Publications by authors named "Sang Ryong Jeon"

96 Publications

Microsurgery Versus Endovascular Treatment - Which Is Adequate for Initial Treatment of Spinal Dural Arteriovenous Fistula: A Case Series.

Neurospine 2021 Jun 30;18(2):344-354. Epub 2021 Jun 30.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: Considering the adverse natural history of spinal dural arteriovenous fistula (sDAVF), clinical outcomes may be worsened if the initial occlusive trial does not achieve complete fistula occlusion. We aimed to analyze the initial success rate of microsurgery and embolization and confirm the effects of initial treatment success on the clinical outcomes of sDAVF patients. In addition, we investigated the factors associated with initial treatment failure.

Methods: A total of 38 patients treated for sDAVF at a single institution over a 14-year period were retrospectively reviewed. Clinical outcomes according to the initial treatment modality were quantitatively analyzed. Demographic characteristics and angioarchitecture data were evaluated to identify factors associated with initial treatment failure.

Results: In the study population, 34 patients underwent embolization as the initial treatment, and complete occlusion of the fistula was achieved in 13 patients (38%). However, all patients who underwent microsurgery showed complete fistula occlusion. Among patients with initial treatment success, gait and micturition were improved with statistical significance (p < 0.001 each). However, in cases of initial treatment failure, only mild improvements in gait and micturition were observed, which were not statistically significant (p = 0.097 and p = 0.375, respectively). A narrow feeding artery diameter (p = 0.007) and embolization of the artery only (p = 0.002) were identified as factors associated with initial treatment failure.

Conclusion: To achieve symptomatic improvement and prevent neurological deterioration due to recurrence, the initial definite occlusion of the fistula is important. Despite advances in endovascular techniques, microsurgical occlusion is still superior in terms of initial complete obliteration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14245/ns.2040826.413DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8255761PMC
June 2021

Optimal Ratio of Wnt3a Expression in Human Mesenchymal Stem Cells Promotes Axonal Regeneration in Spinal Cord Injured Rat Model.

J Korean Neurosurg Soc 2021 May 28. Epub 2021 May 28.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: Through our previous clinical trials, the demonstrated therapeutic effects of MSC in chronic spinal cord injury (SCI) were found to be not sufficient. Therefore, the need to develop stem cell agent with enhanced efficacy is increased. We transplanted enhanced Wnt3asecreting human mesenchymal stem cells (hMSC) into injured spines at 6 weeks after SCI to improve axonal regeneration in a rat model of chronic SCI. We hypothesized that enhanced Wnt3a protein expression could augment neuro-regeneration after SCI.

Methods: Thirty-six Sprague-Dawley rats were injured using an Infinite Horizon (IH) impactor at the T9-10 vertebrae and separated into five groups : 1) phosphate-buffered saline injection (injury only group, n=7); 2) hMSC transplantation (MSC, n=7); 3) hMSC transfected with pLenti vector (without Wnt3a gene) transplantation (pLenti-MSC, n=7); 4) hMSC transfected with Wnt3a gene transplantation (Wnt3a-MSC, n=7); and 5) hMSC transfected with enhanced Wnt3a gene (1.7 fold Wnt3a mRNA expression) transplantation (1.7 Wnt3a-MSC, n=8). Six weeks after SCI, each 5×105 cells/15 µL at 2 points were injected using stereotactic and microsyringe pump. To evaluate functional recovery from SCI, rats underwent Basso-Beattie-Bresnahan (BBB) locomotor test on the first, second, and third days post-injury and then weekly for 14 weeks. Axonal regeneration was assessed using growth-associated protein 43 (GAP43), microtubule-associated protein 2 (MAP2), and neurofilament (NF) immunostaining.

Results: Fourteen weeks after injury (8 weeks after transplantation), BBB score of the 1.7 Wnt3a-MSC group (15.0±0.28) was significantly higher than that of the injury only (10.0±0.48), MSC (12.57±0.48), pLenti-MSC (12.42±0.48), and Wnt3a-MSC (13.71±0.61) groups (p<0.05). Immunostaining revealed increased expression of axonal regeneration markers GAP43, MAP2, and NF in the Wnt3a-MSC and 1.7 Wnt3a-MSC groups.

Conclusion: Our results showed that enhanced gene expression of Wnt3a in hMSC can potentiate axonal regeneration and improve functional recovery in a rat model of chronic SCI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3340/jkns.2021.0003DOI Listing
May 2021

Risk Factors for High-Grade Meningioma in Brain and Spine: Systematic Review and Meta-analysis.

World Neurosurg 2021 Jul 8;151:e718-e730. Epub 2021 May 8.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address:

Background: Histologic grade has important implications for the management in meningioma. It is important to understand the risk of high-grade meningioma (grades II and III). In this article, we systematically reviewed the histologic grade of meningioma depending on the location and sex and its relationship with recurrence.

Methods: The PubMed and Embase databases were systematically searched until February 4, 2020. We included studies that were not restricted to specific anatomic locations, histologic grade, or the sizes of the tumors. The proportion of high-grade meningiomas depending on the location and sex and the odds ratio (OR) of recurrence were pooled using a random-effects model.

Results: Outcome data were analyzed for 20,336 tumors from 34 studies. We found different proportions of high-grade meningiomas in the brain (12.8%) (95% confidence interval [CI], 10.5%-15.1%) versus the spine (2.4%) (95% CI, 1.0%-3.7%) (P < 0.01). Skull base meningiomas (8.7%) (95% CI, 5.8%-11.6%) had a lower proportion of high-grade meningiomas than non-skull base meningiomas (16.5%) (95% CI, 11.9%-21.1%) (P < 0.01). In addition, high-grade meningiomas were more likely to occur in male patients (18.0%) (95% CI, 10.1%-25.9%) than female patients (7.0%) (95% CI, 3.5%-10.6%) (P = 0.01). Higher rates of recurrence (OR = 13.83) were confirmed for high-grade meningiomas than grade I meningiomas (95% CI, 4.10-46.65) (P < 0.01).

Conclusions: This meta-analysis found that intracranial, nonskull base, and male sex are risk factors for high-grade meningioma, and high-grade meningioma had a much higher recurrence rate as compared with grade I meningioma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2021.04.138DOI Listing
July 2021

A New Indicator Predicting the Degree of Cord Shift After Posterior Decompression of Cervical Ossification of the Posterior Longitudinal Ligament Extended to the C2 Level and Its Clinical Usefulness.

Turk Neurosurg 2020 Oct 16. Epub 2020 Oct 16.

Inje University Ilsan Paik Hospital, Neuroscience & Radiosurgery Hybrid Research Center, College of Medicine, Department of Neurosurgery, 170, Juwharo, Ilsan Seogu, Goyang, Gyeonggi 10380, Republic of Korea.

Aim: We sought to evaluate the usefulness of the rostral line (R-line) as a new index for determining the degree of C2 lamina decompression in the context of ossification of the posterior longitudinal ligament (OPLL) extending to the C2 level.

Material And Methods: The R-line was devised based on the mechanism by which the cord is shifted backward following cervical posterior decompression. According to their R-line status, 36 patients with cervical OPLL extending to the C2 level were divided into two groups of R-line (+)and R-line (-) cases, where the R-line touched the upper half of the posterior C2 lamina in the R-line (+) group and the inferior half of the posterior C2 lamina in the R-line (-) group, respectively.

Results: Eighteen patients were classified as R-line (+) and 18 patients were classified as R-line (-). Total laminectomy of the C2 lamina was more common in the R-line (+) group, while dome-shape C2 laminectomy was more common in the R-line (-) group. All patients requiring reoperation were included in the R-line (+) group. Only the operation type showed a statistically significant difference according to the need for reoperation in the R-line (+) group; specifically, all patients who underwent reoperation in the R-line (+) group had dome-shape C2 laminectomy. It was determined that the risk factor for reoperation in the R-line (+) group was a history of dome-shape C2 laminectomy.

Conclusion: If the R-line touches the upper half of the posterior C2 lamina, total decompression of the C2 lamina should be performed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5137/1019-5149.JTN.31668-20.1DOI Listing
October 2020

Genomic Association Study for Cognitive Impairment in Parkinson's Disease.

Front Neurol 2020 4;11:579268. Epub 2021 Feb 4.

Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

Cognitive impairment is very common in Parkinson's disease (PD) and constitutes the most debilitating complication of this disease. However, to date, few studies have investigated a genome-wide association in the development of cognitive impairment of PD. We aimed to identify the genetic loci associated with cognitive impairment in patients with sporadic PD by ethnicity-specific genotyping. We recruited 1,070 patients with PD and performed a genome-wide association study using the Korean Chip, a microarray chip containing 827,400 single-nucleotide polymorphisms (SNPs) optimized for the Korean population. Multiple logistic regression models adjusting for age, sex, years of education, and disease duration were used to compare between patients with and without cognitive impairment, which was defined using the Mini-Mental Status Examination (MMSE) score (MMSE score ≥ 26 vs. < 26) or the Montreal Cognitive Assessment (MoCA) score (MoCA score ≥24 vs. < 24). SNP rs10495397 was most significantly associated with cognitive impairment based on the MMSE scores (OR = 3.21; 95% CI = 1.96-5.25, = 3.36 × 10) and showed the strongest association with cognitive impairment based on the MoCA scores. However, none of the SNPs were statistically significant after Bonferroni correction. may play a role in cognitive impairment in PD by the pathogenic mechanism of neuroinflammation. However, more studies are needed to replicate and validate the results of our functional study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fneur.2020.579268DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7890115PMC
February 2021

Cervical Alignment Following Posterior Cervical Fusion Surgery: Cervical Pedicle Screw Versus Lateral Mass Screw Fixation.

Spine (Phila Pa 1976) 2021 May;46(10):E576-E583

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Study Design: Retrospective comparative study.

Objective: The aim of this study was to compare cervical sagittal alignment after posterior fusion surgery with lateral mass screw (LMS) and cervical pedicle screw (CPS) fixation.

Summary Of Background Data: LMS fixation in the subaxial cervical spine has become the preferred method of posterior cervical fusion. Although CPS has biomechanical benefits, it also has neurovascular risks. Few studies to date have compared sagittal alignment changes after posterior cervical fusion using CPS and LMS fixation.

Methods: From 2006 to 2017, 71 consecutive patients underwent posterior cervical fusion using CPS (n = 51) or LMS (n = 20) fixation. Patients who underwent fusion with both types of screws and those who planned to undergo additional anterior fusion surgery were excluded. The minimum follow-up period was 12 months. C2-C7 Cobb angle for cervical lordosis (CL), fusion segmental angle (SA), C2-C7 sagittal vertical axis (SVA), and T1 slope (T1S) were measured.

Results: Immediate postoperative SA and SVA differed significantly in patients who underwent CPS and LMS fixation. SA changes were more substantial after CPS fixation, with a significant difference maintained until final follow-up. Over time, CL, SVA, and T1S tended to return to their preoperative states regardless of screw type. Two patients who underwent LMS fixation, but none who underwent CPS fixation, required unplanned or additional anterior fusion surgery for revision.

Conclusion: The present study is the first radiologic comparison of LMS and CPS fixation after posterior-only fusion surgery. CPS resulted in more reliable and well-preserved SA correction, whereas CL and SVA did not differ between the two groups over time due to loss of correction.Level of Evidence: 4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000003845DOI Listing
May 2021

Cognitive profile as a predictor of the long-term outcome after deep brain stimulation in Parkinson's disease.

J Neurol Sci 2020 Oct 28;417:117063. Epub 2020 Jul 28.

Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address:

Background: Although dementia is a contraindication for deep brain stimulation (DBS) in patients with Parkinson's disease (PD), the concept is supported by little scientific evidence. Moreover, it is unclear whether PD with mild cognitive impairment (PD-MCI) or domain-specific cognitive impairments affect the outcome of DBS in non-demented PD patients.

Objective: To investigate the influence of baseline cognitive profiles of PD on the outcome of DBS.

Methods: Baseline cognitive levels of patients with PD who underwent DBS were classified into PD with dementia (PDD) (n = 15), PD-MCI (n = 210), and normal cognition (PD-NC) (n = 79). The impact of the cognitive level on key DBS outcome measures [mortality, nursing home admission, progression to Hoehn&Yahr (HY) stage 5 and progression to PDD] were analyzed using Cox regression models. We also investigated whether impairment of a specific cognitive domain could predict these outcomes in non-demented patients.

Results: Patients with PDD showed a substantially higher risk of nursing home admission and progression to HY stage 5 compared with patients with PD-MCI [hazard ratio (HR) 4.20, P = .002; HR = 5.29, P < .001] and PD-NC (HR 7.50, P < .001; HR = 7.93, P < .001). MCI did not alter the prognosis in patients without dementia, but those with visuospatial impairment showed poorer outcomes for nursing home admission (P = .015), progression to HY stage 5 (P = .027) and PDD (P = .006).

Conclusions: Cognitive profiles may stratify the pre-operative risk and predict long-term outcomes of DBS in PD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jns.2020.117063DOI Listing
October 2020

Long-term Effects of Bilateral Subthalamic Deep Brain Stimulation on Postural Instability and Gait Difficulty in Patients with Parkinson's Disease.

J Mov Disord 2020 May 29;13(2):127-132. Epub 2020 May 29.

Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: The long-term effects of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on postural instability and gait difficulty (PIGD) in patients with Parkinson's disease (PD) remain unclear. In this study, we aimed to evaluate the longterm effects of STN-DBS surgery on PIGD symptoms in patients with advanced-stage PD.

Methods: This study included 49 consecutively included patients with PD who underwent bilateral STN-DBS. The Unified Parkinson's Disease Rating Scale (UPDRS) scores and subscores for PIGD were assessed at baseline and at 1, 3, and 5 years postoperatively. The PIGD subscore was divided into PIGD-motor and PIGD-activities of daily living (ADL) scores according to parts III and II of the UPDRS, respectively.

Results: The PIGD-motor and PIGD-ADL scores at the "medication-off" state improved at 3 and 5 years, respectively. Overall, the UPDRS III and II scores at "medication-off" improved at 5 years. The UPDRS IV score also significantly improved and the levodopa equivalent daily dosage decreased at all follow-ups. Finally, the PIGD-motor score at baseline was able to predict long-term improvement in the PIGD-motor score at the 5-year follow-up.

Conclusion: The STN-DBS has both short- and long-term effects on PIGD, as well as overall motor function, in patients with advanced PD. The degree of PIGD at the preoperative evaluation can be used to predict long-term outcomes after STN-DBS surgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14802/jmd.19081DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7280933PMC
May 2020

The R-line: A New Imaging Index for Decision Making Regarding C2 Lamina Decompression in Cervical Ossification of the Posterior Longitudinal Ligament.

Korean J Neurotrauma 2020 Apr 13;16(1):60-66. Epub 2020 Apr 13.

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: The optimal treatment modality for cervical ossification of the posterior longitudinal ligament (OPLL) including the C2 level remains controversial. Cervical laminoplasty is a widely accepted considering of advantages such as development of few postoperative complications, including kyphosis or neck pain. We encountered seven patients with postoperative disabilities resulting from incomplete decompression after undercutting of the C2 lamina. Based on this experience, we developed a new index to determine the degree of decompression in cervical OPLL-the rostral line (R-line).

Methods: Total of 79 consecutive patients who underwent posterior decompression of cervical OPLL were included in this study. Mean age at the time of operation, the C2-C7 cervical lordotic angle and OPLL thickness at the most stenotic level of the spinal canal, and preoperative/postoperative Japanese Orthopedic Association score was checked in these group. We compared the correspondence between the degree of C2 lamina decompression using the R-line and actual degree of decompression.

Results: In all patients, the R-line touched the upper half of the C2 lamina on preoperative magnetic resonance imaging (MRI). The C2-C3 local segment lordotic angle and maximal degree of spinal cord compression by OPLL were independently correlated to postoperative C2 cord shifting. This result indicates that the R-line is a valid indicator to determine the degree of C2 lamina decompression in OPLL extending to the C2 level.

Conclusion: The results showed that undercutting the C2 lamina can result in incomplete spinal cord decompression and poor clinical outcome if the R-line touches the upper half of the C2 lamina on preoperative MRI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.13004/kjnt.2020.16.e7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7192802PMC
April 2020

Comparison of the Accuracy of C1 Pedicle Screw Fixation Using Fluoroscopy and Free-Hand Techniques in Patients With Posterior Arch Thickness of Less Than 4 mm.

Oper Neurosurg (Hagerstown) 2020 Sep;19(4):429-435

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

Background: C1 pedicle screw insertion is not easy, and more fluoroscopy can be required for safe insertion. Fluoroscopy is time consuming and increases patient radiation exposure. There have been no studies comparing the accuracy of C1 pedicle screw insertion using the fluoroscopy and free-hand techniques.

Objective: To describe a free-hand C1 pedicle screw insertion method in patients with the posterior arch thickness of less than 4 mm in the thinnest part of the groove, and to compare the clinical and radiological outcomes of C1 pedicle screw insertion using fluoroscopy vs using the free-hand technique.

Methods: A total of 25 patients who had atlantoaxial instability with a C1 posterior arch <4 mm and were treated with C1 pedicle screw insertion were included. In 10 patients, fluoroscopy was used for C1 pedicle screw insertion, and 15 patients underwent the free-hand technique. We compared the radiologic and clinical outcomes between the 2 groups.

Results: In patients who underwent the free-hand technique, 96.5% of screws were rated as safe (grade A or B), and 80.0% of screws in the fluoroscopy group were rated as safe. Postoperative occipital neuralgia occurred in one patient in the fluoroscopy group and did not occur in the free-hand technique group. There was no significant difference in the improvement of Nurick grade between the 2 groups.

Conclusion: C1 pedicle screw insertion using the free-hand technique is feasible and safe in patients with a C1 posterior arch <4 mm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opaa067DOI Listing
September 2020

Postoperative Non-Pathological Fever Following Posterior Cervical Fusion Surgery : Is Laminoplasty a Better Preventive Method than Laminectomy?

J Korean Neurosurg Soc 2020 Jul 5;63(4):487-494. Epub 2020 Mar 5.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: To analyze the incidence and characteristics of delayed postoperative fever in posterior cervical fusion using cervical pedicle screws (CPS).

Methods: This study analyzed 119 patients who underwent posterior cervical fusion surgery using CPS. Delayed fever was defined as no fever for the first 3 postoperative days, followed by an ear temperature ≥38°C on postoperative day 4 and subsequent days. Patient age, sex, diagnosis, laminectomy, surgical level, revision status, body mass index, underlying medical disease, surgical duration, and transfusion status were retrospectively reviewed.

Results: Of 119 patients, seven were excluded due to surgical site infection, spondylitis, pneumonia, or surgical level that included the thoracic spine. Of the 112 included patients, 28 (25%) were febrile and 84 (75%) were afebrile. Multivariate logistic regression analysis showed that laminectomy was a statistically significant risk factor for postoperative non-pathological fever (odds ratio, 10.251; p=0.000). In contrast, trauma or tumor surgery and underlying medical disease were not significant risk factors for fever.

Conclusion: Patients who develop delayed fever 4 days after posterior cervical fusion surgery using CPS are more likely to have non-pathologic fever than surgical site infection. Laminectomy is a significant risk factor for non-pathologic fever.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3340/jkns.2019.0191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7365284PMC
July 2020

Optogenetic inactivation of the entopeduncular nucleus improves forelimb akinesia in a Parkinson's disease model.

Behav Brain Res 2020 05 10;386:112551. Epub 2020 Feb 10.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea. Electronic address:

We performed optogenetic inactivation of rats' entopeduncular nucleus (EP, homologous to primates' globus pallidus interna (GPi)) and investigated the therapeutic effect in a rat model of PD. 6-Hydroxydopamine (6-OHDA)-induced hemiparkinsonian rats were injected with either a virus for halorhodopsin expression that is used to inactivate GABAergic neurons or a control virus injection and received optic fiber insertion. All the rats were illuminated by 590 nm of light. Each rat was then subjected to sequential sessions of stepping tests under controlled illumination patterns. The stepping test is a reliable evaluation method for forelimb akinesia. The number of adjusting steps was significantly higher in experimental (optogene with reporter gene expression) (5Hz - 10ms: 15.7 ± 1.9, 5Hz - 100ms: 16.0 ± 1.8, continuous: 21.6 ± 1.9) than control rats (reporter gene expression) (5Hz-10ms: 1.9 ± 1.1, 5Hz-100ms: 2.6 ± 1.0, continuous: 2.5 ± 1.2) (p < 0.001). Continuous EP illumination showed a significantly higher improvement of forelimb akinesia than other illumination patterns (p < 0.01). Optogene expression in the GABAergic neurons of the EP was confirmed by immunohistochemistry. Optogenetic inhibition of EP was effective to improve contralateral forelimb akinesia. However, further studies using prolonged illumination are needed to investigate the best illumination pattern for optogenetic stimulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbr.2020.112551DOI Listing
May 2020

Aberrant Tonic Inhibition of Dopaminergic Neuronal Activity Causes Motor Symptoms in Animal Models of Parkinson's Disease.

Curr Biol 2020 01 9;30(2):276-291.e9. Epub 2020 Jan 9.

Center for Neuroscience, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; Convergence Research Center for Dementia, KIST, Seoul 02792, Korea.

Current pharmacological treatments for Parkinson's disease (PD) are focused on symptomatic relief, but not on disease modification, based on the strong belief that PD is caused by irreversible dopaminergic neuronal death. Thus, the concept of the presence of dormant dopaminergic neurons and its possibility as the disease-modifying therapeutic target against PD have not been explored. Here we show that optogenetic activation of substantia nigra pars compacta (SNpc) neurons alleviates parkinsonism in acute PD animal models by recovering tyrosine hydroxylase (TH) from the TH-negative dormant dopaminergic neurons, some of which still express DOPA decarboxylase (DDC). The TH loss depends on reduced dopaminergic neuronal firing under aberrant tonic inhibition, which is attributed to excessive astrocytic GABA. Blocking the astrocytic GABA synthesis recapitulates the therapeutic effect of optogenetic activation. Consistently, SNpc of postmortem PD patients shows a significant population of TH-negative/DDC-positive dormant neurons surrounded by numerous GABA-positive astrocytes. We propose that disinhibiting dormant dopaminergic neurons by blocking excessive astrocytic GABA could be an effective therapeutic strategy against PD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cub.2019.11.079DOI Listing
January 2020

Treatment outcome and risk factors associated with diffuse axonal injury in patients with moderate to severe head injury.

Turk Neurosurg 2020 Jan 7. Epub 2020 Jan 7.

Asan Medical Center.

Aim: Diffuse axonal injury (DAI) is an important determining factor of morbidity and mortality after traumatic brain injury (TBI). However, its clinical outcome remains a subject of debate.

Material And Methods: A total of 992 TBI patients visited our hospital between 2011 and 2016. Thirty-seven patients diagnosed with DAI were enrolled in this study and stratified by DAI stage: stage I, 20 patients (54.1%); stage II, 4 patients (10.8%); and stage III, 13 patients (35.1%).

Results: The mean age and the median follow-up period were 45.43 years and 13 months, respectively. Patient demographic data and clinical findings on admission showed no differences according to DAI stage, except for the revised trauma score (RTS) (p = 0.026). In univariate analysis, stages I and II vs. III (p = 0.001) and stages I vs. II and III (p = 0.019), transfusion within 24 hours of visit (p = 0.033), shock or cardiac arrest (p = 0.006), traumatic subarachnoid hemorrhage (T-SAH) (p = 0.011), and subdural hematoma (SDH) (p = 0.009) were significantly correlated with Glasgow outcome score (GOS). In multivariate analysis, DAI stage I and II vs. III (p = 0.005) and SDH (p = 0.040) were significant.

Conclusion: Clinically, stage II was more correlated with stage I, rather than stage III. Stage III showed a much poorer outcome compared to stages I and II. Magnetic resonance imaging (MRI) should be promptly performed in all TBI patients when a patient's level of consciousness and cranial computed tomography (CT) does not match, as there is a possibility of stage III DAI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5137/1019-5149.JTN.28132-19.4DOI Listing
January 2020

Current Status and Future Strategies to Treat Spinal Cord Injury with Adult Stem Cells.

J Korean Neurosurg Soc 2020 Mar 6;63(2):153-162. Epub 2019 Dec 6.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Spinal cord injury (SCI) is one of the most devastating conditions and many SCI patients suffer neurological sequelae. Stem cell therapies are expected to be beneficial for many patients with central nervous system injuries, including SCI. Adult stem cells (ASCs) are not associated with the risks which embryonic stem cells have such as malignant transformation, or ethical problems, and can be obtained relatively easily. Consequently, many researchers are currently studying the effects of ASCs in clinical trials. The environment of transplanted cells applied in the injured spinal cord differs between the phases of SCI; therefore, many researchers have investigated these phases to determine the optimal time window for stem cell therapy in animals. In addition, the results of clinical trials should be evaluated according to the phase in which stem cells are transplanted. In general, the subacute phase is considered to be optimal for stem cell transplantation. Among various candidates of transplantable ASCs, mesenchymal stem cells (MSCs) are most widely studied due to their clinical safety. MSCs are also less immunogenic than neural stem/progenitor cells and consequently immunosuppressants are rarely required. Attempts have been made to enhance the effects of stem cells using scaffolds, trophic factors, cytokines, and other drugs in animal and/or human clinical studies. Over the past decade, several clinical trials have suggested that transplantation of MSCs into the injured spinal cord elicits therapeutic effects on SCI and is safe; however, the clinical effects are limited at present. Therefore, new therapeutic agents, such as genetically enhanced stem cells which effectively secrete neurotrophic factors or cytokines, must be developed based on the safety of pure MSCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3340/jkns.2019.0146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054109PMC
March 2020

Posterior Cervical Muscle-Preserving Interspinous Process Approach and Decompression: More Minimally Invasive and Modified Shiraishi's Selective Laminectomy.

World Neurosurg 2020 Jan 16;133:e412-e420. Epub 2019 Sep 16.

Department of Emergency Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung-si, Republic of Korea.

Objective: The cervical extensor musculature is important in cases of neck pain and loss of cervical lordosis after laminoplasty. Therefore, various surgical methods have been developed to preserve the muscle during laminoplasty. We have developed a posterior cervical muscle-preserving interspinous process (MIS) approach and decompression method. We have described the operation details and clinical outcomes of selected patients who have undergone this procedure.

Methods: The MIS approach and decompression method were performed in 20 consecutive patients who had only required central decompression for cervical stenosis. This procedure includes an approach to the interspinous space that is similar to Shiraishi's method but includes decompression without fracturing the spina bifida.

Results: The patients had no complications and did not require conversion to conventional laminoplasty. The mean operative time and mean blood loss was 53.0 minutes and 63.0 mL per level, respectively, and the mean hospital stay was 4.0 days. The mean preoperative and 3-month postoperative modified Japanese Orthopedic Association scores were 12.6 and 16.2, and the mean preoperative and 3-month postoperative neck disability index scores were 15.4 and 2.5, respectively. The postoperative neck visual analog scale score was 0.8. The mean preoperative and postoperative sagittal vertical axis was 1.6 and 1.8 cm, respectively. The mean loss of lordosis was 1.0°, and the mean cervical range of motion did not change from preoperatively to postoperatively.

Conclusions: The MIS approach and decompression method was less invasive than both conventional laminoplasty and Shiraishi's selective laminectomy. It is a safe and effective minimally invasive technique for central stenosis caused by cervical spondylotic myelopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2019.09.041DOI Listing
January 2020

Parkinson Disease-Related Pattern of Glucose Metabolism Associated With the Potential for Motor Improvement After Deep Brain Stimulation.

Neurosurgery 2020 04;86(4):492-499

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Background: Motor dysfunctions in Parkinson disease (PD) patients are not completely normalized by deep brain stimulation (DBS), and there is an obvious difference in the degree of symptom improvement after DBS for each patient.

Objective: To test our hypothesis that each patient has their own restoration capacity for motor improvement after DBS, and to investigate whether regional cerebral glucose metabolism in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans is associated with the capacity for off-medication motor improvement (MIoff) after DBS.

Methods: The MIoff (%) was calculated using the Unified Parkinson's Disease Rating Scale part III in 27 PD patients undergoing DBS in the globus pallidus interna. The standardized uptake value ratios (SUVRs) on FDG-PET were quantitatively measured, and the areas where the SUVR correlated with the MIoff (%) were identified. Also, the areas where the SUVR was significantly different between the 2 MIoff groups (≥60% vs <60%) were determined.

Results: Ten patients achieved MIoff > 60% at 12 mo after DBS. In general, the MIoff (%) was positively correlated with preoperative SUVR in the temporo-parieto-occipital lobes, while it was inversely correlated with the metabolism in the primary motor cortex. The patients in the MIoff < 60% group showed a significant decrease in SUVR in the parieto-occipital lobes, while parieto-occipital metabolism in those with MIoff ≥ 60% was relatively preserved (Mann-Whitney U test, P = .03).

Conclusion: Our findings suggest that the parieto-occipital lobes may be implicated more generally in the prognosis of motor improvement after DBS in advanced PD than other regions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuros/nyz206DOI Listing
April 2020

Anterior Odontoid Screw Fixation for the Treatment of Type 2 Odontoid Fracture with a Kyphotic Angulation or an Anterior Down-slope: A Technical Note.

Neurol Med Chir (Tokyo) 2019 Aug 9;59(8):321-325. Epub 2019 May 9.

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine.

Anterior odontoid screw fixation (AOSF) is difficult and challenging to perform in patients with type 2 odontoid fracture with a kyphotic angulation or an anterior down-slope. To demonstrate two surgical techniques to resolve kyphotic angulation or difficult fracture direction issues. Anterior odontoid screw fixation was performed in two patients with type 2 odontoid fracture with a kyphotic angulation or an anterior down-slope. This technique can avoid sternal blocking using a percutaneous vertebroplasty puncture needle, and can reduce the kyphotic angle using a Cobb elevator in patients with type 2 odontoid fractures with a kyphotic angulation or an anterior down-sloped fracture. In both the patients, AOSF was successfully performed and a successful clinical outcome was achieved. The screws were well-maintained with reduced fracture segment and well-preserved, corrected kyphotic angles were achieved, as observed on cervical X-ray 6 months postoperatively. Our technique is a safe and effective method for the treatment of type 2 odontoid fracture with a kyphotic angulation or an anterior down-slope.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2176/nmc.tn.2018-0249DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6694020PMC
August 2019

Surgical Treatment of Lumbar Spinal Discal Cyst: Is It Enough to Remove the Cyst Only without Following Discectomy?

Neurol Med Chir (Tokyo) 2019 Jun 9;59(6):204-212. Epub 2019 May 9.

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine.

Discal cysts are a rare cause of low back pain and radiculopathy with unknown pathophysiologic mechanism. Associated symptoms are difficult to distinguish from those caused by extruded discs and other spinal canal lesions. Most discal cysts are treated surgically, but it is unclear whether the corresponding intervertebral disc should be excised along with cyst. We conducted a retrospective clinical review of 27 patients who underwent discal cyst excision at our institution between 2000 and 2017. The mean follow-up period was 63.6 months. We recorded symptoms, radiographs, operative findings, postoperative complications, and short- and long-term outcomes. Structured outcome assessment was based on Numeric Rating Scale (NRS) for pain intensity, Oswestry disability index, and Macnab classification. All patients underwent partial hemilaminectomy and microscopic cyst resection without discectomy. All patients had preoperative back or leg pain. Other preoperative clinical features included motor weakness, neurogenic intermittent claudication, and cauda equina syndrome. After surgery, NRS scores of back and leg pain decreased. The other symptoms also improved. During long-term follow-up, patients reported no restrictions on daily life activities, and were satisfied with our intervention. There were no cases of cyst recurrence. We conducted a review of the literature on lumbar discal cysts published before January, 2018. Including our cases, 126 patients were described. We compared two surgical modalities-cystectomy with and without discectomy-to elucidate both effectiveness and long-term complications. We found that microsurgical cystectomy without corresponding discectomy is an effective surgical treatment for lumbar discal cysts, and is associated with a low recurrence rate.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2176/nmc.oa.2018-0219DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6580042PMC
June 2019

The time course of cervical alignment after cervical expansive laminoplasty: Determining optimal cut-off preoperative angle for predicting postoperative kyphosis.

Medicine (Baltimore) 2018 Nov;97(47):e13335

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Retrospective Cohort studyTo analyze cervical lordosis angle (CLA) change after cervical expansive laminoplasty (CEL) over time, and to determine optimal cut-off angle for predicting postoperative kyphosisPostoperative development of sagittal malalignment after laminoplasty is associated with neurological dysfunction and neck pain. However, there is no information on the serial CLA change over time and cut-off angle for predicting postoperative kyphosisThe Cobb angle between C2 and C7 in a series of lateral cervical X-rays in the neutral position was retrospectively reviewed for 36 months. And, the effect of time on CLA after CEL and the risk factors associated with postoperative cervical kyphosis (Cobb's angle ≤0°) were analyzed. Also, the optimal cut-off angle for predicting postoperative kyphosis was determined.A total of 110 cases of CEL for cervical myelopathy were enrolled from February 2005 to May 2010. The mean cervical alignment changed from 12.3 ± 10.4° (mean ± standard deviation [SD]) at the preoperative evaluation to 8.2 ± 11.6°, 10.6 ± 10.1°, 9.1 ± 10.0°, 8.4 ± 11.2°, 8.5 ± 10.5°, 8.1 ± 9.9°, and 8.7 ± 10.1° at 1, 3, 6, 12, 18, 24, and 36 postoperative months, respectively. The cervical lordosis showed statistically significant decreased at the 1st month, then the lordotic angle was partially restored at the 3rd, and 6th, and then no significant changes after the 6th. The only risk factor for kyphosis development was the preoperative CLA. The optimal cut-off preoperative angle for predicting postoperative kyphosis was 8.5°.The decrease of CLA after expansive laminoplasty peaked in the 1st month. Some of the lordotic angles were restored in the 3rd and 6th months, before reaching a plateau after the 6th month. The optimal cut-off preoperative angle for predicting postoperative kyphosis was 8.5°.Level of Evidence of their study: Level 4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MD.0000000000013335DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6393087PMC
November 2018

Clinical outcomes of posterior thoracic cage interbody fusion (PTCIF) to treat trauma and degenerative disease of the thoracic and thoracolumbar junctional spine.

J Clin Neurosci 2019 Feb 22;60:117-123. Epub 2018 Oct 22.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address:

Laminectomy followed by posterolateral fusion (PLF) is a standard procedure for thoracic and thoracolumbar (TL) compressive lesions. However, it is challenging to apply sufficient bone chips as the spinal cord is exposed after the laminectomy. Therefore, we performed posterior thoracic cage interbody fusion (PTCIF) as an alternative technique. A total of 25 patients operated with PTCIF technique between 2012 and 2017 were analyzed in our study. These patients required a posterior decompression and fusion in thoracic and TL spine for traumatic injury or degenerative disease. To evaluate the outcome of bone fusion, computed tomography (CT) was performed at least 3-4 months after PTCIF. The surgery was performed through insertion of screws and cages packed with autologous bone chips in a similar fashion to the posterior lumbar interbody fusion technique. Among 25 patients who underwent PTCIF, 22 patients were involved in our study. The mean age and follow-up interval were 58.6 (28-78) years and 27.1 (6-60) months, respectively. Traumatic spinal injury was diagnosed in 6 patients and degenerative disease in 16 patients. One level PTCIF was performed in 12 patients and 2 levels in 8 patients. After the operation, patients with degenerative disease showed neurological improvement, and trauma cases showed no neurological aggravation. Successful bone fusion was confirmed on CT for all patients. PTCIF is an effective treatment thereby we suggest this approach to be considered as an alternative procedure to decompression and fusion surgery in the thoracic and TL spine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jocn.2018.10.047DOI Listing
February 2019

Early (≤48 Hours) versus Late (>48 Hours) Surgery in Spinal Cord Injury: Treatment Outcomes and Risk Factors for Spinal Cord Injury.

World Neurosurg 2018 Oct 6;118:e513-e525. Epub 2018 Jul 6.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea; Division of Neurosurgical Critical Care, Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address:

Objectives: Surgical management of spinal cord injury (SCI) is challenging. There is no standard guideline regarding the timing of surgery, although physicians have prioritized early surgery over the past decades. Although better outcomes have been observed from these studies, the definition of early surgery has been controversial, although mostly limited to 24-hours after injury. For some hospitals, this early surgery could be difficult to implement in practice. Hence, we re-evaluated the timing of early surgery as surgery within 48 hours and investigated the surgical outcomes of SCI depending on whether surgery was performed early (≤48 hours) or late (>48 hours). The primary outcomes were improvement in the American Spinal Injury Association Impairment Scale (AIS) grade in early and late surgery groups.

Methods: This study was a retrospective cohort study in individuals aged 15-85 years, who underwent surgery for SCI between 2005 and 2016. The rate of AIS grade improvements was measured at 6 months after injury. Of the 86 enrolled patients, 31 (mean, 40.9 ± 12.64 hours) and 55 (mean, 168.25 ± 93.01 hours) patients were assigned to the early and late surgery groups, respectively.

Results: AIS grade improvement was significantly greater in the early than in the late group (P = 0.039). In the early group, there was no significant difference in neurologic improvements among the AIS B, C, and D groups, but the AIS A group showed a significant improvement (P = 0.015). This finding was not observed in the late group (P = 0.060). AIS grade improvement was also significantly greater in the incomplete SCI group than in the complete SCI group, for all measurements (early, P = 0.007, late, P = 0.009). Other factors that significantly affected clinical outcomes were AIS grade on admission and the level of the injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2018.06.225DOI Listing
October 2018

Clinically significant radiographic parameter for thoracic myelopathy caused by ossification of the ligamentum flavum.

Eur Spine J 2019 08 6;28(8):1846-1854. Epub 2018 Sep 6.

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea.

Purpose: To investigate radiographic parameters to improve the accuracy of radiologic diagnosis for ossification of ligamentum flavum (OLF)-induced thoracic myelopathy and thereby establish a useful diagnostic method for identifying the responsible segment.

Methods: We classified 101 patients who underwent surgical treatment for OLF-induced thoracic myelopathy as the myelopathy group and 102 patients who had incidental OLF and were hospitalized with compression fracture as the non-myelopathy group between January 2009 and December 2016. We measured the thickness of OLF (TOLF), cross-sectional area of OLF (AOLF), anteroposterior canal diameter, and the ratio of each of these parameters.

Results: Most OLF cases with lateral-type axial morphology were in the non-myelopathy group and most with fused and tuberous type in the myelopathy group. Most grade-I and grade-II cases were also in the non-myelopathy group, whereas grade-IV cases were mostly observed in the myelopathy group. The AOLF ratio was found to be the best radiologic parameter. The optimal cutoff point of the AOLF ratio was 33.00%, with 87.1% sensitivity and 87.3% specificity. The AOLF ratio was significantly correlated with preoperative neurological status.

Conclusions: An AOLF ratio greater than 33% is the most accurate diagnostic indicator of OLF-induced thoracic myelopathy. In cases of multiple-segment OLF, confirmation of cord signal change on MRI and an AOLF measurement will help determine the responsible segment. AOLF measurement will also improve the accuracy of diagnosis of OLF-induced thoracic myelopathy in cases of grade III or extended-type axial morphology. These slides can be retrieved under Electronic Supplementary Material.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00586-018-5750-6DOI Listing
August 2019

New grading system for the clinical evaluation of patients with spinal vascular lesions.

Neuroradiology 2018 Oct 14;60(10):1035-1041. Epub 2018 Aug 14.

Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Purpose: Neurointerventional approaches have improved myelopathy in patients with spinal vascular lesions by providing effective management, particularly when surgical approaches are difficult. However, there have been challenges in describing and comparing recovery status during the post-treatment period.

Methods: We evaluated 43 patients with venous congestive myelopathy (VCM) using Aminoff-Logue Disability Scale for gait (AL-G) and micturition (AL-M) scores. These results were compared with our new PSMS grading system that evaluates four categories (grades 0-3): pain, sensory symptoms, motor deficit, and sphincter change. Simple linear regression was used to identify the association or trend among the scales. We also calculated an overall area under the receiver operating characteristic curve to compare the predictive ability of the PSMS system with that of the previous grading system (AL-G and AL-M).

Results: Compared with other grading system, the PSMS system was more sensitively correlated with patient status and the results were easy to compare with previous clinical statuses during follow-up. The PSMS system also measured pain, which is commonly associated with spinal dural arteriovenous fistula and not precisely evaluated by other grading system.

Conclusions: The new PSMS grading system for patients with VCM correlated well with the previously used systems and included pain evaluation. This new grading system is an easy tool for the evaluation and comparison of outcomes before and after endovascular treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00234-018-2076-3DOI Listing
October 2018

Importance of the preoperative cross-sectional area of the semispinalis cervicis as a risk factor for loss of lordosis after laminoplasty in patients with cervical spondylotic myelopathy.

Eur Spine J 2018 11 13;27(11):2720-2728. Epub 2018 Aug 13.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43 gil, Songpa-gu, Seoul, 05505, Korea.

Purpose: To investigate the effect of the preoperative cross-sectional area (CSA) of the semispinalis cervicis on postoperative loss of cervical lordosis (LCL) after laminoplasty.

Methods: A total of 144 patients who met the inclusion criteria between January 1999 and December 2015 were enrolled. Radiographic assessments were performed to evaluate the T1 slope, C2-7 sagittal vertical axis (SVA), cephalad vertebral level undergoing laminoplasty (CVLL), preoperative C2-7 Cobb angle, and preoperative CSA of the semispinalis cervicis.

Results: The T1 slope and the summation of the CSAs (SCSA) at each level of the semispinalis cervicis correlated with LCL, whereas the C2-7 SVA, CVLL, and preoperative C2-7 Cobb angle did not. Multiple regression analysis demonstrated that a high T1 slope and a low SCSA of the semispinalis cervicis were associated with LCL after laminoplasty in patients with cervical spondylotic myelopathy (CSM). The CSA of the semispinalis cervicis at the C6 level had the greatest association with LCL, which suddenly decreased with a LCL of 10°. The best cutoff point of the CSA of the semispinalis cervicis at the C6 level, which predicts LCL > 10°, was 154.5 mm (sensitivity 74.3%; specificity 71.6%; area under the curve 0.828; 95% confidence interval 0.761-0.895).

Conclusion: Preoperative SCSA of the semispinalis cervicis was a risk factor for LCL after laminoplasty. Spine surgeons should evaluate semispinalis cervicis muscularity at the C6 level when planning laminoplasty for patients with CSM. These slides can be retrieved under Electronic Supplementary Material.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00586-018-5726-6DOI Listing
November 2018

Biodegradable Screws Containing Bone Morphogenetic Protein-2 in an Osteoporotic Rat Model.

J Korean Neurosurg Soc 2018 Sep 25;61(5):559-567. Epub 2018 Jul 25.

Laboratory of Stem Cell Therapy, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: The aim of this study was to evaluate the effect for biodegradable screws containing bone morphogenetic protein-2 (BMP-2) in an osteoporotic rat model.

Methods: Twenty-four female Wistar rat (250-300 g, 12 weeks of age) were randomized into four groups. Three groups underwent bilateral ovariectomy (OVX). Biodegradable screws with or without BMP-2 were inserted in the proximal tibia in two implantation groups. The extracted proximal metaphysis of the tibiae were scanned by exo-vivo micro-computed tomography. Evaluated parameters included bone mineral density (BMD), trabecular bone volume (BV/TV), trabecular number, trabecular thickness, and trabecular separation (Tb.Sp). The tibia samples were pathologically evaluated by staining with by Hematoxylin and Eosin, and trichrome.

Results: Trabecular formation near screw insertion site was evident only in rats receiving BMP-2 screws. BMD and BV/TV significantly differed between controls and the OVX and OVX with screw groups. However, there were no significant differences between control and OVX with screw BMP groups. Tb.Sp significantly differed between control and OVX and OVX with screw groups (p<0.05), and between the OVX and OVX with screw BMP group (p<0.05), with no statistically significant difference between control and OVX with screw BMP groups. Over the 12 weeks after surgery, bone lamellae in direct contact with the screw developed more extensive and thicker trabecular bone around the implant in the OVX with screw BMP group compared to the OVX with screw group.

Conclusion: Biodegradable screws containing BMP-2 improve nearby bone conditions and enhance ostoeintegration between the implant and the osteoporotic bone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3340/jkns.2017.0297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6129746PMC
September 2018

Diffuse axonal injury (DAI) in moderate to severe head injured patients: Pure DAI vs. non-pure DAI.

Clin Neurol Neurosurg 2018 08 10;171:116-123. Epub 2018 Jun 10.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea; Division of Neurosurgical Critical Care, Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea. Electronic address:

Objective: Diffuse axonal injury (DAI) is known to be associated with poor outcome. DAI often associates with other intracranial injuries but their distinct features have not been established. In this retrospective cohort study, we compared clinical outcomes between pure and non-pure DAI patients.

Patients And Methods: Total of 1047 traumatic brain injury (TBI) patients visited our institute between 2011 and 2017. Age ranged between 15-85 years old and Glasgow coma scale (GCS) score less than 13 were included. DAI was diagnosed in 45 patients using CT and MRI and their clinical features and outcomes were compared depending on their associated cranial injury; 20 patients without evidence of associated injury (Pure DAI group) and other 25 patients with associated injury (Non-pure DAI group). DAI stage was adopted using Gentry, L.R.

Classification: Glasgow outcome scale (GOS) was measured at least 6 months after trauma to evaluate their functional outcome.

Results: The mean age and follow-up period were 45.36 years and 15.09 months, respectively. There were no significant differences between pure and non-pure DAI groups regarding demographic data and clinical findings on their admission. Logistic regression model was used to examine the association between GOS and clinical factors. In this analysis, pure DAI was no significantly different to non-pure DAI (p = 0.607). However, DAI Stage, transfusion, and hypotension on admission were strongly related to poor outcome. Stage III showed sevenfold higher risk when compared to Stage I (p = 0.010). The risk was also high when Stage III was compare to Stage I and II (p = 0.002). Interestingly, no significant difference was observed between Stage I and II (p = 0.847).

Conclusions: Unfavorable outcome was observed in 14 patients (31.11%) which was lower than we expected. Interestingly, non-pure DAI was no worse than pure DAI on their functional outcome. However, DAI Stage III was independently associated with poor outcome when compared to Stage I or I and II. Finally, we concluded that Stage II is clinically more related to Stage I, rather than Stage III.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clineuro.2018.06.011DOI Listing
August 2018

Analysis of the Risk Factors Associated with Prolonged Intubation or Reintubation after Anterior Cervical Spine Surgery.

J Korean Med Sci 2018 Apr 30;33(17):e77. Epub 2018 Jan 30.

Department of Neurological Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Background: Standardized postoperative airway management is essential for patients undergoing anterior cervical spine surgery (ACSS). The paucity of clinical series evaluating these airway complications after ACSS has been resulted in a significant limitation in statistical analyses.

Methods: A retrospective cohort study was performed regarding airway distress (intubation for more than 24 hours or unplanned reintubation within 7 days of operation) developed after ACSS. If prevertebral soft tissue swelling was evident after the operation, patients were managed with prolonged intubation (longer than 24 hours). Preoperative and intraoperative patient data, and postoperative outcome (time to extubation and reintubation) were analyzed.

Results: Between 2008 and 2016, a total of 400 ACSS were performed. Of them, 389 patients (97.25%) extubated within 24 hours of surgery without airway complication, but 11 patients (2.75%) showed postoperative airway compromise; 7 patients (1.75%) needed prolonged intubation, while 4 patients (1.00%) required unplanned reintubation. The mean time for extubation were 2.75 hours (range: 0-23 hours) and 50.55 hours (range: 0-250 hours), respectively. Age ( = 0.015), diabetes mellitus ( = 0.003), operative time longer than 5 hours ( = 0.048), and estimated blood loss (EBL) greater than 300 mL ( = 0.042) were associated with prolonged intubation or reintubation. In prolonged intubation group, all patients showed no airway distress after extubation.

Conclusion: In ACSS, postoperative airway compromise is related to both patients and operative factors. We recommend a prolonged intubation for patients who are exposed to these risk factors to perform a safe and effective extubation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3346/jkms.2018.33.e77DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5909108PMC
April 2018

A Novel Animal Model of Parkinson's Disease Using Optogenetics: Representation of Various Disease Stages by Modulating the Illumination Parameter.

Stereotact Funct Neurosurg 2018 14;96(1):22-32. Epub 2018 Feb 14.

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Background: The classic animal model of Parkinson's disease (PD) using neurotoxin can only simulate fixed stages of the disease by causing irreversible damage to the nigrostriatal system.

Objectives: To develop an optogenetic PD model that can modulate the severity of disease by optical stimulation by introducing the halorhodopsin (NpHR) gene into the substantia nigra compacta.

Methods: Fifteen rats received injections of engineered AAV with NpHR-YFP gene into the substantia nigra. They were then subjected to illumination of 590-nm light wavelengths with 3 optical stimulation conditions, i.e., frequency-width: 5 Hz-10 ms (n = 5), 5 Hz-100 ms (n = 5), and 50 Hz-10 ms (n = 5). Eleven rats received 6-hydroxydopamine injections to establish the conventional PD model.

Results: The optogenetic models showed characteristic PD manifestations, similar to those of the conventional models; the severity of forelimb akinesia correlated with the total illumination value (frequency × width). The group with a low illumination value (5 Hz-10 ms) was comparable to the conventional partial model whereas the groups with high illumination values (5 Hz-100 ms and 50 Hz-10 ms) were similar to the conventional complete model.

Conclusions: An optogenetic PD model has the advantage of more appropriately representing various PD stages by controlling illumination parameters.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000486644DOI Listing
December 2018

Practicality of using the figure-of-eight bandage to prevent fatal wound dehiscence after spinal tumor surgery for upper thoracic metastasis.

Br J Neurosurg 2018 Aug 10;32(4):389-395. Epub 2017 Nov 10.

a Department of Neurological Surgery , Asan Medical Center, University of Ulsan College of Medicine , Seoul , Republic of Korea.

Object: Serious postoperative wound problems can frequently develop after surgery with perioperative RT for upper thoracic metastatic lesions. The figure-of-eight bandage can restrict excessive shoulder motion, which could prevent wound dehiscence. The purpose of this study was to describe the efficacy of using the figure-of-eight bandage to prevent postoperative wound dehiscence.

Methods: Between February 2005 and July 2015, we retrospectively evaluated the medical records of cancer patients who underwent surgery with or without RT for spinal metastasis involving the upper thoracic spine. From January 2009, all patients received figure-of-eight bandaging immediately postoperatively, which was then maintained for 2 months. The outcome measures were the incidence and successful management of wound dehiscence following application of the figure-of-eight bandage.

Results: One hundred and fifteen patients (71 men and 44 women) were enrolled in the present study. A figure-of-eight bandage in conjunction with a thoracolumbosacral orthosis (TLSO) was applied to 78 patients, while only TLSO was applied to 37 patients. The overall rate of wound dehiscence was 4.34% and the mean duration before wound dehiscence was 27.0 days (range, 22-31 days) after surgery. In the TLSO-only group, wound dehiscence occurred in four patients (10.81%), meanwhile there was only one case (1.33%) of wound dehiscence in the group that had received the figure-of-eight bandage with TLSO. Three of four patients with wound dehiscence in the TLSO only group died from unresolved wound problems and another patient was treated with wound closure followed by the application of the figure-of-eight bandage. The only patient with wound dehiscence among the patients who received both the figure-of-eight bandage and TLSO was managed by primary wound closure without further complication.

Conclusion: Current study suggests that the figure-of-eight bandage could prevent wound dehiscence and be used to treat wound problems easily.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/02688697.2017.1400520DOI Listing
August 2018
-->