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Introduction: Spinal metastases (SM) are a frequent complication of cancer and may lead to pathologic vertebral compression fractures (pVCF) and/or metastatic epidural spinal cord compression (MESCC). Based on autopsy studies, it is estimated that about one third of all cancer patients will develop SM. These data may not provide a correct estimation of the incidence in clinical practice., Objective: This systematic review (SR) aims to provide a more accurate estimation of the incidence of SM, MESCC and pVCF in a clinical setting., Methods: We performed a SR of papers regarding epidemiology of SM, pVCF, and MESCC in patients with solid tumors conform PRISMA guidelines. A search was conducted in the PubMed and Web of Science database using the terms epidemiology, prevalence, incidence, global burden of disease, cost of disease, spinal metastas*, metastatic epidural spinal cord compression, pathologic fracture, vertebral compression fracture, vertebral metastas* and spinal neoplasms. Papers published between 1975 and august 2021 were included. Quality was evaluated by the STROBE criteria., Results: While 56 studies were included, none of them reports the actual definition used for MESCC and pVCF, inevitably introducing heterogenity. The overall cumulative incidence of SM and MESCC is 15.67% and 2.84% respectively in patients with a solid tumor. We calculated a mean cumulative incidence in patients with SM of 9.56% (95% CI 5.70%-13.42%) for MESCC and 12.63% (95% CI 7.00%-18.25%) for pVCF. Studies show an important delay between onset of symptoms and diagnosis., Conclusions: While the overall cumulative incidence for clinically diagnosed SM in patients with a solid tumor is 15.67%, autopsy studies reveal that SM are present in 30% by the time they die, suggesting underdiagnosing of SM. Approximately 1 out of 10 patients with SM will develop MESCC and another 12.6% will develop a pVCF. Understanding these epidemiologic data, should increase awareness for first symptoms, allowing early diagnosis and subsequent treatment, thus improving overall outcome., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier GmbH.)

Purpose: The purpose of this paper was to study the incidence and clinical significance of fever after intraventricular neuroendoscopic procedures in children., Methods: We retrospectively assessed all children subjected to an intraventricular neuroendoscopic procedure between 2004 and 2015. Body temperature 6 days postoperatively, symptoms and signs, and eventual cerebrospinal fluid analysis were evaluated. Fever was defined as temperature above 38 °C., Results: Fifty-five children (mean age 4.8 years) had 67 procedures. Forty-three children (47 procedures, 70 %) developed fever, mostly the day of surgery (n = 17; 25 %) or the next day (n = 33; 49 %). All children who were clinically ill (n = 9, including 7 with fever) suffered serious illness, as opposed to none of the children with fever without being clinically ill (n = 36). Fever was unrelated to gender, indication for, and type of procedure and did not influence ETV success rate at 3 months. Children under 1 year less frequently developed fever (p = 0.032)., Conclusions: Fever frequently develops after intraventricular neuroendoscopic procedures in children and follows a rather predictable course, peaking the day of surgery and/or the next day, and rapidly subsiding thereafter. Fever is not a cardinal symptom except when combined with other symptoms in children who are clinically ill (which most of them are not). Close observation avoiding invasive diagnostic tests may suffice for those who are not clinically ill, while extra attention should be paid to those whose temperature rises after day 2 especially when clinically ill, as they likely suffer serious illness. We recommend to closely observe children after any intraventricular neuroendoscopic procedure for at least 5 days.

Background: With the growing use of vagus nerve stimulation (VNS) as a treatment for refractory epilepsy, there is a growing demand for complete removal or replacement of the VNS system. We evaluate the safety and efficacy of complete removal or replacement of the VNS system and provide an extensive description of our surgical technique., Methods: We retrospectively reviewed our patient registry for all VNS surgeries performed between January 2007 (the year of our first complete removal) and May 2014. In order to assess patient satisfaction, a written questionnaire was sent to patients or their caregivers. Additionally, we reviewed all literature on this topic., Results: The VNS system was completely removed in 22 patients and completely replaced in 13 patients. There were no incomplete removals. Revision surgery was complicated by a small laceration of the jugular vein in two patients and by vocal cord paralysis in one patient. Seizure frequency was unaltered or improved after revision surgery. Electrode-related side effects all improved after revision surgery. Twenty-one studies reported a total of 131 patients in whom the VNS system was completely removed. In 95 patients, the system was subsequently replaced. The most frequently reported side effect was vocal cord paresis, which occurred in four patients., Conclusions: Complete removal or replacement of the VNS system including lead and coils is feasible and safe. Although initial results seem promising, further research and longer follow-up are needed to assess whether lead replacement may affect VNS effectiveness.

Study Design: Retrospective analysis of a prospectively collected database of thoracoscopic microdiscectomies performed at the Maastricht University Medical Center., Objective: Many victims of a motor vehicle collision (MVC) report crippling upper back pain resistant to conservative treatment. Although this pain is often regarded as nonspecific or related to a whiplash type of cervical spine injury, this study demonstrates it may be caused by a thoracic disc herniation., Summary of Background Data: Recent literature on bodily pain after whiplash and other MVCs has shown that most patients rather than pain confined to the posterior neck area (0.4%) report pain in multiple body areas, the most frequently affected region being the posterior trunk region, including the posterior neck, posterior shoulder, upper back, lumbar, and buttock areas. Although several patterns determining most variance in pain localization in these patients have been identified, different pathoanatomical and pathophysiological substrates underlying these patterns have not been identified. However, a high incidence of posterior shoulder pain (75%) and upper back pain (66%) is striking., Methods: In a series of 326 thoracoscopic microdiscectomies for one or more symptomatic TDHs, we identified 10 patients whose symptoms had started after an MVC. We analyzed their clinical and radiological presentation, intraoperative findings, and postoperative outcome., Results: All patients (7 females, 3 males; age, 26-58 yr, including 4 with typical whiplash complaints) had reported substantial improvement of their complaints except for their upper back pain. Most hernias were small or medium sized (n = 8), at the apex of the kyphotic curvature (n = 6), and to some extent calcified (n = 7). One year postoperatively, results were excellent in 7, good in 2, and poor in 1., Conclusion: Crippling upper back pain after MVCs may be caused by a (previously asymptomatic) thoracic disc herniation. Although the exact pathophysiological mechanism has not been elucidated, results after thoracoscopic microdiscectomy are quite encouraging.

Objective: Based on the assumption that children with spinal dysraphism are exposed to a large amount of ionising radiation for diagnostic purposes, our objective was to estimate this exposure, expressed in cumulative effective dose., Design: Retrospective cohort study., Settings: The Netherlands., Patients: 135 patients with spinal dysraphism and under 18 years of age treated at our institution between 1991 and 2010., Results: A total of 5874 radiological procedures were assessed of which 2916 (49.6%) involved ionising radiation. Mean cumulative effective dose of a child with spinal dysraphism during childhood was 23 mSv, while the individual cumulative effective dose ranged from 0.1 to 103 mSv. Although direct radiography accounted for 81.7% of examinations, the largest contributors to the cumulative effective dose were fluoroscopic examinations (40.4% of total cumulative effective dose)., Conclusions: Exposure to ionising radiation and associated cancer risk were lower than expected. Nevertheless, the use of ionising radiation should always be justified and the medical benefits should outweigh the risk of health detriment, especially in children.

Background and Purpose: Sprengel's deformity, a rare congenital malformation of the scapula, may be observed in combination with spinal dysraphism. The co-occurrence of these malformations suggests an unknown shared etiology. Therefore, we reviewed the medical records of eight children presenting with both malformations and performed a review of the literature., Patients and Methods: Databases from four university medical centers were searched for children presenting between 1992 and 2012 with spinal dysraphism and a Sprengel's deformity., Conclusion: The combination of spinal dysraphism and Sprengel's deformity is rare, and is associated with segmentation defects of the spine and ribs. Although the etiology of both spinal dysraphism and Sprengel's deformity remains unclear, all deformities of the spine, ribs, and shoulder might result from a common genetic defect affecting somitogenesis.

Background/aims: In addition to effects on seizure frequency in intractable epilepsy, multiple studies report benefits of vagus nerve stimulation (VNS) on behavioural outcomes and quality of life. The present study aims to investigate the effects of VNS on cognition, mood in general, depression, epilepsy-related restrictions and psychosocial adjustment in children with intractable epilepsy, as well as the relation between these effects and seizure reduction., Methods: We conducted a randomized, active-controlled, double-blinded, add-on study in 41 children (age 4-18) with medically refractory epilepsy. We performed cognitive and behavioural testing at baseline (12 weeks), at the end of the blinded phase (20 weeks) in children receiving either high-output or low-output (active control) stimulation, and at the end of the open label phase (19 weeks) with all children receiving high-output stimulation. Seizure frequency was recorded using seizure diaries., Results: VNS did not have a negative effect on cognition nor on psychosocial adjustment. At the end of the follow-up phase we noted an improvement of mood in general and the depression subscale for the entire group, unrelated to a reduction of seizure frequency. At the end of the blinded phase a ≥50% reduction of seizure frequency occurred in 16% of the high-stimulation group and 21% of the low-stimulation group. At the end of the open-label follow-up phase, 26% of the children experienced a seizure frequency reduction of 50% or more (responders)., Conclusions: VNS has additional beneficial effects in children with intractable epilepsy. As opposed to anti-epileptic drugs, there are no negative effects on cognition. Moreover, we observed an improvement of mood in general and depressed feelings in particular, irrespective of a reduction in seizure frequency. These beneficial effects should be taken into account when deciding whether to initiate or continue VNS treatment in these children., (Copyright © 2012 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

Aim: The aim of this study was to evaluate the effects of vagus nerve stimulation (VNS) in children with intractable epilepsy on seizure frequency and severity and in terms of tolerability and safety., Method: In this study, the first randomized active controlled trial of its kind in children, 41 children (23 males; 18 females; mean age at implantation 11y 2mo, SD 4y 2mo, range 3y 10mo-17y 8mo) were included. Thirty-five participants had localization-related epilepsy (25 symptomatic; 10 cryptogenic), while six participants had generalized epilepsy (four symptomatic; two idiopathic). During a baseline period of 12 weeks, seizure frequency and severity were recorded using seizure diaries and the adapted Chalfont Seizure Severity Scale (NHS3), after which the participants entered a blinded active controlled phase of 20 weeks. During this phase, half of the participants received high-output VNS (maximally 1.75mA) and the other half received low-output stimulation (0.25mA). Finally, all participants received high-output stimulation for 19 weeks. For both phases, seizure frequency and severity were assessed as during the baseline period. Overall satisfaction and adverse events were assessed by semi-structured interviews., Results: At the end of the randomized controlled blinded phase, seizure frequency reduction of 50% or more occurred in 16% of the high-output stimulation group and in 21% of the low-output stimulation group (p=1.00). There was no significant difference in the decrease in seizure severity between participants in the stimulation groups. Overall, VNS reduced seizure frequency by 50% or more in 26% of participants at the end of the add-on phase The overall seizure severity also improved (p<0.001)., Interpretation: VNS is a safe and well-tolerated adjunctive treatment of epilepsy in children. Our results suggest that the effect of VNS on seizure frequency in children is limited. However, the possible reduction in seizure severity and improvement in well-being makes this treatment worth considering in individual children with intractable epilepsy., (© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.)

Introduction: We analyze our preliminary experience using the PoleStar N20 mobile intraoperative MR (iMR) system as an adjunct for pediatric brain tumor resection., Methods: We analyzed 11 resections in nine children between 1 month and 17 years old. After resection, we acquired iMR scans to detect residual tumor and update neuronavigation. We compared final iMR interpretation by the neurosurgeon with early postoperative MR interpretation by a neuroradiologist., Results: Patient positioning was straightforward, and image quality (T1 7-min 4-mm sequences) sufficient in all cases. In five cases, contrast enhancement suspect for residual tumor was noted on initial postresection iMR images. In one case, a slight discrepancy with postoperative imaging after 3 months was no longer visible after 1 year. No serious perioperative adverse events related to the PoleStar N20 were encountered, except for transient shoulder pain in two., Conclusions: Using the PoleStar N20 iMR system is technically feasible and safe for both supra- and infratentorial tumor resections in children of all ages. Their small head and shoulders favor positioning in the magnet bore and allow the field of view to cover more than the area of primary interest, e.g., the ventricles in an infratentorial case. Standard surgical equipment may be used without significant limitations. In this series, the use of iMR leads to an increased extent of tumor resection in 45 % of cases. Correlation between iMR and early postoperative MR is excellent, provided image quality is optimal and interpretation is carefully done by someone sufficiently familiar with the system.

Objective: Tight filum syndrome (TFS) is caused by a thick (abnormal T1 MRI), shortened (low-lying conus), or non-elastic filum (strictly normal MRI). We carefully analyzed children treated for suspect TFS with or without radiological abnormalities., Methods: Twenty-five children, operated between 2002 and 2009, were retrospectively identified. All children had been evaluated by a multidisciplinary team preoperatively. Symptoms, signs and diagnostic test results were categorized (neurologic, urologic, orthopedic, dermatologic) and compared pre- and one year postoperatively. Normal MR was defined as conus medullaris (CM) at or above mid-body L2 and filum diameter less than 2 mm. Occult TFS (OTFS) was defined as TFS with normal MR., Demographics: 17 girls, 8 boys, age 2-18 years, including 11 syndromal children., Clinical Presentation: all children had problems in the neurologic category and at least one other category: urologic (n = 17), orthopedic (n = 21), and dermatologic (n = 11). MR findings: low-lying CM (n = 14) including 2 with thick filum, normal CM but fatty filum (n = 2), strictly normal (n = 9). Clinical outcome one year postoperatively: neurologic 20 improved, 5 stabilized; urologic 13 improved, 3 stabilized, 1 worsened; orthopedic (8 children presenting with scoliosis) 3 improved, 4 stabilized, 1 worsened. All children with OTFS (n = 9) improved in at least one and 8 improved in all affected categories., Conclusions: Children with strong clinical suspicion for TFS (≥ 2 affected categories) with or without abnormal MR findings will likely benefit from surgery. In such cases we suggest a detailed full spine MR, a multidisciplinary diagnostic work-up, and eventual untethering through an interlaminar microsurgical approach., (Copyright © 2011 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

Object: Thoracic disc herniations (TDHs) may occasionally present with an acute myelopathy, defined as a variable degree of motor, sensory, and sphincter disturbances developing in less than 24 hours, and resulting in a Frankel Grade C or worse. Confronted with such a patient, the surgeon has to decide whether to perform an emergency operation and whether to use an anterior or posterior approach. The authors analyze their own experience and the pertinent literature, focusing on clinical presentation, imaging findings, surgical timing, technique, and outcome., Methods: Among 250 patients who underwent surgery for symptomatic TDH, 209 had at least 1 year of follow-up at the time of writing, including 8 patients who presented with an acute myelopathy. They were surgically treated using standard thoracoscopic microdiscectomy, careful blood pressure monitoring, and intravenous methylprednisolone. The authors analyzed pre- and postoperative neuroimaging, and Frankel scores preoperatively, at discharge, and 1 year postoperatively., Results: Although 5 patients had multiple TDHs, the symptomatic TDH was invariably situated between T9-10 and T11-12. Seven TDHs were giant, 6 were calcified, 6 were accompanied by myelomalacia, and 4 were accompanied by segmental stenosis. Although sudden dorsalgia was the initial symptom in 6, a precipitating event was noted in only 1. All patients had severe neurological deficits by the time they underwent surgery. Frankel grades improved from B to D in 2 patients, from C to E in 4, and from C to D and B to E in 1 patient each. All patients regained continence and ambulation. Transient complications were CSF leak (in 2 patients), and intraoperative blood loss greater than 1000 ml, reversible ischemic neurological deficit, and subileus (in 1 patient each)., Conclusions: Approximately 4% of TDHs present with an acute myelopathy. They are often situated between T9-10 and T11-12, large or giant, and even calcified. They almost invariably cause important cord compression (sometimes aggravated by an associated segmental stenosis) and myelomalacia. Their clinical presentation may be misleading, and diagnosis may be delayed until other causes (especially vascular) have been excluded and the clinical picture has become more complete. Interestingly, whereas a precipitating event or trauma is rarely present, dorsalgia frequently precedes profound myelopathy and may help to make an early diagnosis. Remarkable recovery is possible even with profound neurological deficit, a delay of several days, in the elderly, and in the presence of myelomalacia, provided the spinal cord is adequately decompressed and intraoperative hypotension is strictly avoided. Although alternative approaches more familiar to most neurosurgeons may be used, the anterior transthoracic approach has the advantage of reaching the TDH in front of the compromised spinal cord, avoiding any manipulation. In experienced hands, thoracoscopic microdiscectomy combines the advantage and versatility of an anterior approach with minimal postoperative discomfort. The authors conclude that TDH-related acute myelopathy may have a favorable outcome when managed correctly, and they strongly recommend that every single patient should undergo surgical treatment.

Bringing evidence to practice is a key issue in modern medicine. The key barrier to information searching is time. Clinical decision support systems (CDSS) can improve guideline adherence. Mounting evidence exists that mobile CDSS on handheld computers support physicians in delivering appropriate care to their patients. Subaxial cervical spine injuries account for almost half of spine injuries, and a majority of spinal cord injuries. A valid and reliable classification exists, including evidence-based treatment algorithms. A mobile CDSS on this topic was not yet available. We developed and tested an iPhone application based on the Subaxial Injury Classification (SLIC) and 5 evidence-based treatment algorithms for the surgical approach to subaxial cervical spine injuries. The application can be downloaded for free. Users are cordially invited to provide feedback in order to direct further development and evaluation of CDSS for traumatic lesions of the spinal column.

Purpose: Our goal was to validate the hypothesis that the lumbosacral angle (LSA) increases in children with spinal dysraphism who present with progressive symptoms and signs of tethered cord syndrome (TCS), and if so, to determine for which different types and/or levels the LSA would be a valid indicator of progressive TCS. Moreover, we studied the influence of surgical untethering and eventual retethering on the LSA., Methods: We retrospectively analyzed the data of 33 children with spinal dysraphism and 33 controls with medulloblastoma. We measured the LSA at different moments during follow-up and correlated this with progression in symptomatology., Results: LSA measurements had an acceptable intra- and interobserver variability, however, some children with severe deformity of the caudal part of the spinal column, and for obvious reasons those with caudal regression syndrome were excluded. LSA measurements in children with spinal dysraphism were significantly different from the control group (mean LSA change, 21.0° and 3.1° respectively). However, both groups were not age-matched, and when dividing both groups into comparable age categories, we no longer observed a significant difference. Moreover, we did not observe a significant difference between 26 children with progressive TCS as opposed to seven children with stable TCS (mean LSA change, 20.6° and 22.4° respectively)., Conclusions: We did not observe significant differences in LSA measurements for children with clinically progressive TCS as opposed to clinically stable TCS. Therefore, the LSA does not help the clinician to determine if there is significant spinal cord tethering, nor if surgical untethering is needed.

Introduction: Although Blake's pouch cyst (BPC) is frequently mentioned in the spectrum of posterior fossa cysts and cystlike malformations since its first description in 1996, its natural history, clinical presentation, specific imaging characteristics, optimal treatment, and outcome are relatively unknown. Consequently, BPC may still be underdiagnosed. We therefore report six cases ranging from a fatal hydrocephalus in a young boy, over an increasing head circumference with or without impaired neurological development in two infants, to a decompensating hydrocephalus at an advanced age., Discussion: We focus on their radiological uniformity, which should help making the correct diagnosis, and widely variable clinical presentation, which includes adult cases as well. Differentiating BPC from other posterior fossa cysts and cystlike malformations and recognizing the accompanying hydrocephalus are essentially noncommunicating, not only have important implications on clinical management but also on genetic counseling, which is unnecessary in case of BPC. In our experience, endoscopic third ventriculostomy is a safe and effective treatment option, avoiding the risks and added morbidity of open surgery, as well as many shunt-related problems.

Background: The purpose of this study is to demonstrate the added value of intraoperative MRI in treating secondary empty sella syndrome., Case Report: We describe the case of a 66-year-old woman who was diagnosed with a prolactinoma stage IIIb. During treatment with cabergoline she presented with a secondary empty sella syndrome resulting in visual symptoms. We performed intraoperative MRI-guided packing of the secondary empty sella. We explain why this is useful in surgical treatment of secondary empty sella syndrome., Conclusion: Intraoperative MRI helps to achieve adequate sellar packing while avoiding insufficient packing as well as overpacking., (© Georg Thieme Verlag KG Stuttgart · New York.)

Introduction: Less than 20 children with intramedullary cavernoma (ImC) have been reported in the English literature; however, cases with an unfavorable outcome may be underreported. Whereas these are predominantly boys, we report two girls who presented with hematomyelia (one cervical, one thoracic) and an acute, severe neurological deficit., Case Material: A 10-year-old girl complaining about lower thoracic pain for several days suddenly developed lower body dysesthesias and paraparesis. Magnetic resonance (MR) demonstrated hematomyelia (T8-T11), intramedullary edema (T6-L1), and an ImC at T9-T10. Within an hour, she progressed to paraplegia and was therefore operated immediately. She slowly recovered regaining independent ambulation and continence. MR after 2 years shows no recurrence. A 7-year-old girl suddenly developed cervicalgia and paresis of her left arm and leg. MR demonstrated hematomyelia and an ImC at C4-C6. She gradually recovered with minimal residual deficit at 3 months and was subsequently operated uneventfully. Multiple cerebral cavernomas and a familial autosomal cavernous malformation syndrome were diagnosed. The following 1.5 years, she complained of intermittent cervicalgia and left brachial dysesthesias, with MR suggesting active residual cavernoma. Interestingly, her complaints gradually disappeared, and she is currently asymptomatic. MR after 3.5 years shows minimal cord swelling no longer suggesting active residual cavernoma., Conclusion: With adequate surgical treatment either in the acute phase in case of dramatic deterioration or after clinical recuperation, prognosis of symptomatic ImC may be surprisingly good. However, subtotally resected lesions and/or syndromal cases may recur, requiring further treatment. Definitive answers await more cases with longer follow-up.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily observed during the first 2 years of life. Most patients present with a solitary cutaneous lesion; however, others present with extracutaneous manifestations or even with systemic involvement. The authors describe a 2-month-old boy in whom was diagnosed a unifocal extracutaneous JXG involving the temporal bone. Unlike 3 other cases of solitary JXGs of the temporal bone in the literature, the present case involved destruction of the dura mater and leptomeningeal enhancement surrounding the entire temporal lobe. The lesion did not regress after an initial biopsy procedure and had to be removed more radically because of progressive mass effect on the brain. The child recently underwent a reconstructive skull procedure and is doing well almost 2 years postoperatively without evidence of disease. This case demonstrates that even in instances of extensive disease a favorable outcome is possible without chemotherapy.

Background: In contrast to what is commonly believed, thoracic disc herniations are not rare lesions. Their etiopathogenesis is largely unknown, but may be linked to trauma, Scheuermann's disease or a degenerative back., Objective: We report two brothers with a symptomatic thoracic disc herniation at T11-T12 and address the possibility of a genetic factor as well as other factors in the etiopathogenesis of (symptomatic) thoracic disc herniations., Clinical Features: Both brothers were in their early thirties and had a physically demanding job, however, only the first one was a smoker and was diagnosed with Scheuermann's disease., Conclusion: The etiology of thoracic disc herniations is likely multifactorial. Their occurrence in siblings may reflect some genetic predisposition or may be merely coincidental, given the high prevalence of thoracic disc herniations in asymptomatic individuals. Further research, including genetic studies, is warranted.

Objects: In this study, a disjunction anomaly mimicking the spinal congenital dermal sinus (DS) is described. This anomaly is referred to as the dermal-sinus-like stalk. Dissimilarities between a true dermal sinus and a dermal-sinus-like stalk are discussed., Clinical Material: Three cases in which a spinal congenital dermal sinus was suspected are presented. A similar anatomical configuration, different from that of a dermal sinus, was found. All cases presented with a skin-covered dimple from which a solid tract was seen continuing intramedullary in two cases and intraspinally in one case. None of the patients presented with signs of infection or an associated dermoid-epidermoid tumor. Clinical, radiological, and surgical findings are discussed. A hypothesis is made on the pathological genesis of this malformation., Conclusion: A dermal-sinus-like stalk is a malformation similar to a spinal congenital dermal sinus but is not associated with DS-related complications. Despite important clinical, radiological, surgical, and histopathological differences, it is difficult to distinguish this malformation from a true DS based on clinical and radiological examination alone. Therefore, surgical intervention, at the time of diagnosis, is recommended in all cases.

Intraspinal dermoid and epidermoid tumors are two histopathological subtypes of cutaneous inclusion tumors of the spine. This classification is based on obsolete embryological knowledge. In fact, according to current embryology, both tumor types consist of ectodermal derivatives. Therefore, we hypothesized that dermoid and epidermoid tumors do not differ in clinical practice. To explore this hypothesis, we studied the clinical, radiological and intraoperative findings of 18 patients, and related these findings to the histopathological characteristics of the tumor. No differences were found between dermoid and epidermoid tumors regarding clinical presentation, radiological examination and outcome, while intraoperative diagnosis by the surgeon correlated with the histopathological diagnosis in only 8 of 18 cases. Therefore, the histopathological difference between intraspinal dermoid and epidermoid tumors is not important in clinical practice and should be avoided. A new nomenclature is proposed in which both tumor types are referred to as 'spinal cutaneous inclusion tumors'., (2009 S. Karger AG, Basel)

A 20 year old male patient who had been successfully treated for epilepsy with vagus nerve stimulation (VNS) for 7 years (50% seizure frequency reduction), had experienced multiple episodes of severe hoarseness, throat pain and impaired breathing during physical exercise. As malfunctioning of the pulse generator was suspected, it was decided to replace the device. During surgery, the pulse generator was found to have broken in two, due to an unstable connection between the battery subunit and the connector subunit. With a new pulse generator seizure frequency reduction was restored. No side effects occurred.

Study Design: This study analyzes the mobility of the aorta relative to the spine in patients with a herniated thoracic disc requiring surgical intervention., Objectives: To determine the mobility of the aorta relative to the spine with the patient in prone and supine position., Summary of Background Data: In anterior scoliosis surgery, safe screw placement is important and knowledge of the position of the aorta relative to the spine is crucial. To the authors' knowledge, there are no studies on the mobility of the aorta relative to the spine with the patient in different positions., Methods: All 50 patients before surgery had a computed tomography (CT) and/or magnetic resonance (MR) scans of the involved spinal segment in supine position, as well as a CT with intrathecal contrast in prone position. The aorta-vertebral angle and the aorta-vertebral distance were measured on as many levels as possible., Results: In supine position, the aorta is positioned left lateral to the vertebral body at midthoracic levels (T4-T8) and more anterior to the vertebral body at lower thoracic levels (T9-L2). In prone position, the aorta moves to a more anteromedial position relative to the vertebra, which is most significant at levels T4 to T8. The mediolateral aorta-vertebral distance according to Sevastik is shorter in prone position, whereas the anterior-posterior distance according to Sucato is larger, especially at levels T5 to T10., Conclusions: We demonstrate a substantial difference in the position of the aorta relative to the spine in prone and in supine position, which is most markedly seen at levels T4 to T8. The aorta is positioned posterolateral to the spine in supine position and more anteromedial in prone position. Before performing anterior thoracolumbar spine surgery, we suggest to measure vertebral body width, as well as the position of the aorta in the prone and in the supine patient to decide if his approach is technically feasible, or if an alternative (contralateral) approach is preferable.

The authors present a rare case of fatal cerebral and cerebellar hemorrhagic infarction following an uneventful thoracoscopic microdiscectomy. They hypothesize that this complication was associated with cortical venous thrombosis secondary to intracranial hypotension, which was caused by an unnoticed leak of cerebrospinal fluid (CSF) into the thoracic cavity. Cortical venous thrombosis and intrathoracic CSF were confirmed at autopsy. The former disorder is the most severe manifestation of the pathophysiological mechanism occurring to a lesser degree in patients affected by mild intracranial hypotension, and occurs more frequently in these patients. Intracranial hypotension (of an orthostatic nature or not) must be considered in the differential diagnosis of every patient who complains of headaches after thoracoscopic or open transthoracic microdiscectomy.

Objectives: In infants less than 1 year of age, the value of endoscopic third ventriculostomy (ETV) is controversial. It is believed to cause more morbidity and to have higher failure rates. We analyzed our data enlarging the reported pool of ETV outcome in infants less than 1 year of age., Materials and Methods: We performed 12 ETVs in ten patients younger than 1 year of age. All patients had predominant supratentorial hydrocephalus. We defined ETV success as a shunt-free follow-up of at least 12 months, however, allowing re-ETV., Conclusion: ETV should be considered as initial treatment and carries low morbidity in these infants. As the immune system rapidly matures, postponing shunt implantation for several months or even weeks would make an ETV procedure worthwhile. On the other hand, as success probability rapidly increases 4 months after birth, re-ETV should always be considered first.

Object: Cases of infected dermal sinus are scarce and detailed surgical anatomical descriptions are hardly found in literature. The clinical, radiological, and surgical findings in four cases of an infected dermal sinus located at the lower spine are presented to elucidate the pathological anatomical configuration., Clinical Material: The first case showed two dermal sinuses with a parallel course extra- and intradurally, ending in a confluence of cavities connected to the conus. In this case, as well as in the fourth case, the signs and symptoms were those of meningitis. The second case presented with meningitis and a subdural empyema, while the third case presented with an intradermoid-intramedullary abscess at the junction between the DS and the conus. This child probably showed signs and symptoms of conus involvement as early as during pregnancy., Conclusion: The anatomy of the nervous elements in this congenital anomaly is heavily disturbed, more particularly in case of infection, due to extensive arachnoidal scarring. The latter renders dissection laborious and recognition of anatomical details difficult, resulting in complete excision of a dermal sinus in less than half of the cases. Despite their variability in presentation, most cases of an infected dermal sinus show similar characteristic features.

Methods: A patient is described in which a complete osteofibrotic dorsally implanted septum was found in combination with a split cord malformation in a single dural tube. This case cannot be explained using the widely used theory as proposed by Pang et al. [Pang D, Dias MS, Ahab-Barmada M (1992) Split cord malformation, part I: A unified theory of embryogenesis for double spinal cord malformations. Neurosurgery 31:451-480] but must be regarded as a combination of type I and II split cord malformation., Results: The authors state that all types of split cord malformation can be reduced to a single derailment during development, with various degrees of severity., Conclusions: The configuration of the malformation is determined by the way the median parts of the mesoderm come to development. Type I and II split cord malformation are not distinct entities.

Purpose: To prospectively investigate the feasibility of contrast material-enhanced magnetic resonance (MR) angiography for visualization of the spinal vasculature in patients referred for video-assisted thoracoscopic surgical treatment of a thoracic herniated disk and to prospectively assess the influence of preoperative imaging of the spinal vasculature on the choice of surgical approach., Materials and Methods: Eight patients (three men and five women; mean age, 58 years; range, 42-83 years) with a thoracic herniated disk underwent contrast-enhanced MR angiography of the thoracoabdominal aorta and posterior branches. Imaging was performed with three-dimensional first-pass contrast-enhanced MR angiographic technique and a triple dose of gadolinium-based contrast agent. Images were analyzed by two observers in consensus to localize the Adamkiewicz artery (AKA) and its connections to the aorta and the anterior spinal artery (ASA). This information was used to determine any change in surgical approach., Results: In all eight patients, the AKA, the ASA, and the connections with the aorta were identified. The AKA originated between T9 and L2 in all patients and derived from the left side of the aorta in 75% (six of eight) of the patients. In three patients in whom the AKA was observed on the left side, the surgical approach was changed to the right side to preserve spinal cord integrity., Conclusion: Preoperative imaging of the AKA is feasible with contrast-enhanced MR angiography. Contrast-enhanced MR angiography can be used to image the main feeding arteries of the spinal cord in patients undergoing thoracoscopic spinal surgery, and results can be used to change the side of surgical approach.

Object: It remains uncertain if closure of a myelomeningocele at midgestation changes the neurological condition at birth in an infant born with spina bifida. The authors conducted a study to provide a detailed analysis of the morphology of the spinal cord with the myelomeningocele at the time fetal surgery usually is performed., Methods: The myelomeningocele of a 20-week-gestation-age fetus was examined, and data were compared with those obtained in a neurologically intact specimen of the same age. In vitro high-field 9.4-tesla magnetic resonance (MR) microscopy was used to examine the fetal material. High-field MR spectroscopy provided images in the three orthogonal planes with a resolution comparable with low-power optical microscopy. The authors observed that the fetal cord of the myelomeningocele specimen was tapered and tethered at S3-4 while the conus medullaris in the normal fetus reaches L-4. No neurulation defects were noted. The axial MR images clearly revealed the nonfusion of the mesodermal structures. The absence of neurulation defects suggests that at least in some cases of spina bifida the spinal cord initially is well developed but is damaged later on chemically and mechanically. This might be an argument in favor of intrauterine myelomeningocele repair. By 20 weeks' gestation, however, the deformation of the cord inside the myelomeningocele is severe. An optimization of the preoperative assessment by means of MR imaging therefore might be considered a valuable contribution to intrauterine surgery. The in vitro high-field MR microscopic findings of this study could be used as references for clinical intrauterine MR imaging., Conclusions: The detailed in vitro high-field MR analysis of a 20-week-gestation-age fetus with spina bifida demonstrated that an improvement of the preoperative intrauterine imaging should be pursued to detect those cases without neurulation defects and with minimal deformation of the spinal cord.

The authors report on four third ventriculostomy procedures in which upward ballooning of the third ventricular floor occurred immediately after perforation of the floor and withdrawal of a Fogarty catheter. The floor herniated into the third ventricle, hindering the endoscopic view. Preoperative magnetic resonance imaging demonstrated a similar anatomy in all four cases, consisting of hydrocephalus, extreme dilation of the third ventricle, and disappearance of the interpeduncular cistern due to a very thin, membranous floor of the third ventricle, which herniated downward, draping over the basilar artery. The authors suggest that excessive rinsing in combination with this anatomical configuration provoked the phenomenon of upward ballooning of the third ventricular floor, which is described in this report.