Comparison of Reoperation after Fusion and after Decompression for Degenerative Lumbar Spinal Stenosis: A Single-Center Experience of 987 Cases.

BACKGROUND AND STUDY AIM: Reoperation for lumbar spinal stenosis (LSS) is technically challenging. Studies comparing preoperative risk factors and reoperation outcomes between spinal fusion and spinal decompression are limited. Thus this study compared fusion and decompression with respect to reoperation rates, preoperative factors related to re-surgery, and clinical outcomes. PATIENTS AND METHODS: This retrospective cohort study included prospectively collected data from patients who underwent revision surgeries for degenerative LSS between May 2001 and March 2015. The reoperation rate, risk factors (proportional hazards analysis of index surgery), surgery type, main reason for revision, and final clinical outcomes (pain, quality-of-life modification, patient satisfaction, and complication rate) were analyzed and compared between the fusion and decompression surgeries. RESULTS: Among 987 cases during 13 years, 25 cases of reoperation after fusion and 23 cases of reoperation after decompression were identified, accounting for reoperation rates of 5.88% and 4.00%, respectively. Combined comorbidities (hazard ratio [HR]: 1.98 for fusion; multilevel involvement [with fusion, HR: 2.92; decompression, HR: 1.95]) were strongly correlated with preoperative demographic risk factor for each procedure. The main reason for reoperation in fusion cases was proximal junctional kyphosis (40%) and implant failure (20%), and in decompression cases, recurrent lesions (48.8%) and incomplete surgery (17.4%) An additional fusion after initial fusion and re-decompression without fusion after initial decompression were the most common surgical procedure. Back pain and patient satisfaction after fusion were better compared with those after decompression. CONCLUSION: The reoperation rate, preoperative risk factors, reason for revision, reoperation type, clinical outcomes, patient satisfaction, and time interval between index and re-surgery were different between the primary fusion and primary decompression. A better understanding of disease pathophysiology and surgical procedure characteristics will facilitate improvement in disease management and the development of treatment strategies.

Safety and completeness of using indocyanine green videoangiography combined with digital subtraction angiography for aneurysm surgery in a hybrid operating theater.

This study aimed to evaluate the safety and completeness of using intraoperative indocyanine green videoangiography (ICGV) combined with intraoperative angiography (IOA) for aneurysm clipping in a hybrid operating room (hOR). All patients who underwent microsurgical clipping in the hOR were identified from prospectively maintained neurosurgical databases. Medical charts and operative videos with ICGV and IOA were reviewed to determine the adequacy of clipping, and clinical and angiographic outcomes were retrospectively analyzed. Fifty-four cerebral aneurysms (ruptured, 31; unruptured, 23) in 50 patients (mean age, 59.4 ± 10.9 y; M:F, 22:28) were evaluated with ICGV and IOA during clipping. Additional IOA led to a clip adjustment during surgery in 9/54 (16.7%) aneurysms for which ICGV had been initially performed. Post-clip perforator compromise occurred in two (3.7%) cases, with a patient with an unruptured aneurysm experiencing permanent injury (grade 3 hemiparesis) and patient with a ruptured aneurysm experiencing transient deficit. Post-clip parent vessel stenosis occurred in one (1.9%) case; however, an ischemic event did not occur because the flow patency was identified by IOA. No other patients with unruptured aneurysms developed new neurologic deficits at discharge. Favorable outcomes (Glasgow Outcome Score [GOS], 4 or 5) were observed in 26/31 patients with ruptured aneurysms. Five patients had unfavorable outcomes (GOS, 2 or 3) from the initial insult. Post-treatment angiography within 1 week showed complete occlusion in 52 (96.3%) aneurysms and minor remnants in two (3.7%) aneurysms. Using combined ICGV and IOA in a hOR may improve the safety and completeness of microsurgical aneurysm clipping.

Endovascular Coiling for a Wide-neck Bifurcated Aneurysm with Anterograde Horizontal Stenting via Microcatheter Looping: A Technical Case Report.

Technical advances with devices such as catheters, balloons, and stents have widened the indications for endovascular coiling for unfavorable aneurysms. The authors report two cases of coil embolization for a wide-neck bifurcated aneurysm with anterograde horizontal stenting via microcatheter looping. Two women, aged 56 and 38 years, respectively, had an undertall- and overwide-neck aneurysm with bifurcated branches at the basilar bifurcation and middle cerebral bifurcation, respectively. The delivery microcatheter was steamed so that it could be looped deliberately to the opposite vessel. The enterprise stent was first anchored to the vessel of the posterior cerebral artery on one side. The remaining portion was spanned into a looped microcatheter to the opposite branch while pushing the stent. The Neuroform Atlas stent was passed directly through the looped segment of the microcatheter at the M2 branch and spanned horizontally by unsheathing. Under horizontal stenting, complete coil embolization was achieved without immediate or delayed complications in both cases. This novel technique presents a viable option for stent-assisted coiling within an optimal anatomy.

Transcervical access via direct neck exposure for neurointerventional procedures in the hybrid angiosuite.

PURPOSE: A complicated course of the femoral route for neurointervention can prevent approaching the target. Thus, we determined whether transcervical access in the hybrid angiosuite is applicable and beneficial in real practice. METHODS: From January 2014 to March 2017, this approach was used in 17 of 453 (3.75%) cases: 11 cerebral aneurysms (4 ruptured, 7 unruptured), 4 acute occlusions of the large cerebral artery, 1 proximal internal carotid artery (ICA) stenosis, and 1 direct carotid cavernous fistula (CCF). RESULTS: All patients were elderly (mean age, 78.1 years). The main cause was severe tortuosity of the supra-aortic course or the supra-aortic and infra-aortic courses (eight and five cases, respectively), orifice disturbance (three cases), and femoral occlusion (one case). Through neck dissection, 6-8Fr guiding catheters were placed via subcutaneous tunneling to enhance device stability and support. All cerebral aneurysms were embolized (eight complete and three neck remnants) using the combination of several additional devices. Mechanical stent retrieval with an 8Fr balloon guiding catheter was successfully achieved in a few runs (mean, 2 times; range, 1-3) within the proper time window (mean skin to puncture, 17 ± 4 min; puncture to recanalization, 25 ± 4 min). Each stent was satisfactorily deployed in the proximal ICA and direct CCF without catheter kick-back. All puncture sites were closed through direct suturing without complications. CONCLUSIONS: In the hybrid angiosuite, transcervical access via direct neck exposure is feasible in terms of device profile and support when the femoral route has an unfavorable anatomy.

Magnetic Resonance Imaging Patterns of Post-Operative Spinal Infection: Relationship between the Clinical Onset of Infection and the Infection Site.

OBJECTIVE: To investigate the magnetic resonance imaging (MRI) findings and the patterns of postoperative spinal infection according to the passage of time. METHODS: Institutional review board approval was obtained, and informed consent was not obtained for the retrospective review of patients' medical records. A total of 43 patients (27 men and 16 women; mean age, 64) diagnosed with postoperative spinal infection were included in this study. We retrospectively reviewed the MRI findings and the medical records and categorized the infection sites based on MRI, i.e., anterior, posterior, and both parts. The duration of the clinical onset from surgery was divided, i.e., acute (≤2 weeks), subacute (2-4 weeks), and late (>4 weeks). RESULTS: Postoperative spinal infection was involved in the posterior part in 31 (72%), anterior part in two (4.7%), and both parts in 10 patients (23.3%). Abscess or phlegmon in the back muscles and laminectomy site were the most common MRI findings. The number of patients with acute, subacute, and late clinical onset were 35, two, and six, respectively (mean, 33.4 days; range, 1-730 days). The mean duration of the clinical onset was 12 days in the posterior part, 15.2 days in both parts, and 456.5 days in the anterior part. CONCLUSION: Postoperative spinal infection usually occurred within four weeks in the posterior part and over time the infection was considered to spread into the anterior part. For the evaluation of postoperative spinal infection, the posterior surgical field was more important than the vertebral body or the disc space on MRI.

Single-Stage Operation for Giant Schwannoma at the Craniocervical Junction with Minimal Laminectomy: A Case Report and Literature Review.

Here we report a single-stage operation we performed on a patient with a large schwannoma that extended from the lower clivus to the cervico-thoracic junction caudally. A number of authors have previously performed multilevel laminectomy to remove giant schwannomas that extend for considerable length. This technique has caused cervical instability such as kyphosis or gooseneck deformity on several occasions. We removed the tumor with a left lateral suboccipital craniectomy with laminectomy only at C1 and without any subsequent surgery-related neurologic deficits. However, this technique requires meticulous preoperative evaluation on existence of Cerebrospinal fluid (CSF) cleft between the tumor and spinal cord on magnetic resonance imaging, of tumor origin located at the upper cervical root, and of detachment of tumor from the origin site.

Surgical Treatment for Falcotentorial Meningiomas.

Among intracranial meningiomas, falcotentorial meningiomas, occurring at the junction of the falx cerebri and tentorial dural folds, are extremely rare. Because of their deep location, they are surrounded by critical structures, and have been regarded as one of the most challenging lesions for surgical treatment. In this study, we describe our surgical strategy for falcotentorial meningiomas and provide a review of our experience.

Biomechanical Comparisons of Pull Out Strengths After Pedicle Screw Augmentation with Hydroxyapatite, Calcium Phosphate, or Polymethylmethacrylate in the Cadaveric Spine.

OBJECTIVE: In vertebrae with low bone mineral densities pull out strength is often poor, thus various substances have been used to fill screw holes before screw placement for corrective spine surgery. We performed biomechanical cadaveric studies to compare nonaugmented pedicle screws versus hydroxyapatite, calcium phosphate, or polymethylmethacrylate augmented pedicle screws for screw tightening torques and pull out strengths in spine procedures requiring bone screw insertion. METHODS: Seven human cadaveric T10-L1 spines with 28 vertebral bodies were examined by x-ray to exclude bony abnormalities. Dual-energy x-ray absorptiometry scans evaluated bone mineral densities. Twenty of 28 vertebrae underwent ipsilateral fluoroscopic placement of 6-mm holes augmented with hydroxyapatite, calcium phosphate, or polymethylmethacrylate, followed by transpedicular screw placements. Controls were pedicle screw placements in the contralateral hemivertebrae without augmentation. All groups were evaluated for axial pull out strength using a biomechanical loading frame. RESULTS: Mean pedicle screw axial pull out strength compared with controls increased by 12.5% in hydroxyapatite augmented hemivertebrae (P = 0.600) and by 14.9% in calcium phosphate augmented hemivertebrae (P = 0.234), but the increase was not significant for either method. Pull out strength of polymethylmethacrylate versus hydroxyapatite augmented pedicle screws was 60.8% higher (P = 0.028). CONCLUSIONS: Hydroxyapatite and calcium phosphate augmentation in osteoporotic vertebrae showed a trend toward increased pedicle screw pull out strength versus controls. Pedicle screw pull out force of polymethylmethacrylate in the insertion stage was higher than that of hydroxyapatite. However, hydroxyapatite is likely a better clinical alternative to polymethylmethacrylate, as hydroxyapatite augmentation, unlike polymethylmethacrylate augmentation, stimulates bone growth and can be revised.

Cryptococcal brainstem abscess mimicking brain tumors in an immunocompetent patient.

Usually fungal infections caused by opportunistic and pathogenic fungi had been an important cause of morbidity and mortality among immunocompromised patients. However clinical data and investigations for immunocompetent pathogenic fungal infections had been rare and neglected into clinical studies. Especially Cryptococcal brainstem abscess cases mimicking brain tumors were also much more rare. So we report this unusual case. This 47-year-old man presented with a history of progressively worsening headache and nausea for 1 month and several days of vomituritions before admission. Neurological and laboratory examinations performed demonstrated no abnormal findings. Previously he was healthy and did not have any significant medical illnesses. A CT and MRI scan revealed enhancing 1.8×1.7×2.0 cm mass lesion in the left pons having central necrosis and peripheral edema compressing the fourth ventricle. And also positron emission tomogram scan demonstrated a hot uptake of fluoro-deoxy-glucose on the brainstem lesion without any evidences of systemic metastasis. Gross total mass resection was achieved with lateral suboccipital approach with neuronavigation system. Postoperatively he recovered without any neurological deficits. Pathologic report confirmed Cryptococcus neoformans and he was successively treated with antifungal medications. This is a previously unreported rare case of brainstem Cryptococcal abscess mimicking brain tumors in immunocompetent host without having any apparent typical meningeal symptoms and signs with resultant good neurosurgical recovery.

The use of magnetic resonance imaging in predicting the clinical outcome of spinal arteriovenous fistula.

PURPOSE: Magnetic resonance imaging (MRI) has been used to screen and follow-up spinal dural arteriovenous fistulae (SDAVF). The purpose of this study was to evaluate the association between MRI findings and neurologic function in SDAVF. This study also investigated clinical features and treatment results of SDAVF. MATERIALS AND METHODS: A total of 15 consecutive patients who underwent embolization or surgery for SDAVF were included. We treated seven (60%) patients with embolization and six (40%) with surgery. We analysed clinical features, MRI findings, treatment results, and neurologic function. Neurologic function was measured by the Aminoff-Logue disability scale (ALS). RESULTS: Patients with longer levels of intramedullary high signal intensity in preoperative T2-weighted images (T2WI) exhibited worse pre- and postoperative ALS scores (r=0.557, p=0.031; r=0.530, p=0.042, Pearson correlation). Preoperative ALS score was significantly correlated with postoperative ALS score (r=0.908, p=0.000, Pearson correlation). The number of levels showing intramedullary high signal intensity in T2WI decreased significantly postoperatively (5.2±3.1 vs. 1.0±1.4, p=0.001, Wilcoxon ranked test). CONCLUSION: The number of involved levels of high signal intensity in preoperative T2WI is useful for predicting pre- and postoperative neurologic function in SDAVF.

Comparative characterization of direct and indirect substrate probes for on-chip transamidating activity assay of transglutaminases.

The development of molecular probes is a prerequisite for activity-based protein profiling. This strategy helps in characterizing the catalytic activity and function of proteins, and how these proteins and protein complexes control biological processes of interest. These probes are composed of a reactive functional group and a reporter tag. The reactive group of these substrate probes has been considered to be important to their design, while the significance of the reporter tag is relatively underestimated. In this study we compare TAMRA-cadaverine and biotin-cadaverine, two substrate probes that have different reporter tags but an identical reactive functional group. We assess the on-chip transamidating activity of two transglutaminases; transglutaminase 2 and blood coagulation factor XIII. Activity assays were more easily executed when using the direct probe TAMRA-cadaverine. However the indirect probe, biotin-cadaverine, provided a wider dynamic range, higher signal-to-noise ratio, and lower limit of detection compared to TAMRA-cadaverine. Additionally, we successfully used the on-chip activity assay using the indirect probe to determine TG2 and FXIII activities in Hela cell lysates and human plasma samples, respectively. These results demonstrate that the reporter tag of the substrate probe is critical for protocol execution, sensitivity, and dynamic range of enzyme activity assays. Furthermore, this study provides a helpful guide for development of new probes, which is necessary for the identification of potential biomarkers and therapeutic targets for treating enzyme-related diseases.

Quantitative kinetics of proteolytic enzymes determined by a surface concentration-based assay using peptide arrays.

Peptide arrays have emerged as a key technology for drug discovery, diagnosis, and cell biology. Despite the promise of these arrays, applications of peptide arrays to quantitative analysis of enzyme kinetics have been limited due to the difficulty in obtaining quantitative information of enzymatic reaction products. In this study, we developed a new approach for the quantitative kinetics analysis of proteases using fluorescence-conjugated peptide arrays, a surface concentration-based assay with solid-phase peptide standards using dry-off measurements, and compared it with an applied concentration-based assay. For fabrication of the peptide arrays, substrate peptides of cMMP-3, caspase-3, caspase-9, and calpain-1 were functionalized with TAMRA and cysteine, and were immobilized onto amine-functionalized arrays using a heterobifunctional linker, N-[γ-maleimidobutyloxy]succinimide ester. The proteolytic activities of the four enzymes were quantitatively analyzed by calculating changes induced by enzymatic reactions in the concentrations of peptides bound to array surfaces. In addition, this assay was successfully applied for calculating the Michaelis constant (K(m,surf)) for the four enzymes. Thus, this new assay has a strong potential for use in the quantitative evaluation of proteases, and for drug discovery through kinetics studies including the determination of K(m) and V(max).

Endovascular treatment of iatrogenic intracranial pseudoaneurysm following stent angioplasty.

Intracranial pseudoaneurysm (IPA) is a rare disease entity associated with blunt trauma or penetration injury and less likely surgical or endovascular procedure. Decision of the therapeutic option is difficult and challenging in the treatment of iatrogenic pseudoaneurysm from the middle cerebral artery (MCA) that is necessary to maintain. We report our experience of reconstructive treatment of iatrogenic IPA, which was developed after stenting and balloon angioplasty, in the left MCA with overlapping Enterprise stents.

Characteristics and management of residual or slowly recurred intracranial aneurysms.

OBJECTIVE: Residual aneurysm from incomplete clipping or slowly recurrent aneurysm is associated with high risk of subarachnoid hemorrhage. We describe complete treatment of the lesions by surgical clipping or endovascular treatment. METHODS: We analyzed 11 patients of residual or recurrent aneurysms who had undergone surgical clipping from 1998 to 2009. Among them, 5 cases were initially clipped at our hospital. The others were referred from other hospitals after clipping. The radiologic and medical records were retrospectively analyzed. RESULTS: All patients presented with subarachnoid hemorrhage at first time, and the most frequent location of the ruptured residual or recurrent aneurysm was in the anterior communicating artery to posterior-superior direction. Distal anterior cerebral artery, posterior communicating artery, and middle cerebral artery was followed. Repositioning of clipping in eleven cases, and one endovascular treatment were performed. No residual aneurysm was found in postoperative angiography, and no complication was noted in related to the operations. CONCLUSION: These results indicate the importance of postoperative or follow up angiography and that reoperation of residual or slowly recurrent aneurysm should be tried if such lesions being found. Precise evaluation and appropriate planning including endovascular treatment should be performed for complete obliteration of the residual or recurrent aneurysm.

A biomechanical study of the instrumented and adjacent lumbar levels after In-Space interspinous spacer insertion.

OBJECT: Interspinous process implants are becoming more common for the treatment of lumber disc degeneration. The authors undertook this study to evaluate the effect of the In-Space interspinous spacer on the biomechanics of the lumbosacral spine. METHODS: Seven L2-S1 cadaver spines were physiologically loaded in extension, flexion, lateral bending, and axial rotation modes. The range of motion (ROM) and intervertebral disc pressure (DP) at the level implanted with an In-Space device and at adjacent levels were measured under 4 experimental conditions. Biomechanical testing was carried out on 7 sequentially prepared specimens in the following states: 1) the intact L2-S1 cadaver spine and 2) the L2-S1 cadaver specimen implanted with an In-Space interspinous spacer at L3-4 (Group 1), 3) after an additional L3-4 discectomy (with the In-Space interspinous spacer still in place) (Group 2), and finally, 4) after removal of the In-Space interspinous spacer, leaving only the discectomized (that is, destabilized) spine model (Group 3). RESULTS: The extension ROM at the implanted level after experimental conditions 2 and 3 above was statistically significantly reduced. An increase of ROM at the adjacent levels compensated for the reduction at the implanted level. However, there was no statistically significant change in ROM in any of the other modes of motion at any of the levels studied. Likewise, the DP reduction at L3-4 during extension was statistically significant, but in all other modes of motion, there was no statistically significant change in DP at any measured level. The In-Space interspinous spacer statistically significantly reduced the ROM of the L3-4 motion segment in Groups 1 and 2 (extension: 67%, p = 0.018 and 70%, p = 0.018; flexion: 72%, p = 0.028 and 80%, p = 0.027). After placement of the In-Space interspinous spacer, the DP was decreased at L3-4 in extension for Groups 1 and 2 in the posterior anular region (63%, p = 0.028; 59%, p = 0.043), Group 2 in the center region (73%, p = 0.028), and Groups 1 and 2 in the anterior anular region (57%, p = 0.018; 60%, p = 0.018). CONCLUSIONS: The In-Space interspinous spacer both stabilizes the spine and reduces the intervertebral DP at the instrumented level during extension. The biomechanics for other modes of motion and at the adjacent levels are not affected statistically significantly, however. The device thus performed as intended. It significantly stabilized the motion segments at the instrumented level, but not at the segment adjacent to the instrumented level.

Novel small molecule activators of beta-catenin-mediated signaling pathway: structure-activity relationships of indirubins.

Based on the beta-catenin-drived Wnt activator of bromoindirubin-3'-oxime (BIO), indirubin analogs were evaluated for beta-catenin-mediated gene expression. A novel indirubin analog, indirubin-5-nitro-3'-oxime (INO), was considered a potential activator, and structure-activity studies were conducted with indirubins. These data suggest that INO might be a novel Wnt activator and has a potential of signaling regulator in beta-catenin-mediated signaling pathways.

Biomechanical evaluation of an interspinous stabilizing device, Locker.

STUDY DESIGN: A biomechanical study. OBJECTIVE: To evaluate the biomechanical properties of a novel dynamic interspinous device named Locke SUMMARY OF BACKGROUND DATA: There has been no biomechanical study on this device. METHODS: Five human cadaveric lumbar spine specimens (L2-S1) were tested in the following sequence: (1) intact state; (2) after removal of the interspinous ligaments of L3-L4; (3) after application of the Locker at the interspinous space; (4) after destabilization of the L3-L4 motion segments; and (5) after reapplication of the Locker to the destabilized segments. Range of motion (ROM) and intradiscal pressure were measured by a video-based motion capture system and needle transducers. RESULTS: Applied to the intact spine, the Locker significantly reduced the ROM of the segment in extension and flexion without significant effect on lateral bending and/or axial rotation. When applied to the destabilized segment, it significantly reduced the ROM in all directions of movement except in axial rotation, where it failed to restore the ROM of the segment. The ROM of adjacent segments was not significantly affected by the application of the Locker. Pressures at the posterior anulus and central nucleus were decreased by application of the Locker. CONCLUSION: The Locker showed a significant stabilizing effect on the spinal motion segment both in the intact and destabilized spine without any significant effect on adjacent segments. It also decreased the pressures of the posterior anulus and central nucleus significantly. However, in the destabilized spine, it showed no stabilizing effect in axial rotation. This biomechanical property should be considered in clinical application.

Valve pressure upgrade may produce progressive deterioration of vision in children with slit ventricle syndrome.

Recently, valve upgrade and/or endoscopic third ventriculostomy, which have the merit of no additional shunting, were introduced for the treatment of slit ventricle syndrome, because lumboperitoneal shunting entails various complications including development of Chiari malformation, shunt malfunction, and infection. However, the safety of valve upgrading is not confirmed, especially in a child with slit ventricle syndrome developed as a result of pseudotumor cerebri. A 5-year-old boy with pseudotumor cerebri presented with headache, intermittent vomiting, and sudden deterioration of visual acuity. His cerebrospinal pressure during lumbar puncture was 69 cm H(2)O and his magnetic resonance imaging revealed only small ventricles. He underwent a ventriculoperitoneal shunt resulting in dramatic improvement. Four months later, he returned with recurrent spontaneous valve malfunction with recurrent severe headache and visual deterioration. After shunt revision with a programmable valve, his intermittent valve malfunction was improved by upgrading the valve opening pressure. However, his visual acuity became progressively aggravated. He underwent a lumboperitoneal shunt with low-pressure valve, which resulted in the disappearance of intermittent headaches and a deterioration of visual acuity. We suggest that valve pressure upgrade in children with slit ventricle syndrome after ventriculoperitoneal shunt for pseudotumor cerebri may produce acute deterioration of vision that had already been compromised, even within the normal intracranial pressure range and with improvement of associated symptoms.

Infantile lumbosacral spinal subdural abscess with sacral dermal sinus tract.

STUDY DESIGN: Clinical case report of a spinal subdural abscess in an infant presenting with sacral dermal sinus tract (DST). OBJECTIVES: To suggest that sacral DST with caudal direction may require surgical resection as early as possible. SUMMARY OF BACKGROUND DATA: DST may induce the formation of a spinal abscess. However, it is sometimes difficult to decide on early surgical resection for DST, especially in cases that are located at a lower level than the lumbar spine and directed caudally that is not accompanied by cerebrospinal fluid leakage. METHODS: A 9-month-old girl was transferred due to intermittent fever and vomiting, with the midline sinus of the lower back at the second sacral spinal level. She showed mild tenderness of the lower back and slight weakness of both lower extremities with increased residual urine volume of the bladder. Magnetic resonance imaging (MRI) showed that the low-lying sacral DST traced into the subdural space with caudal orientation, and the presence of extensive subdural spinal abscess from the first lumbar spine to the fourth sacrum. RESULTS: Emergency resection of the sacral DST was performed after laminotomy from the first lumbar spine to the second sacrum, and the subdural spinal abscess was also surgically removed. After 8 weeks of intravenous antibiotic treatment, she showed no neurologic deficit and no evidence of residual abscess on MRI. CONCLUSION: We suggest that even low-lying sacral DST may require surgical resection as early as possible because it may result in indolent and extensive spinal abscesses.

A large arachnoid cyst of the lateral ventricle extending from the supracerebellar cistern--case report.

BACKGROUND: The pathogenetic mechanism of intraventricular arachnoid cyst development is still controversial, but is believed to originate from the vascular mesenchyme or as an extension of the arachnoid cyst in the subarachnoid space into the ventricle through the choroidal fissure. We report a case supporting the extension hypothesis and suggest differential points between an intraventricular arachnoid cyst that extended from the supracerebellar space and a lateral ventricular diverticulum that extended into the supracerebellar cistern. CASE DESCRIPTION: A 12-month-old girl presented with macrocephaly and developmental delay. Her magnetic resonance imaging showed an arachnoid cyst that had developed from the supracerebellar space in the posterior fossa, and which extended into the left lateral ventricle resulting in expansion of the left lateral ventricle and displacing the choroids plexus anteriorly and laterally and the midline to the right. We treated an intraventricular arachnoid cyst by endoscopic fenestration resulting in dramatic reduction of the intraventricular arachnoid cyst with large bilateral subdural fluid collection. We performed a subduroperitoneal shunt for subdural fluid collection and subsequent cystoperitoneal shunt for the remnant cyst. CONCLUSION: We suggest that this case supports the extension hypothesis from the subarachnoid space through the choroidal fissure into the lateral ventricle. We also suggest that one of the radiological differential points between an intraventricular arachnoid cyst and a ventricular diverticulum is displacement and compression of the choroid plexus of the lateral ventricle.