Anatomical damages in the spinal nerve roots and the spinal cord after brachial plexus injury: descriptive study from a cohort of consecutive patients who underwent DREZ-lesioning for pain-practical implications.

BACKGROUND: Systematic descriptions of anatomical damage after brachial plexus injury (BPI) at the intradural level have been scarcely reported in detail. However, considering these damages, not only in the spinal nerve roots but also in the spinal cord itself, is crucial in determining the appropriate surgical approach to restore upper limb function and address refractory pain. Therefore, the authors present a descriptive study focusing on intradural findings observed during microsurgical DREZ-lesioning. METHODS: This study enrolled 19 consecutive patients under the same protocol. Microsurgical observation through exposure of C4 to Th1 medullary segments allowed to describe the lesions in spinal nerve roots, meninges, and spinal cord. Electrical stimulation of the ventral roots checked the muscle responses. RESULTS: Extensive damage was observed among the 114 explored roots (six roots per patient), with only 21 (18.4%) ventral (VR) and 17 (14.9%) dorsal (DR) roots retaining all rootlets intact. Damage distribution varied, with the most frequent impairments in C6 VRs (18 patients) and the least in Th1 VRs (14 patients), while in all the 19 patients for the C6 DRs (the most frequently impaired) and in 14 patients for Th1 DRs (the less impaired). C4 roots were found damaged in 12 patients. Total or partial avulsions affected 63.3% and 69.8% of DRs and VRs, respectively, while 15.8% and 14.0% of the 114 DRs and VRs were atrophic, maintaining muscle responses to stimulation in half of those VRs. Pseudomeningoceles were present in 11 patients but absent in 46% of avulsed roots. Adhesive arachnoiditis was noted in 12 patients, and dorsal horn parenchymal alterations in 10. CONCLUSIONS: Knowledge of intradural lesions post-BPI helps in guiding surgical indications for repair and functional neurosurgery for pain control.

[Chinese expert consensus on the surgical treatment of neuropathic pain by the spinal cord dorsal root entry zone].

In order to promote the standardization of the treatment of neuropathic pain by spinal dorsal root entry surgery, alleviate the pain of certain specific neuropathic pain patients, and improve their quality of life and survival, experts with experience in neuropathic pain and spinal dorsal root entry surgery were organized by Functional Neurosurgery Group of the Neurosurgery Branch of the Chinese Medical Association and Functional Neurosurgery Expert Committee of Chinese Congress of Neurological Surgeons to write this consensus. Based on a systematic review and summary of literature and clinical evidence at home and abroad, this consensus discusses the diagnosis and drug treatment of neuropathic pain, clinical application of, spinal dorsal root entry surgery the selection of patients receiving surgery of dorsal root entry zone, preoperative examination, surgical procedures, postoperative management, and the prevention and management of postoperative complications, and forms 12 recommended recommendations, providing reference and guidance for clinical work on the treatment of neuropathic pain through spinal dorsal root entry surgery.

[Efficacy analysis of OLIF combined with posterior percutaneous internal fixation in patients with lumbar spinal stenosis with or without redundant nerve roots].

OBJECTIVE: To investigate the clinical efficacy of oblique lumbar interbody fusion(OLIF) combined with posterior percutaneous internal fixation in patients with lumbar spinal stenosis with or without redundant nerve roots(RNRs). METHODS: A retrospective analysis of 92 patients with lumbar spinal stenosis treated by oblique lateral lumbar interbody fusion combined with posterior percutaneous internal fixation from June 2019 to June 2022 was performed. There were 32 males and 60 females, aged from 44 to 82 years old with an average of (63.67±9.93) years old. All patients were divided into RNRs positive group and RNRs negative group according to redundancy or not before operation. There were 38 patients in RNRs positive group, including 15 males and 23 females. The age ranged from 45 to 82 years old with an average of (65.45±10.37) years old. The disease duration was 24.00(12.00, 72.00) months. There were 54 patients in RNRs negative group, including 17 males and 37 females. The age ranged from 44 to 77 years old with an average of (62.42±9.51) years old. The disease duration was 13.50(9.00, 36.00) months. The general data of patients were recorded, including operation time, intraoperative blood loss and complications. The imaging parameters before and after operation were observed, including the number of stenosis segments, intervertebral space height, lumbar lordosis angle and dural sac area. The visual analogue scale (VAS) was used to evaluate the back and lower extremity pain, and the Oswestry disability index (ODI) was used to evaluate the activities of daily living. RESULTS: All patients were followed up for 8 to 18 months with an average of (11.04±3.61) months, and no complications were found during the follow-up period.The number of stenosis segments in RNRs positive group (1.71±0.46) was more than that in RNRs negative group(1.17±0.38). In RNRs positive group, intervertebral space height, dural sac area, low back pain VAS, lower extremity pain VAS, ODI score were (1.11±0.19) cm, (0.46±0.17) cm2, (5.39±1.00) scores, (5.05±1.01) points, (55.74±4.05) points, respectively. RNRs negative groups respectively (0.97±0.23) cm, (0.69±0.26) cm2, (4.50±0.77) scores, (4.00±0.58) scores, (47.33±3.43) %. In RNRs positive group, intervertebral space height, dural sac area, low back pain VAS, leg pain VAS, ODI score were (1.60±0.19) cm, (0.74±0.36) cm2, (3.39±0.72) scores, (3.05±1.01) scores, (46.74±4.82) scores, respectively. RNRs negative groups respectively (1.48±0.25) cm, (1.12±0.35) cm2, (3.00±0.82) scores, (3.00±0.82) scores, (37.67±3.58) %. The postoperative intervertebral space height, dural sac area, low back pain VAS score, lower extremity pain VAS and ODI score of the patients in the RNRs positive group and the negative group were significantly improved compared with those before operation, and the differences were statistically significant (P<0.05). There were statistically significant differences in the number of stenosed segments, preoperative intervertebral space height, dural sac area, low back pain VAS, lower extremity pain VAS, and ODI between the two groups(P<0.05). There were significant differences in postoperative intervertebral space height and postoperative ODI between the two groups(P<0.05), but there was no significant difference in intervertebral space height before and after operation and ODI score before and after operation(P>0.05). There were significant differences in operation time, intraoperative blood loss, postoperative dural sac area, difference of dural sac area before and after operation, postoperative low back pain VAS, difference of low back pain VAS score before and after operation, difference of lower extremity pain VAS before and after operation between the two groups(P<0.05). CONCLUSION: OLIF combined with posterior percutaneous internal fixation has a good effect on patients with or without RNRs. Multi-segmental lumbar spinal stenosis and decreased dural sac area may lead to the occurrence of RNRs, and LSS patients with RNRs have more severe symptoms. LSS patients with RNRs have worse surgical outcomes than those without RNRs.

Aberrant Dorsal Nerve Root as a Concomitant Cause of Spinal Cord Tethering Associated with a Dorsal Type Lipomyelomeningocele in a Child With Caudal Agenesis.

ABSTRACT: Tethered cord syndrome is a neurological disorder closely associated with congenital spinal dysraphism. Aberrant dorsal nerve roots may be one of the possible and relatively rare tethering pathologies, especially in the complex form of occult spinal dysraphism such as caudal regression syndrome or split cord malformation. We report an illustrative case of caudal regression syndrome with spinal cord tethering due to a combination of a contiguous bundle of an aberrant dorsal nerve root, and a dorsal-type lipomyelomeningocele, with a thickened filum terminale treated with microneurosurgical untethering.

Cervical Nerve Root Block Using a Curved Blunt Needle and Posterior Approach.

BACKGROUND: Cervical transforaminal epidural steroid injections have become less popular due to the risk of catastrophic complications they pose. However, cervical nerve root blocks are useful for surgical planning in patients with cervical radicular pain syndromes. OBJECTIVES: Our aim was to find a method of performing cervical selective nerve root blocks that removed the risk of catastrophic complications. STUDY DESIGN: Retrospective case review. SETTING: Academic multidisciplinary spine center. METHODS: Among patients, 50 consecutive cases were retrospectively reviewed for immediate pain scores and follow-up results. In the intervention, a posterior approach using a curved blunt needle was employed for cervical selective nerve root blocks to minimize the risk of arterial injection. To measure the outcomes, we used quantitative pain severity scores and qualitative responses. RESULTS: This technique detailed in this study has a high immediate analgesic effect that can be used for diagnostic purposes. It is not known if this technique has prognostic value with respect to surgery. The prolonged response rate is about 50%, which is in line with other techniques. LIMITATIONS: This study had no control group. CONCLUSION(S): Cervical selective nerve root blocks using a curved blunt needle and a posterior approach are effective in selectively identifying nerves that cause clinical symptoms. This technique minimizes the risk of arterial or spinal cord impingement and therefore may be safer than transforaminal selective nerve root blocks.

Boundary cap neural crest stem cells promote angiogenesis after transplantation to avulsed dorsal roots in mice and induce migration of endothelial cells in 3D printed scaffolds.

Dorsal root avulsion injuries lead to loss of sensation and to reorganization of blood vessels (BVs) in the injured area. The inability of injured sensory axons to re-enter the spinal cord results in permanent loss of sensation, and often also leads to the development of neuropathic pain. Approaches that restore connection between peripheral sensory axons and their CNS targets are thus urgently need. Previous research has shown that sensory axons from peripherally grafted human sensory neurons are able to enter the spinal cord by growing along BVs which penetrate the CNS from the spinal cord surface. In this study we analysed the distribution of BVs after avulsion injury and how their pattern is affected by implantation at the injury site of boundary cap neural crest stem cells (bNCSCs), a transient cluster of cells, which are located at the boundary between the spinal cord and peripheral nervous system and assist the growth of sensory axons from periphery into the spinal cord during development. The superficial dorsal spinal cord vasculature was examined using intravital microscopy and intravascular BV labelling. bNCSC transplantation increased vascular volume in a non-dose responsive manner, whereas dorsal root avulsion alone did not decrease the vascular volume. To determine whether bNCSC are endowed with angiogenic properties we prepared 3D printed scaffolds, containing bNCSCs together with rings prepared from mouse aorta. We show that bNCSC do induce migration and assembly of endothelial cells in this system. These findings suggest that bNCSC transplant can promote vascularization in vivo and contribute to BV formation in 3D printed scaffolds.

The Diagnostic Role of Adding the Hoffman Reflex for L5 Radiculopathy in the Electrodiagnostic Laboratory: A Cross-sectional Study.

OBJECTIVES: To investigate changes in the H-reflex in patients with monoradiculopathies involving L5 or S1 levels by stimulating the sciatic nerve and recording simultaneously from the tibialis anterior (TA), peroneus longus (PL), and soleus (S) muscles. METHODS: Patients with unilateral radicular back pain with L5 or S1 root compression on MRI, participated in this cross-sectional study. The H-reflex over the TA, PL, and S muscles was simultaneously recorded by sciatic nerve stimulation. The H-reflex latency was compared with that of the contralateral extremity. RESULTS: Fifty-eight patients (29 patients L5; 29 patients S1 radiculopathy) were included in the study. There were significant delays in the latency of the H-reflex over TA (30.95±2.31-29.21±1.4) and PL (31.05±2.85-29.02±1.99) muscles on the affected side in patients with L5 radiculopathy. However, the latency of the S H-reflex was similar on both sides. In contrast, in patients with S1 radiculopathy, there was a significant delay in the latency of soleus H reflex (32.76±3.45-29.9±3.19), while the significant delay was not detected in the TA and PL muscles. However, the cutoff values for the H-reflex latency of all muscles were not found to have clinical significance. CONCLUSIONS: The study presents that the H-reflex study, recorded from the TA, PL, and S muscles by sciatic nerve stimulation, is of interest but has minimal contribution to radiculopathy diagnosis in conventional electrodiagnostic tests.

Sacral nerve root metastasis in a patient with lung carcinoma resembling neurinoma - a case report and literature review.

Intradural extramedullary metastases from systemic neoplasms are very rare, with an incidence ranging from 2% to 5% of all secondary spinal diseases. We present the case of a 53-year-old man diagnosed with lung adenocarcinoma with symptoms of severe back pain and tibial paresis. The magnetic resonance imaging (MRI) revealed an intradural lesion originating from the right S1 nerve root mimicking neurinoma. Total tumor removal was achieved via posterior midline approach. The histological examination was consistent with lung carcinoma metastasis. Due to the rarity of single nodular nerve root metastases, MRI images may be misinterpreted as nerve sheath tumors, such as schwannomas or neurofibromas. We performed a brief literature review outlining the mainstay of diagnosis, therapeutic approach, and the prognosis of these rare lesions.

Repeated L5 Nerve Root Compromise Detected with Motor Evoked Potentials (MEP), but Not Electromyography (EMG): A Case Report.

We report a case where neuromonitoring, using motor evoked potentials (MEP), detected an intraoperative L5 nerve root deficit during a lumbosacral decompression and instrumented fusion procedure. Critically, the MEP changes were not preceded nor accompanied by any significant spontaneous electromyography (sEMG) activity. Presumptive L5 innervated muscles, including tibialis anterior (TA), extensor hallucis longus (EHL) and gluteus maximus, were targets for nerve root surveillance using combined MEP and sEMG techniques. During a high-grade spondylolisthesis correction procedure, attempts to align a left-sided rod resulted in repeated loss and recovery cycles of MEP from the TA and EHL. No accompanying EMG alerts were associated with any of the MEP changes nor were MEP variations seen from muscles innervated above and below L5. After several attempts, the rod alignment was achieved, but significant MEP signal decrement (72% decrease) remained from the EHL. Postoperatively, the patient experienced significant foot drop on the left side that recovered over a period of 3 months. This case contributes to a growing body of evidence that exclusive reliance on sEMG for spinal nerve root scrutiny can be unreliable and MEP may provide more dependable data on nerve root patency.

Embryonic stem cells overexpressing high molecular weight FGF2 isoform enhance recovery of pre-ganglionic spinal root lesion in combination with fibrin biopolymer mediated root repair.

BACKGROUND: Spinal ventral root avulsion results in massive motoneuron degeneration with poor prognosis and high costs. In this study, we compared different isoforms of basic fibroblast growth factor 2 (FGF2), overexpressed in stably transfected Human embryonic stem cells (hESCs), following motor root avulsion and repair with a heterologous fibrin biopolymer (HFB). METHODS: In the present work, hESCs bioengineered to overexpress 18, 23, and 31 kD isoforms of FGF2, were used in combination with reimplantation of the avulsed roots using HFB. Statistical analysis was conducted using GraphPad Prism software with one-way or two-way ANOVA, followed by Tukey's or Dunnett's multiple comparison tests. Significance was set at *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001. RESULTS: For the first set of experiments, rats underwent avulsion of the ventral roots with local administration of HFB and engraftment of hESCs expressing the above-mentioned FGF2 isoforms. Analysis of motoneuron survival, glial reaction, and synaptic coverage, two weeks after the lesion, indicated that therapy with hESCs overexpressing 31 kD FGF2 was the most effective. Consequently, the second set of experiments was performed with that isoform, so that ventral root avulsion was followed by direct spinal cord reimplantation. Motoneuron survival, glial reaction, synaptic coverage, and gene expression were analyzed 2 weeks post-lesion; while the functional recovery was evaluated by the walking track test and von Frey test for 12 weeks. We showed that engraftment of hESCs led to significant neuroprotection, coupled with immunomodulation, attenuation of astrogliosis, and preservation of inputs to the rescued motoneurons. Behaviorally, the 31 kD FGF2 - hESC therapy enhanced both motor and sensory recovery. CONCLUSION: Transgenic hESCs were an effective delivery platform for neurotrophic factors, rescuing axotomized motoneurons and modulating glial response after proximal spinal cord root injury, while the 31 kD isoform of FGF2 showed superior regenerative properties over other isoforms in addition to the significant functional recovery.

Skin and not dorsal root stimulation reduces hypertonus in thoracic motor complete spinal cord injury: a single case report.

On demand and localized treatment for excessive muscle tone after spinal cord injury (SCI) is currently not available. Here, we examine the reduction in leg hypertonus in a person with mid-thoracic, motor complete SCI using a commercial transcutaneous electrical stimulator (TES) applied at 50 or 150 Hz to the lower back and the possible mechanisms producing this bilateral reduction in leg tone. Hypertonus of knee extensors without and during TES, with both cathode (T11-L2) and anode (L3-L5) placed over the spinal column (midline, MID) or 10 cm to the left of midline (lateral, LAT) to only active underlying skin and muscle afferents, was simultaneously measured in both legs with the pendulum test. Spinal reflexes mediated by proprioceptive (H-reflex) and cutaneomuscular reflex (CMR) afferents were examined in the right leg opposite to the applied LAT TES. Hypertonus disappeared in both legs but only during thoracolumbar TES, and even during LAT TES. The marked reduction in tone was reflected in the greater distance both lower legs first dropped to after being released from a fully extended position, increasing by 172.8% and 94.2% during MID and LAT TES, respectively, compared with without TES. Both MID and LAT (left) TES increased H-reflexes but decreased the first burst, and lengthened the onset of subsequent bursts, in the cutaneomuscular reflex of the right leg. Thoracolumbar TES is a promising method to decrease leg hypertonus in chronic, motor complete SCI without activating spinal cord structures and may work by facilitating proprioceptive inputs that activate excitatory interneurons with bilateral projections that in turn recruit recurrent inhibitory neurons.NEW & NOTEWORTHY We present proof of concept that surface stimulation of the lower back can reduce severe leg hypertonus in a participant with motor complete, thoracic spinal cord injury (SCI) but only during the applied stimulation. We propose that activation of skin and muscle afferents from thoracolumbar transcutaneous electrical stimulation (TES) may recruit excitatory spinal interneurons with bilateral projections that in turn recruit recurrent inhibitory networks to provide on demand suppression of ongoing involuntary motoneuron activity.

Redundant nerve roots on magnetic resonance imaging can predict ongoing denervation in patients with lumbar spinal stenosis.

INTRODUCTION/AIMS: Redundant nerve roots (RNRs) are abnormally elongated and tortuous nerve roots that develop secondary to degenerative spinal stenosis. RNRs have been associated with poorer clinical outcomes after decompression surgery; however, studies on their clinical characteristics are limited. This study aimed to investigate the association between RNRs and denervation potentials, that is, abnormal spontaneous activity (ASA), on electromyography. METHODS: We retrospectively reviewed data of patients who underwent an electrodiagnostic study of the lower extremities between January 2020 and March 2023. Of these, patients with lumbar central spinal stenosis, as seen on magnetic resonance imaging, were included. We analyzed clinical and imaging data, including presence of ASA, and compared them according to the presence of RNRs. Multivariable logistic regression analysis was employed to identify factors associated with development of ASA. RESULTS: Among the 2003 patients screened, 193 were included in the study. RNRs were associated with advanced age (p < .001), longer symptom duration (p = .009), smaller cross-sectional area of the dural sac at the stenotic level (p < .001), and higher frequency of ASA (p < .001). Higher probability of ASA was correlated with greater RNR severity (p < .001). In the multivariable logistic regression analysis, ASA occurrence was associated with smaller cross-sectional area, multiple stenotic sites, and severe-grade RNRs. DISCUSSION: The presence of RNRs, particularly severe-grade RNRs, was identified as a significant risk factor for the development of ASA on electromyography. This finding may aid physicians in estimating the prognosis of patients with central spinal stenosis.

Nonbinary 2D Distribution Tool Maps Autonomic Nerve Fiber Clustering in Lumbosacral Ventral Roots of Rhesus Macaques.

Neuromodulation of the peripheral nervous system (PNS) by electrical stimulation may augment autonomic function after injury or in neurodegenerative disorders. Nerve fiber size, myelination, and distance between individual fibers and the stimulation electrode may influence response thresholds to electrical stimulation. However, information on the spatial distribution of nerve fibers within the PNS is sparse. We developed a new two-dimensional (2D) morphological mapping tool to assess spatial heterogeneity and clustering of nerve fibers. The L6-S3 ventral roots (VRs) in rhesus macaques were used as a model system to map preganglionic parasympathetic, γ-motor, and α-motor fibers. Random and ground truth distributions of nerve fiber centroids were determined for each VR by light microscopy. The proposed tool allows for nonbinary determinations of fiber heterogeneity by defining the minimum distance between nerve fibers for cluster inclusion and comparisons with random fiber distributions for each VR. There was extensive variability in the relative composition of nerve fiber types and degree of 2D fiber heterogeneity between different L6-S3 VR levels within and across different animals. There was a positive correlation between the proportion of autonomic fibers and the degree of nerve fiber clustering. Nerve fiber cluster heterogeneity between VRs may contribute to varied functional outcomes from neuromodulation.

Are brake response times altered post CT-guided cervical spine nerve root injections?

OBJECTIVES: To assess if brake response times are altered pre and post CT-guided cervical spine nerve root injections. METHODS: Brake response times were assessed before and after CT-guided cervical spine nerve root injections in a cohort of patients. The average of 3 brake response times was recorded before and 30 min after injection. Statistical analysis was performed using GraphPad. A paired Student t-test was used to compare the times before and after the injections. RESULTS: Forty patients were included in this study. The mean age was 55 years. There were 17 male and 23 female patients. There was no significant difference in the mean pre and post CT-guided cervical spine nerve root injection brake response times; 0.94 s (range 0.4-1.2 s) and 0.93 s (range 0.5-1.25 s), respectively (P = .77). CONCLUSIONS: Brake response time did not significantly differ pre and 30 min post CT-guided cervical spine nerve root injections. ADVANCES IN KNOWLEDGE: To the authors' best knowledge, there are no current studies assessing brake response times post CT-guided cervical spine nerve root injections. While driving safety cannot be proven by a single metric, it is a useful study in demonstrating that this is not inhibited in a cohort of patients.

Syringo-Subarachnoid Shunt with Tube Versus T-Tube via the Dorsal Root Entry Zone Approach for Eccentric Syringomyelia.

OBJECTIVE: This study compared the clinical therapeutic efficacy of syringo-subarachnoid shunt placement with direct tube and T-tube via the dorsal root entry zone (DREZ) approach for treatment of eccentric syringomyelia. METHODS: A retrospective study was performed of 41 patients with idiopathic or secondary eccentric syringomyelia from November 2011 to December 2022. Syringo-subarachnoid shunt placement with direct tube or T-tube via the DREZ approach was performed. The modified Japanese Orthopaedic Association low back pain scale was used to investigate the severity of clinical symptoms. Magnetic resonance imaging was used to investigate therapeutic efficacy（reduction of the cavity volume by >10% was considered an improvement and 50% was considered a significant improvement). RESULTS: Incision length of the spinal cortex in the direct tube group was shorter than in the T-tube group (3.10 ± 0.28 cm vs. 5.03 ± 0.19 cm), with a significant difference between the 2 groups (t = -52.56, P < 0.001). Modified Japanese Orthopaedic Association score 3 months postoperatively was significantly better than the preoperative score in both the direct tube group（t = 40.954, P < 0.001） and the T-tube group（t = 24.769, P < 0.001）. Statistical comparison revealed there was no difference in imaging improvement between the direct tube group and T-tube group 3 months (χ2 = 0.20, P = 0.655) and 12 months (χ2 = 0.21, P = 0.647) postoperatively. CONCLUSIONS: Syringo-subarachnoid shunt placement with direct tube via the DREZ approach for treatment of eccentric syringomyelia is safer than with T-tube via the DREZ approach due to smaller incision length and less of a space-occupying effect with same therapeutic efficacy.

The pathophysiological role of endoneurial inflammatory edema in early classical Guillain-Barré syndrome.

The objective of this review was to analyze the pathophysiological role of endoneurial inflammatory edema in initial stages of classic Guillain-Barré syndrome (GBS), arbitrarily divided into very early GBS (≤ 4 days after symptom onset) and early GBS (≤ 10 days). Classic GBS, with variable degree of flaccid and areflexic tetraparesis, encompasses demyelinating and axonal forms. Initial autopsy studies in early GBS have demonstrated that endoneurial inflammatory edema of proximal nerve trunks, particularly spinal nerves, is the outstanding lesion. Variable permeability of the blood-nerve barrier dictates such lesion topography. In proximal nerve trunks possessing epi-perineurium, edema may increase the endoneurial fluid pressure causing ischemic changes. Critical analysis the first pathological description of the axonal form GBS shows a combination of axonal degeneration and demyelination in spinal roots, and pure Wallerian-like degeneration in peripheral nerve trunks. This case might be reclassified as demyelinating GBS with secondary axonal degeneration. Both in acute motor axonal neuropathy and acute motor-sensory axonal neuropathy, Wallerian-like degeneration of motor fibers predominates in the distal part of ventral spinal roots abutting the dura mater, another feature re-emphasizing the pathogenic relevance of this area. Electrophysiological and imaging studies also point to a predominant alteration at the spinal nerve level, which is a hotspot in any early GBS subtype. Serum biomarkers of axonal damage, including neurofilament light chain and peripherin, are increased in the great majority of patients with any early GBS subtype; endoneurial ischemia of proximal nerve trunks could contribute to such axonal damage. It is concluded that inflammatory edema of proximal nerve trunks is an essential pathogenic event in early GBS, which has a tangible impact for accurate approach to the disease.

Post-traumatic lumbar nerve root entrapment into the spinous process of the lumbar spine.

Thoracolumbar fractures constitute a significant portion of spinal trauma, accounting for 15-20% of the cases. These fractures, caused by high-impact injuries, may involve tears of the posterior ligamentous complex, presenting a high chance of neurological injury ranging from dural tears to spinal root avulsion. This case report discusses a rare occurrence of avulsion of lumbosacral nerve roots posteriorly, becoming entrapped in the fractured spinous process of the L2 lumbar vertebra, leading to cauda equina syndrome following trauma and its implications during surgery.

New-Onset Tinnitus After Dorsal Root Ganglion Stimulator Implantation: A Case Report.

Dorsal column (dcSCS) and dorsal root ganglion stimulation (DRG-S) complications are similar, typically related to placement and device failure. We present the first case of tinnitus after DRG-S implantation. The patient presented with complex regional pain syndrome (CRPS) type 2. After previous failed treatments, she had a lumbosacral DRG-S trial, which provided relief; however, she briefly noted ringing in her ears. After permanent implantation, she reported persistent, intolerable left-sided tinnitus. Tinnitus can be modulated by secondary somatosensory inputs to the cochlear nucleus from the dcSCS. Therefore, lumbosacral DRG-S stimulating distal sensory neurons leading to tinnitus is a feasible complication.

Intraoperative High-Resolution Color-Coded Ultrasound to Identify the Posterior Median Sulcus for Midline Myelotomy in Intramedullary Spinal Cord Surgery.

A 14-year-old boy presented with a 2-year history of slowly increasing weakness and atrophy in the right forearm and leg. Magnetic resonance imaging (MRI) revealed an intramedullary diffusely infiltrating lateralized tumor at C3-7. An extended biopsy was planned. After laminotomy and durotomy, the swollen spinal cord was noted to be rotated by 45° with the right dorsal root entry zone being in the midline. A 15 MHz linear ultrasound probe was used to identify the midline by visualizing the dorsal median sulcal vein within the midline raphe. A myelotomy was made in that zone without deterioration of somatosensory evoked potentials (SEPs) and an extended biopsy was performed. Histological examination revealed a pilocytic astrocytoma. Modern intraoperative high-resolution color-coded ultrasound enables the identification of the midline in intramedullary spinal cord lesions even when the spinal cord anatomy is distorted.