The Fate of Proximal Junctional Vertebral Fractures after Long-Segment Spinal Fixation : Are There Predictable Radiologic Characteristics for Revision surgery?

ObjectiveTo investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation. MethodsA total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics ResultsDespite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121–3.190; p=0.017). ConclusionProximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.     

Usefulness of Simple Rod Rotation to Correct Curve of Adolescent Idiopathic Scoliosis

ObjectiveTo correct apical vertebral rotation for adolescent idiopathic scoliosis (AIS), direct vertebral derotation (DVD) or simple rod rotation (SRR) might be considered. The aim of the present study is to introduce the surgical experiences of AIS by a Korean neurosurgeon and to evaluate the effectiveness of SRR for apical vertebral rotation.MethodsA total of 9 patients (1 male and 8 females) underwent scoliosis surgery by a neurosurgeon of our hospital. The Lenke classifications of the patients were 1 of 1B, 2 of 1C, 1 of 2A, 1 of 2C, 3 of 5C and 1 of 6C. Surgery was done by manner of simple rod rotation on the concave side and in situ coronal bending. Coronal Cobb''s angles, vertebral rotation angles and SRS-22 were measured on a plain standing X-ray and CT before and after surgery.ResultsThe mean follow up period was 25.7 months (range : 5–52). The mean number of screw positioning level was nine (6–12). The mean age was 16.4 years (range : 13–25) at surgery. The mean Risser grade was 3.7±0.9. The apical vertebral rotation measured from the CT scans was 25.8±8.5° vs. 9.3±6.7° (p<0.001) and the Coronal Cobb''s angle was 53.7±10.4° vs. 15.4±6.5° (p<0.001) preoperatively and postoperative, respectively. The SRS-22 improved from 71.9 preoperatively to 90.3 postoperatively. There were no complications related with the operations.ConclusionSRR with pedicle screw instrumentation could be corrected successfully by axial rotation without complications. SRR might serve as a good option to correct AIS deformed curves of AIS.     

The Effect of the Pedicle-Facet Angle on Degenerative Cervical Spondylolisthesis

ObjectiveTo measure the orientation of the facet joints of cervical spine (C-spine) segments in the sagittal plane, known as the pedicle-facet (P-F) angle, and to use these measurements to evaluate the relationship between the P-F angle and the amount of vertebral anterolisthesis in patients with degenerative cervical spondylolisthesis (DCS).MethodsA retrospective case-control study was performed including 30 age- and sex-matched patients with DCS and 30 control participants. Anterior-posterior and lateral view radiographs of the C-spine were obtained in a standing position. The P-F angle at all cervical levels and the amount of anterolisthesis at C4-5 were measured from lateral view plain radiographs.ResultsThe P-F angles at C4-5 were 141.14±7.14° for the DCS group and 130.53±13.50° (p=0.012) for the control group, and at C5-6 were 137.46±8.53° for the DCS group and 128.53±16.01° for the control group (p=0.001). The mean P-F angle at C4-5 did not correlate with the amount of anterolisthesis (p=0.483). The amount of anterior slippage did correlate with age (p<0.001).ConclusionThe P-F angle was intrinsically higher at C4-5, compared to C5-6, in both the DCS and control groups, which might explain the increased likelihood for anterolisthesis of C4. Higher P-F angles in the DCS group may be a predisposing factor to slippage. The P-F angle may interact with age to increase incidence of anterolisthesis with increasing age.     

Morphological Assessment of Cadaveric Radial,Brachial and Subclavian Arteries: A Neurointerventional Approach

ObjectiveThe transradial catheterization (TRC) is becoming widespread, primarily for neurointerventions. Therefore, the evaluation of radial artery puncture in clinical practice and a better understanding of the anatomy are important to improve the safety of neuroendovascular surgery.MethodsTen formalin-fixed adult Korean cadavers were dissected to expose radial artery (RA), brachial artery (BrA) and subclvian artery (ScA), bilaterally. Vessel lengths and diameters were meaured using a caliper and distance between the specific point of vessels and the anatomical landmarks including the radial styloid process, the medial epicondyle of the humerus, the sternoclavicular joint, and the vertebral artery orifice were also measured.ResultsThe average length between the radial (RAPS) and the BrA puncture sites (BrAPS) and between the vertebral artery orifice (VAO) and the BrA bifurcation (BrAB) did not differ between sides (p>0.05). The average length between the radial styloid process (RSP) and the RAPS was 13.41±2.19 mm, and the RSP was 26.85±2.47 mm from the median nerve (MN). The mean length between the medial epicondyle (ME) and the BrAPS as 44.23±5.47 mm, whereas the distance between the ME and the MN was 42.23±4.77 mm. The average VAO-ScA angle was 70.94±6.12°, and the length between the ScA junction (SCJ) and the VAO was 60.30±8.48 mm.ConclusionThis study provides basic anatomical information about the radial artery and the brachial route and can help improving new techniques, selection of size and shape of catheters for TRC. This can help neurointerventionists who adopt a transradial neuroendovascular approach and offers comprehensive and safe care to their patients.     

The Change of Sagittal Alignment of the Lumbar Spine after Dynesys Stabilization and Proposal of a Refinement

ObjectiveDynesys® is one of the pedicle-based dynamic lumbar stabilization systems and good clinical outcome has been reported. However, the cylindrical spacer between the heads of the screws undergoes deformation during assembly of the system. The pre-strain probably change the angle of instrumented spine with time and oblique-shaped spacer may reduce the pre-strain. We analyzed patients with single-level stabilization with Dynesys® and simulated oblique-shaped spacer with finite element (FE) model analysis.MethodsConsecutive 14 patients, who underwent surgery for single-level lumbar spinal stenosis and were followed-up more than 24 months (M : F=6 : 8; age, 58.7±8.0 years), were analyzed. Lumbar lordosis and segmental angle at the index level were compared between preoperation and postoperative month 24. The von Mises stresses on the obliquely-cut spacer (5°, 10°, 15°, 20°, 25°, and 30°) were calculated under the compressive force of 400 N and 10 Nm of moment with validated FE model of the L4-5 spinal motion segment with segmental angle of 16°.ResultsLumbar lordosis was not changed, while segmental angle was changed significantly from -8.1±7.2° to -5.9±6.7° (p<0.01) at postoperative month 24. The maximum von Mises stresses were markedly decreased with increased angle of the spacer up to 20°. The stress on the spacer was uneven with cylindrical spacer but it became even with the 15° oblique spacer.ConclusionThe decreased segmental lordosis may be partially related to the pre-strain of Dynesys. Further clinical and biomechanical studies are required for relevant use of the system.     

Comparison of Spinal Canal Expansion Following Cervical Laminoplasty Based on the Preoperative Lamina Angle : A Simulation Study

ObjectiveExpansion in the spinal canal area (SCA) after laminoplasty is one of the critical factors to relieve the preoperative symptoms. No previous study has compared the increases in SCA achieved by open-door laminoplasty (ODL) and double door laminoplasty (DDL) according to the preoperative lamina angle (LA). This study was designed to clarify the relationship between the laminoplasty opening angle (OA)/laminoplasty opening size (OS) and increases in the SCA following ODL and DDL according to the preoperative LA using a simulation model. MethodsThe simulation model was constructed and validated by comparing the clinical data of 64 patients who had undergone C3–C6 laminoplasty (43 patients with ODL and 21 patients with DDL). SCA expansion was predicted with a verified simulation model at various preoperative LAs (from 28° to 32°) with different OAs (40° to 44°) and OSs (10 mm to 14 mm) recruited from patient data. ResultsThe constructed simulation model was validated by comparing clinical data and revealed a very high degree of correlation (r=0.935, p<0.001). In this validated model, at the same OA, the increase in SCA was higher following ODL than following DDL in the usual LA (p<0.05). At the same OS, the increase in SCA was slightly larger following DDL than following ODL, but the difference was not significant (p>0.05). The difference was significant when the preoperative LA was narrower or much wider. ConclusionBased on clinical data, a simulation model was constructed and verified that could predict increases in the SCA following ODL and DDL. When applying this model, prediction in SCA increase using the OS parameter was more practical and compatible with clinical data. Both laminoplasties achieved enough SCA, and there was no significant difference between them in the usual range.     

Analyzing the Significance of T1 Slope minus Cervical Lordosis in Patients with Anterior Cervical Discectomy and Fusion Surgery

ObjectiveAccurate measurement of T1 slope (a component of T1s minus cervical lordosis [CL]) is often constrained by anatomical limitations. In this situation, efforts should be made to find the exact meaning of T1s-CL and whether there are any alternatives to it. MethodsWe enrolled 117 patients who received two-level anterior cervical discectomy and fusion (ACDF). Occipital slope, C2 slope (C2s), C7 slope (C7s), T1, O-C2 angle (O-C2A), C2-7 angle (C2-7A), O-C7 angle (O-C7A), T1s-CL, C7-T1 angle (C7-T1A), and C2-7 sagittal vertical axis were measured. We determined 16° (T1s-CL) as the reference point for dividing subjects into the mismatch group and the balance group, and a comparative analysis was performed. ResultsThe mean value of C7-T1A was constantly maintained within 2.6° peri-operatively. In addition, C2s and T1s-CL showed the same absolute change (Δ|0.8|°). The mean values of T1s-CL of the mismatch and balance groups were 23.0° and 7.6°, respectively. The five factors with the largest differences between the two groups were as follows : C2s (Δ13.3°), T1s-CL (Δ15.4°), O-C2A (Δ8.7°), C2-7A (Δ14.7°), and segmental angle (Δ7.9°) before surgery. Only four factors showed statistically significant change between the two groups after ACDF : T1s-CL (Δ4.0° vs. Δ0.2°), C2s (Δ3.2° vs. Δ0.7°), O-C2A (Δ2.6° vs. Δ1.3°), C2-7A (Δ6.3° vs. Δ1.3°). A very strong correlation between T1s-CL and C2s was also found (r=|0.88–0.96|). ConclusionC2s itself may be the essential key to represent T1s-CL. The amounts and directions of change of these two factors (T1s-CL and C2s) were also almost identical. The above phenomenon was re-confirmed once again through the correlation analysis.     

Partial Pedicle Subtraction Osteotomy for Patients with Thoracolumbar Fractures : Comparative Study between Burst Fracture and Posttraumatic Kyphosis

ObjectiveTo evaluate the surgical outcomes of partial pedicle subtraction osteotomy (PPSO) in patients with thoracolumbar fractures and compare the outcomes of PPSO for burst fractures with those for posttraumatic kyphosis (PTK). MethodsFrom June 2013 to May 2019, 20 consecutive adult patients underwent PPSO for thoracolumbar fractures at the levels of T10 to L2. Of these patients, 10 underwent surgery for acute fractures (burst fractures), and 10 for sequelae of thoracolumbar fractures (PTK). Outcomes of PPSO were evaluated and compared between the groups. ResultsTwenty patients (each 10 patients of burst fractures and PTK) with a mean age of 64.7±11.1 years were included. The mean follow-up period was 21.8±11.0 months. The mean correction of the thoracolumbar angle was -34.9°±18.1° (from 37.8°±20.5°preoperatively to 2.8°±15.2° postoperatively). The mean angular correction at the PPSO site was -38.4°±13.6° (from 35.5°±13.6° preoperatively to -2.9°±14.1° postoperatively). The mean preoperative sagittal vertical axis was 93.5±6.7 cm, which was improved to 37.6±35.0 cm postoperatively. The mean preoperative kyphotic angle at the PPSO site was significant greater in patients with PTK (44.8°±7.2°) than in patients with burst fractures (26.2°±12.2°, p=0.00). However, the mean postoperative PPSO angle did not differ between the two groups (-5.9°±15.7° in patients with burst fractures and 0.2°±12.4° in those with PTK, p=0.28). The mean angular correction at the PPSO site was significantly greater in patients with PTK (-44.6°±10.7°) than in those with burst fractures (-32.1°±13.7°, p=0.04). The mean operation time was 188.1±37.6 minutes, and the mean amount of surgical bleeding was 1030.0±533.2 mL. There were seven cases of perioperative complications occurred in five patients (25%), including one case (5%) of neurological deficit. The operation time, surgical bleeding, and complication rates did not differ between groups. ConclusionIn cases of burst fracture, PPSO provided enough spinal cord decompression without corpectomy and produced sagittal correction superior to that achieved with corpectomy. In case of PTK, PPSO achieved satisfactory curve correction comparable to that achieved with conventional PSO, with less surgical time, less blood loss, and lower complication rates. PPSO could be a viable surgical option for both burst fractures and PTK.     

Long-Term Outcome of Posterior Cervical Inclinatory Foraminotomy

ObjectiveA modified surgical technique of posterior cervical foramintomy called posterior cervical inclinatory foraminotomy (PCIF) was introduced in previous preliminary article. PCIF allows better preservation of facet joint and capsule than conventional techniques. The authors conducted a study to investigate long-term outcomes of PCIF.MethodsWe retrospectively reviewed demographic, radiologic, and clinical data from the patients who underwent PCIFs at our institution. Criteria included a minimum of 48 month follow-up and PCIFs for patients with radiculopathy from foraminal stenosis (C2–T1; single or multilevel) with persistent or recurrent root symptoms despite conservative treatment for more than 3 months. Patients who had undergone previous cervical operation were excluded. The visual analogue scale (VAS) score was used for clinical follow-up, and radiologic follow-up was performed to compare the changes of cervical sagittal alignment, focal angle and disc-space height of treated segment.ResultsThe PCIFs were performed between April 2007 and March 2011 on 46 patients (32 males and 14 females) with a total of 73 levels affected. The average duration of follow-up was 74.4 months. Improvements in radiculopathic pain were seen in 39 patients (84.7%), and VAS score decreased from 6.82±1.9 to 2.19±1.9. Posterior neck pain also improved in 25 patients (71.4%) among 35 patients, and VAS score decreased from 4.97±2.0 to 2.71±1.9. The mean disc-space heights of treated segment were 5.41±1.03 mm preoperatively and decreased to 5.17±1.12 mm postoperatively. No statistically significant changes in cervical sagittal alignment, focal angle were seen during the follow-up period (Cox proportional hazards analysis and Student t-test, p>0.05).ConclusionThe PCIF is highly effective in treating patients with cervical spondylotic radiculopathy, leading to long-lasting relief in pain. Long-term radiologic follow-up showed no significant spinal angular imbalance.     

Blood flow distribution during heat stress: cerebral and systemic blood flow

The purpose of the present study was to assess the effect of heat stress-induced changes in systemic circulation on intra- and extracranial blood flows and its distribution. Twelve healthy subjects with a mean age of 22±2 (s.d.) years dressed in a tube-lined suit and rested in a supine position. Cardiac output (Q), internal carotid artery (ICA), external carotid artery (ECA), and vertebral artery (VA) blood flows were measured by ultrasonography before and during whole body heating. Esophageal temperature increased from 37.0±0.2°C to 38.4±0.2°C during whole body heating. Despite an increase in Q (59±31%, P<0.001), ICA and VA decreased to 83±15% (P=0.001) and 87±8% (P=0.002), respectively, whereas ECA blood flow gradually increased from 188±72 to 422±189 mL/minute (+135%, P<0.001). These findings indicate that heat stress modified the effect of Q on blood flows at each artery; the increased Q due to heat stress was redistributed to extracranial vascular beds.     

Do Obliquity and Position of the Oblique Lumbar Interbody Fusion Cage Influence the Degree of Indirect Decompression of Foraminal Stenosis?

ObjectiveOblique lumbar interbody fusion (OLIF) is a surgical technique that utilizes a large interbody cage to indirectly decompress neural elements. The position of the cage relative to the vertebral body could affect the degree of foraminal decompression. Previous studies determined the position of the cage using plain radiographs, with conflicting results regarding the influence of the position of the cage to the degree of neural foramen decompression. Because of the cage obliquity, computed tomography (CT) has better accuracy than plain radiograph for the measurement of the obliquely inserted cage. The objective of this study is to find the correlation between the position of the OLIF cage with the degree of indirect decompression of foraminal stenosis using CT and magnetic resonance imaging (MRI). MethodsWe review imaging of 46 patients who underwent OLIF from L2-L5 for 68 levels. Segmental lordosis (SL) was measured in a plain radiograph. The positions of the cage were measured in CT. Spinal canal cross-sectional area (SCSA), and foraminal crosssectional area (FSCA) measurements using MRI were taken into consideration. ResultsPatients’ mean age was 69.7 years. SL increases 3.0±5.1 degrees. Significant increases in SCSA (33.3%), FCSA (43.7% on the left and 45.0% on the right foramen) were found (p<0.001). Multiple linear regression analysis shows putting the cage in the more posterior position correlated with more increase of FSCA and decreases SL correction. The position of the cage does not affect the degree of the central spinal canal decompression. Obliquity of the cage does not result in different degrees of foraminal decompression between right and left side neural foramen. ConclusionCage position near the posterior part of the vertebral body increases the decompression effect of the neural foramen while putting the cage in the more anterior position correlated with increases SL.     

The intra‐arterial selective cooling infusion system: A mathematical temperature analysis and in vitro experiments for acute ischemic stroke therapy

IntroductionThe neuroprotection of acute ischemic stroke patients can be achieved by intra‐arterial selective cooling infusion using cold saline, which can decrease brain temperature without influencing the body core temperature. This approach can lead to high burdens on the heart and decreased hematocrit in the scenario of loading a high amount of liquid for longtime usage. Therefore, autologous blood is utilized as perfusate to circumvent those side effects.MethodsIn this study, a prototype instrument with an autologous blood cooling system was developed and further evaluated by a mathematical model for brain temperature estimation.ResultsHypothermia could be achieved due to the adequate cooling capacity of the prototype system, which could provide the lowest cooling temperature into the blood vessel of 10.5°C at 25 rpm (209.7 ± 0.8 ml/min). And, the core body temperature did not alter significantly (−0.7 ~ −0.2°C) after 1‐h perfusion. The cooling rate and temperature distributions of the brain were analyzed, which showed a 2°C decrease within the initial 5 min infusion by 44 ml/min and 13.7°C perfusate.ConclusionThis prototype instrument system could safely cool simulated blood in vitro and reperfuse it to the target cerebral blood vessel. This technique could promote the clinical application of an autologous blood perfusion system for stroke therapy.     

Quantification of Pediatric Cervical Spine Growth at the Cranio-Vertebral Junction

Objective

The purpose of this study was to investigate morphological change at the craniovertebral junction (CVJ) region using computed tomography.

Methods

A total of 238 patients were included in this study, and mean age was 47.8±21.3 months. Spinal canal diameter, Power''s ratio, McRae line, antero-posterior C1 ring height, atlantoaxial joint space, C2 growth, epidural space from the dens (M-PB-C2) and longitudinal distance (basion to C2 lower margin, B-C2) were measured. The mean value of each parameter was assessed for individual age groups. The cohorts were then divided into three larger age groups : infancy (I) (≤2 years), very early (VE) childhood (2-5 years) and early (E) childhood (5≥ years).

Results

Spinal canal diameter increased with age; however, this value did not increase with statistical significance after VE age. A significant age-related difference was found for all C2 body and odontoid parameters (p<0.05). Mean McRae line was 8.5, 8, and 7.5 mm in the I, VE, and E groups, respectively. The M-PB-C2 line showed up-and-down dynamic change during early pediatric periods.

Conclusion

Expansion of the spinal canal was restricted to the very early childhood period (less than 5 years) in the CVJ region; however, the C2 body and odontoid process increased continuously with age. The above results induced a dynamic change in the M-PB-C2 line. Although C2 longitudinal growth continued with age, the McRae line showed relatively little change.     

Transcranial Direct Middle Meningeal Artery Puncture for the Onyx Embolization of Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus

ObjectiveThe aim of this prospective study was to evaluate the efficacy of bone cement-augmented percutaneous short segment fixation for treating Kummell''s disease accompanied by severe osteoporosis.MethodsFrom 2009 to 2013, ten patients with single-level Kummell''s disease accompanied by severe osteoporosis were enrolled in this study. After postural reduction for 1-2 days, bone cement-augmented percutaneous short segment fixation was performed at one level above, one level below, and at the collapsed vertebra. Clinical results, radiological parameters, and related complications were assessed preoperatively and at 1 month and 12 months after surgery.ResultsPrior to surgery, the mean pain score on the visual analogue scale was 8.5±1.5. One month after the procedure, this score improved to 2.2±2.0 and the improvement was maintained at 12 months after surgery. The mean preoperative vertebral height loss was 48.2±10.5%, and the surgical procedure reduced this loss to 22.5±12.4%. In spite of some recurrent height loss, significant improvement was achieved at 12 months after surgery compared to preoperative values. The kyphotic angle improved significantly from 22.4±4.9° before the procedure to 10.1±3.8° after surgery and the improved angle was maintained at 12 months after surgery despite a slight correction loss. No patient sustained adjacent fractures after bone cement-augmented percutaneous short segment fixation during the follow-up period. Asymptomatic cement leakage into the paravertebral area was observed in one patient, but no major complications were seen.ConclusionBone cement-augmented percutaneous short segment fixation can be an effective and safe procedure for Kummell''s disease.     

Comparison between Anterior Cervical Decompression with Fusion and Posterior Cervical Fusion with Wide Facetectomy for Treatment of Severe Bony Foraminal Stenosis

ObjectiveTo compare the anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF) with wide facetectomy in the treatment of parallel-shaped bony foraminal stenosis (FS). MethodsThirty-six patients underwent surgery due to one-or-two levels of parallel-shaped cervical FS. ACDF was performed in 16 patients, and PCF using CPS was performed in 20 patients. All patients were followed up at 1, 3, 6, and 12 months postoperatively. Standardized outcome measures such as Numeric rating scale (NRS) score for arm/neck pain and Neck disability index (NDI) were evaluated. Cervical radiographs were used to compare the C2–7 Cobb’s angle, segmental angle, and fusion rates. ResultsThere was an improvement in NRS scores after both approaches for radicular arm pain (mean change -6.78 vs. -8.14, p=0.012), neck pain (mean change -1.67 vs. -4.36, p=0.038), and NDI score (-19.69 vs. -18.15, p=0.794). The segmental angle improvement was greater in the ACDF group than in the posterior group (9.4°±2.7° vs. 3.3°±5.1°, p=0.004). However, there was no significant difference in C2–7 Cobb angle between groups (16.2°±7.9° vs. 14.8°±8.5°, p=0.142). As a complication, dysphagia was observed in one case of the ACDF group. ConclusionIn the treatment of parallel-shaped bony FS up to two surgical levels, segmental angle improvement was more favorable in patients who underwent ACDF. However, PCF with wide facetectomy using CPS should be considered as an alternative treatment option in cases where the anterior approach is burdensome.     

The accuracy of anterior-posterior measurements in the assessment of spinal canal compromise in burst fractures

Abstract

The amount of spinal canal compromise is one of the primary criteria employed to specify treatment of thoracolumbar burst fractures. Canal compromise has been calculated utilizing measurement of anterior-posterior canal or by calculating the area of the involved spinal canal on CT scans. Since these measurements are critical to surgical decision making; we have compared anterior-posterior measurements with area measurements to assess the variability between these two techniques. Three mm axial CT scans from ten patients with thoracolumbar burst fractures were studied. The axial CT images at the midpoints of the vertebral bodies at the levels above and below the fracture level, and the axial CT image demonstrating the most significant canal compromise at the fracture level were digitized using an optical scanner. Using the Image 1.43 software, the anterior-posterior dimensions and area dimensions of each axial CT scan were obtained and the amount of canal compromise calculated. Linear measurements consistently overestimate the extent of spinal canal compromise as compared to the true area of canal compromise (6-46%, p < 0.005). This amount of variation did not correlate with the level, patient age or the extent of canal compromise. This preliminary study suggests that the two measurement techniques used to guide surgical decision making are not comparable. Further evaluation comparing the use of linear and area measurements is warranted. [Neurol Res 1994; 16: 410-412]     

Fimasartan-Based Blood Pressure Control after Acute Cerebral Ischemia: The Fimasartan-Based Blood Pressure Control after Acute Cerebral Ischemia Study

Background and PurposeBlood pressure (BP) control is strongly recommended, but BP control rate has not been well studied in patients with stroke. We evaluated the BP control rate with fimasartan-based antihypertensive therapy initiated in patients with recent cerebral ischemia.MethodsThis multicenter, prospective, single-arm trial involved 27 centers in South Korea. Key inclusion criteria were recent cerebral ischemia within 90 days and high BP [systolic blood pressure (SBP) >140 mm Hg or diastolic blood pressure (DBP) >90 mm Hg]. BP lowering was initiated with fimasartan. BP management during the follow-up was at the discretion of the responsible investigators. The primary endpoint was the target BP goal achievement rate (<140/90 mm Hg) at 24 weeks. Key secondary endpoints included achieved BP and BP changes at each visit, and clinical events (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT03231293","term_id":"NCT03231293"}}NCT03231293).ResultsOf 1,035 patients enrolled, 1,026 were included in the safety analysis, and 951 in the efficacy analysis. Their mean age was 64.1 years, 33% were female, the median time interval from onset to enrollment was 10 days, and the baseline SBP and DBP were 162.3±16.0 and 92.2±12.4 mm Hg (mean±SD). During the study period, 55.5% of patients were maintained on fimasartan monotherapy, and 44.5% received antihypertensive therapies other than fimasartan monotherapy at at least one visit. The target BP goal achievement rate at 24-week was 67.3% (48.6% at 4-week and 61.4% at 12-week). The mean BP was 139.0/81.8±18.3/11.7, 133.8/79.2±16.4/11.0, and 132.8/78.5±15.6/10.9 mm Hg at 4-, 12-, and 24-week. The treatment-emergent adverse event rate was 5.4%, including one serious adverse event.ConclusionsFimasartan-based BP lowering achieved the target BP in two-thirds of patients at 24 weeks, and was generally well tolerated.     

Clinical Efficacy and Safety of Controlled Distraction-Compression Technique Using Expandable Titanium Cage in Correction of Posttraumatic Kyphosis

ObjectiveTo investigate the clinical efficacy and safety of the controlled distraction-compression technique using an expandable titanium cage (ETC) in posttraumatic kyphosis (PTK). MethodsWe retrospectively studied and collected data on 20 patients with PTK. From January 2014 to December 2017, the controlled distraction-compression technique using ETC was consecutively performed in 20 patients with PTK of the thoracolumbar zone (range, 36–82 years). Among them, nine were males and 11 were females and the mean age was 61.5 years. The patients were followed regularly at 1, 3, 6, and 12 months, and the last follow-up was more than 2 years after surgery. ResultsThe mean follow-up period was 27.3±7.3 months (range, 14–48). The average operation time was 286.8±33.1 minutes (range, 225–365). The preoperative regional kyphotic angle (RKA) ranged from 35.6° to 70.6° with an average of 47.5°±8.1°. The immediate postoperative mean RKA was 5.9°±3.8° (86.2% correction rate, p=0.000), and at the last follow-up more than 2 years later, the mean RKA was 9.2°±4.9° (80.2% correction rate, p=0.000). The preoperative mean thoracolumbar kyphosis was 49.1°±9.2° and was corrected to an average of 8.8°±5.3° immediately after surgery (p=0.000). At the last follow-up, a correction of 11.9°±6.3° was obtained (p=0.000). The preoperative mean back visual analog scale (VAS) score was 7.9±0.8 and at the last follow-up, the VAS score was improved to a mean of 2.3±1.0 with a 70.9% correction rate (p=0.000). The preoperative mean Oswestry disability index (ODI) score was 32.3±6.9 (64.6%) and the last follow-up ODI score was improved to a mean of 6.85±2.9 (3.7%) with a 78.8% correction rate (p=0.000). The overall complication was 15%, with two of distal junctional fractures and one of proximal junctional kyphosis and screw loosening. However, there were no complications directly related to the operation. ConclusionPosterior vertebral column resection through the controlled distraction-compression technique using ETC showed safe and good results in terms of complications, and clinical and radiologic outcomes in PTK. However, to further evaluate the efficacy of this surgical procedure, more patients need long-term follow-up and there is a need to apply it to other diseases.     

Limited Unilateral Decompression and Pedicle Screw Fixation with Fusion for Lumbar Spinal Stenosis with Unilateral Radiculopathy: A Retrospective Analysis of 25 Cases

ObjectiveLumbar spinal stenosis is conventionally treated with surgical decompression. However, bilateral decompression and laminectomy is more invasive and may not be necessary for lumbar stenosis patients with unilateral radiculopathy. We aimed to report the outcomes of unilateral laminectomy and bilateral pedicle screw fixation with fusion for patients with lumbar spinal stenosis and unilateral radiculopathy.MethodsPatients with lumbar spinal stenosis with unilateral lower extremity radiculopathy who received limited unilateral decompression and bilateral pedicle screw fixation were included and evaluated using visual analog scale (VAS) pain and the Oswestry Disability Index (ODI) scores preoperatively and at follow-up visits. Ligamentum flavum thickness of the involved segments was measured on axial magnetic resonance images.ResultsTwenty-five patients were included. The mean preoperative VAS score was 6.6±1.6 and 4.6±3.1 for leg and back pain, respectively. Ligamentum flavum thickness was comparable between the symptomatic and asymptomatic side (p=0.554). The mean follow-up duration was 29.2 months. The pain in the symptomatic side lower extremity (VAS score, 1.32±1.2) and the back (VAS score, 1.75±1.73) significantly improved (p=0.000 vs. baseline for both). The ODI improved significantly postoperatively (6.60±6.5; p=0.000 vs. baseline). Significant improvement in VAS pain and ODI scores were observed in patients receiving single or multi-segment decompression fusion with fixation (p<0.01).ConclusionLimited laminectomy and unilateral spinal decompression followed by bilateral pedicle screw fixation with fusion achieves satisfactory outcomes in patients with spinal stenosis and unilateral radiculopathy. This procedure is less damaging to structures that are important for maintaining posterior stability of the spine.     

Cardiovagal Baroreflex Sensitivity in Parkinson's Disease and Multiple-System Atrophy

MethodsTwo methods were used for determining the BRS: a spontaneous method (spontaneous BRS) and the reflexive baroreflex gain (cardiovagal BRS) from phases II and IV of the Valsalva maneuver (VM) in PD_OH and MSA-P_OH.ResultsThe spontaneous BRS (5.04±0.66 ms/mm Hg vs. 4.78±0.64 ms/mm Hg, p=0.54) and the cardiovagal BRS from phase II of the VM (0.96±0.75 ms/mm Hg vs. 1.34±1.51 ms/mm Hg, p=0.76) did not differ between PD_OH and MSA-P_OH, but the cardiovagal BRS from phase IV of the VM (0.03±0.07 ms/mm Hg vs. 2.86±2.39 ms/mm Hg, p=0.004) was significantly lower in PD_OH.ConclusionsThe cardiovagal BRS from phase IV of the VM has potential for differentiating PD_OH and MSA-P_OH, indicating a difference in the pathophysiological mechanisms underlying the autonomic dysfunction in the two disorders.