A New Classification for Cervical Ossification of the Posterior Longitudinal Ligament Based on the Coexistence of Segmental Disc Degeneration

Objective@#: Classification systems for cervical ossification of the posterior longitudinal ligament (OPLL) have traditionally focused on the morphological characteristics of ossification. Although the classification describes many clinical features associated with the shape of the ossification, including the concept of spondylosis seems necessary because of the similarity in age distribution. @*Methods@#: Patients diagnosed with OPLL who presented with increase signal intensity (ISI) on magnetic resonance imaging were surgically treated in our department. The patients were divided into two groups (pure versus degenerative) according to the presence of disc degeneration. @*Results@#: Of 141 patients enrolled in this study, more than half (61%) were classified into the degenerative group. The pure group showed a profound male predominance, early presentation of myelopathy, and a different predilection for ISI compared to the degenerative group. The mean canal compromise ratio (CC) of the ISI was 47% in the degenerative group versus 61% in the pure group (p<0.0000). On the contrary, the global and segment motions were significantly larger in the degenerative group (p<0.0000 and p=0.003, respectively). The canal diameters and global angles did not differ between groups. @*Conclusion@#: Classifying cervical OPLL based on the presence of combined disc degeneration is beneficial for understanding the disorder’s behavior. CC appears to be the main factor in the development of myelopathy in the pure group, whereas additional dynamic factors appear to affect its development in the degenerative group.

Coronavirus Disease (COVID-19) Outbreak and Its Impact on Spinal Daily Practice : Preliminary Report from a Single (Regional) University Hospital in Republic of Korea

Objective@#: Since the first discovery of the 2019 novel coronavirus (COVID-19), rapid and wide spread of the disease has been reported and the World Health Organization announced that a ‘pandemic’ has started. Up to date there is little known regarding the impact of this outbreak on spinal specialists’ daily clinical practice. We intended to evaluate how COVID-19 has affected the number of spinal disease patients we meet and operate in daily practice. @*Methods@#: The de-identified data regarding number of patients visiting the spine clinic at a tertiary referral hospital and a secondary level hospital from January, February and March of 2017 to 2020 were retrospectively reviewed. The number of out-patient department (OPD) visits, number of emergency room (ER) visits as well as number of surgeries performed during the reviewed period were collected and analyzed, comparing 2020 to the previous 3 years. @*Results@#: The number of daily OPD visits showed a steady decrease starting from January, and presented a statistically significant decrease by early March 2020, compared to the previous 3 years. During the same period, decrease in number of daily ER visits was statistically significant as well. The number of elective surgeries or number of surgeries for patients admitted via ER during COVID-19 outbreak remained similar to that of 2017–2019 suggesting, despite the decrease of patients visiting the hospital for spinal diseases, those whom required surgery still visited the hospital. The results were consistant among other hospital level. @*Conclusion@#: The outbreak of COVID-19 affected our daily practice as OPD and ER visits reduced but did not affect the number of surgeries. We believe that this report will be informative to spinal specialists worldwide fighting the COVID-19 pandemic.

Non-Operatively Treated Thoracolumbar Burst Fracture with Posterior Ligamentous Complex Injury: Case Report and Consideration on the Limitation of Thoracolumbar Injury Classification and Severity (TLICS) Score

Fractures at the thoracolumbar region are commonly followed after major traumatic injuries, and up to 20% of these fractures are known to be burst fractures. Making surgical decisions for these patients are of great interest however there is no golden standard so far. Since the introduction of Thoracolumbar Injury Classification and Severity (TLICS) score in 2007, it has been widely used as a referential guideline for making surgical decisions in thoracolumbar fractures. However, there is still limitations in this system. In this clinical case report, we introduce a L1 burst fracture after motor vehicle injury, who was successfully treated conservatively even while she was graded as a TLICS 5 injury. A case report is presented as well as discussion on the limitations of this grading system.

A Rare Case of Lumbar Traumatic Intradiscal Hematoma Followed by Repeatative Occupation Related Minor Trauma

A case of surgically treated intervertebral disc extrusion with intraoperatively confirmed intradiscal hematoma in a 30-year-old physical trainer is presented. Preoperative magnetic resonance imaging revealed downward migrating disc herniation, without definite suggestive findings of intradiscal hematoma. Intervertebral disc herniation with concomitant intradiscal hematoma is extremely rare, but could occur in patients who have excessive axial stress to the spine occupationally. In our case, the patient was an occupational physical trainer who had repetitive minor trauma to the lumbar spine. Although the patient did not have any clear history of major trauma to the spine, the intraoperative findings revealed intradiscal hematoma, which is very rare. The presence of intradiscal hematoma is to be suspected even when preoperative imaging studies shows indefinite findings of hematoma, considering the change in signal intensity of hematoma by time.

The Korean Spinal Neurosurgery Society ; Are We Reimbursed Properly for Spinal Neurosurgical Practices under the Korean Resource Based Relative Value Scale Service?

OBJECTIVES: The Korean Resource Based Relative Value Scale (K-RBRVS) was introduced in 2001 as an alternative of the previous medical fee schedule. Unfortunately, most neurosurgeons are unfamiliar with the details of the K-RBRVS and how it affects the reimbursement rates for the surgical procedures we perform. We summarize the K-RBRVS in brief, and discuss on how the relative value (RV) of the spinal neurosurgical procedures have changed since the introduction in 2001. METHODS: We analyzed the change of spinal procedure RVs since 2001, and compared it with the change of values in the brain neurosurgical procedures. RVs of 88 neurospinal procedures on the list of K-RBRVS were analyzed, while 24 procedures added during annual revisions were excluded. RESULTS: During the past 15 years, RVs for spinal procedures have increased 62.8%, which is not so different with the cumulative increase of consumer prices during this time period or the increase rate of 92.3% for brain surgeries. When comparing the change of RVs in more complex procedures between spinal and brain neurosurgery, the increase rate was 125.3% and 133%, respectively. CONCLUSION: More effort of the society of spinal surgeons seems to be needed to get adequate reimbursement, as there have been some discrimination compared to brain surgeons in the increase of RVs. And considering the relative underestimation of spinal neurosurgeons’ labor, more objective measures of neurospinal surgeons’ work and productivity should be developed for impartial reimbursement.

Risk Factors for Delayed Hinge Fracture after Plate-Augmented Cervical Open-Door Laminoplasty

OBJECTIVE: Delayed hinge fracture (HF) that develops after cervical open door laminoplasty can be a source of postoperative complications such as axial pain. However, risk factors related to this complication remain unclear. We performed a retrospective clinical series to determine risk factors for delayed HF following plate-only open-door cervical laminoplasty. METHODS: Patients who underwent plate-only open-door laminoplasty and had available postoperative computed tomography (CT) scans (80 patients with 270 laminae) were enrolled. Hinge status, hinge gutter location, open location, hinge width, number of screws used, operation level, and open angle were observed in the CT to determine radiographic outcome. Demographic data were collected as well. Radiographic and clinical parameters were analyzed using univariate and multivariate logistic regression analysis to determine the risk factors for HF. RESULTS: Univariate logistic regression analysis results indicated poor initial hinge status, medially placed hinge gutter, double screw fixation on the elevated lamina, upper surgical level, and wide open angle as predictors for HF (p<0.05). Initial hinge status seemed to be the most powerful risk factor for HF (p=0.000) and thus was collinear with other variables. Therefore, multivariate logistic regression analysis was performed excluding initial hinge status, and the results indicated that medially placed hinge gutter, double screw fixation on the elevated lamina, and upper surgical level were risk factors for HF after adjustment for other confounding factors. CONCLUSION: To prevent HF and to draw a successful postoperative outcome after cervical laminoplasty, surgical and clinical precautions should be considered.

Matrix Degradative Enzymes and Their Inhibitors during Annular Inflammation: Initial Step of Symptomatic Intervertebral Disc Degeneration

OBJECTIVE: Symptomatic disc degeneration develops from inflammatory reactions in the annulus fibrosus (AF). Although inflammatory mediators during annular inflammation have been studied, the roles of matrix metalloproteinases (MMPs) and their inhibitors have not been fully elucidated. In this study, we evaluated the production of MMPs and tissue inhibitors of metalloproteinase (TIMPs) during annular inflammation using an in vitro co-culture system. We also examined the effect of notochordal cells on annular inflammation. METHODS: Human AF (hAF) pellet was co-cultured for 48 hours with phorbol myristate acetate-stimulated macrophage-like THP-1 cells. hAF pellet and conditioned media (CM) from co-cultured cells were assayed for MMPs, TIMPs, and insulin-like growth factor (IGF)-1 levels using real-time reverse-transcriptase polymerase chain reaction and enzyem-linked immunosorbent assay. To evaluate whether notochordal cells affected MMPs or TIMPs production on annular inflammation, hAF co-cultured with notochordal cells from adult New Zealand White rabbits, were assayed. RESULTS: MMP-1, -3, -9; and TIMP-1 levels were significantly increased in CM of hAF co-cultured with macrophage-like cells compared with hAF alone, whereas TIMP-2 and IGF-1 levels were significantly decreased (p<0.05). After macrophage exposure, hAF produced significantly more MMP-1 and -3 and less TIMP-1 and -2. Interleukin-1beta stimulation enhanced MMP-1 and -3 levels, and significantly diminished TIMP-2 levels. Co-culturing with rabbit notochordal cells did not significantly influence MMPs and TIMPs production or COL1A2 gene expression. CONCLUSION: Our results indicate that macrophage-like cells evoke annular degeneration through the regulation of major degradative enzymes and their inhibitors, produced by hAF, suggesting that the selective regulation of these enzymes provides future targets for symptomatic disc degeneration therapy.

Non-Dural-Based Spinal Meningioma : The First Case Report of a Fibrous Subtype and a Review of the Literature

Spinal meningiomas typically adhere to the dura matter. Non-dural based spinal meningiomas are rare and most are clear cell meningiomas. We report here the first case of a fibrous meningioma with non-dural attachment. The patient was a 49-year-old female, who complained of numbness in the legs and a gait disturbance. Magnetic resonance imaging revealed a 1.7x1.4-cm mass in the C7-T1 intra-dural extramedullary space, showing peripheral gadolinium enhancement without a "dural tail sign". A complete microsurgical resection was performed. The mass was covered with a white membrane but was not adhered to the dura, and its appearance was consistent with a neurilemmoma. The histopathological diagnosis was fibrous-type meningioma. The recovery of the patient was uneventful. No surgical complications and no recurrence of the tumor had occurred at the 6-month follow-up.

Nonconvulsive Seizures of Traumatic Brain Injury Patients / 대한신경손상학회지

OBJECTIVE: Seizures are common consequence of traumatic brain injury and have been reported in clinical series as an incidence of 15% to 22%. Among them, nonconvulsive seizures (NCS) are often unrecognized during the early period of neurosurgical hospitalization because their clinical presentations can be misunderstood as consequent symptoms of clinical course, and the diagnosis can be confirmed only by the electroencephalographic (EEG) recording. METHODS: We retrospectively reviewed our clinical database of traumatic brain injury (TBI) patients admitted between March 2008 and September 2012. Twenty one patients with suspicious symptoms of NCS, such as decrease of consciousness, aphasia or irritability, were included. Routine wake and sleep EEG or bedside continuous EEG monitoring were done in all patients. RESULTS: Ten out of twenty-one patients showed abnormal activities on EEG. Ictal discharges were documented on four patients. Based on clinical symptoms and EEG findings, these four patients were diagnosed as NCS. Two out of four NCS patients showed EEG findings of nonconvulsive status epilepticus (NCSE). Another six patients with abnormal EEG activities were considered as 'suspicious NCS' because only interictal activities were recorded on EEG but increasing dose or adding on antiepileptics relieved their symptoms. All NCS/NCSE were successfully controlled by appropriate antiepileptic therapy. CONCLUSION: Our result showed that NCS was diagnosed in about 20% of patients with suspicious symptoms. There's a possibility that actual NCS might have happened more. Because untreated NCS/NCSE might cause worse clinical outcome, careful observation and urgent EEG recordings should be considered in a patient with suspicious NCS symptoms.

Clinical Efficacy of Acute Monitoring Cortical Activity Using Subdural Strip Electrode after Decompressive Craniectomy / 대한신경손상학회지

OBJECTIVE: Decompressive craniectomy is widely used in cases of uncontrolled intracranial hypertension, including traumatic brain injury or acute stroke. Physiological monitorings, such as intracranial pressure or electroenecephalography (EEG) are critical for patients in the acute phase. We retrospectively reviewed our experience of continuous electrocorticography (ECoG) monitoring by subdural strip electrode in patients who performed decompressive craniectomy and assessed its clinical efficacy. METHODS: Patients who underwent decompressive craniectomy because of severe intracranial hypertension were included. 4 Channel strip electrodes were inserted on the frontal cortex before closure. 24-hour continuous monitoring of ECoG was done to identify abnormal electrical activity. The level of consciousness was assessed according to Glasgow Coma Scale (GCS). In patients with malignant intracranial hypertension, barbiturate coma therapy was considered. RESULTS: Fifteen patients (9 men and 6 women) were included and the mean age was 55.7 years (from 17 to 80). The initial mean GCS score was 7.9 (from 3 to 14). In six out of fifteen patients, abnormal spike activities were identified, and one of these six patients was diagnosed as nonconvulsive status epilepticus (NCSE). Cortical spreading depression (CSD) was suspected in five. Three patients underwent barbiturate coma therapy and ECoG monitoring of these patients showed typical burst suppression pattern, which was used for indicator of therapeutic level. The mean duration of strip electrode and ECoG monitoring was 3.5 days, and there was no complication. CONCLUSION: Continuous ECoG monitoring using subdural strip electrode was useful to detect abnormal brain activity in the acute period after decompressive craniectomy.

Unusual Fatal Infections after Anterior Cervical Spine Surgeries

We report two cases of cervical spinal epidural abscess (SEA), which are related to anterior cervical surgeries. The first case reveals a late postoperative infection without any predisposing factor. The second case reveals combined complication of infection and instrument failure (artificial disc). Both two cases manifested ascending infections that are unusual courses of anterior cervical infections. The abscess extended upwards and, finally, caused life threatening bacterial meningitis. We suggest aggressive surgical interventions with anti-bacterial therapies in such cases.

Radiological Significance of Ligamentum Flavum Hypertrophy in the Occurrence of Redundant Nerve Roots of Central Lumbar Spinal Stenosis

OBJECTIVE: There were previous reports of redundant nerve roots (RNRs) focused on their clinical significance and pathogenesis. In this study, we investigated the significant radiologic findings that correlate with RNRs occurrence. These relations would provide an advanced clue for clinical significance and pathogenesis of RNRs. METHODS: Retrospective research was performed with data from 126 patients who underwent surgery for central lumbar spinal stenosis (LSS). Finally, 106 patients with common denominators (inter-observer accuracy : 84%) were included on this study. We divided the patients into two groups by MRI, patients with RNRs and those with no RNRs (NRNRs). Comparative analyses were performed with clinical and radiologic parameters. RESULTS: RNRs were found in 45 patients (42%) with central LSS. There were no statistically significant differences between the two groups in severity of symptoms. On the other hand, we found statistically significant differences in duration of symptom and number of level included (p<0.05). In the maximal stenotic level, ligamentum flavum (LF) thickness, LF cross-sectional area (CSA), dural sac CSA, and segmental angulation are significantly different in RNRs group compared to NRNRs group (p<0.05). CONCLUSION: RNRs patients showed clinically longer duration of symptoms and multiple levels included. We also confirmed that wide segmental angulation and LF hypertrophy play a major role of the development of RNRs in central LSS. Together, our results suggest that wide motion in long period contribute to LF hypertrophy, and it might be the key factor of RNRs formation in central LSS.

Notochordal Cells Influence Gene Expression of Inflammatory Mediators of Annulus Fibrosus Cells in Proinflammatory Cytokines Stimulation

OBJECTIVE: Notochordal cells in the intervertebral disc interact with nucleus pulposus (NP) cells and support the maintenance of disc homeostasis by regulation of matrix production. However, the influence of notochordal cells has not been evaluated in the annulus fibrosus (AF), which is the primary pain generator in the disc. We hypothesized that the notochordal cell has the capacity to modulate inflammatory mediators secreted by AF cells secondary to stimulation. METHODS: Notochordal and AF cells were isolated from adult New Zealand white rabbits. AF pellets were cultured with notochordal cell clusters or in notochordal cell-conditioned media (NCCM) for 24 or 48 hours with proinflammatory cytokines at varying concentrations. Gene expression in AF pellets were assayed for nitric oxide synthase (iNOS), cyclo-oxygenase (COX)-2, and interleukin (IL)-6 by real time reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: AF pellet in NCCM significantly decreased the iNOS and COX-2 messenger ribonucleic acid (mRNA) levels compared to AF pellets alone and AF pellets with notochordal cells (p < 0.05). AF pellet resulted in dose-dependent iNOS and COX-2 expression in response to IL-1beta, stimulation, demonstrating that 1 ng/ml for 24 hours yielded a maximal response. AF pellet in NCCM significantly decreased the expression of iNOS and COX-2 in response to 1ng/ml IL-1beta, stimulation at 24 hours (p < 0.05). There was no difference in IL-6 expression compared to AF pellets alone or AF pellets with notochordal cell clusters. CONCLUSION: We conclude that soluble factors from notochordal cells mitigate the gene expression of inflammatory mediators in stimulated AF, as expected after annular injury, suggesting that notochordal cells could serve as a novel therapeutic approach in symptomatic disc development.

Korean Guideline Development for the Evaluation of Permanent Impairment of the Spine: Proposal by the Korean Academy of Medical Sciences Committee

The criteria for the evaluation of spinal impairment are diverse, complex, and have no standardized form. This makes it difficult and somewhat troublesome to accurately evaluate spinal impairment patients. A standardized guideline was studied for the evaluation of spinal impairment, based on the American Medical Association (AMA) Guides and the McBride method. This guideline proposal was developed by specialty medical societies under the Korean Academy of Medical Sciences. In this study, the grades of impairment were assessed by dividing patients into three different categories: spinal cord impairment, spinal injury impairment and spinal disorder impairment. The affected regions of the spine are divided into three: the cervical region, the thoracic region, and the lumbosacral region. The grade of impairment was differentially evaluated according to the affected region. The restricted range of motion was excluded in the evaluation spinal impairment because of low objectivity. Even though the new Korean guideline for the evaluation of spinal impairment has been proposed, it should be continuously supplemented and revised.

Meningeal Hemangiopericytoma: Study of 6 Cases and Review of the Literatures

OBJECTIVE: Hemangiopericytoma is known as a malignant tumor originating from pericytes and rarely occurs in the central nervous system. We present 6 cases of pathologically confirmed meningeal hemangiopericytoma. METHODS: Retrospective study was done based on patient's recordings including radiological studies. Each case of tumors was treated surgically and postoperative radiotherapy was done. RESULTS: There were 5 cases of intracranial and 1 case of spinal hemangiopericytomas. Three of 5 intracranial hemangiopericytomas were located at tentorial region. Total tumor removal was done in 4 cases and postoperative local recurrence (or regrowth) was noted in 3 cases despite of postoperative external radiation therapy, 2 of which had died. CONCLUSION: Our cases show more frequent tentorial locations and poor clinical outcomes of hemangiopericytomas compared with meningiomas.

Clinical Analysis of Poor grade Subarachnoid Hemorrhage Patients / 대한뇌혈관외과학회지

PURPOSE: Subarachnoid hemorrhage (SAH) resulting from aneurysmal rupture carries a high rate of morbidity and mortality despite of intensive care. Owing to the advance in surgical techniques, the management results of good grade patients have shown better outcomes than the past, but those of poor grade patients have been still unsatisfactory. The aim of this study is to determine the treatment and the prognostic factors in the poor grade SAH patients. METHOD: We have analyzed 43 patients of Hunt & Hess (H&H) grade IV and V among 438 SAH patients treated between 1998 and 2004. The patients were divided into two groups (Good outcome group and Poor outcome group) according to the management outcomes. Each group was analyzed about the various prognosis factors; age, sex, H&H grade, Fisher grade, location and size of aneurysm, timing of operation, and complications. RESULTS: Among the various factors evaluated, the preoperative H&H grade only showed statistical significance (P value=0.0173). The better H&H grade seemed to show the more favorable outcome, especially surgically treated cases. CONCLUSIONS: An aggressive treatment including early surgery seems to contribute to a better outcome of poor grade SAH patients, especially H&H grade IV. But further clinical study should be researched to improve clinical outcomes in H&H grade V patients.

C-1 Root Schwannoma with Aggressive Lateral Mass Invasion

Schwannomas are relatively common, benign tumors that are thought to arise from the nerve sheath cell. Schwannomas of the C1 root are extremely rare and seldom invade lateral masses because they gradually increase in size and can extend through the wide space behind the lateral mass instead of the intervertebral foramen. We present here an unusual case of a benign schwannoma that aggressively invaded the lateral mass of C-1.

Prognostic Factors of Primary Intraventricular Hemorrhage

OBJECTIVE: Primary intraventricular hemorrhage(PIVH) is uncommon and accounts for only 3.1 % of all non-traumatic intracerebral hemorrhage. The aim of this study is to analyze clinical characteristics, image features, etiology and prognostic factors of outcome in patients with PIVH. METHODS: We identified 25 patients with PIVH during 9-year period between 1994 and 2002 at our institute. The clinical data, complimentary examination, outcome and computed tomographic blood amounts were reviewed. RESULTS: Major symptoms included sudden decreased level of consciousness, headache, nausea/vomiting and neck stiffness. Cerebral angiography was performed in 12 patients(48%) and revealed vascular malformation in 6 patients(24%). The positive result of angiography was more common in young patients and among vascular malformation the incidence of Moyamoya disease was relatively high(4 patients). Other causative factors were coagulation disorder, arterial hypertension, tumor bleeding. Outcome were death in 9 patients(36%): 7 patients(28%) died by direct consequence of bleeding and 2 patients died after other adverse events(sepsis, hepatic failure) but prognosis of survivor was good. Factors correlating with the outcome were the presence of coagulopathy, initial Glasgow Coma Scale(GCS), obstruction of 4th ventricle and ventricular blood amount including hemorrhagic dilatation of temporal horn of lateral ventricle, 3rd and 4th ventricle. CONCLUSION: The poor prognosis factors of PIVH are the presence of coagulopathy, low initial GCS, obstruction of 4th ventricle and large ventricular blood amount. Additionally patients whose initial clinical condition is not serious need an appropriate work up including cerebral angiography, because cause of bleeding is vascular malformation especially in young patients.

Extraventricular Cystic Neurocytoma

We report a case of extraventricular neurocytoma(left parietal lobe) in a young man presented with hemiparesis. The tumor, a radiologically well-circumscribed, cystic and enhancing mass, was partially removed. The patient, who received postoperative radiotherapy, is living well after 15 months of follow-up. Pathology showed a well-differentiated lesion composed of uniform, round cells with perinuclear halos in a neuropil background, immunohistochemically positive for neuronal markers. This was a cystic extraventricular neurocytoma(glio-neuronal tumor) arising from the left parietal lobe. Its features were consistent with neurocytoma pathologically and were different from those of intraventricular neurocytoma pathophysiologically. We outline the morphological and immunohistochemical evaluations necessary to recognize this rare tumor.

Fibrous Dysplasia Involving the Fronto-Orbital Bone: Surgical Experience

OBJECTIVE: To suggest early surgical treatment of fronto-orbital fibrous dysplasia, the authors present the surgical experiences of fronto-orbital fibrous dysplasia in 8 cases. METHODS: A total of 8 surgically treated patients with fronto-orbital fibrous dysplasia is included in this study. There were 4 males and 4 females with age range between 6 and 50(average 23.5 years). All presented with painless bulging mass in fronto-orbital region, and seven had varying degrees of proptosis with variable degrees of visual symptoms. Six cases were treated with radical resection and immediate orbital and cranial reconstruction using polymethylmethacrylate(PMMA) and miniplates. Two cases were treated with minimal resection and contouring using autogenous bone graft. RESULTS: No complications were seen except transient ptosis and wound infection in one case, respectively. There were no signs of recurrence during follow-up period(up to 4 years). Cosmetic results were acceptable in 7 seven patients but reoperation was required in remaining one patient 4 years after first operation. The patients who had visual symptoms showed improvement postoperatively. CONCLUSION: These results emphasize the importance of the early treatment with surgical approach in patients with fronto-orbital fibrous dysplasia who have visual sympotoms and cosmetinc problems. However, further study with larger population is warranted to validate early surgical correction in patients with varying degrees of symptomatologies.