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.

Evaluating the diagnostic accuracy of 3D contrast-enhanced magnetic resonance angiography versus digital subtraction angiography in spinal dural arteriovenous fistulas.

OBJECTIVE: Spinal dural arteriovenous fistulas (SDAVFs) often go undiagnosed, leading to irreversible spinal cord dysfunction. Although digital subtraction angiography (DSA) is the gold standard for diagnosing SDAVF, DSA is invasive and operator dependent, with associated risks. MR angiography (MRA) is a promising alternative. This study aimed to evaluate the performance of MRA as an equal alternative to DSA in investigating, diagnosing, and localizing SDAVF. METHODS: Prospectively collected data from a single neurosurgeon at a large tertiary academic center were searched for SDAVFs. Eligibility criteria included any patient with a surgically proven SDAVF in whom preoperative DSA, MRA, or both had been obtained. The eligible patients formed a consecutive series, in which they were divided into DSA and MRA groups. DSA and MRA were the index tests that were compared to the surgical SDAVF outcome, which was the reference standard. Accurate diagnosis was considered to have occurred when the imaging report matched the operative diagnosis to the correct spinal level. Comparisons used a two-sample t-test for continuous variables and Fisher-Freeman-Halton's exact test for categorical variables, with p < 0.05 specifying significance. Univariate, bivariate, and multivariate analyses were conducted to investigate group associations with DSA and MRA accuracy. Positive predictive value, sensitivity, and accuracy were calculated. RESULTS: A total of 27 patients with a mean age of 63 years underwent surgery for SDAVF. There were 19 male (70.4%) and 8 female (29.6%) patients, and the mean duration of symptoms at the time of surgery was 14 months (range 2-48 months). Seventeen patients (63%) presented with bowel or bladder incontinence. Bivariate analysis of the DSA and MRA groups further revealed no significant relationships between the characteristics and accuracy of SDAVF diagnosis. MRA was found to be more sensitive and accurate (100% and 73.3%) than DSA (85.7% and 69.2%), with a subanalysis of the patients with both preoperative MRA and DSA showing that MRA had a greater positive predictive value (78.6 vs 72.7), sensitivity (100 vs 72.7), and accuracy (78.6 vs 57.1) than DSA. CONCLUSIONS: In surgically proven cases of SDAVFs, the authors determined that MRA was more accurate than DSA for SDAVF diagnosis and localization to the corresponding vertebral level. Incomplete catheterization at each vertebral level may result in the failure of DSA to detect SDAVF.

Spinal Cord Injury: Emerging Technologies.

The mainstay of treatment for spinal cord injury includes decompressive laminectomy and elevation of mean arterial pressure. However, outcomes often remain poor. Extensive research and ongoing clinical trials seek to design new treatment options for spinal cord injury, including stem cell therapy, scaffolds, brain-spine interfaces, exoskeletons, epidural electrical stimulation, ultrasound, and cerebrospinal fluid drainage. Some of these treatments are targeted at the initial acute window of injury, during which secondary damage occurs; others are designed to help patients living with chronic injuries.

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.

Intraoperative Neurophysiologic Monitoring and Mapping During Surgery on Intramedullary Spinal Cord Tumors in Children and Adolescents.

SUMMARY: Surgical resection of intramedullary spinal cord tumors carries significant risks of neurologic deficits, especially in cases of infiltrative tumors. In pediatric patients, this type of surgery may be associated with a high risk of poor neurologic outcome. Intraoperative neurophysiologic monitoring has been adopted as part of the clinical routine by many centers as a useful adjunct for intraoperative assessment of neurologic integrity. To what extent intraoperative neurophysiologic mapping strategies may further support intraoperative decision-making is still a matter of debate. Here, we report on a small cohort of five pediatric patients in whom mapping with the double-train paradigm was used to identify the dorsal column and corticospinal tract and to guide the surgical resection. We also discuss the possible benefits and challenges regarding the available literature.

Intramedullary spinal capillary hemangioma with secondary neurulation defect in children.

Intramedullary spinal capillary hemangioma is a rare occurrence in pediatric patients, and only limited cases have been reported. This study presents the first two cases of spinal capillary hemangioma co-present with retained medullary cord and one case of spinal capillary hemangioma with lumbosacral lipomatous malformation. Previous literature on ten patients with this pathology was reviewed. We speculated pathogenesis, imaging features, and histopathologic findings of the disease.

Full Endoscopic Transforaminal Thoracic Discectomy Operative Technique.

Thoracic disc herniations are a degenerative pathology of the thoracic spine wherein a portion of nucleus pulposis herniates into the epidural space, potentially causing spinal cord or nerve root compression. Traditional surgical treatment for patients with thoracic disc herniations requires relatively invasive anterior or posterolateral approaches that involve extensive muscular dissection and removal of bone in order to access and remove the disc herniation without causing undue compression of the spinal cord. Full endoscopic thoracic discectomy is a minimally invasive technique which allows for the resection of thoracic disc herniations through a small (1 cm) incision, minimizing collateral tissue trauma and obviating the need for the extensive muscle dissection and bony removal required for traditional surgical approaches. In this article, we describe in detail the operative technique for full endoscopic thoracic discectomy and discuss the pearls and pitfalls of the technique. We also provide a review of the outcomes and complications as seen in the literature.

Spinal cord schistosomiasis in a 6-year-old child with complete recovery after spine surgery and medical treatment: case report and discussion.

Spinal cord schistosomiasis is a rare and severe form of schistosomiasis. The prognosis is largely conditioned by early diagnosis and treatment. The authors present a case of spinal cord schistosomiasis complicated by spinal cord compression syndrome. This is the case of a 6-year-old patient who presented with febrile gastroenteritis followed by complete paralysis of both lower limbs of sudden onset following a brief stay in a village setting with notion of multiple baths at a stream. Spinal cord MRI revealed an enlarged spinal cord spanning D10 to D12 with heterogeneous contrast enhancement and a syrinx cavity above the lesion. Biological workup revealed an inflammatory syndrome. Treatment consisted of decompressive laminectomy with biopsy of the lesion and a syringo-subarachnoid shunt. Pathological analysis revealed fragments of central nervous system tissues with an infiltrate composed of lymphocytes, plasmocytes, and macrophages producing granulomatous foci lined with areas of necrosis in addition to a large contingent of polynuclear eosinophils, agglutinating around or covering in some places elongated ovoid structures, with relatively thick eosinophilic shells and presenting a terminal spur. Adjuvant treatment consisted of praziquantel and corticotherapy for 1 month. The evolution showed marked improvement in the neurological deficits. She now walks unassisted and has good sphincter control. Spinal cord schistosomiasis is rare in our context; its diagnosis is difficult. The treatment is both medical and surgical.

Concomitant Thoracic Spinal Dural Arteriovenous Fistula and Spinal Cavernous Malformation.

Both spinal dural arteriovenous fistula (SDAVF) and spinal cavernous malformation (SCM) are uncommon vascular malformations. To our knowledge, such a case of SDAVF concomitant with SCM has not been reported. We encountered a case of a 55-year-old man who had weakness and numbness in both lower extremities. Magnetic resonance imaging showed a round-shape lesion identified as a cavernous malformation in the middle segment of the thoracic spine, with spinal edema and obvious flow voids. Diagnostic angiography revealed an SDAVF fed by the right T7 radicular artery with venous drainage. The intramedullary venous hypertension due to fistula was suspected of inducing the formation of SCM. This case may provide new insight into the pathogenesis of SCM.

Risk factors for C5 palsy: a systematic review and multivariate analysis.

OBJECTIVE: Postoperative C5 palsy (C5P) is a known complication in cervical spine surgery. However, its exact pathophysiology is unclear. The authors aimed to provide a review of the current understanding of C5P by performing a comprehensive, systematic review of the existing literature and conducting a critical appraisal of existing evidence to determine the risk factors of C5P. METHODS: A systematic search of PubMed/MEDLINE (January 1, 2019, to July 2, 2021), EMBASE (inception to July 2, 2021), and Cochrane (inception to July 2, 2021) databases was conducted. Preestablished criteria were used to evaluate studies for inclusion. Studies that adjusted for one or more of the following factors were considered: preoperative foraminal diameter (FD) at C4/5, posterior spinal cord shift at C4/5, preoperative anterior-posterior diameter (APD) at C4/5, preoperative spinal cord rotation, and change in C2-7 Cobb angle. Studies were rated as good, fair, or poor based on the Quality in Prognosis Studies (QUIPS) tool. Random effects meta-analyses were done using methods outlined by Cochrane methodologists for pooling of prognostic studies. Overall quality (strength) of evidence was based on Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methods for prognostic studies. The protocol for this review was published on the PROSPERO (CRD264358) website. RESULTS: Of 303 potentially relevant citations of studies, 12 met the inclusion criteria set a priori. These works provide moderate-quality evidence that preoperative FD substantially increases the odds of C5P in patients undergoing posterior cervical surgery. Pooled estimates across 7 studies in which various surgical approaches were used indicate that the odds of C5P approximately triple for each millimeter decrease in preoperative FD (OR 3.05, 95% CI 2.07-4.49). Preoperative APD increases the odds of C5P, but the confidence is low. Across 3 studies, each using different surgical approaches, each millimeter decrease in preoperative APD was associated with a more than 2-fold increased odds of C5P (pooled OR 2.51, 95% CI 1.69-3.73). Confidence that there is an association with postoperative C5P and posterior spinal cord shift, change in sagittal Cobb angle, and preoperative spinal cord rotation is very low. CONCLUSIONS: The exact pathophysiological process resulting in postoperative C5P remains an enigma but there is a clear association with foraminal stenosis, especially when performing posterior procedures. C5P is also related to decreased APD but the association is less clear. The overall quality (strength) of evidence provided by the current literature is low to very low for most factors. Systematic review registration no.: CRD264358 (https://www.crd.york.ac.uk/prospero/).

In-vivo testing of a novel wireless intraspinal microstimulation interface for restoration of motor function following spinal cord injury.

BACKGROUND: Spinal cord injury causes a drastic loss in motor and sensory function. Intraspinal microstimulation (ISMS) is an electrical stimulation method developed for restoring motor function by activating the spinal networks below the level of injury. Current ISMS technology uses fine penetrating microwires to stimulate the ventral horn of the lumbar enlargement. The penetrating wires traverse the dura mater through a transdural conduit that connects to an implantable pulse generator. OBJECTIVE: A wireless, fully intradural ISMS implant was developed to mitigate the potential complications associated with the transdural conduit, including tethering and leakage of cerebrospinal fluid. METHODS: Two wireless floating microelectrode array (WFMA) devices were implanted in the lumbar enlargement of an adult domestic pig. Voltage transients were used to assess the electrochemical stability of the interface. Manual flexion and extension movements of the spine were performed to evaluate the mechanical stability of the interface. Post-mortem 9T MRI imaging was used to confirm the location of the electrodes. RESULTS: The WFMA-based ISMS interface successfully evoked extension and flexion movements of the hip joint. Stimulation thresholds remained stable following manual extension and flexion of the spine. CONCLUSION: The preliminary results demonstrate the surgical feasibility as well as the functionality of the proposed wireless ISMS system.

Predictors of Skip Laminotomy for Placement of Paddle Leads for Spinal Cord Stimulation.

OBJECTIVES: Placement of a standard paddle lead for spinal cord stimulation (SCS) requires a laminotomy for positioning of the lead within the epidural space. During initial placement, an additional laminotomy or laminectomy, termed a "skip" laminotomy, may be necessary at a higher level to pass the lead to the appropriate midline position. Patient and radiographic factors that predict the need for a skip laminotomy have yet to be identified. MATERIALS AND METHODS: Participants who underwent SCS paddle placement at Albany Medical Center between 2016 and 2017 were identified. Operative reports were reviewed to identify the paddle type, level of initial laminotomy, target level, and skip laminotomy level. Preoperative thoracic magnetic resonance images (MRIs) were reviewed, and spinal canal diameter, interpedicular distance, and dorsal cerebral spinal fluid thickness were measured for each participant when available. RESULTS: A total of 106 participants underwent thoracic SCS placement. Of these, 97 had thoracic MRIs available for review. Thirty-eight participants required a skip laminotomy for placement of the paddle compared with 68 participants who did not. There was no significant difference in demographic features including age, sex, body mass index, and surgical history. Univariate analyses that suggested trends were selected for further analysis using binary logistic regression. Level of initial laminotomy (odds ratio [OR] = 1.51, p = 0.028), spinal canal diameter (OR = 0.71, p = 0.015), and dorsal cerebrospinal fluid thickness (OR = 0.61, p = 0.011) were correlated with skip laminotomy. Target level (OR = 1.27, p = 0.138) and time from trial (1.01, p = 0.117) suggested potential association. The multivariate regression was statistically significant, X2(10) = 28.02, p = 0.002. The model explained 38.3% of the variance (Nagelkerke R2) and predicted skip laminectomy correctly in 73.3% of cases. However, for the multivariate regression, only a decrease in spinal canal diameter (OR = 0.59, p = 0.041) was associated with a greater odds of skip laminotomy. CONCLUSIONS: This study aims to characterize the patient and radiographic factors that may predict the need to perform a skip laminotomy during the initial placement of SCS paddles. Here, we show that radiographic and anatomic variables, primarily spinal canal diameter, play an important role in predicting the need for a skip laminotomy. Furthermore, we suggest that target level for placement and level of initial laminotomy also may contribute. Further investigation of the predictive factors for performing a skip laminotomy would help optimize surgical planning and preoperative patient selection and counseling.

Limited exposure to preserve stability and achieve complete excision of limited dorsal myeloschisis - the "Skip-Hop Laminectomy" technique: a technical note.

OBJECTIVE: The fibroneural stalk of an LDM has variable thickness, complexity, and length, which can span 5 to 6 vertebral segments from its skin attachment to its "merge point" with the dorsal spinal cord. Therefore, complete resection may require extensive multi-level laminotomies. In this technical note, a modification of the procedure is presented that avoids long segment laminectomies while ensuring complete excision of long LDM stalks. RESULTS: An illustrative case of resection of LDM is presented using skip laminectomies. The technique ensures complete removal of the stalk, thus reducing the risk of future intradural dermoid development, while at the same time minimizes the risk for delayed kyphotic deformity. CONCLUSIONS: A technique of "skip-hop" proximal and distal short segment laminectomies in cases of LDM optimizes the objectives of complete stalk resection with preservation of spinal integrity.

Exoscope Efficacy and Feasibility in Pediatric Spinal Neurosurgery: A Single-Institution Cohort Case Series.

BACKGROUND: The exoscope has emerged as an efficacious microscope in adult spinal neurosurgery providing improved operative field visibility and surgeon ergonomics. However, outcome data and feasibility are underrepresented in the pediatric literature. We present the largest case series aimed at assessing operative and clinical outcomes in pediatric patients undergoing various exoscope-assisted spinal surgeries. METHODS: A retrospective review was conducted on all consecutive pediatric (age <18 years) spinal surgeries performed with the use of an exoscope by 3 senior surgeons at a single institution from 2020-2023. Demographics and clinical and operative outcomes were reviewed and analyzed. RESULTS: Ninety-six exoscope-assisted pediatric spine surgeries were performed on 89 unique patients, 41 (42.7%) of which were male. The mean age at surgery was 12 (±5.3) years. Spinal cord detethering (55.8%) was the most common procedure performed. The overall mean operative time for all procedures was 155 (±86) minutes, and the mean estimated blood loss was 18 (±41) mL. The mean length of stay was 5.4 (±6.5) days. There were 14 (14.6%) patients with complications in this cohort. At final follow-up, 64 (83.1%) of symptomatic patients reported neurologic symptom improvement. CONCLUSIONS: Using the exoscope in a variety of pediatric spinal surgeries resulted in an acceptable average operative time, estimated blood loss, length of stay, and rate of neurologic symptom improvement. The exoscope appears to be an efficacious option for pediatric neurosurgical spinal procedures.

Spinal Cord Stimulation Paddle-to-Percutaneous Revision: Case Series and Technical Description.

OBJECTIVE: Spinal cord stimulators (SCSs) can be implanted via a percutaneous or paddle approach, the latter technique requiring a laminotomy or laminectomy. Revision surgery may be necessary in instances of migrated, misplaced, or failed stimulators. When revision of a percutaneous system is necessary, it is common to replace the electrodes with a paddle SCS. This study aims to describe a case series of patients with failed paddle SCS electrodes who underwent revision with percutaneous SCS hardware. METHODS: A series of 5 patients were retrospectively analyzed. Medical records were reviewed for demographic data, operative technique, postoperative follow-up, and complications. RESULTS: Five patients were included in this series. The median age was 63 (range 51-84), and the median duration from initial implantation to revision surgery was 19 months (range 5-60). The median operative duration was 92 minutes (mean 99 ± 19.6 minutes). The median length of follow-up after surgery was 24 months (mean 21.8 ± 6.0 months). All patients had improved pain relief and therapeutic coverage with no complications. CONCLUSIONS: Paddle-to-percutaneous SCS surgery is a feasible and durable revision option in appropriately selected patients.

[Prevention and Treatment of Ischemic Spinal Cord Injury].

In recent years, the widespread use of thoracic/thoracoabdominal stent grafting and a better understanding of spinal cord blood supply have led to quite a few change in measures to prevent spinal cord injury. It is essential to understand the characteristics of spinal cord blood flow, which is complicated by collateral pathways, and to strive to maintain spinal cord blood flow during surgery. It is also important to plan staged repair as much as possible in any treatment modality. Particular attention must be paid to the prevention of second attacks, especially after thoracic/thoracoabdominal endovascular aortic repair without segmental artery reconstruction. Systemic circulatory and respiratory management, improvement of anemia, and cerebrospinal fluid drainage with attention to drainage rates, may be effective as preventive and therapeutic measures for spinal cord injury.

Comparison study of anterior cervical zero-profile fusion cage (ROI-C) and traditional titanium plate plus fusion technique for the treatment of spinal cord type cervical spondylosis.

A retrospective comparative study. To compare and analyze the differences in the efficiency and safety of ROI-C and traditional titanium plate with fusion cage for the treatment of CSM patients. Clinical data of 105 patients with CSM who underwent surgical treatment at our hospital from January 2019 to December 2020 were retrospectively reviewed. Patients were divided into ROI-C and traditional groups according to the different fusion methods. The operation time, intraoperative blood loss, preoperative and postoperative JOA score, NDI score, cervical Cobb angle, intervertebral space height, and postoperative complications were recorded and compared between the 2 groups. A total of 105 patients were included in this study, with 57 patients in the ROI-C group and 48 patients in the traditional group. The baseline data were similar between the 2 groups (P > .05). The operative time, intraoperative blood loss, and the incidence of postoperative dysphagia were significantly lower in the ROI-C group than in the traditional group (P < .05). There were no significant differences in the JOA score, NDI score, cervical Cobb angle, intervertebral space height, the incidence of postoperative axial symptoms, and adjacent segment degeneration between the 2 groups (P > .05). However, both groups showed significant improvement in the JOA score, NDI score, cervical Cobb angle, and intervertebral space height compared with before surgery (P < .05). The ROI-C zero-profile internal fixation system and traditional titanium plates with fusion cages can achieve satisfactory clinical treatment results for CSM patients. However, ROI-C has advantages of a shorter operative time, less blood loss, and less postoperative dysphagia. Therefore, the ROI-C zero-profile internal fixation system can be safely and effectively used to treat patients with CSM.

Implantation of Surgical Paddle Electrodes Using Percutaneous Biportal-Endoscopic Technique for Spinal Cord Stimulation: An Anatomical Feasibility Study in Human Cadavers.

BACKGROUND: Spinal cord stimulation is a technique in which different types of electrodes are placed in the spinal epidural space for neuromodulation. Surgical paddle electrodes (SEs) are usually implanted by a surgeon by performing open surgery with laminectomy. Recent advances in endoscopic spine surgery provide another option for minimally invasive SE implantation. OBJECTIVES: This anatomical study aims to examine the feasibility of implanting SEs in thoracic and cervical spine segments, discussing the specific advantages and disadvantages compared with previously reported methods. STUDY DESIGN: Laboratory study with Institutional Review Board No B2023-056. METHODS: Four fresh adult cadavers (2 women, 2 men) were operated on in this study. The posterior unilateral biportal endoscopic surgical approach, the accessibility to the intraspinal epidural space, and the technical possibilities and limitations of implantation of SEs were evaluated, as well as the surgical duration and complications. RESULTS: All the planned steps of the operation were successfully accomplished in all 4 cadavers. A total of 8 electrodes were successfully implanted through the working portal. Among them, 4 were located in the cervical segment and 4 in the thoracic segment. The proper position of the electrodes was also verified by fluoroscopy. No rupture of dura occurred during the operation. Except for the first cadaver, the duration of surgery did not exceed 1 hour. LIMITATIONS: Anatomical study on human cadavers, the quantity of cadavers, and the steep learning curve. CONCLUSIONS: The results of this anatomical study show that the SEs can be satisfactorily implanted in cervical and thoracic segments using the unilateral biportal endoscopic technique.