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Background: Complete resection is essential for achieving seizure freedom in children with drug-resistant epilepsy due to focal cortical dysplasia (FCD). However, identifying altered structures intraoperatively can be challenging, potentially leading to reoperations. This study assessed the impact of intraoperative MRI (iMRI)., Methods: We conducted a single-center retrospective study at Alder Children's Hospital from 2013 to 2022. The study included all children diagnosed with FCD, analyzing demographics, iMRI use, the rate of continued iMRI-guided surgery and reoperations, histology, and seizure outcomes at 1-year follow-up., Results: Thirty-two pediatric patients (median age: 10 years, 21 males and 11 females) underwent surgery for FCD. Of them 8 (25 %) had FCD Type I, 19 (59.4 %) had FCD Type II, and 1 patient (3.1 %) had FCD Type III. iMRI was used in 27 patients (84.4 %), and 17 (63 %) of these patients required further iMRI-guided surgery. Four patients underwent reoperation in a separate session. At 1-year follow-up, seizure outcomes in the iMRI group were Engel I in 15 patients (71.4 %), Engel II in 4 (19 %), and Engel III and IV in 1 patient (4.8 %) each. Five patients (15.6 %) had superficially localized lesions and underwent surgery without iMRI. None of them required reoperation, and four (80 %) were seizure-free at 1 year. Seven patients were lost to follow-up., Conclusion: iMRI plays a significant role in identifying residual epileptogenic tissue in surgery for FCD, influencing surgical decisions and leading to additional iMRI-guided resections. Most patients with iMRI-guided surgery achieved favorable seizure outcomes (Engel I) at 1 year of follow-up. Long-term follow-up is needed to validate these findings and to confirm sustained seizure control., Competing Interests: Declaration of competing interest 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., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: We assessed the accuracy and performed a directional analysis of robot-assisted implantation of stereoelectroencephalography (SEEG) depth electrodes in children using the frameless neurolocate 3D registration module., Methods: Thirteen children with epilepsy undergoing stereotactic robot-assisted insertion of SEEG electrodes were included. Six children were operated on with standard frame-based registration while 7 with the use of the frameless neurolocate registration module. Accuracy and directional analysis of orthogonal and oblique electrodes were assessed by calculating the absolute error, the radial error, the angle error, and the Euclidean distance., Results: Of 172 electrodes 89 were implanted in the 6 standard frame-based mode patients and 83 in the 7 neurolocate patients. The overall mean age was 12.2 ± 4.4 years (range 2-17). The mean number of electrodes in each patient was 13.2 ± 2.04 (range 9-17). The median radial error of electrode placement in the neurolocate patients (1.08 mm, [IQR: 1.26]) was significantly less when compared with standard frame-based mode patients (1.49 mm, [IQR 1.25)]; p  = 0.04). The same applies to the median angle error which was in the neurolocate group 1.61° [IQR: 1.46] and in the standard frame-based group 2.16° [IQR: 2.09]; p  = 0.019. Directional analysis of electrode trajectories in the neurolocate group showed that in the x-axis the median absolute error of orthogonal electrodes (0.4 mm, [IQR: 0.475]) was less when compared with oblique electrodes (0.7 mm, [IQR: 1.2]; p  = 0.007). In the standard frame-based mode group in the y-axis, the median absolute error of orthogonal electrodes (0.7 mm, [IQR: 1.3]) was less compared with oblique electrodes (1.25 mm, [IQR: 1.6]; p  = 0.03)., Conclusion: In paediatric patients, robot-assisted SEEG depth electrode implantation with the non-invasive and easy-to-use frameless neurolocate registration module is a consistent and accurate procedure.

Background: Like in all posterior fossa surgeries the avoidance of cerebrospinal fluid (CSF) leaks is of paramount importance for foramen magnum decompression in Chiari I malformation in children. The present technical note decribes the experience with the creation of a T-shaped myofascial cuff to reduce the risk of postoperative CSF leaks., Methods: The medical records of 98 children were evaluated. They underwent foramen magnum decompression without dural closure using a T-shaped myofascial cuff whose incision lines run completely within the fascia and the muscles not extending beyond their attachment line to the bone., Results: There were 2 CSF leaks and no infections in 98 operated patients. The follow-up was between 4 and 48 months., Conclusions: The placement of a T-shaped myofascial cuff allows for watertight closure of the muscles and the fascia which is likely to reduce the rate of CSF leaks in pediatric Chiari I patients operated on without closure of the dura., Competing Interests: Declaration of competing interest 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., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: The most common cause of cerebral vasospasm is subarachnoid hemorrhage, less frequently it occurs after trauma, infection, and tumor resection. Vasospasm in children is rare and has not been systematically investigated in posterior fossa surgery., Methods: The authors undertook a single-center retrospective study of all the pediatric patients who underwent surgery on the posterior fossa and presented with postoperative symptomatic vasospasm in the period from January 2018 to February 2024. Subsequently, a systematic literature review in accordance with the PRISMA guidelines was performed in the PubMed and Scopus databases to identify the published papers on symptomatic vasospasm after posterior fossa surgery in children., Results: Of the 178 patients who underwent surgery on the posterior fossa, only one patient was diagnosed with symptomatic diffuse vasospasm on postoperative day 21. The systematic literature review provided further 9 children. The underlying pathology comprised 8 intra-axial lesions with 4 medulloblastomas, 1 schwannoma in the medulla oblongata, 1 pilocytic astrocytoma, 1 primitive neuroectodermal tumor, and 1 arteriovenous malformation. The extra-axial lesions were 1 hypoglossal schwannoma and 1 oculomotor nerve schwannoma., Conclusion: Iatrogenic symptomatic vasospasm after posterior fossa surgery in children is a rare complication with an outcome ranging from complete recovery to the death of the patient. It is important for all staff involved in the care of patients undergoing surgery on the posterior fossa to be aware of this rare postoperative complication. The small number of patients affected does not allow a substantiated conclusion to be drawn about predictive risk factors., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Scaphocephaly is the most common form of craniosynostosis, characterized by premature closure of the sagittal suture. Surgical intervention is the standard treatment, aimed at correcting cranial shape and improving the cephalic index (CI), the key metric to quantify postsurgical outcomes. Controversies exist in the literature regarding the optimal timing of surgery and the choice of surgical technique. At our center, children aged 6 to 24 months presenting with sagittal synostosis and frontal bossing without significant occipital bullet undergo subtotal (anterior 2/3) vault remodeling, whereas those with both occipital bullet and frontal bossing are treated with total vault remodeling. This retrospective monocenter study tracks the progression of CI in pediatric patients undergoing these 2 techniques at 3 timepoints. From 2007 to 2015 the authors operated on 32 patients, excluding syndromic cases and reoperations. Twenty-three patients underwent subtotal and 9 total vault remodeling. The mean age at surgery was 12.66 months (range 6-24 months). The CI improved significantly in all patients after surgery. Overall, the CI increased from 66.67% preoperatively to 76.67% postoperatively and to 76.83% at 4 years. In the subtotal vault remodeling group, CI increased from 67.27% to 76.81% postoperatively, reaching 77.27% at 4 years. In the total vault remodeling group, CI rose from 65.11% to 76.29% postoperatively but decreased to 75.07% at 4 years. The authors' data show a sustained improvement in CI postoperatively, with a slight reduction in the total vault remodeling group at long-term follow-up., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Purpose: Chorea is a clinical sign characterized by involuntary, rapid, unpredictable, and irregular muscle movements that can affect various parts of the body. It can be seen in various medical conditions, both neurological and systemic, of genetic and acquired etiology. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has been used to treat various types of chorea. The aim of this study was to evaluate the efficacy of GPi DBS for chorea in pediatric patients., Methods: The authors undertook a single-center retrospective study of all pediatric patients who underwent DBS in the period from July 2017 to April 2024 to identify those presenting with chorea., Results: Three patients with chorea underwent bilateral posteroventral GPi DBS without surgical complications. The mean age at operation was 14.2 years (range: 1.5 years), and the mean follow-up was 49 months (range: 15 months). Two of the 3 patients experienced a positive effect on chorea with an improvement in functional status. In one patient, the pre- and postop Gross Motor Function Classification System (GMFCS) score was 4, while his Burke-Fahn-Marsden Dystonia Scale (BFMDS) score improved from 102/20 pre- to 53.5/20 postop. In the other patient the GMFCS score improved from 4 preop to 3 postop. His preop BFMDS score was not available, postop it was 83/120. In the patient who did not experience a positive effect on chorea the pre- and postop GMFCS score was 4, her BFMDS score was 84.5/120 pre- and 100/120 postop., Conclusion: Bilateral GPi DBS can be safely administered to pediatric patients with choreiform movement disorders, and it could be an effective treatment option for managing chorea in certain patients., Competing Interests: Declarations. Ethics approval: All procedures were performed in accordance with the Declaration of Helsinki, 1964, and its later amendments. The study was approved by our institution’s research advisory board. Consent to participate: The requirement for informed consent was waived because of the retrospective nature of the study. Consent for publication: The patients’ parents or carers have consented to submission of this manuscript to the journal. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background:  Postoperative intracranial hypotension-associated venous congestion (PIHV) is a rare event. The authors report the case of a patient presenting with PIHV after spinal surgery following the sudden loss of cerebrospinal fluid (CSF) induced by suction drainage., Methods:  A 69-year-old patient underwent uneventful revision surgery for wound dehiscence after lumbar surgery with placement of a subfascial suction drain., Results:  Postoperatively, the patient presented with fluctuating consciousness and a generalized tonic-clonic seizure. Computed tomography (CT) and serial magnetic resonance imaging (MRI) were performed showing convexity subarachnoid hemorrhages (SAHs), diffuse swelling of the brain and thalami and striatum bilaterally without diffusion restriction, and signs of intracranial hypertension resulting in pseudohypoxic brain swelling in PIHV. A dural leak at L3-L4 was treated with several CT-guided patches combining autologous blood and fibrin glue injections. The patient recovered without neurologic deficit and follow-up MRI revealed progressive complete reversal of brain swelling, and re-expansion of CSF spaces., Conclusion:  PIHV is a rare but potentially fatal entity. Awareness of PIHV after cranial or spinal surgery leads to early treatment of CSF hypovolemia and possibly better clinical outcome. Following acute CSF volume loss, an acute elevation of cerebral blood volume overcoming autoregulatory mechanisms seems a likely explanation for diffuse cerebral vasogenic edema and SAH in PIHV., Competing Interests: None declared., (Thieme. All rights reserved.)

Saethre-Chotzen syndrome (SCS) is a syndromic craniosynostosis with pathogenic variants in the TWIST1 gene showing a broad phenotypic spectrum. Controversies exist in the literature regarding surgical management with single one-stage versus patient-tailored surgery and the related reoperation rate for intracranial hypertension of up to 42%. At our center, SCS patients are offered patient-tailored surgery with single-stage fronto-orbital advancement and remodeling or fronto-orbital advancement and remodeling and posterior distraction in an individually determined order. The authors' database identified 35 confirmed SCS patients between 1999 and 2022. Involved sutures in craniosynostosis were left unicoronal (22.9%), bicoronal (22.9%), sagittal (8.6%), bicoronal and sagittal (5.7%), right unicoronal (2.9%), bicoronal and metopic (2.9%), bicoronal, sagittal and metopic (2.9%), and bilateral lambdoid (2.9%). There was pansynostosis in 8.6% and no craniosynostosis in 14.3% of the patients. Twenty-six patients, 10 females, and 16 males were operated on. Mean age at the first surgery was 1.70 years, and 3.86 years at the second surgery. Eleven of 26 patients had invasive intracranial pressure monitoring. Three patients presented with papilledema before the first surgery and 4 afterward. Four of the 26 operated patients were operated initially elsewhere. The other 22 patients were initially referred to our unit and underwent patient-tailored surgery. Nine of these patients (41%) had a second surgery, and 3 (14%) of them were because of raised intracranial pressure. Seven (27%) of all operated patients had a complication. Median follow-up was 13.98 years (range, 1.85-18.08). Patient-tailored surgery in a specialized center and long-term follow-up allow for a low reoperation rate for intracranial hypertension., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Objective: Subcortical band heterotopia is a rare X-linked neuronal migration disorder primarily in females often associated with drug-resistant epilepsy. The aim of this study is to review the literature for non-pharmacological treatment options of drug-resistant epilepsy in subcortical band heterotopia., Material and Methods: In accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we performed a systematic review. Entering the keywords "double cortex," "subcortical band heterotopia," and "subcortical laminar heterotopia," we searched Scopus and PubMed databases. We paid particular attention to type of invasive and non-invasive treatment, radiological presentation, and outcome. We also describe a related case report, managed at Alder Hey Children's Hospital, Liverpool., Results: The systematic literature review yielded 25 patients with subcortical band heterotopia and drug-resistant epilepsy who underwent non-pharmacological treatment. Including our patient, 26 patients were reported. The patients' mean age at seizure onset was 6.5 years (range 0.2-23) with a female sex predilection (5.25:1). The patients' mean age at invasive or non-invasive treatment was 21.5 years (range 6.5-51). The 26 patients underwent 29 non-pharmacological treatments. Ten patients underwent corpus callosotomy; 8 patients had a formal temporal lobectomy. Three patients had focal cortical resection. Two patients respectively had multiple subpial transections, insertion of a vagal nerve stimulator, or deep brain stimulation of the bilateral anterior nuclei of the thalamus. One patient underwent responsive focal neurostimulation. Another patient had transcutaneous stimulation of the vagal nerve. Sixteen patients reported a reduction or the disappearance of the seizures; 1 patient had no improvement. The outcome of 2 patients was classified class I, of 1 patient class II, of 1 patient class III, and of 5 patients class IV according to the Engel Epilepsy Surgery Outcome Scale., Conclusion: Mainly corpus callosotomy and formal temporal lobectomy have been performed as non-pharmacological treatment with few cases published overall. Several other invasive procedures and one non-invasive technique are based on case reports. The small number of reported cases prevents drawing a firm conclusion as to which non-pharmacological treatment is the best treatment option for refractive epilepsy in patients with subcortical band heterotopia., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Lumbar disc herniation is most common degenerative alteration of the spine. Whenever surgical therapy proves to be necessary, recurrent disc herniation is most frequent concern. Here, primary aim was to determine the percentage of patients eligible for insertion of an annular closure device (ACD). Secondary aim to evaluate 12-month incidence of recurrent disc herniation at the operated level. Our hypothesis was that ACD might help in preventing recurrent disc herniation., Methods: Patients in a single Swiss neurosurgical center underwent limited discectomy alone (n=41, group 1) versus limited discectomy plus ACD (n=12, group 2). Mean postoperative follow-up period was 12months., Results: Twelve out of 53 patients (22.6%) were eligible for ACD implantation. Patients of group 2 were significantly taller (mean 176cm, P=0.007) as compared with group 1 (mean 170). The only statistically significant difference of intraoperative parameters between group 1 and 2 was amount of nucleus materiel removed (P=0.01), being greater in group 2 (mean 0.9) as compared with group 1 (mean 0.3). In group 1 six patients (6/41, 14.6%) presented with symptomatic reherniation at same level of surgery, while in group 2 only one patient experienced recurrence (1/12, 8.3%). No adverse events were reported., Discussion: In the current study one out of five patients with lumbar disc herniation was considered suitable for ACD placement. In vast majority of these patients reherniation was precluded on the short-term basis. Patients with ACD were taller and had intraoperatively a higher volume of the nucleus pulposus materiel removed., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Introduction: Iatrogenic syringomyelia has previously been described preoperatively due to space occupying lesions and postoperatively predominantly postspinal CSF drainage. Iatrogenic syringomyelia after cranial surgery is a rare entity. The purpose of this study is to review the current literature for iatrogenic syringomyelia following cranial surgery in children., Material and Methods: We performed a systematic review in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and meta-analyses) guidelines. Using keywords "de novo," "acquired," "iatrogenic," "postoperative development," and "syringomyelia," we searched PubMed and Scopus databases. We paid particular attention to type of surgery, clinical presentation, management, and outcome. We also present a relevant case report, operated on at John Radcliffe Hospital, Oxford., Results: The systematic literature review provided 19 cases of iatrogenic syringomyelia postcranial surgery in pediatric patients, in addition to our case report, resulting in a total of 20 cases reported. The patients' mean age at surgery preceding syringomyelia was 8.1 years (range 0.1-17) with a female sex predilection (2.7:1). The mean time of manifestation of the iatrogenic syringomyelia after surgery was 5.7 years (range 0.1-51), and the median time to presentation was 1.7 years. Nine children had surgery for Chiari I malformation before formation of the syrinx, 8 patients underwent shunt surgery, 2 children had intracranial tumor surgery, and 1 patient had lambdoid and sagittal suturectomy for scaphocephaly before developing a syrinx. Surgery after the manifestation of the iatrogenic syrinx resolved the symptoms in 9 patients; in 8 patients, the symptoms partially resolved; and in 1 patient, the symptoms persisted. After surgery addressing the syrinx, it resolved in 5, decreased in size in 10, and remained unchanged in 2 of the patients., Conclusion: Iatrogenic syringomyelia after cranial surgery in pediatric patients occurs mainly after decompressive surgery for Chiari I malformation, shunt surgery, and less frequently following intracranial tumor surgery. Risk factors are postoperative intracranial scarring, shunt malfunction, and mass effect on the foramen magnum. Surgery addressing the iatrogenic syrinx seems to be effective in the majority of the patients in terms of clinical and radiological outcome., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Meningoencephaloceles of the skull base most commonly occur as a sequela of head trauma or they can more rarely be congenital malformations. Several types of encephalocele exist depending on anatomic features and localisation. Clinical presentation and symptoms can vary. Different methods of management and repair of the concurring skull base defects have been described and ranging vary from endoscopic to open surgical approaches. We report the case of a 56-year-old Caucasian woman with the diagnosis of right sided spontaneous transethmoidal meninoencephalocele. Clinical presentation of this rare pathology, methods of diagnostic and management and its outcome are presented. Spontaneous skull base meningoencephaloceles are rare entities, without clear underlying etiologies. Multidisciplinary management is recommended. The transnasal endoscopic approach provides a wide skull base exposure with more advantages and less morbidity in comparison with the conventional open approach., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Nontraumatic intradiploic pseudomeningoceles and de novo syringomyelia formation are very rare entities. The authors have previously reported the case of a 4-year-old girl who underwent foramen magnum decompression without dural closure for Chiari I malformation. Three years after the operation an intradiploic pseudomeningocele was documented, but the patient was lost to follow-up without undergoing revision surgery. Four years later, at the age of 11 years, the patient returned for treatment of intensifying symptoms. Radiological imaging then showed an increase in the size of the intradiploic pseudomeningocele and a new cervical syrinx. The patient underwent a first revision surgery in which a part of the internal layer of the occipital bone was removed and arachnoid scar lysis was performed. Two months later the syrinx had worsened, and in a second revision surgery a pseudomeningocele-peritoneal shunt was placed. Here, the authors describe what is to their knowledge the first case of an intradiploic pseudomeningocele and de novo syringomyelia formation following Chiari I decompressive surgery.

Competing Interests: Conflict of Interest None declared.

Purpose: There are numerous publications about the technical aspects of decompressive surgery for Chiari I malformation highlighting many variations of this procedure. Each approach has its followers. Bony decompression of the foramen magnum alone or with the removal of a portion of the posterior arch of C1, dural splitting with keeping arachnoid intact, and durotomy are described. Dural closure is done with various materials. We retrospectively reviewed foramen magnum decompression without dural repair (FMDWDR) following the technique used by Gardener and Williams as an option in pediatric patients with Chiari I malformation in terms of complication rate and clinical outcome., Methods: The surgical database of our unit identified 65 consecutive children who underwent FMDWDR surgery for Chiari I malformation between 2009 and 2016. The retrospective assessment included patient demographics, clinical data, surgical technique, revision rate, complications, and clinical outcome., Results: Durotomy without repair was performed in 65 patients. Complications included aseptic meningitis and subdural hematoma respectively in three cases, intradiploic CSF collections in three patients, and CSF leaks in six children. The CSF leak rate has reduced dramatically after introducing a technical modification. Revision surgery was performed in seven cases. None of the patients was identified with postoperative hydrocephalus or infection. There was no mortality and no long-term surgical morbidity. In terms of clinical outcome, 52 patients reported postoperative improvement, 10 were clinically unchanged, and three noticed worsening of symptoms., Conclusion: Applying a "T"-shaped fascial incision which allows a watertight closure of the fascia FMDWDR is still a safe and effective treatment option for Chiari I malformation in children.

Competing Interests: There are no conflicts of interest.

Lumbar spine revision surgery is considered as challenging and related to longer operation time and complications because of the loss of anatomical landmarks and the formation of postoperative epidural fibrosis. Minimal invasive lumbar spinal surgery techniques have been refined over the last 5 years but the reexposure of the dura, the formation of postsurgical scar tissue and related dural tears remain a source of complications. For lumbar spinal revision surgery we advocate the minimal invasive Extraforaminal Lumbar Interbody Fusion (ELIF) technique. It employs a working corridor of 45° relative to the midline. This angle permits bypassing laterally the dural sac and postoperative epidural fibrosis so that dural tears do not occur. ELIF is performed without an expandable tubular retractor system, it is atraumatic following the natural intermuscular cleavage plane between the multifidus muscle and the longissimus thoracis muscle pars lumborum. Postoperatively the muscles do not show signs atrophy or fatty degeneration. In case of discectomy alone there is no need for the removal of the facets, if intracanalar lesions are targeted the partial removal of the superior facet is sufficient. ELIF represents an alternative to posterior lumbar interbody fusion (PLIF), conventional open transforaminal lumbar interbody fusion (TLIF), and minimal invasive (MIS) TLIF for lumbar spinal revision surgery., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The objective of decompressive surgery for Chiari I malformation is to create additional space to accommodate the ectopic cerebellar tonsils and to improve the flow of cerebrospinal fluid. To the best of our knowledge, we report the first case of a patient with previous Chiari I decompression presenting 5 years after surgery at the same time as an intraosseous C2 and a suboccipital intradiploic cerebrospinal fluid accumulation. Because of the progressive nature of the C2 cerebrospinal fluid collection causing bone destruction, surgical management was indicated. To avoid the erosion of the bone, we propose that the iatrogenic exposure of the diploe and the vertebral spongiosa that may come into contact with the cerebrospinal fluid should be sealed off with bone wax or a similar material.

Background  Extraforaminal lumbar interbody fusion (ELIF) surgery is a muscle-sparing approach that allows the treatment of various degenerative spinal diseases. It is technical challenging to perform the ELIF approach at the L5-S1 level because the sacral ala obstructs the view of the intervertebral disk space. Methods  We reported earlier on the ELIF technique in which the intervertebral disk is targeted at an angle of 45 degrees relative to the midline. In this article we describe the technical process we developed to overcome the anatomic relation between the sacral ala and the intervertebral disk space L5-S1 that hinders the ELIF approach at this level. We then report in a retrospective analysis on the short-term clinical and radiologic outcome of 100 consecutive patients with degenerative L5-S1 pathologies who underwent ELIF surgery. Results  The L5-S1 ELIF approach could be realized in all patients. The short-term clinical outcome was evaluated 5 months after surgery: 92% of the patients were satisfied with their postoperative result; 8% had a poor result. Overall, 17% of the patients presented light radicular or low back pain not influencing their daily activity, and 82% of the patients working before surgery returned to work 3 to 7 months after surgery. The radiologic outcome was documented by computed tomography at 5 months after surgery and showed fusion in 99% of the patients. Lumbar magnetic resonance imaging performed in 5 patients at 6 months after surgery revealed the integrity of the paraspinal muscles. Conclusions  ELIF surgery at the L5-S1 level is technically feasible for various degenerative spinal diseases. Analysis of the clinical and radiologic data in a consecutive retrospective cohort of patients who underwent this surgical procedure showed a good short-term clinical outcome and fusion rate., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (Georg Thieme Verlag KG Stuttgart · New York.)

Intradiploic cerebrospinal fluid (CSF) collections are rare findings. The authors describe two pediatric patients with iatrogenically induced occipital CSF collections after decompressive surgery for Chiari I malformation. The first patient presents a large occipital intradiploic pseudomeningocele and the second patient an intradiploic pseudomeningocele merging with an ossified occipitocervical pseudomeningocele. Though being rarities after decompression for Chiari I malformation, intradiploic fluid collection and ossified pseudomeningocele should be considered if patients represent with aggravating presurgical or new symptoms.

Background  Postoperative epidural fibrosis (PEF) localized around the exposed dura and nerve roots is a known radiologic entity seen after lumbar surgery. Although excessive PEF is associated with residual and new lumbar pain and radiculopathy, its role as the generator of the pain is still discussed. Various materials acting as an adhesion barrier have been tested. There is no undebated class I evidence that any one of them is suitable to reduce or avoid PEF and provide a better clinical outcome. In revision surgery, the dissection of epidural scar tissue is time consuming and related to an elevated risk of dural tear and nerve damage. To avoid the formation of posterior PEF, we propose a surgical approach whose working corridor is situated lateral to the dural sac and the nerve roots: the extraforaminal lumbar interbody fusion (ELIF) technique. Methods  Description of ELIF surgical technique. Conclusions  The ELIF technique is a muscle-sparing approach to the intervertebral disk space and the spinal canal that avoids the formation of posterior PEF. It represents an option to treat various degenerative lumbar spinal diseases as well as offering another approach for revision surgery in patients who have developed PEF., (Georg Thieme Verlag KG Stuttgart · New York.)

We report the first case of a patient diagnosed with Floating-Harbor syndrome (FHS) and Chiari I malformation. The 3-year-old girl was of proportional short stature, had delay of language development, conductive hearing loss and a high threshold of pain. Diagnosis of Chiari I malformation may be difficult in FHS patients who present with communication problems. Clinicians following patients with FHS should be aware of a possible relation between FHS and Chiari I malformation., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

In patients with traumatic brain injury (TBI) and ischemic hemispheric stroke (IHS), supratentorial decompressive craniectomy (DC) is performed when intracranial pressure (ICP) is unresponsive to medical treatment. There are numerous publications about the indications of supratentorial DC, the selection of patients eligible for surgery, the complications of the procedure, and the neurological outcome of operated patients. Only few papers, however, describe comprehensively the technical aspects of this procedure. DC consists of a variety of steps that can be conducted in different manners. Based on the literature reviewed, this article gathers features that had been developed with the intent to improve the decompressive effect of this surgery and evaluates if there is a strong recommendation for clinical practice. The existing literature does not supply class I evidence of how an ideal DC should be designed to reduce peri- and postoperative complications and to provide the best functional outcome.

The authors report the case of a 58-year-old man presenting with a 3-year history of clinical signs of progressive cervical spondylotic myelopathy (CSM). Magnetic resonance imaging showed a severe stenosis of the cervical spinal canal at C3-4 and C5-6 levels due to multiple discopathies. High signal intensities on T2-weighted MR images of the spinal cord and low signal intensities on T1-weighted images at the C2-6 levels were noted, as was contrast enhancement at the C3-4 level. The patient underwent a bilateral decompressive laminectomy at C3-6. The patient did not show any clinical improvement. Thus, further cervical MR imaging was performed and the differential diagnosis of an intramedullary tumor was considered in view of the persisting intramedullary enhancement. This diagnosis prompted a second operation involving a posterior midline myelotomy and excision of an intramedullary ependymoma at the C3-4 level. Intramedullary tumors should be considered in the differential diagnosis of CSM with an atypical pattern of MR imaging features.

We report the case of a Menière's disease patient affected by normal pressure hydrocephalus (NPH) who presented a cerebrospinal fluid (CSF) pressure-dependent hearing impairment after shunting. This side-effect was not only reversible and reproducible but occurred at a high opening pressure when the valve setting was lowered by only 0.7 mmHg (10 mmH(2)O). This observation suggests that hearing in Menière's disease might be very sensitive to small reductions of intracranial pressure (ICP) and that these patients should be informed of this potential risk, which can compromise the efficacy of the shunt.

Objective: Electrophysiological recordings of the error-related negativity (ERN) and functional imaging data point to an involvement of medial frontal cortex (including the anterior cingulate cortex, ACC) and dorsolateral prefrontal cortex (DLPFC) in the detection and correction of performance errors. Here, we studied this network by applying trains of rapid transcranial magnetic stimulation (rTMS) prior to the recording of the ERN., Methods: Low-frequency (0.9 Hz) rTMS was applied to medial frontal or lateral frontal regions (different sessions) for 60 s immediately before each 3 min ERN recording in 11 healthy young subjects. The ERN was obtained by multichannel recordings in a typical Eriksen flanker task with instructions calling for immediate error correction in case a performance error was detected by the subject. Event-related potentials were quantified and statistically evaluated using standard methodology., Results: Compared to a no-stimulation control condition, medial frontal stimulation led to a small but reliable decrease in the number of corrected errors as well as to an attenuation of the ERN and an increase of the subsequent error-positivity (Pe). No effect on these components was seen after lateral frontal stimulation. No reliable effects on the lateralized readiness potential were observed., Conclusions: Functional lesions by rTMS appear to interfere with the functions of the medial frontal cortex in error detection and correction.

Using event-related brain potentials, the time course of error detection and correction was studied in healthy human subjects. A feedforward model of error correction was used to predict the timing properties of the error and corrective movements. Analysis of the multichannel recordings focused on (1) the error-related negativity (ERN) seen immediately after errors in response- and stimulus-locked averages and (2) on the lateralized readiness potential (LRP) reflecting motor preparation. Comparison of the onset and time course of the ERN and LRP components showed that the signs of corrective activity preceded the ERN. Thus, error correction was implemented before or at least in parallel with the appearance of the ERN component. Also, the amplitude of the ERN component was increased for errors, followed by fast corrective movements. The results are compatible with recent views considering the ERN component as the output of an evaluative system engaged in monitoring motor conflict.