Utility of diffusion tensor imaging for guiding the treatment of lumbar disc herniation by percutaneous transforaminal endoscopic discectomy

AbstractThe purpose of this study was to evaluate the utility of diffusion tensor imaging (DTI) for guiding the treatment of lumbar disc herniation (LDH) by percutaneous transforaminal endoscopic discectomy (PTED). We collected the clinical data of a total of 19 patients: 10 with unilateral S1 nerve root injury, 6 with unilateral L5 nerve root injury, and 3 with unilateral L5 and S1 nerve root injury. All patients underwent DTI before surgery, 3 days post-surgery, 30 days post-surgery, and 90 days post-surgery. The comparison of the fractional anisotropy (FA) values of compressed lateral nerve roots before surgery and 3, 30, and 90 days post-surgery demonstrated the recovery of nerve roots to be a dynamic process. A significant difference was found in the FA values between compressed lateral nerve roots preoperatively and normal lateral nerve roots before surgery, 3 days post-surgery and 30 days post-surgery (p < 0.05). There was no significant difference in FA values between compressed lateral nerve roots and normal ones 90 days post-surgery (p > 0.05). DTI can be used for the accurate diagnosis of LDH, as well as for postoperative evaluation and prognosis, and it is thus useful for the selection of surgical timing.

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Feasibility of Using Intraoperative Neuromonitoring in the Prophylaxis of Dysesthesia in Transforaminal Endoscopic Discectomies of the Lumbar Spine

Brain Sciences ◽

10.3390/brainsci10080522 ◽

2020 ◽

Vol 10 (8) ◽

pp. 522

Author(s):

Paulo Sérgio Teixeira de Carvalho ◽

Max Rogério Freitas Ramos ◽

Alcy Caio da Silva Meireles ◽

Alexandre Peixoto ◽

Paulo de Carvalho ◽

...

Keyword(s):

Nerve Root ◽

Statistical Power ◽

Motor Evoked Potentials ◽

Lumbar Disc ◽

Intraoperative Neurophysiological Monitoring ◽

Neurophysiological Monitoring ◽

Control Group ◽

Nerve Root Injury ◽

Root Injury ◽

Sensory Evoked

(1) Background: Postoperative nerve root injury with dysesthesia is the most frequent sequela following lumbar endoscopic transforaminal discectomy. At times, it may be accompanied by transient and rarely by permanent motor weakness. The authors hypothesized that direct compression of the exiting nerve root and its dorsal root ganglion (DRG) by manipulating the working cannula or endoscopic instruments may play a role. (2) Objective: To assess whether intraoperative neurophysiological monitoring can help prevent nerve root injury by identifying neurophysiological events during the initial placement of the endoscopic working cannula and the directly visualized video endoscopic procedure. (3) Methods: The authors performed a retrospective chart review of 65 (35 female and 30 male) patients who underwent transforaminal endoscopic decompression for failed non-operative treatment of lumbar disc herniation from 2012 to 2020. The patients’ age ranged from 22 to 86 years, with an average of 51.75 years. Patients in the experimental group (32 patients) had intraoperative neurophysiological monitoring recordings using sensory evoked (SSEP), and transcranial motor evoked potentials (TCEP), those in the control group (32 patients) did not. The SSEP and TCMEP data were analyzed and correlated to the postoperative course, including dysesthesia and clinical outcomes using modified Macnab criteria, Oswestry disability index (ODI), visual analog scale (VAS) for leg and back pain. (4) Results: The surgical levels were L4/L5 in 44.6%, L5/S1 in 23.1%, and L3/L4 in 9.2%. Of the 65 patients, 56.9% (37/65) had surgery on the left, 36.9% (24/65) on the right, and the remaining 6.2% (4/65) underwent bilateral decompression. Postoperative dysesthesia occurred in 2 patients in the experimental and six patients in the control group. In the experimental neuromonitoring group, there was electrodiagnostic evidence of compression of the exiting nerve root’s DRG in 24 (72.7%) of the 32 patients after initial transforaminal placement of the working cannula. A 5% or more decrease and a 50% or more decrease in amplitude of SSEPs and TCEPs recordings of the exiting nerve root were resolved by repositioning the working cannula or by pausing the root manipulation until recovery to baseline, which typically occurred within an average of 1.15 min. In 15 of the 24 patients with such latency and amplitude changes, a foraminoplasty was performed before advancing the endoscopic working cannula via the transforaminal approach into the neuroforamen to avoid an impeding nerve root injury and postoperative dysesthesia. (5) Conclusion: Neuromonitoring enabled the intraoperative diagnosis of DRG compression during the initial transforaminal placement of the endoscopic working cannula. Future studies with more statistical power will have to investigate whether employing neuromonitoring to avoid intraoperative compression of the exiting nerve root is predictive of lower postoperative dysesthesia rates in patients undergoing videoendoscopic transforaminal discectomy.

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Anatomy of the L5 nerve root in the pelvis for safe sacral screw placement: a cadaveric study

Journal of Neurosurgery Spine ◽

10.3171/2021.8.spine21962 ◽

2021 ◽

pp. 1-6

Author(s):

Shota Tamagawa ◽

Takatoshi Okuda ◽

Hidetoshi Nojiri ◽

Tatsuya Sato ◽

Rei Momomura ◽

...

Keyword(s):

Nerve Root ◽

Sagittal Plane ◽

Pedicle Screws ◽

Cadaveric Study ◽

Nerve Roots ◽

Nerve Root Injury ◽

Inflection Points ◽

Root Injury ◽

The Right ◽

Intervertebral Foramina

OBJECTIVE Previous reports have focused on the complications of L5 nerve root injury caused by anterolateral misplacement of the S1 pedicle screws. Anatomical knowledge of the L5 nerve root in the pelvis is essential for safe and effective placement of the sacral screw. This cadaveric study aimed to investigate the course of the L5 nerve root in the pelvis and to clarify a safe zone for inserting the sacral screw. METHODS Fifty-four L5 nerve roots located bilaterally in 27 formalin-fixed cadavers were studied. The ventral rami of the L5 nerve roots were dissected along their courses from the intervertebral foramina to the lesser pelvis. The running angles of the L5 nerve roots from the centerline were measured in the coronal plane. In addition, the distances from the ala of the sacrum to the L5 nerve roots were measured in the sagittal plane. RESULTS The authors found that the running angles of the L5 nerve roots changed at the most anterior surface of the ala of the sacrum. The angles of the bilateral L5 nerve roots from the right and left L5 intervertebral foramina to their inflection points were 13.77° ± 5.01° and 14.65° ± 4.71°, respectively. The angles of the bilateral L5 nerve roots from the right and left inflection points to the lesser pelvis were 19.66° ± 6.40° and 20.58° ± 5.78°, respectively. There were no significant differences between the angles measured in the right and left nerve roots. The majority of the L5 nerves coursed outward after changing their angles at the inflection point. The distances from the ala of the sacrum to the L5 nerve roots in the sagittal plane were less than 1 mm in all cases, which indicated that the L5 nerve roots were positioned close to the ala of the sacrum and had poor mobility. CONCLUSIONS All of the L5 nerve roots coursed outward after exiting the intervertebral foramina and never inward. To prevent iatrogenic L5 nerve root injury, surgeons should insert the S1 pedicle screw medially with an angle > 0° toward the inside of the S1 anterior foramina and the sacral alar screw laterally with an angle > 30°.

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Riluzole effects on behavioral sensitivity and the development of axonal damage and spinal modifications that occur after painful nerve root compression

Journal of Neurosurgery Spine ◽

10.3171/2014.2.spine13672 ◽

2014 ◽

Vol 20 (6) ◽

pp. 751-762 ◽

Cited By ~ 17

Author(s):

Kristen J. Nicholson ◽

Sijia Zhang ◽

Taylor M. Gilliland ◽

Beth A. Winkelstein

Keyword(s):

Spinal Cord ◽

Dorsal Horn ◽

Nerve Root ◽

Mechanical Allodynia ◽

Thermal Hyperalgesia ◽

Neuronal Firing ◽

Nerve Roots ◽

Nerve Root Injury ◽

Root Injury ◽

Behavioral Sensitivity

Object Cervical radiculopathy is often attributed to cervical nerve root injury, which induces extensive degeneration and reduced axonal flow in primary afferents. Riluzole inhibits neuro-excitotoxicity in animal models of neural injury. The authors undertook this study to evaluate the antinociceptive and neuroprotective properties of riluzole in a rat model of painful nerve root compression. Methods A single dose of riluzole (3 mg/kg) was administered intraperitoneally at Day 1 after a painful nerve root injury. Mechanical allodynia and thermal hyperalgesia were evaluated for 7 days after injury. At Day 7, the spinal cord at the C-7 level and the adjacent nerve roots were harvested from a subgroup of rats for immunohistochemical evaluation. Nerve roots were labeled for NF200, CGRP, and IB4 to assess the morphology of myelinated, peptidergic, and nonpeptidergic axons, respectively. Spinal cord sections were labeled for the neuropeptide CGRP and the glutamate transporter GLT-1 to evaluate their expression in the dorsal horn. In a separate group of rats, electrophysiological recordings were made in the dorsal horn. Evoked action potentials were identified by recording extracellular potentials while applying mechanical stimuli to the forepaw. Results Even though riluzole was administered after the onset of behavioral sensitivity at Day 1, its administration resulted in immediate resolution of mechanical allodynia and thermal hyperalgesia (p < 0.045), and these effects were maintained for the study duration. At Day 7, axons labeled for NF200, CGRP, and IB4 in the compressed roots of animals that received riluzole treatment exhibited fewer axonal swellings than those from untreated animals. Riluzole also mitigated changes in the spinal distribution of CGRP and GLT-1 expression that is induced by a painful root compression, returning the spinal expression of both to sham levels. Riluzole also reduced neuronal excitability in the dorsal horn that normally develops by Day 7. The frequency of neuronal firing significantly increased (p < 0.045) after painful root compression, but riluzole treatment maintained neuronal firing at sham levels. Conclusions These findings suggest that early administration of riluzole is sufficient to mitigate nerve root–mediated pain by preventing development of neuronal dysfunction in the nerve root and the spinal cord.

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Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 15: Electrophysiological monitoring and lumbar fusion

Journal of Neurosurgery Spine ◽

10.3171/2014.4.spine14324 ◽

2014 ◽

Vol 21 (1) ◽

pp. 102-105 ◽

Cited By ~ 15

Author(s):

Alok Sharan ◽

Michael W. Groff ◽

Andrew T. Dailey ◽

Zoher Ghogawala ◽

Daniel K. Resnick ◽

...

Keyword(s):

Nerve Root ◽

Lumbar Fusion ◽

Pedicle Screws ◽

Limited Evidence ◽

Direct Stimulation ◽

Nerve Roots ◽

Fusion Surgery ◽

Nerve Root Injury ◽

Root Injury ◽

Stimulation Of

Intraoperative monitoring (IOM) is commonly used during lumbar fusion surgery for the prevention of nerve root injury. Justification for its use stems from the belief that IOM can prevent nerve root injury during the placement of pedicle screws. A thorough literature review was conducted to determine if the use of IOM could prevent nerve root injury during the placement of instrumentation in lumbar or lumbosacral fusion. There is no evidence to date that IOM can prevent injury to the nerve roots. There is limited evidence that a threshold below 5 mA from direct stimulation of the screw can indicate a medial pedicle breach by the screw. Unfortunately, once a nerve root injury has taken place, changing the direction of the screw does not alter the outcome. The recommendations formulated in the original guideline effort are neither supported nor refuted with the evidence obtained with the current studies.

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A novel anatomo-physiologic high-grade spondylolisthesis model to evaluate L5 nerve stretch injury after spondylolisthesis reduction

Neurosurgical Review ◽

10.1007/s10143-021-01721-z ◽

2021 ◽

Author(s):

Basem Ishak ◽

Clifford A. Pierre ◽

Darius Ansari ◽

Stefan Lachkar ◽

Alexander von Glinski ◽

...

Keyword(s):

Nerve Root ◽

Nerve Palsy ◽

Mechanical Strain ◽

Pedicle Screws ◽

High Grade ◽

Nerve Roots ◽

Nerve Root Injury ◽

Root Injury ◽

Fresh Frozen ◽

Measurable Change

AbstractL5 nerve palsy is a well-known complication following reduction of high-grade spondylolisthesis. While several mechanisms for its occurrence have been proposed, the hypothesis of L5 nerve root strain or displacement secondary to mechanical reduction remains poorly studied. The aim of this cadaveric study is to determine changes in morphologic parameters of the L5 nerve root during simulated intraoperative reduction of high-grade spondylolisthesis. A standard posterior approach to the lumbosacral junction was performed in eight fresh-frozen cadavers with lumbosacral or lumbopelvic screw fixation. Wide decompressions of the spinal canal and L5 nerve roots with complete facetectomies were accomplished with full exposure of the L5 nerve roots. A 100% translational slip was provoked by release of the iliolumbar ligaments and cutting the disc with the attached anterior longitudinal ligament. To evaluate the path of the L5 nerves during reduction maneuvers, metal bars were inserted bilaterally at the inferomedial aspects of the L5 pedicle at a distance of 10 mm from the midpoint of the L5 pedicle screws. There was no measurable change in length of the L5 nerve roots after 50% and 100% reduction of spondylolisthesis. Mechanical strain or displacement during reduction is an unlikely cause of L5 nerve root injury. Further anatomical or physiological studies are necessary to explore alternative mechanisms of L5 nerve palsy in the setting of high-grade spondylolisthesis correction, and surgeons should favor extensive surgical decompression of the L5 nerve roots when feasible.

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PATHOANATOMIC BASIS FOR STRETCH-INDUCED LUMBAR NERVE ROOT INJURY WITH A REVIEW OF THE LITERATURE

Neurosurgery ◽

10.1227/01.neu.0000347002.67982.8f ◽

2009 ◽

Vol 65 (1) ◽

pp. 161-168 ◽

Cited By ~ 15

Author(s):

Sameer A. Kitab ◽

Vincent J. Miele ◽

William F. Lavelle ◽

Edward C. Benzel

Keyword(s):

Spinal Deformity ◽

Nerve Root ◽

Nerve Roots ◽

Nerve Root Injury ◽

Functional Spinal Unit ◽

Root Injury ◽

Lumbar Nerve Root ◽

The Face ◽

Anterior Posterior

Abstract OBJECTIVE Persistent pain originating from a dysfunctional lumbar motion segment poses significant challenges in the clinical arena. Although the predominance of the existing spine literature has addressed nerve root compression as the principal cause of pain, it is equally likely that a stretch mechanism may be responsible for all or part of the pathology. METHODS The literature supporting the role of stretch damage as a primary cause of nerve root injury and pain was systematically reviewed. Pathoanatomic considerations between nerve roots and juxtaposed environment are described and correlated with the available literature. Potential anatomic relationships that may lead to stretch-induced injury are delineated. RESULTS A dynamic lumbar functional spinal unit that encloses a tethered nerve root can create significant stretch and/or compression. This phenomenon may be present in a variety of pathological conditions. These include anterior, posterior, and rotatory olisthesis as well as degenerative conditions such as the loss of disc interspace height and frank multisegment spinal deformity. Although numerous studies have demonstrated that stretch can result in nerve damage, the pathophysiology that may associate nerve stretch with chronic pain has yet to be determined. CONCLUSION The current literature concerning stretch-related injury to nerve roots is reviewed, and a conceptual framework for its diagnosis and treatment is proposed and graphically illustrated using cadaveric specimens. The dynamic biomechanical and functional interrelationships between neural structures and adjacent connective tissue elements are particularly important in the face of spinal deformity.

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Unique Complications of Percutaneous Endoscopic Lumbar Discectomy and Percutaneous Endoscopic Interlaminar Discectomy

January 2018 - Pain Physician ◽

10.36076/ppj.2018.2.e105 ◽

2018 ◽

Vol 1 (21;1) ◽

pp. E105-E112 ◽

Cited By ~ 1

Author(s):

Ma Xuexiao

Keyword(s):

Nerve Root ◽

Epidural Hematoma ◽

Surgical Techniques ◽

Lumbar Discectomy ◽

Nerve Root Injury ◽

Root Injury ◽

Endoscopic Discectomy ◽

Posterior Neck ◽

Nerve Root Pain ◽

Endoscopic Lumbar Discectomy

Background: Percutaneous endoscopic discectomy (PED) includes 2 main procedures: percutaneous endoscopic lumbar discectomy (PELD) and percutaneous endoscopic interlaminar discectomy (PEID), both of which are minimally invasive surgical procedures that effectively deal with lumbar degenerative disorders. Because of the challenging learning curve for the surgeon and the individual characteristics of each patient, preventing and avoiding complications is difficult. The most common complications, such as nucleus pulposus omission, nerve root injury, dural tear, visceral injury, nerve root induced hyperalgesia or burning-like nerve root pain, postoperative dysesthesia, posterior neck pain, and surgical site infection, are difficult to avoid; however, more focus on these issues perioperatively may be in order. Additionally, unique and unexpected complications can also occur, such as retroperitoneal hematoma (RPH), intraoperative seizures, and thrombophlebitis, among others. Objective: We aim to delineate unique complications during PED and accumulate strategies to prevent significant morbidity and improve surgical techniques. Study Design: A retrospective cohort study of patients undergoing PEID or PELD from October 2014 to January 2016. Setting: Affiliated hospitals of Qingdao University. Methods: Patients with lumbar disc herniation (LDH) who underwent PEID and PELD were retrospectively analyzed. Complications were recorded and analyzed pre and postoperatively. We assessed clinical outcomes using the visual analog scale (VAS) and Oswestry Disability Index (ODI) and classified the results into “excellent,” “good,” “fair,” or “poor” based on the modified MacNab criteria. All of the patients were followed for more than one year to evaluate their recovery from complications. Results: From October 2014 to January 2016, 426 patients with LDH underwent PEID (106 cases) or PELD (320 cases). Common complications and occurrence rates were as follows: the incomplete removal of herniated discs was 1.4% (6/426), recurrence 2.8% (12/426), nerve root injury 1.2% (5/426), dural tear 0.9% (4/426), and nerve root induced hyperalgesia or burning-like nerve root pain 2.3% (10/426); no posterior neck pain or surgical site infection occurred. Unique complications included: passage of the working channel through the spinal canal into the disc space (one case), super-elastic nerve hook caught by exiting nerve root (one case), epidural hematoma (one case), radicular artery injury and massive bleeding (one case) which was revised by micro-endoscopic discectomy, and intraoperative seizure (one case). No serious consequences occurred after active medical intervention, and most patients had good recovery by 3 months postoperatively with physical therapy. Limitations: The main limitations of this study are the retrospective study design, limited case number, and short follow-up period. Conclusions: PEDs are effective and minimally invasive methods for the surgical treatment of LDH, causing fewer complications due to the very minimal operational trauma for the muscle-ligament complex and stability of the spine. Nevertheless, because of the difficult learning curve for surgeons, lack of experience with the requisite surgical techniques, and enhanced clinical responsibility, a variety of problems may occur. Especially concerning are the unique complications mentioned here, which potentially lead to severe injury for the patient and require diligent preventive measures. Key words: Unique complications, epidural, hematoma, interlaminar, transforaminal, PEID, PELD

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The Strategy and Early Clinical Outcome of Percutaneous Full-Endoscopic Interlaminar or Extraforaminal Approach for Treatment of Lumbar Disc Herniation

BioMed Research International ◽

10.1155/2016/4702946 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Weijun Kong ◽

Wenbo Liao ◽

Jun Ao ◽

Guangru Cao ◽

Jianpu Qin ◽

...

Keyword(s):

Clinical Outcome ◽

Nerve Root ◽

Lumbar Disc ◽

Clinical Results ◽

Herniated Disc ◽

Surgical Technology ◽

Nerve Root Injury ◽

Endoscopic Discectomy ◽

Preoperative Ct ◽

Puncture Technique

Objective is to analyze the surgical strategy, safety, and clinical results of percutaneous full-endoscopic discectomy through interlaminar or extraforaminal puncture technique for LDH. Preoperative CT and MRI were analyzed, which were based on the main location of the herniated disc and its relationship with compressed nerve root. Sixty-two patients satisfied the inclusion criteria during the period from August 2012 to March 2014. We use percutaneous full-endoscopic discectomy through different puncture technique to remove the protrusive NP for LDH. Sixty patients completed the full-endoscopic operation successfully. Their removed disc tissue volume ranged from 1.5 mL to 3.8 mL each time. Postoperative ODI and VAS of low back and sciatica pain were significantly decreased in each time point compared to preoperative ones. No nerve root injury, infection, and other complications occurred. The other two patients were shifted to open surgery. No secondary surgery was required and 91.6% of excellent-to-good ratio was achieved on the basis of Macnab criteria at postoperative 12 months. Acquired benefits are fewer complications, rapid recovery, complete NP removal, effective nerve root decompression, and satisfactory cosmetic effect as well. This is a safe, effective, and rational minimally invasive spine-surgical technology with excellent clinical outcome.

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Rating Spinal Nerve Extremity Impairment Using the Sixth Edition

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2009.julaug01 ◽

2009 ◽

Vol 14 (4) ◽

pp. 1-6

Author(s):

Christopher R. Brigham

Keyword(s):

Nerve Root ◽

Spinal Nerve ◽

Upper Extremities ◽

Motor Deficits ◽

Nerve Injuries ◽

Sixth Edition ◽

Federal Employee ◽

Nerve Root Injury ◽

Root Injury ◽

Rating Process

Abstract The AMAGuides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, does not provide a separate mechanism for rating spinal nerve injuries as extremity impairment; radiculopathy was reflected in the spinal rating process in Chapter 17, The Spine and Pelvis. Certain jurisdictions, such as the Federal Employee Compensation Act (FECA), rate nerve root injury as impairment involving the extremities rather than as part of the spine. This article presents an approach to rate spinal nerve impairments consistent with the AMA Guides, Sixth Edition, methodology. This approach should be used only when a jurisdiction requires ratings for extremities and precludes rating for the spine. A table in this article compares sensory and motor deficits according to the AMA Guides, Sixth and Fifth Editions; evaluators should be aware of changes between editions in methodology used to assign the final impairment. The authors present two tables regarding spinal nerve impairment: one for the upper extremities and one for the lower extremities. Both tables were developed using the methodology defined in the sixth edition. Using these tables and the process defined in the AMA Guides, Sixth Edition, evaluators can rate spinal nerve impairments for jurisdictions that do not permit rating for the spine and require rating for radiculopathy as an extremity impairment.

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