Shorter survival time of adolescents and young adult patients than older adults with spinal cord glioblastoma: a multicenter study

OBJECTIVE

Cancers in adolescents and young adults (AYAs) (age 15-39 years) often present with unique characteristics and poor outcomes. To date, spinal cord glioblastoma, a rare tumor, remains poorly understood across all age groups, including AYAs. This comparative study aimed to investigate the clinical characteristics and outcomes of spinal cord glioblastoma in AYAs and older adults (age 40-74 years), given the limited availability of studies focusing on AYAs.

METHODS

Data from the Neurospinal Society of Japan's retrospective intramedullary tumor registry (2009-2020) were analyzed. Patients were dichotomized on the basis of age into AYAs and older adults. Univariate and multivariate Cox proportional hazards regression models were utilized to explore risk factors for overall survival (OS).

RESULTS

A total of 32 patients were included in the study, with a median (range) age of 43 (15-74) years. Of these, 14 (43.8%) were AYAs and 18 (56.2%) were older adults. The median OS was 11.0 months in AYAs and 32.0 months in older adults, and the 1-year OS rates were 42.9% and 66.7%, respectively, with AYAs having a significantly worse prognosis (p = 0.017). AYAs had worse preoperative Karnofsky Performance Status (KPS) than older patients (p = 0.037). Furthermore, AYAs had larger intramedullary tumors on admission (p = 0.027) and a significantly higher frequency of intracranial dissemination during the clinical course (p = 0.048). However, there were no significant differences in the degrees of surgical removal or postoperative radiochemotherapy between groups. The Cox proportional hazards regression model showed that AYAs (HR 3.53, 95% CI 1.17-10.64), intracranial dissemination (HR 4.30, 95% CI 1.29-14.36), and no radiation therapy (HR 57.34, 95% CI 6.73-488.39) were risk factors for mortality for patients of all ages. Worse preoperative KPS did not predict mortality in AYAs but did in older adults. The high incidence of intracranial dissemination may play an important role in the poor prognosis of AYAs, but further studies are needed.

CONCLUSIONS

The clinical characteristics of AYAs with spinal cord glioblastoma differ from those of older adults. The prognosis of AYAs was clearly worse than that of older adults. The devastating clinical course of spinal glioblastoma in AYAs was in line with those of other cancers in this age group.

Two Cases of Atypical Teratoid/Rhabdoid Tumor in the Spinal Cord: Loss of SMARCB1 in a Child and Loss of SMARCA4 in an Adult

We compare two cases of primary spinal atypical teratoid/rhabdoid tumor (AT/RT), which rarely occurs in adults marked by SMARCA4 inactivation, and SMARCB1 inactivation for pediatric cases. AT/RT represents a highly malignant neoplasm comprising poorly differentiated constituents and rhabdoid cells, with SMARCB1(INI1) or infrequently SMARCA4 (BRG1) inactivation. These tumors are predominantly found in children but are rare in adults. While AT/RT can arise anywhere in the central nervous system, spinal cord localization is comparatively scarce. Despite mutation or loss of SMARCB1 at the 22q11.2 locus serving as the genetic hallmark of AT/RTs, infrequent cases of SMARCA4 inactivation with intact SMARCB1 protein expression are significant. We present each case of primary spinal tumors in a child and an adult, showing loss of the SMARCB1 and SMARCA4 proteins, respectively. Both tumors met the AT/RT diagnostic criteria. The histopathology demonstrated the presence of rhabdoid cells in both cases. Diagnosing primary spinal AT/RT with SMARCB1 protein loss remains a challenge. Nevertheless, the presence of SMARCB1 positivity alone must be noted to be insufficient to exclude the possibility of AT/RT diagnosis. In cases in which the diagnosis of AT/RT is highly suspected clinically, additional testing is warranted, including SMARCA4 analysis.

Epidemiology and Comparative Analysis of Outcomes of Intramedullary Spinal Cord Tumor Between Pediatric and Adult Patients

STUDY DESIGN

This was as clinical retrospective study.

OBJECTIVES

We sought to evaluate the characteristics of Pediatric intramedullary spinal cord tumors (PISCTs) and to identify differences between pediatric and adult intramedullary spinal cord tumors.

SUMMARY OF BACKGROUND DATA

PISCTs represent a rare clinical entity with limited evidence-base in the literature.

METHODS

This study is a subanalysis of the retrospective multicenter observational study authorized by the Neurospinal Society of Japan, including consecutive patients with spinal intramedullary tumors treated surgically at 58 institutions between 2009 and 2020. Data on 1080 intramedullary spinal cord tumors were obtained, consisting of 91 pediatric and 939 adult patients. Survival was compared using Cox hazard regression while clinical differences were evaluated using multivariable logistic regression that controlled for confounders.

RESULTS

Pediatric patients had a shorter overall, and progression-free, survival than adults. Pediatric patients with ISCTs were likely to have scoliosis [odds ratio (OR) = 6.49, 95% CI: 2.26-18.7], short preoperative symptom duration (OR = 0.99, 95% CI: 0.98-0.99), lower incidence of paresthesia (OR = 0.41, 95% CI: 0.22-0.77), higher incidence of paresis (OR = 2.10, 95% CI: 1.01-4.35), histopathology of astrocytoma (OR = 2.97, 95% CI: 1.19-7.43), and postoperative functional deterioration upon discharge (OR = 2.83, 95% CI: 1.43-5.58). Age was not a statistically significant prognostic factor of overall survival among the pediatric cohort.

CONCLUSION

We found that the clinical characteristics of ISCTs differed between pediatric and adult patients. In terms of histopathological types, astrocytoma was most common in pediatric patients. ISCT occurring at an early age may not be an indicator for poor prognosis.

Predictors of Progression-Free Survival in Patients With Spinal Intramedullary Ependymoma: A Multicenter Retrospective Study by the Neurospinal Society of Japan

BACKGROUND AND OBJECTIVES

Ependymoma is the most common spinal intramedullary tumor. Although clinical outcomes have been described in the literature, most of the reports were based on limited numbers of cases or been confined to institutional experience. The objective of this study was to analyze more detailed characteristics of spinal intramedullary ependymoma (SIE) and provide clinical factors associated with progression-free survival (PFS).

METHODS

This retrospective observational multicenter study included consecutive patients with SIE in the cervical or thoracic spine treated surgically at a total of 58 institutions between 2009 and 2020. The results of pathological diagnosis at each institute were confirmed, and patients with myxopapillary ependymoma, subependymoma, or unverified histopathology were strictly excluded from this study. Outcome measures included surgical data, surgery-related complications, postoperative systemic adverse events, postoperative adjuvant treatment, postoperative functional condition, and presence of recurrence.

RESULTS

This study included 324 cases of World Health Organization grade II (96.4%) and 12 cases of World Health Organization grade III (3.6%). Gross total resection (GTR) was achieved in 76.5% of cases. Radiation therapy (RT) was applied after surgery in 16 cases (4.8%), all of which received local RT and 5 of which underwent chemotherapy in combination. Functional outcomes were significantly affected by preoperative neurological symptoms, tumor location, extent of tumor resection, and recurrence. Multivariate regression analysis suggested that limited extent of tumor resection or recurrence resulted in poor functional outcomes. Multiple comparisons among the groups undergoing GTR, subtotal resection and biopsy, or partial resection of the tumor showed that the probability of PFS differed significantly between GTR and other extents of resection.

CONCLUSION

When GTR can be safely obtained in the surgery for SIE, functional maintenance and longer PFS can be expected.

The Impact of Adjuvant Radiotherapy on Clinical Performance Status in Patients With Grade II Spinal Cord Astrocytoma - A Nationwide Analysis by the Neurospinal Society of Japan

OBJECTIVE

The impact of adjuvant radiotherapy on overall survival (OS) and progression-free survival (PFS) of patients with grade II spinal cord astrocytomas remains controversial. Additionally, the relationship between progression and clinical deterioration after radiotherapy has not been well investigated.

METHODS

This study included 53 patients with grade II intramedullary spinal cord astrocytomas treated by either subtotal, partial resection or open biopsy. Their clinical performance status was assessed immediately before operation and 1, 6, 12, 24, and 60 months after surgery by Karnofsky Performance Scale (KPS). Patients with and without adjuvant radiotherapy were compared.

RESULTS

The groups with and without radiation comprised 23 and 30 patients with a mean age of 50.3 ± 22.6 years (range, 2-88 years). The mean overall disease progression rate was 47.1% during a mean follow-up period of 48.4 ± 39.8 months (range, 2.5-144.5 months). In the radiation group, 11 patients (47.8%) presented with progressive disease, whereas 14 patients (46.7%) presented with progressive disease in the group without radiation. There were no significant differences in OS or PFS among patients with or without adjuvant radiotherapy. KPS in both groups, especially radiation group, gradually decreased after operation and deteriorated before the confirmation of disease progression.

CONCLUSION

Adjuvant radiotherapy did not show effectiveness regarding PFS or OS in patients with grade II spinal cord astrocytoma according to classical classification based on pathohistological findings.

Clinical Characteristics and Long-term Outcomes of Spinal Pilocytic Astrocytomas: A Multicenter Retrospective Study by the Neurospinal Society of Japan

OBJECTIVE

The characteristics, imaging features, long-term surgical outcomes, and recurrence rates of primary spinal pilocytic astrocytomas (PAs) have not been clarified owing to their rarity and limited reports. Thus, this study aimed to analyze the clinical presentation, radiological features, pathological findings, and long-term outcomes of spinal PAs.

METHODS

Eighteen patients with spinal PAs who were surgically treated between 2009 and 2020 at 58 institutions were included in this retrospective multicenter study. Patient data, including demographics, radiographic features, treatment modalities, and long-term outcomes, were evaluated.

RESULTS

Among the 18 consecutive patients identified, 11 were women and 7 were men; the mean age at presentation was 31 years (3-73 years). Most PAs were located eccentrically, were solid or heterogeneous in appearance (cystic and solid), and had unclear margins. Gross total resection (GTR), subtotal resection (STR), partial resection (PR), and biopsy were performed in 28%, 33%, 33%, and 5% of cases, respectively. During a follow-up period of 65 ± 49 months, 4 patients developed a recurrence; however, the recurrence-free survival did not differ significantly between the GTR and non-GTR (STR, PR, and biopsy) groups.

CONCLUSION

Primary spinal PAs are rare and present as eccentric and intermixed cystic and solid intramedullary cervical tumors. The imaging features of spinal PAs are nonspecific, and a definitive diagnosis requires pathological support. Surgical resection with prevention of neurological deterioration can serve as the first-line treatment; however, the resection rate does not affect recurrence-free survival. Investigation of relevant molecular biomarkers is required to elucidate the regrowth risk and prognostic factors.

Description of the Diversity in Surgical Indication and Surgical Strategies for Primary Spinal Cord Tumors: A Nationwide Survey by the Neurospinal Society of Japan

OBJECTIVE

To assess the current management of primary spinal cord tumors (PSCTs) and determine whether and to what extent there are differences in surgical strategies for PSCTs.

METHODS

The Neurospinal Society of Japan conducted a survey between April 1 and 30, 2021. Certified spine surgeons were requested for information on the frequency of surgeries in 2020 and the surgical strategies adopted for each PSCTs. The following tumor histologies were focused: schwannoma, meningioma, and cauda equina tumor as extramedullary tumors; and ependymoma, hemangioblastoma, astrocytoma, and cavernoma as intramedullary tumors. The participants were divided according to their response as follows: experts, who had experienced ≥ 100 surgeries for PSCTs, and nonexperts.

RESULTS

Among 308 participants (63%), 35 (11%) were experts. The total number of PSCTs in 2020 was 802 of which 564 tumors were extramedullary and 223 were intramedullary. Schwannoma accounted for 53% of the extramedullary tumors, and ependymoma accounted for 39% of the intramedullary tumors. Surgical strategies significantly differed among both the experts and nonexperts groups. Some discrepancies in the adopted surgical strategies were observed between groups. Some of the nonexperts, and none of the experts, ruled out surgery for schwannomas (Eden type 4), astrocytomas, or cavernomas. Five nonexperts (2.2%), and none of the experts, resected the entire dura for meningiomas.

CONCLUSION

A nationwide survey revealed that a sufficient consensus did not exist regarding surgical strategies for PSCTs. A disease-specific registry for PSCTs is necessary in academic societies.

[Posterior Surgical Techniques for Cervical Spine]

Currently, various posterior surgical techniques are available for cervical spondylotic myelopathy. These techniques include laminoplasty and laminectomy with or without fusion, and are often used in patients with multilevel cervical stenosis. They were developed with the intent to reduce the risk of complications such as injury to the spinal cord and nerve roots, C5 palsy, postlaminectomy membrane, and postoperative kyphosis. Posterior decompression for cervical spondylotic myelopathy is effective in improving neurological function in patients with appropriate surgical indications.

Symptomatic Chiari type 1 malformation associated with acromegaly: A case report

Background

Here, we report a patient who presented with both symptomatic acromegaly and symptomatic Chiari I malformation (CM1) with a C2-T5 syrinx.

Case Description

A 63-year-old female presented with bilateral arm dysesthesias and back pain. For approximately the past 30 years, she had chronic signs of acromegaly (i.e. an enlarged forehead, jaw, and nose, and enlarged hands and feet). When the cervical magnetic resonance showed a CM1 (tonsillar herniation) with C2-T5 syringomyelia, she underwent foramen magnum decompression and C1 posterior arch resection. Postoperatively, she was asymptomatic. The added finding of a growth hormone (GH)-producing pituitary lesion was treated medically with endocrine therapy, as she had incidentally required surgery/chemotherapy for a newly diagnosed colon cancer.

Conclusion

Symptomatic CM1, syrinx, and acromegaly may occur together. Appropriately treatment may include a suboccipital decompression, and C1 arch resection surgery, followed by either surgical or medical treatment for the GH-producing pituitary adenoma.

Risk assessment of vertebral compressive fracture using bone mass index and strength predicted by computed tomography image based finite element analysis

BACKGROUND

A main purpose of osteoporosis diagnosis is to evaluate the bone fracture risk. Some bone mass indices evaluated using bone mineral density has been utilized clinically to assess the degree of osteoporosis. On the other hand, Computed tomography image based finite element analysis has been developed to evaluate bone strength of vertebral bodies. The strength of a vertebra is defined as the load at the onset of compressive fracture. The objective of this study was therefore to propose a new feasible method to combine the advantages of the two osteoporotic indices such as the bone mass index and the bone strength.

METHODS

Three-dimensional finite element models of 246 vertebral bodies from 88 patients were constructed using the computed tomography images. Finite element analysis was then conducted to evaluate their strength values. The Pearson's correlation analysis was also conducted between the vertebral strength and bone mass indices.

FINDINGS

It was found that relatively weak positive correlations existed between the strength and the bone mass indices. A new assessment method was then proposed by combining the strength and the bone mass index. "high risk zone" corresponding to low strength with normal bone mass was found from the assessment method.

INTERPRETATION

Singe bone mass index cannot predict the fracture risk with high standard. The results of fracture risk assessment conducted by the new method clearly indicated the necessity and effectiveness to take both the strength and the bone mass index into account.

HGG-12. A CASE OF PEDIATRIC SPINAL HIGH-GRADE GLIOMA WITH NTRK1 GENE FUSION

INTRODUCTION

Tumors arising from the spinal cord are uncommon, especially high-grade tumors in pediatric patients. We report a case of high-grade glioma in the spinal cord harboring NTRK1 gene fusion, who received effective entrectinib therapy. CASE REPORT: A 5-year-old boy presented right hemiparesis and MR imaging revealed an intramedullary enhancing mass at the vertebral body level between C3 and Th1. He underwent microsurgical partial resection and the histological diagnosis was low-grade astrocytoma. After the first-line chemotherapy with vincristine and carboplatin, his right hemiparesis deteriorated and recurrent MR imaging showed growth of the tumor. He underwent microsurgical partial resection again and the histological examination was high-grade glioma with endothelial proliferation and necrosis. The chemoradiotherapy with temozolomide and focal irradiation of 50.4 Gy were given, and his neurological symptom slightly improved. One month later, he presented respiratory disturbance and required assisted ventilation with tracheostomy. MR imaging showed tumor progression invading upward to medulla oblongata. NTRK1 gene fusion was detected in the previous surgical specimen by a gene panel testing, and he received entrectinib, a potent inhibitor of tropomyosin receptor kinase (TRK). Since then, no tumor progression has been demonstrated for several months by MRI and he has been stable neurologically.

CONCLUSION

High-grade spinal cord tumors are rare and effective treatment strategies have not been addressed. Although the frequency of the gene fusion is very low in pediatric gliomas, identification of the driver gene aberration like in this case by a gene panel can provide potential targeted therapies for selected patients.

DIPG-04. THERAPEUTIC STRATEGY FOR DIFFUSE MIDLINE GLIOMAS. A SINGLE CENTER EXPERIENCE

INTRODUCTION

Diffuse midline gliomas have unfavorable prognoses due to the difficulty of surgery and chemo-radiation resistances. The purpose of this study is to overview our surgical experiences and prognoses of this challenging neoplasm.

MATERIALS AND METHODS

Five patients of diffuse midline gliomas who were treated between 2016 and 2019 were enrolled. Tumor locations, surgical procedures, molecular diagnoses, and prognoses were retrospectively reviewed.

RESULTS

There were 3 male and 2 female patients, and the median age was 15 years ranged from 7 to 21 years. Tumors were located at the basal ganglia in 1 patient, thalamus in 1, brain stem in 2, and cervical spine in 1. Mutations of H3 K27M genes were detected in 4 surgically treated patients, except for 1 patient, who were radiologically diagnosed as diffuse intrinsic pontine glioma (DIPG). Focal irradiation of ranged 35 to 54Gy were administered in all cases along with temozolomide in 2 cases and bevacizumab in 2 cases. The median survival time was 13 months ranged from 4 to 18 months.

DISCUSSION

Supratentorial tumors were maximumly resected, whereas just biopsies were performed in cases of exophytic brain stem and spinal tumors. Diagnosis of DIPG was made without using surgical specimens. Therapeutic strategies should be discussed with a concern to the patients’ qualities of life for this tumor entity with dismal prognosis.

Constraint-induced movement therapy promotes motor recovery after neonatal stroke in the absence of neural precursor activation

Neonatal stroke is a leading cause of long-term disability and currently available rehabilitation treatments are insufficient to promote recovery. Activating neural precursor cells (NPCs) in adult rodents, in combination with rehabilitation, can accelerate functional recovery following stroke. Here, we describe a novel method of constraint-induced movement therapy (CIMT) in a rodent model of neonatal stroke that leads to improved functional outcomes, and we asked whether the recovery was correlated with expansion of NPCs. A hypoxia/ischemia (H/I) injury was induced on postnatal day 8 (PND8) via unilateral carotid artery ligation followed by systemic hypoxia. One week and two weeks post-H/I, CIMT was administered in the form of 3 botulinum toxin (Botox) injections, which induced temporary paralysis in the unaffected limb. Functional recovery was assessed using the foot fault task. NPC proliferation was assessed using the neurosphere assay and EdU immunohistochemistry. We found that neonatal H/I injury alone expands the NPC pool by >2.5-fold relative to controls. We determined that using Botox injections as a method to provide CIMT results in significant functional motor recovery after H/I. However, CIMT does not lead to enhanced NPC activation or migration into the injured parenchyma in vivo. At the time of functional recovery, increased numbers of proliferating inflammatory cells were found within the injured motor cortex. Together, these findings suggest that NPC activation following CIMT does not account for the observed functional improvement and suggests that CIMT-mediated modification of the CNS inflammatory response may play a role in the motor recovery.

Balloon Kyphoplasty under Three-dimensional Radiography Guidance

Percutaneous balloon kyphoplasty (PBKP) is generally performed under two-dimensional (2D) radiography guidance (lateral- and anteroposterior (A-P) views) using C-arm fluoroscopy. However, 2D images taken by single-plane or bi-plane fluoroscopy cannot provide information regarding axial views, particularly the Z axis. Lack of information regarding the Z axis prevents the creation of three-dimensional (3D) images. Currently, there has been a progress in interventional X-ray systems, and they are capable of providing 3D radiographic images using a rotational angiography mode which is used to create 3D angiographies. In this report, we described the usefulness of 3D radiography guidance. Patients treated by PBKP was designed to evaluate the efficacy of 3D radiography guidance. These patients experienced osteoporotic vertebral fractures with severe pain. We retrospectively analyzed patients who underwent PBKP from February to December 2016. All patients had a single-level vertebral fracture and underwent surgery by 2D or 3D radiography guidance. We performed 16 patients in 3D radiography guidance, and 10 patients in traditional 2D radiography guidance. This 3D radiography guided PBKP increase the amount of the polymethyl methacrylate (PMMA) injection compared with ordinary 2D method. As a result, postoperative vertebral height and alignment were significantly improved. Both groups have no complication. To confirm the final results and make PBKP more effective, 3D radiography guidance is feasible and safe for balloon kyphoplasty.

Transforaminal Lumbar Interbody Fusion for Lumbar Degenerative Disorders: Mini-open TLIF and Corrective TLIF

Minimally invasive transforaminal lumbar interbody fusion (TLIF) as a short fusion is widely accepted among the spine surgeons. However in the long fusion for degenerative kyphoscoliosis, corrective spinal fixation by an open method is thought to be frequently selected. Our objective is to study whether the mini-open TLIF and corrective TLIF contribute to the improvement of the spinal segmental and global alignment. We divided the patients who performed lumbar fixation surgery into three groups. Group 1 (G1) consisted of mini-open TLIF procedures without complication. Group 2 (G2) consisted of corrective TLIF without complication. Group 3 (G3) consisted of corrective TLIF with instrumentation-related complication postoperatively. In all groups, the lumbar lordosis (LL) highly correlated with developing surgical complications. LL significantly changed postoperatively in all groups, but was not corrected in the normal range in G3. There were statistically significant differences in preoperative and postoperative LL and mean difference between the pelvic incidence (PI) and LL between G3 and other groups. The most important thing not to cause the instrumentation-related failure is proper correction of the sagittal balance. In the cases with minimal sagittal imbalance with or without coronal imbalance, short fusion by mini-open TLIF or long fusion by corrective TLIF contributes to good clinical results if the lesion is short or easily correctable. However, if the patients have apparent sagittal imbalance with or without coronal imbalance, we should perform proper correction of the sagittal spinal alignment introducing various technologies.

Blockade of gap junction hemichannel protects secondary spinal cord injury from activated microglia-mediated glutamate exitoneurotoxicity

We previously demonstrated that activated microglia release excessive glutamate through gap junction hemichannels and identified a novel gap junction hemichannel blocker, INI-0602, that was proven to penetrate the blood-brain barrier and be an effective treatment in mouse models of amyotrophic lateral sclerosis and Alzheimer disease. Spinal cord injury causes tissue damage in two successive waves. The initial injury is mechanical and directly causes primary tissue damage, which induces subsequent ischemia, inflammation, and neurotoxic factor release resulting in the secondary tissue damage. These lead to activation of glial cells. Activated glial cells such as microglia and astrocytes are common pathological observations in the damaged lesion. Activated microglia release glutamate, the major neurotoxic factor released into the extracellular space after neural injury, which causes neuronal death at high concentration. In the present study, we demonstrate that reduction of glutamate-mediated exitotoxicity via intraperitoneal administration of INI-0602 in the microenvironment of the injured spinal cord elicited neurobehavioral recovery and extensive suppression of glial scar formation by reducing secondary tissue damage. Further, this intervention stimulated anti-inflammatory cytokines, and subsequently elevated brain-derived neurotrophic factor. Thus, preventing microglial activation by a gap junction hemichannel blocker, INI-0602, may be a promising therapeutic strategy in spinal cord injury.

A morphologically atypical case of atlantoaxial rotatory subluxation

A rare case of atlantoaxial rotatory subluxation occurred after pediatric cervical spine surgery performed to remove a dumbbell-shaped meningioma at the level of the C1/C2 vertebrae. This case is classified as a post-surgical atlantoaxial rotatory subluxation, but has a very rare morphology that has not previously been reported. Although there are several reports about post-surgical atlantoaxial rotatory subluxation, an important point of this case is that it might be directly related to the spinal cord surgery in C1/C2 level. On day 6 after surgery, the patient presented with the Cock Robin position, and a computed tomography scan revealed a normal type of atlantoaxial rotatory subluxation. Manual reduction was performed followed by external fixation with a neck collar. About 7 months after the first surgery, the subluxation became severe, irreducible, and assumed an atypical form where the anterior tubercle of C1 migrated to a cranial position, and the posterior tubercle of C1 and the occipital bone leaned in a caudal direction. The pathogenic process suggested deformity of the occipital condyle and bilateral C2 superior facets with atlantooccipital subluxation. A second operation for reduction and fixation was performed, and the subluxation was stabilized by posterior fixation. We encountered an unusual case of a refractory subluxation that was associated with an atypical deformity of the upper spine. The case was successfully managed by posterior fixation.

Posterior fixation for atlantoaxial subluxation in a case with complex anomaly of persistent first intersegmental artery and assimilation in the C1 vertebra

We report a very rare case of atlantoaxial subluxation (AAS) with persistent first intersegmental artery (PFIA) and assimilation in the atlas (C1) vertebra. This case demonstrates the difficulty of deciding on a surgical strategy for complex anomalies. A 63-year-old man presented with gait disturbance, neck pain, and severe dysesthesia in his left arm. Past history included a whiplash injury. Dynamic X-ray studies demonstrated an irreducible AAS and assimilation of C1. This subluxation was slightly deteriorated in an extended position. A three-dimensional computed tomography angiography (3DCTA) indicated that the PFIA was located on the left side. We performed a C1 posterior arch resection and C1 lateral mass–axis pedicle screw (C1LM–C2PS) fixation using the modified technique of skewering the occipital condyle and C1 lateral mass. The patient had no postoperative morbidity and his symptoms disappeared immediately after operation. Complex anomalies cause difficulty in determining surgical strategy although several surgical methods for simple craniovertebral junction anomaly have been reported. To avoid significant morbidities associated with vertebral artery injury, surgical strategies for these complex conditions are discussed. The modified technique of a C1 lateral mass screw penetrating the occipital condyle is a viable treatment option.

Transvertebral anterior cervical foraminotomy: midterm outcomes of clinical and radiological assessments including the finite element method

PURPOSE

The aim of this study was to compare the clinical features, radiological changes, biomechanical effects, and efficacy in patients treated by transvertebral anterior foraminotomy. Preservation of segmental motion and avoidance of adjacent segment degeneration are theoretical advantages of transvertebral anterior foraminotomy. In practice, this procedure is minimally invasive and has shown good clinical results, especially in patients with unilateral cervical radiculopathy.

METHOD

We conducted a retrospective minimum 2-year follow-up study of the cervical spine of patients treated by transvertebral anterior foraminotomy at our institution. Radiological outcomes, which were estimated by measuring disc and functional spinal unit heights, and the angle and range of motion (ROM) from C2 to C7 of the functional spinal unit and adjacent segments were evaluated. Furthermore, a three-dimensional finite element method was used to biomechanically analyze the strength of the postoperative vertebral body.

RESULTS

Between 2004 and 2009, 34 patients underwent surgery. The improvement rate was 94.2 %. The average flexion-extension ROM from C2 to C7 was 36.6 ± 16.6°. On plain radiographs, the disc height and ROM and height of the functional spinal unit in the operated segment were not significantly decreased relative to the preoperative levels. The finite element method also revealed that there was no difference in strength between the pre- and postvertebral bodies.

CONCLUSIONS

These results demonstrate that biomechanical stability was achieved. Transvertebral anterior cervical foraminotomy did not limit motion in the operated and adjacent segments and did not cause a significant decrease in disc and vertebral heights after surgery.

[Two cases of spontaneous intracranial hypotension with bilateral chronic subdural hematomas]

Spontaneous intracranial hypotension (SIH) is characterized by postural headaches without obvious cause and is occasionally related to chronic subdural hematomas (CSHs). Brain sag due to decrease in cerebrospinal fluid, and growing CSHs may occur secondary to a decrease in intracranial pressure. Therapy for this condition differs from that for mere traumatic CSHs and is controversial. We report 2 cases of CSH related to SIH. One patient required drainage of the CSHs and an epidural self-blood patch. Furthermore, this patient had to undergo reoperation for drainage of the CSHs. The other patient was cured after the first time the CSHs were drained.

Effects and complications of stereotactic aspiration for spontaneous intracerebral hemorrhage

Stereotactic aspiration of intracerebral hemorrhage (ICH) improves the general condition of patients, promotes improvement of consciousness, and decreases the incidence of pneumonia, but may induce rebleeding. The present study investigated the effects of stereotactic aspiration and factors that inhibit rebleeding in 70 consecutive patients who underwent stereotactic aspiration for ICH. Consciousness was significantly improved after surgery. Of patients who underwent surgery on day 0 or 1, 5 patients developed pneumonia and 29 patients did not. Of patients who underwent surgery on day 2 or later, 14 patients developed pneumonia and 22 patients did not. Early surgery within 2 days significantly reduced the rate of aspiration pneumonia. Patients with rebleeding tended to have liver dysfunction and hemorrhagic tendency. Early stereotactic aspiration of ICH facilitates better patient management than conservative treatment in patients with moderate consciousness disturbance. Patients with liver dysfunction and hemorrhagic tendency should be identified.