Search

Objective To assess the predictive value of swab cultures of cryopreserved skull flaps during cranioplasties for surgical site infections (SSIs). Methods A retrospective review was conducted of consecutive patients who underwent delayed cranioplasties with cryopreserved autografts between 2009 and 2017. The results of cultures obtained from swabs and infected surgical sites were assessed. The accuracy, sensitivity, and specificity of swab cultures for SSIs were evaluated. Results The study included 422 patients categorized into two groups, swab and nonswab, depending on whether swab cultures were implemented during cranioplasties. The overall infection rate was 7.58%. No difference was seen in infection rates between groups. There were 18 false-positive and no true-positive swab culture results. All bacteria between swab cultures and SSI cultures were discordant. Meanwhile, there were 19 false-negative swab cultures. The results showed high specificity but low sensitivity for swab cultures to predict SSI occurrence and the pathogens. Conclusions Owing to low accuracy and sensitivity, swab cultures of cryopreserved autografts should not be routinely performed during delayed cranioplasties.

Background Balloon microcatheters are widely used for endovascular treatment. However, no reports on direct coil embolization from dual-lumen balloon microcatheters are available in the literature. This report is the first description of direct coil embolization using this type of balloon microcatheter for looming bleeding emergencies. Methods This retrospective review demonstrates the indications and advantages of coil embolization from an inflated balloon catheter to reduce blood loss and simultaneously occlude bleeding. Results Five patients who underwent emergency endovascular treatment using coil embolization directly delivered from a dual-lumen balloon were identified. Etiologies included vertebro-vertebral arteriovenous fistula, ruptured vertebral artery dissecting aneurysm, vertebral artery injury during cervical spinal operation, and failed stent retrieval procedures for acute infarction. Complete hemostasis was achieved with all procedures. Conclusion Our experience demonstrates the feasibility of direct coil embolization by using a dual-lumen balloon to rapidly halt bleeding in some rare emergency situations, which may save lives.

ObjectivesFor the endovascular intervention of acute ischemic stroke, a transcervical route is an alternative approach in patients with challenging anatomical variations. Percutaneous puncture is a common way, but it can cause many fatal complications. Direct carotid artery exposure is an alternative for reducing complications. We demonstrate a technique of direct carotid exposure in patients for whom transfemoral or transbrachial approaches were impossible. We present patient outcomes and discuss the indications and limitations of this procedure.MethodsWe retrospectively reviewed the cases of patients undergoing direct carotid exposure for acute ischemic stroke in a hybrid angiography suite and presented the details of the technique.ResultsAmong 548 consecutive patients with acute large vessel strokes who were treated by emergency endovascular thrombectomy or stenting between January 2015 and September 2020 in our center, only 8 (1.46%) required a transcervical approach. Of them, 7 underwent direct carotid exposure with successful recanalization and good clinical outcomes.ConclusionsDirect carotid exposure for endovascular stroke treatment is effective and advantageous in patients with challenging anatomical variations. Performing this procedure in carefully selected patients in the hybrid angiography suite can be beneficial in terms of open surgeries, saving time, and decreasing the risk of postoperative complications.

Cerebrospinal fluid (CSF) leakage due to incidental durotomy is an inherent complication of spine surgery. With appropriate treatment, complications of CSF leakage, such as headache and even meningitis, can be reduced. CSF leakage could be detected on the basis of correlated clinical symptoms; diagnosis should be based on these symptoms and appropriate imaging studies. However, the diagnosis of CSF leakage remains a challenge, especially if incidental durotomy is unrecognized during surgery; even if incidental durotomy is detected and repaired intraoperatively, the severity of the leakage and quality of the primary dural repair are difficult to evaluate postoperatively. Rapid, inexpensive, and safe methods of detecting CSF-containing samples are currently lacking; hence, the development of a point-of-care test (POCT) method to improve diagnostic efficiency is necessary. We developed a high-sensitivity lateral flow immunoassay with a stacking pad (sLFIA) for quantitative detection of β-trace protein (BTP), a specific CSF marker. The BTP concentration in 39 clinical samples was calculated using a calibration equation for test-line intensity and evaluated by a standard laboratory method. To avoid the hook effect, we diluted each sample prior to testing. The correlation coefficient between the enzyme-linked immunosorbent assay and our BTP sLFIA method was 0.991 A 75-fold sample dilution was applied owing to the hook effect point, identified as 175 ng mL

Acquired pial arteriovenous fistula (pAVF) is an extremely rare intracranial vascular malformation, with few case reports in the English literature. This study presents a thorough review and analysis of all acquired pAVF cases from the literature in addition to an illustrated case.We report a case with de novo development of intracranial pAVF after craniotomy. A medical literature database search between 1975 and 2018, including the Medline, Ovid, and PubMed databases, was performed to identify all reports with possible acquired lesions. Differences between these acquired lesions and previously reported primary lesions were evaluated.A total of 8 patients with de novo formation of acquired pAVF were included in this series. Most of these pAVFs were fed and drained via a similar arteriovenous pattern, from distal/cortical branches of the middle cerebral artery (6/8, 75%) to the superficial middle cerebral vein (6/8, 75%). Compared with a previously reported primary pAVF series, acquired pAVF tended to be asymptomatic (P0.0001) and found essentially in adults (P = 0.0061). Fewer venous varices (P = 0.0049) and associated intracranial mass effect (P = 0.0189) were found in the cases of acquired pAVF. All 4 reported acquired pAVFs that were treated microsurgically resulted in complete angiographic obliteration (4/4, 100%). The overall outcome was good or stable even with observation only (7/8, 87.5%).Acquired pAVF is highly correlated with sentinel neurosurgical procedures or venous occlusion events. These lesions should be regarded as a different disease entity from primary pAVF because of the relatively low-flow shunting and benign clinical course.

Background Cranioplasty is a relatively simple and straightforward intervention; however, it is associated with a high incidence of postoperative seizures. Postcranioplasty seizures, especially early seizures, are common and associated with poor outcomes and longer hospital stays. Protocols for preventing and managing early seizures have not been well established. Methods The medical records of 595 patients who underwent cranioplasty were retrospectively reviewed. Of these patients, 259 had preexisting seizures and 336 had no seizures before cranioplasty. Prophylactic antiepileptic drugs (AEDs) were administered to patients who had no seizures before cranioplasty for 1 week, whereas an advanced AED regimen was administered to patients with preexisting seizures. Subsequently, clinical characteristics, occurrence of recurrent seizures, early seizures, and postoperative complications were analyzed. Results Our previous study showed positive results for prophylaxis in new-onset early seizures. In the patients with preexisting seizures, 46.7% of the patients (121/259) experienced recurrent seizures after cranioplasty and 17.4% of the patients (45/259) experienced early recurrent seizures within 1 week of their operation. In the group who received the advanced AEDs, early recurrent seizures were significantly reduced to 8.7% compared with the regular group (20.5%; P = 0.027). Younger age and preoperative hydrocephalus engendered a higher risk of recurrent seizures. The number of previous craniotomies was observed to have a trend of increasing early recurrent seizures. Conclusions Cranioplasty is associated with a high incidence of postoperative seizures. Our management protocol for postcranioplasty seizures includes seizure prophylaxis and advanced use of AEDs, which can reduce the occurrence of early seizures.

Background Dual antiplatelet therapy is widely used for stent-assisted coil embolization (SACE) for unruptured intracranial aneurysms (UIAs) to prevent thromboembolic events (TEs). Compared to clopidogrel associated with aspirin, knowledge of the safety and efficacy of ticagrelor is lacking in large studies to date. Methods A retrospective cohort study was conducted from January 2016 to December 2018 with at least one year of follow-up in a single institution and systemic review. Results Altogether, 153 patients with UIA receiving SACE were separated into two groups: 113 patients receiving clopidogrel plus aspirin and 40 patients receiving ticagrelor plus aspirin. Acute in-stent thrombotic events were noted in two patients in the clopidogrel group (1.77%) and none in the ticagrelor group (0%). Additionally, one patient (0.88%) in the clopidogrel group had an early ischemic stroke (Conclusion Compared to the clopidogrel based regimen, ticagrelor can also reduce TEs without increasing bleeding tendency for SACE of UIAs. Ticagrelor combined with low-dose aspirin is a safe and effective alternative option for SACE.

Background: Posterior reversible encephalopathy syndrome (PRES) is considered a benign entity and is usually reversible with only medical management, but persistent neurologic deficits and disabili...

Background Treatment for circumferential vertebral artery dissecting aneurysms (VADAs) remains challenging. Stent-assisted coil embolization is the most common treatment technique. However, this approach presents high rates of incomplete occlusion and recurrence, often requiring the addition of second or third stents for reconstruction. A flow diverter may achieve favorable clinical outcomes, but it cannot result in immediate aneurysm occlusion and is limited by strict antiplatelets and expensive price. We report excellent results of a 1-stage modified balloon-in-stent technique for circumferential VADA. Methods A total of 12 patients were treated with the modified balloon-in-stent technique for VADAs. A homogeneous coil was used to fill the aneurysm sac, followed by deployment of 1 self-expandable stent and in-stent Scepter balloon angioplasty. Clinical presentations, outcomes, and imaging results were evaluated over at least 2 years of follow-up. Results Our 12 patients were examined during a mean follow-up period of 36.2 months (range, 2–5 years). The initial symptoms presented included subarachnoid hemorrhage (5 of 12; 41.7%), ischemia (3 of 12; 25.0%), and nonischemia (4 of 12; 33.3%). The modified BIS technique and coil embolization were successful in all patients. No technique-related complications or recanalization occurred during follow-up. Conclusions We demonstrated an innovative modified BIS technique to treat circumferential VADA by using a coiling basket followed by the deployment of a self-expandable stent and in-stent Scepter balloon angioplasty. This strategy is safe, feasible, and cost effective and was not associated with recurrence or complications over at least 2 years of follow-up.

Background: Cerebral vasospasm still results in high morbidity and mortality rates in patients after aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to establish a protocol for the management of vasospasm and demonstrate our experience of angioplasty using the Scepter XC balloon catheter. Methods: An image survey was arranged if early symptomatic vasospasm occurred, or on the 7th day following aneurysmal SAH. In patients with clear consciousness, balloon angioplasties were performed for symptomatic vasospasms, which were not improved within 6-12 hours after maximal medical treatments. In unconscious patients, balloon angioplasties were performed for all patients with angiographic vasospasms. We retrospectively reviewed clinical findings, radiological results, and functional outcomes for these patients. Results: Fifty patients underwent Scepter XC balloon angioplasty among 396 consecutive patients who accepted endovascular or surgical treatments for ruptured aneurysms. All angioplasty procedures were successful without complications. 100% angiographic improvement and 94% clinical improvement were reached immediately after the angioplasties. A favorable functional outcome (modified Rankin Score of ≤2) could be achieved in 82% of patients. Even in patients with poor clinical grading (Hunt–Hess grade 4–5), a clinical improvement rate of 87.5% and favorable functional outcome rate of 70.8% could still be achieved. Conclusion: Balloon angioplasty with Scepter XC balloon catheter is safe and effective for post-SAH vasospasm. This device’s extra-compliant characteristics could considerably improve the quality of angioplasty procedures. For all patients, even those with poor neurological status, aggressive evaluation and early treatment of vasospasm can noticeably improve clinical outcomes.

Severe neurological complications following infective endocarditis remain a major problem with high mortality rate. The long-term neurological consequences following infective endocarditis remain uncertain. Otherwise, neurosurgeries could be performed after these complications; however, few clinical series have reported the results. Therefore, we utilized a large, nationwide database to unveil the long-term mortality and neurosurgical outcome following infective endocarditis. We included patients with a first-time discharge diagnosis of infective endocarditis between January 2001 and December 2013 during hospitalization. Patients were further divided into subgroups consisting of neurological complications under neurosurgical treatment and complications under non-neurosurgical treatment. Long-term result of symptomatic neurological complications after infective endocarditis and all-cause mortality after different kinds of neurosurgeries were analyzed. There were 16,495 patients with infective endocarditis included in this study. Symptomatic neurological complications occurred in 1,035 (6.27%) patients, of which 279 (26.96%) accepted neurosurgical procedures. Annual incidence of neurological complications gradually increased from 3.6% to 7.4% (P P = 0.012, increased from 20% initially to nearly 50% over the 5-year follow-up). However, neurosurgery had no effect on the long-term mortality rate (50.9% vs. 47.6%, P = 0.451). Incidence of neurological complications post-infective endocarditis is increasing, and patients with these complications have higher mortality rates than patients without. Neurosurgery in these populations was not associated with higher long-term mortality. Therefore, it should not be ruled out as an option for those with neurological complications.

Objective Increased intracranial pressure (ICP) is a well-known complication after aneurysmal subarachnoid hemorrhage (aSAH). This study focused on the different temporal changes in ICP, mean arterial pressure, and cerebral perfusion pressure at the early stage of aSAH, throughout aneurysm embolization, and their effects on improvement in angiographic perfusion patterns. Methods Twenty-seven patients with aSAH were evaluated who underwent coiling and cerebrospinal fluid (CSF) drainage. Diagnostic angiography was performed to confirm the presence and location of the vascular lesion. The transit time of the capillary filling phase was defined as a surrogate of cerebral perfusion. Capillary filling transit times were compared before and after CSF drainage. Univariate and multivariate analyses were performed to identify associations between different physical parameters and capillary filling transit times. Results By univariate analysis, average capillary transit time before CSF drainage had a significant correlation with initial ICP (P = 0.0004; R2 = 0.398) but not systemic pressure (mean arterial pressure or cerebral perfusion pressure). Improvement in capillary filling pattern (i.e., a decrease in angiographic capillary transit time after CSF drainage) was seen in patients with high initial ICP and correlated with ICP difference after ventricular drainage (P = 0.0001 and P Conclusions Decreasing ICP by CSF drainage strongly correlated with improved cerebral microcirculation after aSAH. Further development of ICP control protocols that can provide better ICP management of patients with aSAH is warranted.

Background A ruptured vertebral artery dissecting aneurysm (VADA) with a high clinical grade (Hunt and Hess grade 5) has a devastating prognosis. Because of the high rebleeding rate and location, rapid mortality can occur in patients owing to brainstem compression. Adjuvant decompression of the posterior fossa after securing the aneurysm may improve the outcomes of these patients. Methods Between January 2011 and December 2016, 22 patients who presented with Hunt and Hess grade 5 ruptured VADA underwent endovascular treatment. Patients were divided into 2 groups: group 1 (n = 12) received conventional endovascular treatment of VADA and external ventricular drainage, and group 2 (n = 10) received external ventricular drainage and suboccipital craniectomy for posterior fossa decompression after rapid endovascular trapping of VADA. Results In group 2, the survival rate and good clinical outcome rate (modified Rankin scale score ≤2) were 80% and 60%, respectively, which were favorable to the corresponding rates in group 1 (66.67% and 16.67%). Moreover, 80% of patients (8/10) in group 2 regained consciousness compared with 50% of patients in group 1. Conclusions Adjuvant decompression of the posterior fossa can improve outcomes in patients with Hunt and Hess grade V ruptured VADA.

Background Vasospasm is a major cause of morbidity and mortality in patients after aneurysmal subarachnoid hemorrhage. Early treatment of ruptured aneurysms is advocated; delayed intervention complicates the treatment strategy leading to significant vasospasm and poor prognosis. We report an endovascular protocol for occlusion of the unsecured aneurysm and angioplasty for vasospasm in a single session. Methods Between January 2011 and May 2017, among 660 patients with aneurysmal subarachnoid hemorrhage, 24 patients with significant vasospasm and unsecured ruptured cerebral aneurysm were reviewed. Continuous nimodipine drip through a pressure line of the guiding catheter was set up. Aggressive angioplasty with a compliant balloon catheter either before or after embolization of the aneurysm in the major branches of vasospastic territory was performed. The goal was complete embolization of the aneurysm. Results Of 24 patients, 17 had ischemic symptoms at presentation, and the average delay from aneurysm rupture to presentation was 7.58 days. Angioplasty and nimodipine drip were performed on all patients. Severity of vasospasm was significantly reduced, and outcome improved in each patient. Two patients required a second angioplasty. In 20 patients, embolization of aneurysms was achieved without any aneurysmal sac or residual neck. Clinical outcome was good recovery (modified Rankin Scale score 0–2) in 23 patients (95.8%) and moderate disability in 1 patient (modified Rankin Scale score 3). Conclusions Aggressive endovascular treatment of patients with unsecured ruptured cerebral aneurysm and associated vasospasm is safe and effective.

Neurocutaneous melanosis (NCM) is characterized by diffuse or focal proliferation of melanin-producing cells over the skin or leptomeninges. Even without malignant transformation, the prognosis is poor after symptomatic progression of NCM, resulting from either mass effect in central nervous system or hydrocephalus. We reported a 26-year-old female patient with rapid deterioration after the onset of NCM. Despite no solid tumor formation, elevated cerebrospinal fluid protein content, which complicated shunting procedure, associated with hydrocephalus played the key role in clinical deterioration. Adult onset of NCM with Dandy–Walker malformation was never reported in our literature review. Diagnosis and treatment for such disease entity are discussed.

Background Proximal anterior cerebral artery (A1) aneurysms are rare among all intracranial aneurysms and are regarded as difficult to treat endovascularly. Treatment is even more challenging in patients with ruptured aneurysms and acute subarachnoid hemorrhage owing to the small size and proximity to perforators. Though challenging, endovascular treatment can provide favorable outcomes in such patients. We report our case series of endovascular treatment in ruptured proximal A1 aneurysms. Methods Between January 2010 and December 2017, 1200 aneurysms were treated endovascularly at our center. There were 15 patients with 15 ruptured proximal A1 aneurysms who presented with subarachnoid hemorrhage. Five patients underwent simple coiling, 9 underwent balloon-assisted coiling, and 1 underwent catheter protective coiling. Medical records and angiographic results were obtained retrospectively. Results All aneurysms were successfully treated with endovascular techniques. Multiplicity rate was 53.3% (n = 8). Initial complete obliteration rate was 93.3% (n = 14), with a 13.3% recurrence rate (n = 2). One patient experienced intraoperative bleeding; this was the only procedure-related complication. Eleven patients (73.3%) had a good clinical outcome. When excluding Hunt and Hess grade 4 patients, the good outcome rate was 81.8%. Conclusions Ruptured proximal A1 aneurysm is a rare condition and is highly associated with multiple aneurysms. Despite being a more difficult and complicated technique, endovascular coiling performed in high-volume, experienced medical centers is an effective modality with excellent clinical outcomes.

Cranioplasty is a technically simple procedure intended to repair defects of the skull to provide protection after craniectomy, improve functional outcomes, and restore cosmesis. Several materials have been used for the restoration of skull defects, including autologous bone grafts (AGs), polymethyl methacrylate (PMMA) flaps, and titanium mesh (T-mesh). However, the long-term results of cranioplasty after use of these materials are controversial.Medical records of 596 patients who underwent cranioplasty at our medical center between 2009 and 2015 with at least 2.5 years of follow-up were retrospectively reviewed. Patients were classified into 3 groups according to the materials used: AG, three-dimensional PMMA, and T-mesh. Demographic and clinical characteristics and postoperative complications were analyzed.Cranioplasty with AG had the highest bone flap depression rate (4.9%; P = 0.02) and was associated with a 26% long-term bone flap resorption. Younger age was a risk factor for bone flap resorption. T-mesh had a higher risk of postoperative skin erosion and bone exposure (17%; P = 0.004). Patients with diabetes, previous craniotomy, or hydrocephalus showed a higher risk of postoperative skin erosion. PMMA was associated with the highest rate of postoperative infection (14.4%3 months, 28.1%3 months; P0.05), and previous craniotomy may increase the infection risk after cranioplasty with PMMA.Complications after cranioplasty are high, and the various types of cranioplasty materials used are associated with different complications. Surgeons need to be aware of these potential complications and should choose the appropriate material for each individual patient.

Children with abusive head trauma tend to have worse outcomes than children with accidental head trauma. However, current predictors of poor outcomes for children with abusive head trauma are still limited. We aim to use clinical data to identify early predictors of poor outcome at discharge in children with abusive head trauma. In the 10-year observational retrospective cohort study, children aged between zero and four years with abusive or accidental head trauma were recruited. Multivariate logistic regression models were applied to evaluate factors associated with poor prognosis in children with abusive head trauma. The primary outcome was mortality or a Glasgow Coma Scale (GCS) motor component score of less than 6 at discharge. A total of 292 head trauma children were included. Among them, 59 children had abusive head trauma. In comparison to children with accidental head trauma, children with abusive head trauma were younger, had more severe head injuries, and experienced a higher frequency of post-traumatic seizures. Their radiologic findings showed common presence of subdural hemorrhage, cerebral edema, and less epidural hemorrhage. They were more in need of neurosurgical intervention. In the multivariate analysis for predictors of poor outcome in children with abusive head trauma, initial GCS &le, 5 (versus GCS &gt, 5 with the adjusted odds ratio (OR) = 25.7, 95% confidence interval (CI) = 1.5&ndash, 432.8, p = 0.024) and older age (per year with the adjusted OR = 3.3, 95% CI = 1.2&ndash, 9.5, p = 0.024) were independently associated with poor outcome. These findings demonstrate the characteristic clinical differences between children with abusive and accidental head trauma. Initial GCS &le, 5 and older age are predictive of poor outcome at discharge in children with abusive head trauma.

OBJECTIVEDiverse treatment results are observed in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH). Significant initial perfusion compromise is thought to predict a worse treatment outcome, but this has scant support in the literature. In this cohort study, the authors correlate the treatment outcomes with a novel poor-outcome imaging predictor representing impaired cerebral perfusion on initial CT angiography (CTA).METHODSThe authors reviewed the treatment results of 148 patients with poor-grade aSAH treated at a single tertiary referral center between 2007 and 2016. Patients with the “venous delay” phenomenon on initial CTA were identified. The outcome assessments used the modified Rankin Scale (mRS) at the 3rd month after aSAH. Factors that may have had an impact on outcome were retrospectively analyzed.RESULTSCompared with previously identified outcome predictors, the venous delay phenomenon on initial CTA was found to have the strongest correlation with posttreatment outcomes on both univariable (p < 0.0001) and multivariable analysis (OR 4.480, 95% CI 1.565–12.826; p = 0.0052). Older age and a higher Hunt and Hess grade at presentation were other factors that were associated with poor outcome, defined as an mRS score of 3 to 6.CONCLUSIONSThe venous delay phenomenon on initial CTA can serve as an imaging predictor for worse functional outcome and may aid in decision making when treating patients with poor-grade aSAH.

OBJECTIVECranioplasty is a relatively simple and less invasive intervention, but it is associated with a high incidence of postoperative seizures. The incidence of, and the risk factors for, such seizures and the effect of prophylactic antiepileptic drugs (AEDs) have not been well studied. The authors’ aim was to evaluate the risk factors that predispose patients to postcranioplasty seizures and to examine the role of seizure prophylaxis in cranioplasty.METHODSThe records of patients who had undergone cranioplasty at the authors’ medical center between 2009 and 2014 with at last 2 years of follow-up were retrospectively reviewed. Demographic and clinical characteristics, the occurrence of postoperative seizures, and postoperative complications were analyzed.RESULTSAmong the 583 patients eligible for inclusion in the study, 247 had preexisting seizures or used AEDs before the cranioplasty and 336 had no seizures prior to cranioplasty. Of these 336 patients, 89 (26.5%) had new-onset seizures following cranioplasty. Prophylactic AEDs were administered to 56 patients for 1 week after cranioplasty. No early seizures occurred in these patients, and this finding was statistically significant (p = 0.012). Liver cirrhosis, intraoperative blood loss, and shunt-dependent hydrocephalus were risk factors for postcranioplasty seizures in the multivariable analysis.CONCLUSIONSCranioplasty is associated with a high incidence of postoperative seizures. The prophylactic use of AEDs can reduce the occurrence of early seizures.

Objective Degenerative spondylolisthesis of the spine is less common in the lower thoracic region than in the lumbar and cervical regions. However, lower thoracic degenerative spondylolisthesis may develop secondary to intervertebral disc degeneration. Most of our patients are found to have concomitant lumbar spondylosis. By retrospective review of our cases, current diagnosis and treatments for this rare disease were discussed. Materials and methods We present a series of 5 patients who experienced low back pain, progressive numbness, weakness and even paraparesis. Initially, all of them were diagnosed with lumbar spondylosis at other clinics, and 1 patient had even received prior decompressive lumbar surgery. However, their symptoms continued to progress, even after conservative treatments or lumbar surgeries. These patients also showed wide-based gait, increased deep tendon reflex (DTR), and urinary difficulty. All these clinical presentations could not be explained solely by lumbar spondylosis. Thoracolumbar spinal magnetic resonance imaging (MRI), neurophysiologic studies such as motor evoked potential (MEP) or somatosensory evoked potential (SSEP), and dynamic thoracolumbar lateral radiography were performed, and a final diagnosis of lower thoracic degenerative spondylolisthesis was made. Results Bilateral facet effusions, shown by hyperintense signals in T2 MRI sequence, were observed in all patients. Neurophysiologic studies revealed conduction defect of either MEP or SSEP. One patient refused surgical management because of personal reasons. However, with the use of thoracolumbar orthosis, his symptoms/signs stabilized, although partial lower leg myelopathy was present. The other patients received surgical decompression in association with fixation/fusion procedures performed for managing the thoracolumbar lesions. Three patients became symptom-free, whereas in 1 patient, paralysis set in before the operation; this patient was able to walk with assistance 6 months after surgical decompression. The average Nurick scale score improved from 3.75 before the operation to 2 after the operation. Conclusion Lower thoracic degenerative spondylolisthesis is a rare disease, which may occur concomitantly with lumbar spondylosis and confuse clinicians. Diagnosis should be made properly, especially because symptoms/signs cannot be explained purely on the basis of the available images. Micromotion due to facet joint laxity and disc degeneration was believed as the cause of progressive myelopathy. Posterior decompression with fixation/fusion procedure was appropriate for the treatment of thoracic spondylolisthesis secondary to thoracic disc degeneration.

Object Spontaneous spinal epidural hematoma (SSEH) is a rare disease. The goal of this study was to clarify the treatment results and management options in SSEH. Methods Patients with SSEH who were surgically treated in the authors' center between June 2003 and June 2008 were included in this study. Patients were treated as early as possible if their neurological deficits were incomplete or had been complete for 12 hours or less. The patients were assigned to 1 of 2 groups based on completeness of preoperative cord dysfunction (complete vs incomplete deficit). Surgical outcomes of the 2 groups were compared by functional performance, coded as Nurick grades at 1, 3, and 6 months after the operation. Also compared were duration of hospital stay and the number of days needed to regain the ability to function independently (defined as Nurick Grades 1 and 2) after the operation. Results There were 17 patients (7 female and 10 male) with pathologically confirmed SSEH. Coagulopathy, greater size (length) of SSEH, and preoperative complete spinal dysfunction were found to contribute to poor postoperative functional recovery (p < 0.05). Patients with incomplete preoperative deficits (ASIA Impairment Scale Grades B, C, and D) were able to achieve functional independent recovery within a month after surgery and had significantly better outcomes (lower Nurick grades) at 1, 3, and 6 months postoperatively than those with complete deficits (p < 0.001, p = 0.027, and p = 0.027, respectively). Median time to independent functional recovery and median length of hospital stay were significantly shorter in patients with incomplete preoperative deficits than in those with complete deficits (6 vs 110 and 9 vs 58 days, respectively; both p < 0.001). Conclusions Impaired preoperative hemostasis contributes to larger size of SSEH, high probability of postoperative recurrence of spinal epidural hematoma, and poor functional recovery following surgical evacuation. Incomplete spinal cord dysfunction before surgery predicts good outcome and warrants emergent evacuation of SSEH especially in the cervical and thoracic regions, where the clots are located in proximity to the spinal cord.

This letter presents a new approximate spatial correlation formulation of arbitrary angle-of-arrival (AoA) scenarios. The proposed approximation scheme can be applied to the parameterized three-dimensional (3-D) spatial correlation formulation taking antenna mutual coupling effect into consideration. Computation time can thus be significantly saved using the new spatial correlation formulation, which is beneficial for gauge of multiple-input multiple-output (MIMO) antenna systems.

We employed a multilayered dielectric slab to implement subwavelength target detection by utilizing ultrawideband (UWB) time-reversal (TR) techniques. Simulation results with/without the multilayered dielectric slab are presented to show the benefit of the multilayered dielectric slab structure using finite-difference time-domain (FDTD) method.

Among patients with medulloblastoma, an unrare aggressive central nervous system (CNS) tumor found mostly in the posterior fossa, drop metastasis from primary location to anatomically lower sites including whole spinal cord is known as a potential way for tumor to spread. There were already lots of extensive discussions regarding diagnosis and treatment for such common neurologic complication in systemic cancer; however, fewer were found about medulloblastoma. This study aimed to reexamine the possible known prognostic factors, especially drop metastasis, and defined the influence of them. We retrospectively review a series of 36 patients who suffered from posterior fossa medulloblastoma and found leptomeningeal metastasis in 12 of them. Incidence, diagnosis, prognostic factors, and treatments for this common complication are discussed. The magnetic resonance images (MRI) of these patients were reviewed. The time sequence between primary surgical procedure and development of MRI evidences of drop metastasis was used for subgrouping. Log-rank test was used for survival analysis. By survival analysis, patients with late drop metastasis, defined as new radiologic evidence of leptomeningeal involvement after primary CNS procedures, were found to have significant survival difference to those with early metastasis defined as drop metastasis found at the time of diagnosis (log-rank test, p = 0.0047). Further stratification of patients within this group may help in evaluation of prognosis and development of different treatment strategies.

How to efficiently make good use of the limited frequency spectrum is one of the main issues in the whole communication systems. Multiple-input-multiple-output (MIMO) antennas technology offers an effective solution to achieve the goal of maximal spectral efficiency with multiple antennas at both transmitter and receiver ends. MIMO shows the potential as the solution for the next generation communication systems. Radiation efficiency is an important issue when referring to the performance of multiple antennas systems in desire for high power efficiency. Realizing multiple antennas systems in radio channels becomes challenging because of the unavoidable mutual coupling effect between multiple antennas in portable devices. Mutual coupling effect distorts the antenna far-field patterns and therefore has great impact on how much power radiates without reflection resulting from impedance mismatch and absorption by adjacent antenna elements. We therefore proposed the newly defined radiation efficiency, which is based on total active reflection coefficient (TARC) in this work. The TARC-based radiation efficiency can take into account the effect when ports of the multiple antennas system are fed with signals of different phases simultaneously. Moreover, the survey of how port termination networks impact on radiation efficiency is conducted as the gauge to judge if a given multiple antennas system is well designed and further helps how we may improve the performance of the MIMO antennas systems.

STUDY DESIGN Case report. OBJECTIVE To report a case of lumbar intraneural hemorrhagic cyst after anticoagulation therapy that caused progressive radiculopathy and cauda equina syndrome. The possible pathogenic mechanism, associated diseases, and treatment options are discussed. SUMMARY OF BACKGROUND DATA Various pathological processes can cause progressive cauda equina syndrome. However, there have been no reports of progressive cauda equina syndrome due to compression from an intraneural hemorrhagic cyst after anticoagulation therapy. METHODS A case of lumbar intradural intraneural hemorrhagic cyst with progressive cauda equina syndrome after anticoagulation therapy is presented. RESULTS A 42-year-old-female patient complained at presentation of progressive bilateral lower extremity radiating pain, numbness, and urinary difficulty during the previous 2 months. Lumbar magnetic resonance imaging revealed an L1 cystic lesion with marked mass effect on the surrounding nerve roots. Complete drainage and excision of the lesion was performed, which resulted in excellent postoperative symptoms relief. Pathological examination revealed no definite neoplastic process except some nerve fibers with hemosiderin stain along the cyst wall. On the basis of a combination of intraoperative findings and pathology, an intradural intraneural hemorrhagic cyst that developed after systemic anticoagulation therapy was diagnosed. CONCLUSION This is the first report of an intradural intraneural hemorrhagic cyst causing progressive cauda equina syndrome due to anticoagulation therapy. Surgical excision of the cyst is the definite treatment of choice. LEVEL OF EVIDENCE N/A.

A novel three-tap passive equalizer design is proposed in this work. Comparing with traditional passive equalizers, the proposed design has three-tap equalization and shows higher flexibility of design, which can compensate the ISI effectively which long channels bring and is easy to fabricate in multi-layer PCB process. Moreover, the significant improvement of eye opening and jitter are demonstrated with the adoption of the proposed equalizer in a long SAS 6Gbps channel.

In order to improve the electrical channel designs with FPC board, a novel FPC structure is proposed in this work. The new transmission line structure not only shows the merit of precise impedance control of FPC board but also avoids the common-mode issue which arises from the meshed ground. Moreover, the new transmission line structure is compatible with the traditional FPC manufacturing process and can be manufactured without extra cost. This proposed structure was validated with 3D EM simulation and experiment, and assured of the feasibility and practiced in mass production to implement PCI-Express signals on FPC successfully.

Spontaneous spinal epidural hematoma (SSEH) is a rare disease. The goal of this study was to clarify the treatment results and management options in SSEH.Patients with SSEH who were surgically treated in the authors' center between June 2003 and June 2008 were included in this study. Patients were treated as early as possible if their neurological deficits were incomplete or had been complete for 12 hours or less. The patients were assigned to 1 of 2 groups based on completeness of preoperative cord dysfunction (complete vs incomplete deficit). Surgical outcomes of the 2 groups were compared by functional performance, coded as Nurick grades at 1, 3, and 6 months after the operation. Also compared were duration of hospital stay and the number of days needed to regain the ability to function independently (defined as Nurick Grades 1 and 2) after the operation.There were 17 patients (7 female and 10 male) with pathologically confirmed SSEH. Coagulopathy, greater size (length) of SSEH, and preoperative complete spinal dysfunction were found to contribute to poor postoperative functional recovery (p0.05). Patients with incomplete preoperative deficits (ASIA Impairment Scale Grades B, C, and D) were able to achieve functional independent recovery within a month after surgery and had significantly better outcomes (lower Nurick grades) at 1, 3, and 6 months postoperatively than those with complete deficits (p0.001, p = 0.027, and p = 0.027, respectively). Median time to independent functional recovery and median length of hospital stay were significantly shorter in patients with incomplete preoperative deficits than in those with complete deficits (6 vs 110 and 9 vs 58 days, respectively; both p0.001).Impaired preoperative hemostasis contributes to larger size of SSEH, high probability of postoperative recurrence of spinal epidural hematoma, and poor functional recovery following surgical evacuation. Incomplete spinal cord dysfunction before surgery predicts good outcome and warrants emergent evacuation of SSEH especially in the cervical and thoracic regions, where the clots are located in proximity to the spinal cord.

This paper presents TARC-based radiation efficiency evaluates how the radiation efficiency varies when the antenna ports excite signals with different phases. Moreover, the survey of how port termination networks impact on radiation efficiency is conducted as the gauge to judge if a given multiple antenna system is well designed and further helps how we may improve the performance of the multiple antenna system.

This paper proposes a new approximate correlation calculation where the angle-of-arrival (AoA) distribution is the uniform distribution. Moreover, this study takes mutual coupling effect into consideration and investigates how mutual coupling affects the correlation.