Intramedullary Spinal Cord Lesions: A Single-Center Experience

The application value and improved warning criterion of D-wave monitoring in intramedullary spinal cord tumor surgery

BACKGROUND CONTEXT

The primary treatment method for intramedullary spinal cord tumor (IMSCT) is surgical resection, but this procedure carries a significant risk of neurological damage. Intraoperative neurophysiological monitoring (IONM) has become a necessary adjunctive tool for IMSCT resection.

PURPOSE

The current study aimed to explore the application value of D-wave monitoring in IMSCT surgery, and tried to investigate a tailored criterion for its early warning.

STUDY DESIGN

A retrospective clinical study.

PATIENT SAMPLE

A retrospective analysis was conducted based on the data of patients who underwent IMSCT surgeries performed by the same neurosurgical team at our hospital. IONM was applied in all surgeries. According to inclusion and exclusion criteria, ultimately 90 patients were enrolled in the study.

OUTCOME MEASURES

The McCormick Scale (MMS) was applied to assess the functional outcome through outpatient visits or telephone follow-up at one month and six months postoperatively. Patients with an MMS grade over II one month after surgery were considered to have newly developed postoperative motor dysfunction (PMD). If the MMS grade could be restored to I or II six months after surgery, it was defined as a short-term PMD. Otherwise, it was defined as a long-term PMD.

METHODS

The predictive value of different IONM modalities, including somatosensory evoked potential (SEP), muscle motor evoked potential (MEP), and D-wave for PMD, was assessed with sensitivity, specificity, positive predictive value, negative predictive value, and subsequent logistic regression analysis. At last, the cut-off value of the D-wave amplitude reduction ratio for predicting PMD was obtained through the receiver operating characteristic (ROC) curve analysis.

RESULTS

SEP showed the worst performance in predicting short-term and long-term PMD. Significant MEP changes were indicated as an independent predictive factor for short-term PMD (OR 5.062, 95% CI 1.947-13.166, p=.001), while D-wave changes were demonstrated as an independent predictor for long-term PMD (OR 339.433, 95% CI 11.337-10770.311, p=.001). The optimum cut-off value of the D-wave amplitude reduction ratio for predicting long-term PMD was 42.18%, with a sensitivity of 100% and a specificity of 93.8% (AUC=0.981, p<.001).

CONCLUSIONS

D-wave monitoring showed extremely high specificity in predicting PMD compared to SEP and MEP monitoring. Moreover, the authors suggested that a D-wave amplitude reduction of over 40% during IMSCT surgery generally indicates long-term PMD for patients.

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.

Predictors for spinal deformity following resection of intramedullary tumor via posterior approach: a systematic review and meta-analysis

PURPOSE

The present study aimed to identify the clinical predictive factors for worsened spinal deformity (SD) following surgical resection via posterior approach for primary intramedullary tumors.

METHODS

A systematic search was performed using PubMed, Web of Science, and Scopus databases to extract potential references. Observational studies reporting predictive factors for worsened SD following surgical resection via posterior approach for primary intramedullary tumors were included. The odds ratio (OR) was calculated for dichotomous parameters.

RESULTS

Four retrospective cohort studies were included in the meta-analysis. They were comprised of two groups of patients; those who developed SD (n = 87) and those who did not (n = 227). For patients with IMSCTs, age under 25 years as well as age under 13 years were the demographic variables associated with postoperative SD (odds ratio [OR] 3.92; p = 0.0002 and OR 4.22; p = 0.003). In both the fusion and the non-fusion subgroups, preoperative spinal deformity strongly predicted postoperative SD (OR 11.94; p < 0.001), with the risk highly elevated among the non-fusion patients (OR 24.64; p < 0.0002). Thoracolumbar junction involvement was also found to be a predictor of postoperative SD for patients with IMSCT (OR 2.89; p = 0.02).

CONCLUSION

This study highlights the importance of considering age, preoperative spinal deformity, and thoracolumbar junction involvement as predictors of postoperative spinal deformity following surgical resection for IMSCT. These findings may provide guidance for the management of these patients, including the development of preoperative planning strategies and the selection of the most appropriate surgical approach for high-risk patients.

Comparison of the Recurrence and Surgical Outcome of Spinal Hemangioblastoma in Sporadic and Von Hippel-Lindau Diseases: A Subanalysis of a Nationwide Study by the Neurospinal Society of Japan

OBJECTIVE

This study aimed to clarify the relationship between recurrence and the extent of resection in surgery for intramedullary spinal hemangioblastoma (sHB) and its impact on von Hippel-Lindau (vHL) disease.

METHODS

Data on sHB cases followed up for at least 6 months after surgery were extracted from a nationwide registry of 1,033 consecutive spinal intramedullary tumors surgically treated between 2009 and 2020, and were retrospectively categorized into a sporadic or vHL group. The diagnosis of vHL disease was made at each institution based on clinical findings.

RESULTS

A total of 168 patients (sporadic group, 101; vHL group, 67) were included in the study. Compared with the sporadic group, the vHL group had a younger onset (45.4 ± 16.8 years vs. 39.6 ± 14.1 years, p = 0.02), more preoperative motor (47.5% vs. 68.7%, p < 0.01) and gait (37.6% vs. 61.2%, p < 0.01) impairments, and more patients with worsening neurological symptoms at discharge (p = 0.02). The gross total resection (GTR) rates and the recurrence rates were not statistically different between the sporadic and the vHL groups. GTR significantly improved recurrence-free survival compared to non-GTR in all patient analysis (p < 0.01) but this trend was not observed in the sporadic group. Physical functional improvement from discharge to 6 months after surgery was observed in the sporadic group (p < 0.01) but not in the vHL group.

CONCLUSION

A high GTR rate may sufficiently decrease susceptibility to recurrence, especially in patients with sHB with vHL. In sporadic sHB, postoperative functional improvement can be expected, and the long-term functional prognosis is favorable.

Clinical Characteristics and Treatment Outcomes of Long-Level Intramedullary Spinal Cord Tumors: A Consecutive Series of 43 Cases

Objective: Long-level intramedullary spinal cord tumors (LIMSCTs) cause complex treatment issues. However, LIMSCTs have rarely been analyzed separately. The authors reported a large case series of LIMSCTs and analyzed the clinical characteristics and treatment outcomes.Methods: The medical data of patients with LIMSCTs at our institution between January 2015 and December 2019 were retrospectively reviewed. Demographics, tumor size and location, pathology, extent of resection, and neurological functional status were collected.Results: A total of 43 consecutive cases were included. Twenty-three cases (53.5%) of LIMSCTs were ependymal tumors. All patients with ependymal tumors achieved gross total resection (GTR). In ependymal tumor cases, 3 cases (13%) of ependymal tumors experienced postoperative neurological deterioration, and 66% of them showed an improvement at follow-up; 25.6% were low-grade astrocytic tumors. The rates of GTR, subtotal resection (STR) and partial resection (PR) were 63.6%, 27.3%, and 9.1%, respectively. Twenty-seven percent cases showed postoperative neurological worsening, and 33% of them had an improvement at follow-up; 20.9% were high-grade astrocytic tumors. The excision rates were 44.4% for GTR, 44.4% for STR, and 11% for PR, respectively. Fifty-five percent cases showed postoperative neurological worsening, and none of them had an improvement at follow-up.Conclusion: In this series, all LIMSCTs were gliomas. Aggressive tumor resection did not increase the risk of long-term functional deterioration in ependymal tumors and low-grade astrocytic tumors, but in high-grade astrocytic tumors, patients had a higher risk of neurological deterioration and difficulty in recovery. In ependymal tumors and low-grade astrocytic tumors, patients can achieve long-time survival after performing aggressive tumor resection.

First Clinical Report of the Intraoperative Macro- and Micro-Photodiagnosis and Photodynamic Therapy Using Talaporfin Sodium for a Patient with Disseminated Lumbar Medulloblastoma

Photodiagnosis (PD) and photodynamic therapy (PDT) using the second-generation photosensitizer talaporfin sodium together with an exciting laser for primary intracranial malignant tumors is well recognized in Japan, and many medical institutions are introducing this new therapeutic option. In particular, intraoperative PDT using talaporfin sodium for infiltrating tumor cells in the cavity walls after the resection of malignant glioma is now covered by health insurance after receiving governmental approvement, and this method has been recommended in therapeutic guidelines for primary malignant brain tumors in Japan. On the other hand, experimental and clinical studies on the development of novel therapeutic strategies for malignant spinal cord tumors have not been reported to date, although their histological features are almost identical to those of intracranial malignant tumors. Therefore, the clinical outcomes of malignant spinal cord tumors have been less favorable than those of malignant brain tumors. In this report, we performed the PD and PDT using talaporfin sodium on a patient with a metastatic lumbar lesion that was detected on magnetic resonance image (MRI) 50 months after the resection of cerebellar medulloblastoma who presented with lumbago and sciatica. We were able to detect the target lesion in the conus medullaris using a surgical microscope, and detected the disseminated medulloblastoma cells floating in the cerebrospinal fluid using a compact fluorescence microscope. Furthermore, we performed PDT to the resected lumbar lesion with the adjuvant platinum-based chemotherapy, and the patient survived a meaningful life for more than 2 years after the lumbar surgery. This report describes the first case of a human patient in whom the efficacy of PD and PDT was demonstrated for a malignant spinal cord tumor.