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Neurosurgical Focus May 2024Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony...
OBJECTIVE
Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony structures at the craniovertebral junction (CVJ). Radical cytoreductive surgery improves survival but also carries significant morbidity, including the potential for occipitocervical (OC) destabilization requiring instrumented fusion. The published experience on OC fusion after CVJ chordoma resection is limited, and the anatomical predictors of OC instability in this context remain unclear.
METHODS
PubMed and Embase were systematically searched according to the PRISMA guidelines for studies describing skull base chordoma resection and OC fusion. The search strategy was predefined in the authors' PROSPERO protocol (CRD42024496158).
RESULTS
The systematic review identified 11 surgical case series describing 209 skull base chordoma patients and 116 (55.5%) who underwent OC instrumented fusion. Most patients underwent lateral approaches (n = 82) for chordoma resection, followed by midline (n = 48) and combined (n = 6) approaches. OC fusion was most often performed as a second-stage procedure (n = 53), followed by single-stage resection and fusion (n = 38). The degree of occipital condyle resection associated with OC fusion was described in 9 studies: total unilateral condylectomy reliably predicted OC fusion regardless of surgical approach. After lateral transcranial approaches, 4 studies cited at least 50%-70% unilateral condylectomy as necessitating OC fusion. After midline approaches-most frequently the endoscopic endonasal approach (EEA)-at least 75% unilateral condylectomy (or 50% bilateral condylectomy) led to OC fusion. Additionally, resection of the medial atlantoaxial joint elements (the C1 anterior arch and tip of the dens), usually via EEA, reliably necessitated OC fusion. Two illustrative cases are subsequently presented, further exemplifying how the extent of CVJ bony elements removed via EEA to achieve complete chordoma resection predicts the need for OC fusion.
CONCLUSIONS
Unilateral total condylectomy, 50% bilateral condylectomy, and resection of the medial atlantoaxial joint elements were the most frequently described independent predictors of OC fusion in skull base chordoma resection. Additionally, consistent with the occipital condyle harboring a significantly thicker joint capsule at its posterolateral aspect, an anterior midline approach seems to tolerate a greater degree of condylar resection (75%) than a lateral transcranial approach (50%-70%) prior to generating OC instability.
Topics: Humans; Chordoma; Skull Base Neoplasms; Occipital Bone; Spinal Fusion; Cervical Vertebrae; Female; Atlanto-Occipital Joint; Male; Adult; Middle Aged
PubMed: 38691866
DOI: 10.3171/2024.3.FOCUS248 -
Child's Nervous System : ChNS :... Jan 2024Autosomal dominantly inherited neurofibromatosis type I (NF1) is a systemic disorder caused by a mutation of a gene on chromosome 17q11.2 and characterized by multiple... (Review)
Review
Autosomal dominantly inherited neurofibromatosis type I (NF1) is a systemic disorder caused by a mutation of a gene on chromosome 17q11.2 and characterized by multiple café-au-lait spots, lentiginous macules, Lisch nodules of the iris, and tumors of the nervous system. Bony manifestations such as scoliosis, dysplasia of the greater sphenoidal wing, tibial pseudoarthrosis, short stature, and macrocephaly have been reported in approximately 50% of patients. However, calvarial bone defects are rare. After screening 324 articles, 23 cases (12 adult and 11 pediatric patients) of occipital bone defects in NF1 patients were selected. All patients had a single/multiple bone defect over the lambdoid suture. Adjacent benign plexiform neurofibromas were observed in 14 patients (60.8%, 7 adults and 7 children); one adult patient was diagnosed with neurofibrosarcoma. Meningoencephalocele over the occipital defect was noted in 8 cases (34.78%, all adults). Cranioplasty was performed in only 17.39% of patients. Histologic examination was performed in 7 of the 15 patients with associated neurofibromas/neurofibrosarcomas. Biopsy of the bone margins surrounding the defect was performed in only one case. Pathologic examination of the herniated parieto-occipital or cerebellar tissue was not performed in any of the patients studied. We report the case of a 9-year-old girl with NF1 and a significant occipital bone defect and performed a systematic review of the relevant literature to highlight the challenges in treating this condition and to investigate the underlying mechanisms contributing to bone defects or dysplasia in NF1.
Topics: Adult; Female; Humans; Child; Neurofibromatosis 1; Cafe-au-Lait Spots; Mutation; Encephalocele; Occipital Bone
PubMed: 37993698
DOI: 10.1007/s00381-023-06232-4 -
Neurosurgery Oct 2023Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or...
BACKGROUND
Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or obstruction of the flow of cerebrospinal fluid. Diagnosis and treatment of CIM is varied, and guidelines produced through systematic review may be helpful for clinicians.
OBJECTIVE
To perform a systematic review of the medical literature to answer specific questions on the diagnosis and treatment of CIM.
METHODS
PubMed and Embase were queried between 1946 and January 23, 2021, using the search strategies provided in Appendix I of the full guidelines.
RESULTS
The literature search yielded 430 abstracts, of which 79 were selected for full-text review, 44 were then rejected for not meeting the inclusion criteria or for being off-topic, and 35 were included in this systematic review.
CONCLUSION
Four Grade C recommendations were made based on Class III evidence, and 1 question had insufficient evidence. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/2-symptoms .
Topics: Humans; Neurosurgeons; Arnold-Chiari Malformation; Patients; Evidence Gaps; Foramen Magnum
PubMed: 37646519
DOI: 10.1227/neu.0000000000002634 -
Neurosurgery Oct 2023Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or...
BACKGROUND
Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or obstruction of the flow of cerebrospinal fluid. Diagnosis and treatment of CIM is varied, and guidelines produced through systematic review may be helpful for clinicians.
OBJECTIVE
To perform a systematic review of the medical literature to answer specific questions on the diagnosis and treatment of CIM.
METHODS
PubMed and Embase were queried between 1946 and January 23, 2021, using the search strategies provided in Appendix I of the full guidelines.
RESULTS
The literature search yielded 567 abstracts, of which 151 were selected for full-text review, 109 were then rejected for not meeting the inclusion criteria or for being off-topic, and 42 were included in this systematic review.
CONCLUSION
Three Grade C recommendations were made based on Level III evidence. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/1-imaging .
Topics: Humans; Neurosurgeons; Arnold-Chiari Malformation; Patients; Foramen Magnum
PubMed: 37646512
DOI: 10.1227/neu.0000000000002633 -
Forensic Science, Medicine, and... Mar 2024The objective of this study is to determine whether the morphometric evaluation of the foramen magnum using computed tomography can be used as an accurate tool in... (Meta-Analysis)
Meta-Analysis Review
The objective of this study is to determine whether the morphometric evaluation of the foramen magnum using computed tomography can be used as an accurate tool in estimating the sex of an individual. An extensive search of the databases, PubMed, ProQuest, Google Scholar, and Scopus, was carried out to procure articles that fulfilled the inclusion criteria. The AQUA tool was used to assess the quality of the included studies. A random effects model was used for the meta-analysis of the eligible studies using the STATA software, version 16, 2019 at 95% CI and p ≤ 0.05. Eleven eligible articles that measured the transverse and sagittal diameters of the foramen magnum using computed tomography were included in this study. The sagittal diameter of the foramen magnum was greater than the transverse diameter, and both the diameters were greater in males than in females. Meta-analysis revealed that both transverse and sagittal diameters were more reliable for male sex estimation. Since there is a dimensional variation between the male and female foramen magnum, it can be used for initial sex identification and also as an auxiliary to other advanced methods of sex estimation.
Topics: Humans; Male; Female; Foramen Magnum; Sex Determination by Skeleton; Tomography, X-Ray Computed
PubMed: 36971895
DOI: 10.1007/s12024-023-00613-6 -
Journal of Clinical Neuroscience :... Apr 2023Dural arteriovenous fistulas (DAVF) of the craniocervical junction (CCF) are an uncommon entity with the following venous drainage pattern: inferior, superior and mixed.... (Review)
Review
BACKGROUND
Dural arteriovenous fistulas (DAVF) of the craniocervical junction (CCF) are an uncommon entity with the following venous drainage pattern: inferior, superior and mixed. Patients may present with subarachnoid hemorrhage, myelopathy or brainstem dysfunction. CCJ DAVF can be treated with microsurgery or with transarterial and transvenous embolization, depending on the venous drainage pattern. We present our institutional experience of treating CCJ DAVFs along with a systematic review of the literature.
METHODS
Six patients with CCJ DAVF were treated at our institution over five years. Data was collected using electronic medical record review. Systematic review was performed on CCJ DAVF using the PubMed database from 1990 to 2021. We characterized venous drainage patterns, treatment choices, and outcomes to create a classification system.
RESULTS
50 case reports, consisting of 115 patients, were included in our review. 61 (53.0 %) patients had inferior drainage while 32 (27.8 %) patients had superior drainage and 22 (19.2 %) patients had mixed venous drainage. Patients with inferior drainage had the fistulous connection at the foramen magnum while patients with superior drainage had a fistulous connection at C1-C2 (p value = 0.026). Patients with inferior drainage were more likely to present with myelopathy while patients with superior drainage presented with hemorrhage (p value = 0.000).
CONCLUSIONS
Classifying the venous drainage pattern is essential in making treatment decision. Transvenous embolization works best with large superior venous drainage. If endovascular treatment is not an option, then surgical clipping can achieve successful cure. Transarterial embolization is a reasonable option in cases with a large arterial feeder.
Topics: Humans; Central Nervous System Vascular Malformations; Embolization, Therapeutic; Foramen Magnum; Subarachnoid Hemorrhage; Drainage
PubMed: 36787670
DOI: 10.1016/j.jocn.2023.02.004 -
Neurosurgical Focus Nov 2022Foramen magnum meningiomas (FMMs) pose a unique challenge given their intimate anatomical relationship with the craniovertebral junction. While resection has been...
OBJECTIVE
Foramen magnum meningiomas (FMMs) pose a unique challenge given their intimate anatomical relationship with the craniovertebral junction. While resection has been studied extensively, much less has been reported about the use of stereotactic radiosurgery (SRS) for FMMs. This study includes what is to the authors' knowledge the first systematic review in the literature that summarizes patient and treatment characteristics and synthesizes outcomes following SRS for FMMs.
METHODS
A retrospective chart review was conducted at a single major academic institution, and a systematic review was performed according to PRISMA guidelines. The initial search on the PubMed and Scopus databases yielded 530 results. Key data extracted from both databases included Karnofsky Performance Status (KPS) score and neurological deficits at presentation, tumor location, treatment indication, target volume, single versus multiple fractions, marginal and maximum doses, isodose line, clinical and radiographic follow-up times, and primary (clinical stability and local control at last follow-up) and secondary (mortality, adverse radiation events, time to regression, progression-free survival) outcomes.
RESULTS
The study patients included 9 patients from the authors' institution and 165 patients across 4 studies who received SRS for FMMs. The weighted median age at treatment was 60.2 years, and 73.9% of patients were female. Common presenting symptoms included headache (33.9%), dizziness/ataxia (29.7%), cranial nerve deficit(s) (27.9%), numbness (22.4%), weakness (15.2%), and hydrocephalus (4.2%). Lateral/ventrolateral (64.2%) was the most common tumor location. SRS was utilized as the primary therapy in 63.6% of patients and as salvage (21.8%) or adjuvant (14.5%) therapy for the rest of the patients. Most patients (91.5%) were treated with a single fraction. A tumor with a weighted median target volume of 2.9 cm3 was treated with a weighted median marginal dose, maximum dose, and isodose line of 12.9 Gy, 22.8 Gy, and 58%, respectively. Clinical stability and local control at last follow-up were achieved in 98.8% and 97.0% of patients, respectively. Only one possible adverse radiation event occurred, and no mortality directly related to the tumor or SRS was reported.
CONCLUSIONS
In this retrospective analysis and systematic review, the authors demonstrate SRS to be an effective and safe treatment option for carefully selected patients with FMMs.
Topics: Humans; Female; Male; Meningioma; Radiosurgery; Foramen Magnum; Retrospective Studies; Treatment Outcome; Skull Base Neoplasms; Meningeal Neoplasms; Follow-Up Studies
PubMed: 36321282
DOI: 10.3171/2022.8.FOCUS22299 -
Imaging Science in Dentistry Dec 2021The clivus is a region in the anterior section of the occipital bone that is commonly imaged on large-volume cone-beam computed tomography (CBCT). There have been... (Review)
Review
PURPOSE
The clivus is a region in the anterior section of the occipital bone that is commonly imaged on large-volume cone-beam computed tomography (CBCT). There have been several reports of incidental clivus variations and certain pathological entities that have been attributed to the variations. This study aimed to evaluate the effects of these variations within the scope of dentistry.
MATERIALS AND METHODS
Medical databases (PubMed, Scopus, and Web of Science) were searched using a controlled vocabulary (clival anomalies, cone-beam CT, canalis basilaris medianus, fossa navicularis magna, clival variation). The search was limited to English language, humans, and studies published in the last 25 years. The articles were exported into RefWorks® and duplicates were removed. The remaining articles were screened and reviewed for supporting information on variations of the clivus on CBCT imaging.
RESULTS
Canalis basilaris medianus and fossa navicularis magna were the most common anomalies noted. Many of these variations were asymptomatic, with most patients unaware of the anomaly. In certain cases, associated pathologies ranged from developmental (Tornwaldt cyst), to acquired (recurrent meningitis). While no distinct pathognomonic aspects were noted, there were unique patterns of radiographic diagnosis and treatment modalities. Most patients had a normal course of follow-up.
CONCLUSION
Interpretation of CBCT volumes is a skill every dentist must possess. When reviewing large-volume CBCT scans, the clinician should be able to distinguish pathology from normal anatomic variations within the skull base. The majority of clivus variations are asymptomatic and will remain undetected unless incidentally noted on radiographic examinations.
PubMed: 34987995
DOI: 10.5624/isd.20210039 -
OTO Open 2021Aneurysmal bone cysts (ABCs) are blood-filled, locally destructive, benign bone tumors. Our objective was to conduct a systematic review outlining patient demographics,...
OBJECTIVE
Aneurysmal bone cysts (ABCs) are blood-filled, locally destructive, benign bone tumors. Our objective was to conduct a systematic review outlining patient demographics, clinical characteristics, management, and outcomes of those with ABCs of the craniofacial bones.
DATA SOURCES
Using PubMed, Cochrane, and Embase databases, 116 studies were included.
REVIEW METHODS
Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a systematic review was conducted. Data including patient demographics, clinical characteristics, treatment strategies, and patient outcomes were collected.
RESULTS
A total of 127 patients from 116 studies were identified. Age ranged from 8 months to 90 years, with a mean age of 19.0 years. The most commonly affected craniofacial locations were the mandible (n = 31, 24.4%), temporal bone (n = 21, 16.5%), and occipital bone (n = 14, 11.0%). The most common presenting symptoms included a nontender mass (n = 51, 40.2%), a tender mass (n = 31, 24.4%), and generalized headache (n = 30, 23.6%). Imaging modalities included computed tomography (CT) and magnetic resonance imaging (MRI) (n = 77, 60.6%), CT alone (n = 31, 24.4%), and MRI alone (n = 8, 6.2%). All patients underwent surgical resection, with 1 patient requiring adjuvant radiation in addition to surgery. In total, 121 patients were disease-free and symptom-free without evidence of recurrence (17.4-month mean follow-up, 5.4 months average time to first recurrence).
CONCLUSION
The current literature's characterization of ABCs in craniofacial bones is limited to case reports and case series. Given the rarity of these tumors, head and neck surgeons may rely on systematic reviews such as the present analysis to guide management.
PubMed: 34723050
DOI: 10.1177/2473974X211052950 -
Child's Nervous System : ChNS :... Sep 2021Iatrogenic syringomyelia has previously been described preoperatively due to space occupying lesions and postoperatively predominantly postspinal CSF drainage....
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.
Topics: Adolescent; Arnold-Chiari Malformation; Child; Child, Preschool; Female; Foramen Magnum; Humans; Iatrogenic Disease; Infant; Magnetic Resonance Imaging; Syringomyelia
PubMed: 34156512
DOI: 10.1007/s00381-021-05268-8