Spinal surgery is primarily performed to improve neurological function; compared with intracranial surgery, it is rarely conducted to address life-threatening conditions. As the goal of treatment is functional recovery, postoperative complications must be minimized. Appropriate perioperative management is therefore essential, and includes careful preoperative neurological evaluation; postoperative monitoring of neurological, respiratory, and circulatory status; and early detection and management of complications. Several complications of spinal surgery require attention. Firstly, airway obstruction caused by cervical swelling after anterior cervical surgery, postoperative epidural hematoma leading to neurological deterioration, and cerebrospinal fluid (CSF) leakage are the major complications requiring urgent intervention. Cervical spine surgery has several characteristic complications, depending on the surgical approach; for example, anterior procedures may cause airway compromise, esophageal injury, or recurrent laryngeal nerve palsy, whereas posterior procedures are more commonly associated with C5 palsy and surgical site infection. Thoracic spine surgery requires careful postoperative management as the spinal canal is relatively narrow, while the spinal cord is vulnerable to ischemia. In lumbar spine surgery, symptoms primarily involve the cauda equina, while major complications include epidural hematoma, CSF leakage, and surgical site infection. Appropriate perioperative evaluation and prompt management of complications at the spinal level are essential for achieving favorable surgical outcomes.

Chiari malformation type I is a structural anomaly of the posterior fossa characterized by cerebellar tonsillar herniation through the foramen magnum, often associated with disrupted cerebrospinal fluid dynamics and elevated intracranial pressure. Papilledema is a rare ophthalmic manifestation in Chiari malformation type I, typically linked to increased intracranial pressure. Isolated visual symptoms without signs of intracranial pressure in pediatric Chiari malformation type I are particularly rare and poorly understood. We report a rare pediatric case of Chiari malformation type I in a 9-year-old girl presenting solely with bilateral papilledema and visual impairment, without typical symptoms of raised intracranial pressure such as headache. Magnetic resonance imaging revealed cerebellar tonsillar descent and cervical syringomyelia. Due to progressive visual decline and the absence of alternative diagnoses, the patient underwent foramen magnum decompression with C1 laminectomy. Postoperatively, visual acuity significantly improved, although papilledema persisted at 9 months. This case challenges the conventional view that papilledema in Chiari malformation type I is solely caused by elevated intracranial pressure. Alternative mechanisms, such as localized venous congestion, mechanical stress on the optic nerve, or regional cerebrospinal fluid flow disturbances, may contribute to papilledema. Persistent papilledema despite clinical improvement supports the hypothesis of localized rather than global intracranial pressure elevation. Pediatric presentations may differ from adult cases in symptomatology and pathophysiology, requiring careful diagnostic and therapeutic considerations. Surgical decompression may lead to functional visual recovery even if anatomical signs such as papilledema persist. This case underscores the need for further research into atypical presentations and underlying mechanisms of Chiari malformation type I, especially in pediatric populations.

Abstract Spinal intramedullary tumors comprise a heterogeneous group of entities with diverse histopathological features, making their diagnosis particularly challenging. With the introduction of DNA methylation profiling, the underlying biological diversity of these tumors has been increasingly clarified and systematized; however, owing to the rarity of these tumors, case accumulation remains limited, and significant challenges persist. In this study, we identified two cases of spinal ependymal tumors exhibiting a methylation profile of spinal (SP-) subependymoma (SEPN). Both cases occurred in elderly patients and demonstrated circumscribed growth consistent with low-grade ependymal tumors; however, these tumors did not exhibit the typical histopathological features required for a diagnosis of SEPN in the 2021 WHO classification of central nervous system (CNS) tumors, showing indistinct cluster formation, an astrocytic immunohistochemical profile suggested by Olig2 expression, and relatively elevated Ki-67 labeling indices of 4.5% and 3.1%. At the molecular level, both cases harbored telomerase reverse transcriptase promoter mutations and whole chromosome 7 gain. On two-dimensional t-distributed stochastic neighbor embedding analysis, both clustered within the SP-SEPN methylation class at its periphery, with low classifier calibration scores (0.70 and 0.69). According to the current WHO classification, these cases are designated as low-grade ependymal tumors (CNS WHO grade 2) with methylation profile of SP-SEPN because they do not meet the essential WHO histopathological criteria. Ependymal tumors exhibiting a methylation profile consistent with SEPN, but discordant histopathological features have been increasingly recognized, and the appropriate classification of such tumors remains a subject of ongoing debate. These cases provide important insights into the histopathological diversity of ependymal tumors and contribute to establishing a more comprehensive and systematic classification of ependymal tumors.

Abstract This report describes a rare and challenging case of severe lumbar spinal canal stenosis resulting from extensive, concurrent lumbar ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF). A 44-year-old female patient who initially presented with numbness and gait instability due to thoracic spinal cord compression was successfully managed by thoracic decompression and fusion. However, she subsequently developed lower back pain, buttock pain, and numbness along both legs due to severe multilevel lumbar stenosis from L2 to L5. Surgical management involved multilevel posterior laminectomy with careful removal of extensive ossified ligaments. Postoperatively, the patient's symptoms improved, and lumbar alignment was maintained without the need for fusion. This case highlights the surgical complexity of extensive multilevel lumbar ossification and the necessity of comprehensive whole-spine evaluations in managing spinal ligament ossification. Timely surgical intervention is also crucial in preventing permanent neurological deficits.

Abstract Bilateral hemifacial spasm (BHFS) is rare and typically arises from neurovascular compression of the facial nerve. Optimal treatment strategies, including the timing and laterality of microvascular decompression (MVD), remain uncertain. We report a case of a 43-year-old man with a 10-year history of left hemifacial spasm, and right-sided symptoms beginning 1 year prior to initial evaluation. Magnetic resonance imaging demonstrated bilateral neurovascular compression at the root exit zone. The patient underwent staged bilateral MVD—left MVD first, followed by right MVD after 6 months—resulting in complete resolution of symptoms without surgical complications. We also reviewed 15 previously published reports encompassing 51 BHFS cases to investigate clinical characteristics, imaging findings, and treatment outcomes. Among 23 patients who underwent MVD in these reports, 15 had unilateral and 8 had bilateral procedures; however, systematic documentation of contralateral symptom outcomes following unilateral MVD was available in only a few reports, limiting evidence-based comparisons between unilateral and bilateral surgical strategies. The present case, combined with the literature review, suggests that a staged approach—initial MVD on the more severely affected side followed by an observation period, with contralateral MVD reserved for persistent symptoms—can be a safe and effective strategy for BHFS. Careful imaging assessment, prioritization of the predominant symptoms, and individualized management are crucial for patients with BHFS.

Objective Maintaining the occipito-axial (O–C2) angle following occipitocervical fusion is crucial to prevent postoperative complications. Although automated O–C2 measurement has been reported, practical methods that provide rapid results for routine practice remain limited. This study aimed to develop a deep learning model using the YOLO (You Only Look Once) object detection algorithm to automatically identify anatomical landmarks and rapidly calculate the O–C2 angle. Methods A retrospective analysis was conducted using cervical spine radiographs from 2 independent facilities. The internal dataset comprised 574 lateral cervical radiographs from 271 patients for model development, while the external validation dataset included 100 radiographs from 100 patients. Model performance was evaluated against manual measurements by 3 expert raters. Results The model demonstrated excellent detection performance, achieving perfect metrics for the hard palate (F1 score: 1.00) and high performance for the occipital bone (F1 score: 0.97), anteroinferior corner of C2 (F1 score: 0.99), and posteroinferior corner of C2 (F1 score: 0.99). For O–C2 angle estimation, the mean absolute error was 2.35° and root mean squared error was 2.98°, with an accuracy of 94.7% for determining the presence or absence of the O–C2 angle (i.e., whether all 4 anatomical landmarks were simultaneously detected). Bland-Altman analysis revealed minimal bias (0.57°; 95% confidence interval, -0.06° to 1.12°) with limits of agreement from -5.19° to 6.33°. Inference time was approximately 0.14 s per image. Conclusion Our deep learning model enables rapid and accurate O–C2 angle measurement on lateral cervical radiographs, demonstrating performance comparable to expert raters and potential clinical utility.

Objective: Parkinson disease (PD) is frequently characterized by a forward-bent posture that increases biomechanical stress on the lumbar spine, which increases the rate of subsequent lumbar surgeries after spinal fusions. This study aimed to evaluate the rates of additional lumbar surgeries following spinal fusion in patients with PD.Methods: Data from the Health Insurance Review and Assessment Service of the Republic of Korea were retrospectively analyzed. PD was identified using the International Classification of Diseases, 10th Revision code G20. Patients with PD were matched with those without PD in a 3:1 ratio based on sex, age, and Charlson Comorbidity Index using the greedy nearest neighbor matching method. The primary outcome was the rate of subsequent lumbar surgeries following spinal fusion within the 7-year follow-up period. The timing of these reoperations was also assessed.Results: A total of 2,287 patients with PD and 6,861 matched patients without PD were included in this study. The prevalence of PD among patients undergoing lumbar fusion surgery remained stable throughout the study period. Patients with PD had 1.6-fold higher odds to undergo reoperation compared with the non-PD cohort. No significant difference was observed in the timing of additional surgeries between the groups.Conclusion: Patients with PD faced 1.6-fold higher odds of subsequent lumbar surgeries following spinal fusion compared to those without the disease. This finding suggests the need for a cautious treatment approach and thorough preoperative optimization when considering lumbar fusion in this population.

Intraoperative transcranial motor-evoked potential recordings commonly utilize the belly tendon montage method; however, its reliability in large lower limb muscles such as the quadriceps femoris and hamstring muscles can be limited. We hypothesized that placing the reference electrode on the fibular head (fibular head reference electrode method) would improve waveform clarity and stability compared to belly tendon montage. This retrospective study analyzed 101 patients who underwent transcranial motor-evoked potential monitoring during spinal surgery at Nagoya University Hospital from October 2021 to August 2023. We compared compound muscle action potential amplitude, baseline waveform derivation success rate, noise amplitude, signal-to-noise ratio, and mean consecutive ratio between belly tendon montage and fibular head reference electrode method. Fibular head reference electrode method showed significantly higher median compound muscle action potential amplitudes in quadricep femoris (202.5 μV vs. 52.5 μV) and hamstring muscles (131.0 μV vs. 33.3 μV) with p < 0.001. Baseline waveform derivation success rates also improved with fibular head reference electrode method (quadricep femoris: 76.5% vs. 50.5%; hamstring muscles: 73.5% vs. 39.8%; p < 0.001). When noise amplitude increased, the signal-to-noise ratio improved significantly (p < 0.001), and mean consecutive ratio indicated better waveform stability in hamstring muscles. For predicting postoperative paralysis, fibular head reference electrode method yielded a sensitivity of 100% and a negative predictive value of 100% in both quadricep femoris and hamstring muscles, with specificities of 93.5% and 95.6%, respectively. These findings suggest that fibular head reference electrode method improves the reliability, clarity, and predictive value of transcranial motor-evoked potential monitoring in spinal surgery and may represent a superior alternative to conventional belly tendon montage.

OBJECTIVE:This study aimed to evaluate the radiological outcomes of occipitocervical fusion (OCF) for traumatic craniocervical junction (CCJ) instability by analyzing changes in preoperative and postoperative computed tomography (CT)-measured radiological parameters. METHODS:We retrospectively analyzed 20 consecutive adult trauma patients who underwent OCF for CCJ instability at a single center from January 2015 to May 2023. Clinical features, surgical outcomes, and preoperative and postoperative CT-measured parameters (basion-dens interval [BDI], basion-axial interval [BAI], atlanto-dental interval [ADI], space available for the cord, clivus-canal angle) were evaluated. Patients were grouped according to whether their preoperative parameter values were within or outside the normal range, and changes were compared between the groups. RESULTS:All patients underwent OCF without neurological deterioration, except for 1 death from polytrauma. Significant postoperative improvements were observed in BDI for patients with abnormal preoperative BDI >8.5 mm (-4.27 ± 3.67 mm) compared to those with normal BDI <8.5 mm (0.11 ± 1.84 mm, P = 0.0194), and in ADI for those with abnormal preoperative ADI >2 mm (-1.88 ± 0.61 mm vs. 0.02 ± 0.16 mm, P = 0.0011). BAI improved significantly in patients with abnormal preoperative BAI < -4 mm (9.07 ± 5.74 mm, P = 0.0154) and >12 mm (-8.45 ± 4.65 mm, P = 0.0078) compared to those within normal limits. Space available for the cord (<14 mm) and clivus-canal angle (>160° or <145°) showed trends toward improvement but without statistical significance. Postoperative complications included dysphagia (10%), hardware failure (10%), and surgical site infection (5%). CONCLUSIONS:OCF effectively stabilizes traumatic CCJ instability, improves key CT-measured radiological parameters, and supports favorable neurological outcomes.

OBJECTIVE:Paravertebral foramen screws (PVFSs) have been developed for better pullout strength than lateral mass screws do and lower the risk of vertebral artery and nerve injury than do pedicle screws. While the original method involves insertion using lateral fluoroscopy, its reliability may be limited. This report is the first to assess the accuracy of PVFS insertion under navigation. Given the inherent inaccuracies associated with navigation systems, the authors propose and evaluate a novel stepwise method of inserting PVFSs, called stepwise PVFS with a focus on achieving the correct screw tip location for good cortical bone purchase. METHODS:The authors conducted a retrospective analysis of 12 patients (78 screws) who underwent cervical spine fixation with stepwise PVFS under O-arm navigation between October 2022 and February 2024. The accuracy of screw placement was evaluated using postoperative computed tomography (CT) scans. RESULTS:A total of 78 PVFSs were inserted in 5 men and 7 women, with an average age of 75 years (range, 52-85 years). The mean follow-up period was 471 days (range, 47-834 days). There were no adverse events related to screw insertion. Postoperative CT scans revealed that 70 screws (90%) were placed in the ideal position. Among the 8 screws that did not achieve the ideal position, 4 had lateral deviation (located in a lateral mass), whereas the other 4 were too short. There were no cases of screw loosening at the final follow-up. CONCLUSION:The present study demonstrates that the stepwise PVFS method under navigation guidance achieves higher accuracy in PVFS placement compared with conventional fluoroscopy-guided PVFS, as reported in previous studies.

Spinal ependymomas are common intramedullary tumors that can show dynamic changes in magnetic resonance imaging findings over time. This study aimed to analyze these imaging changes and their implications for perioperative management. The retrospective study included patients diagnosed with World Health Organization grade 2 spinal ependymoma who underwent surgical resection and had at least 2 preoperative magnetic resonance imaging scans. Patients were divided into 2 groups based on the presence or absence of radiographic changes on magnetic resonance imaging. Magnetic resonance imaging analyses included non-contrast T1- and T2-weighted images, as well as gadolinium-enhanced T1-weighted images when available. Key features evaluated included intraparenchymal edema, hemosiderin deposition, syringomyelia, and cyst components. Changes in tumor size and contrast enhancement patterns were documented. Radiographic changes were identified in 4 out of 15 cases (26.7%). All cases with imaging changes exhibited hemosiderin deposition or hemorrhage, significantly higher than in cases without changes (100% vs. 18.2%, p < 0.05). No significant differences were observed in the presence of cystic components, syringomyelia, or edema between the groups. In the group with radiographic changes, the timeframe for these changes in the images ranged from 3 days to several years. Spinal ependymomas can demonstrate dynamic magnetic resonance imaging changes during the preoperative period, including both growth and reduction in tumor size. The presence of hemosiderin deposition or hemorrhage might be associated with these imaging changes. Proper timing of magnetic resonance imaging is crucial for informing surgical planning and optimizing treatment strategies for patients with spinal ependymomas.

Sacroiliac joint dysfunction is one of the causes of lower back pain, and although it has characteristic pain locations and aggravating factors, it is difficult to diagnose and is often overlooked. A case of relief of typical pain symptoms due to sacroiliac joint dysfunction by spinal cord stimulation is presented. A 60-year-old woman presented with severe chronic pain in the left lumbar, lower buttock, iliac, and groin areas that worsened even when sitting for short periods, as well as numbness in the right lower extremity. The patient had chronic lower back pain since experiencing acute lumbosacral sprains in her 20s and 40s, and her symptoms worsened without any trigger in her 60s. Standard imaging examinations showed no lesions that could be causing the pain, and blood tests showed no inflammation or other abnormalities. Although pharmacological treatment did not provide sufficient analgesia, sacroiliac joint block provided a significant analgesic effect, leading to a definitive diagnosis of sacroiliac joint dysfunction. A spinal cord stimulation trial was performed using percutaneous 8-contact leads placed at the thoracic vertebra 8-11 level, and pain relief was confirmed. One month later, 2 new percutaneous 16-contact leads and an implantable pulse generator were implanted simultaneously. One month after implantation, the visual analog scale and the quick inventory of depression symptomatology scores decreased dramatically from 83 to 8 and from 16 to 4, respectively. In addition, the numbness of the right lower extremity disappeared. These analgesic effects were sustained for 12 months.

Stem cell therapy employing stem cells from human exfoliated deciduous teeth (SHED) has demonstrated efficacy in treating peripheral nerve injury; however, the precise underlying mechanisms remain largely undefined. In this study, we investigated the effects of SHED on signal transducer and activator of transcription 3 (STAT3), a key mediator of inflammation following sciatic nerve injury (SNI). The left sciatic nerve was transected (cut group), sutured and wrapped with cellulose (suture group), or sutured and enveloped with SHED-soaked cellulose (SHED group). The L4-5 segments of the spinal cord were harvested up to 7 days post-SNI, and tissues were separated into ipsilateral and contralateral regions for molecular and immunohistochemical analyses. In the SHED group, the sciatic functional index showed significant improvement compared with the suture group beginning at 4 weeks postinjury, and tibialis anterior muscle mass was markedly restored at 12 weeks. STAT3 phosphorylation at Tyr705 (p-STAT3) was prominently elevated between 12 and 48 h post-SNI on the ipsilateral side, but not contralaterally. This phosphorylation was localized to motor neurons in the anterior horn and was substantially attenuated by SHED administration between 24 and 48 h postinjury. Moreover, interleukin (IL)-6 expression was significantly reduced at 12 h, while p-STAT3 and importin β1 levels were notably decreased between 12 and 24 h. Erk signaling was significantly activated in S100β-positive Schwann cells (SCs) on day 4 at the site of SNI in the SHED group. These results suggest that SHED mitigate neuroinflammation by suppressing IL-6 expression and modulating STAT3 activation, while concurrently enhancing remyelination through Erk signaling activation in SCs at the injury site. Collectively, these findings underscore the therapeutic promise of SHED as a potent and innovative intervention for peripheral nerve avulsion injuries.

Background/Objectives: Lasmiditan is a newly developed drug for the acute treatment of migraine attacks, but factors associated with its efficacy remain unclear. This study aimed to confirm the efficacy of lasmiditan started at 50 mg under various dosing conditions and identify factors associated with its efficacy. Methods: There are four reasons for prescribing lasmiditan: as an add-on to triptan, if triptan is ineffective, if triptan produces side effects, and when triptan is contraindicated. Lasmiditan was administered at a dose of 50 mg. The efficacy of lasmiditan was defined as the disappearance of headache or a 50% or greater reduction in headache intensity within two hours after dosing. This study included 108 patients with migraines who took lasmiditan. Results: The results for efficacy and the side effects of lasmiditan were as follows: effective without side effects (22), effective with mild side effects (32), ineffective (14), and severe side effects (40). The efficacy rate of lasmiditan 50 mg was 50.0% (54/108). The following factors were found to be associated with lasmiditan’s efficacy: sex, migraine classification, calcium channel blockers, and anti-calcitonin gene-related peptide monoclonal antibody (CGRP-mAb) treatment. The overall incidence of side effects was 66.7%, and the dropout rate was 37.0%. Somnolence was more prevalent in the effective group, and other side effects were more prevalent in patients who dropped out due to the side effects of lasmiditan. Conclusions: Lasmiditan is likely to be effective in males with severe migraine classification and receiving CGRP-mAb treatment. If mild somnolence is a side effect, the drug can be continued and may be effective.