Amp: 200 Amp: 200
          Voltage: 397 Voltage: 272 Voltage: 328
          Right Vast Med Right Vast Med Right Vast Med
          Amp:350 Amp:350 Amp:350
          Voltage: 48 Voltage: 55 Voltage: 42
          Left Tib Ant Left Tib Ant Left Tib Ant
          Amp:450 Amp:500 Amp:450
          Voltage: 122 Voltage: 47 Voltage: 97
          Right Tib Ant Right Tib Ant Right Tib Ant
          Amp:350 Amp:350 Amp:350
          Voltage: 153 Voltage: 148 Voltage: 153
          Left Bicep Fem Left Bicep Fem Left Bicep Fem
          Amp: 400 Amp: 450 Amp: 450
          Voltage: 1116 Voltage: 247 Voltage: 74
          Right Bicep Fem Right Bicep Fem Right Bicep Fem
          Amp:250 Amp:350 Amp:400
          Voltage: 43 Voltage: 62 Voltage: 79
21 Lumbar hemilaminotomy, foraminotomy, partial facetectomy and diskectomy L3-L4 Just lower back pain Left sided      
22 Lumbar Lamiectomy L4-L5 Bilateral leg symptoms Right Sided      
23 Endoscopic Hemilamiotomy L4-L5 Right sided leg pain, L4-L5 Right Sided      
24 XLIF, PPSx2 L4-L5 Unkown Unknown      
25 Lumbar Laminectomy L4-L5 Bilateral leg symptoms Left sided      
26 Lumbar Laminectomy L4-L5 Right sided radicular pain Bilateral      
27 Lumbar Laminectomy L4-L5 Bilateral leg pain Bilateral      
28 Endoscopic Disectomy L4-L5 Right sided leg pain, L4-L5 Right Sided      
29 MAS TLIF L4-L5 Left sided leg pain Left sided      
30 Lumbar Laminectomy L4-L5 Lumbar and bilateral front thigh pain Bilateral      
31 Lumbar Laminectomy L4-L5 Symptoms which are consistent with  peripheral neauropather in multiple levels Bilateral      
32 Hemilamiotomy, foraminotomy, discectomy, medial facetectomy L4-L5 Right sided radiular pain Right      
33 Lumbar Laminectomy L4-L5 Low back pain and left sided radicular pain, minor right-sided pain which is intermittent Left to right      
34 Lumbar Laminectomy L4-L5 Left sided radicular pain Left to right      
35 Hemilamiotomy, foraminotomy, discectomy, medial facetectomy L4-L5 Left sided radicular pain Left sided      
36 Lumbar Laminectomy L4-L5 Bilateral radicular pain Bilateral      
37 Lumbar Lamiectomym foraminotomy L4-L5 Bilateral leg pain Bilateral      
38 XLIF, PPSx2 L4-L5 Unknown Unknown      
39 MIS laminectomy L4-L5 Unknown Unknown      
40 Lumbar Lamiectomy L4-L5 Right sided radiular pain Right Sided      
41 Endoscopic Hemilamiotomy L5-S1 Right sided leg pain, L5-S1 Right Sided      
42 Revision Open lami L5-S1 Bilateral leg symptoms, S1 Bilateral      
43 Hemilamiotomy, foraminotomy, discectomy L5-S1 Right sided radiular pain, heriated disc at L5-S1 Right Sided      
44 Lumbar hemilaminotomy/foraminotomy L5-S1 Right sided radiular pain, severe in the L5 and S1 distrubution Right Sided      
45 Minimally invasive microdiskectomy and hemilaminotomy L5-S1 Right sided lower extremity radicolopathy referable to L5-S1 foraminal root Right Sided      
46 XLIF Unknown Unknown Unknown      
47 PSF Unknown  Unknown Unknown      
48 Unknown Unknown Unknown Unknown      
49 Decompression Unknown Unknown Unknown      
50 Decompression Unknown Unknown Unknown      
51 Decompression Unknown Unknown Unknown      

Author Info

William Taylor*
 
Department of Neurosurgery, University of California, San Diego Campus Point, CA, USA
 

Citation: Taylor W. Transabdominal motor action potentials (TaMAP) for lateral approach neuromonitoring in spine surgery: novel case series of 51 patients in proof-of-concept demonstration. J Neurol Neurophy, 2020, 11(7), 510.

Received Date: Aug 04, 2020 / Accepted Date: Nov 05, 2020 / Published Date: Nov 25, 2020

Copyright: 2020 Taylor W. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.