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Objective: The craniovertebral junction (CVJ) presents intricate anatomical challenges. In severe or irreducible malformations, complications such as reduction loss and fixation failure may occur, necessitating revision surgery. The posterior facet joint distraction and fusion (PFDF) technique, offers a solely posterior approach for revisions. Hence, we delineate varied revision scenarios, proposing surgical strategies and technical details to enhance outcomes and mitigate risks, thereby enriching the neurosurgical community's repertoire. Methods: This was a retrospective cohort study, analyzed patient data from Xuanwu Hospital, between 2017 to 2023. All patients had a history of surgical treatment for CVJ malformations, and experienced failure or loss of reduction. The distance from the odontoid process tip to the Chamberlain's line (DCL), the atlantodental interval (ADI), clivus‐canal angle, cervicomedullary angle, width of subarachnoid space, CVJ area, and width of syrinx were used for radiographic assessment. Japanese Orthopaedic Association (JOA) scores and SF‐12 scores were used for clinical assessment. Independent sample t‐tests were employed. A significance level of p < 0.05 indicates statistically significant differences. Results: We analyzed data from 35 patients. For patients who underwent PFDF, the postoperative DCL, ADI, and clivus‐canal angle significantly improved. For all patients, the postoperative cervicomedullary angle, width of subarachnoid space, CVJ area, and width of syrinx all demonstrated significant improvement, indicating the relief of neural compression. All patients showed significant improvement in both symptoms and clinical assessments. Conclusion: Severe atlantoaxial joint locking or ligament contracting are the fundamental cause of reduction and fixation failure. Anterior odontoidectomy is indicated for patients with robust bony fusion of the atlantoaxial joint in an unreduced position. The PFDF technique is safe and effective for patients with incomplete atlantoaxial bony fusion. Preoperative assessment of surgical feasibility and vertebral artery status ensures surgical safety and efficacy. [ABSTRACT FROM AUTHOR]

Rosai-Dorfman disease (RDD) with craniocervical junction involvement is a rare clinical entity. We present herein a case of a pediatric patient with craniocervical junction RDD which was surgically treated. A 10-year-old female with a history of B-cell acute lymphoblastic leukemia (B-ALL) in remission and RDD presented with frontal migraine headaches. She previously had a right posterior chest wall lesion which was biopsy-proven RDD. She was found on imaging to have a dural-based right craniocervical junction lesion. Given her history of B-ALL, after a multidisciplinary discussion, the decision was made to proceed with resection with possible initiation of cobimetinib or clofarabine. The patient underwent a suboccipital craniotomy, C1 laminectomy, and resection of the dural-based lesion. Gross total resection was achieved, and histopathology confirmed the diagnosis of RDD. She was discharged home on postoperative day 4. No recurrence was seen on follow-up imaging at 3 months. We conducted a systematic literature review examining all cases of pediatric intracranial RDD and all cases of craniocervical junction RDD. This represents, to the best of our knowledge, only the second case of pediatric craniocervical junction RDD. Although RDD is often self-limiting, medical treatment is often considered for intracranial disease, but tissue confirmation is necessary. Surgical resection provides histopathologic diagnosis and can sometimes serve as definitive treatment for a particular lesion. [ABSTRACT FROM AUTHOR]

Purpose: To describe a case of an anomalous posterosuperior course of the V3 segment of the right vertebral artery (VA) that penetrated the occipital bone (wall of the jugular foramen). Methods: A 33-year-old healthy woman underwent cranial magnetic resonance (MR) imaging and MR angiography from the upper cervical to the intracranial region using a 3-Tesla scanner to screen for asymptomatic brain lesions, including cerebrovascular diseases. Results: MR angiography showed no pathological arterial lesions such as aneurysms; however, there was an anomalous posterosuperior course of the V3 segment of the right VA. On MR angiographic source images and coronal reformatted images, the right VA was observed to penetrate the occipital bone lateral to the right hypoglossal canal and is located on the inferoposteromedial wall of the right jugular foramen and enter the posterior fossa at a higher level than the foramen magnum. Conclusion: We present a case in which the right VA showed an anomalous posterosuperior course at the craniovertebral junction. It is extremely rare for a VA to take a higher course. To our knowledge, this is the first report of such a VA variation in the relevant English-language literature. We speculated that the right VA of our patient was formed by the persistence of one more cephalad primitive artery than the first intersegmental artery, not by the persistence of the primitive hypoglossal artery. Careful observation of MR angiographic source is useful and important for identifying the VA penetrating the occipital bone. [ABSTRACT FROM AUTHOR]

Objective: To perform a morphometric analysis of the upper cervical spine (UCS) by means of cone-beam computed tomography (CBCT) for the diagnosis of malformations or craniocervical instabilities in patients with cleft lip and palate (CLP) and class III malocclusion. Materials and Methods: A total of 72 CBCTs from adult patients (48 male and 24 female) with Angle Class III malocclusion were divided into three groups: 1) Unilateral cleft lip and palate (UCLP) (n = 29; male = 65.5%; age = 24, 2 ± 4.2 years); 2) Bilateral cleft lip and palate (BCLP) (n = 18; male = 83.3%; age = 26.4 ± 6.0 years); 3) Control group (CON) (n = 25; male = 56.0%; age = 27.8 ± 9.3 years). The version 11.7 of the Dolphin® software (Chatsworth, California, USA) was used to evaluate the morphometric measurements and anomalies of the UCS. Data were analyzed by descriptive and inferential statistics (p ≤ 0.05). Results: For the UCLP, BCLP and CON groups, respectively, the measures were: atlantodental interval (2.1 ± 0.5; 2.1 ± 0.4; 2.0 ± 0.3 mm), basion-opisthion (35.9 ± 3.2; 36.4 ± 3.0; 34.7 ± 1.9 mm), hyoid-C3 (34.5 ± 3.7; 34.5 ± 5.2; 35.3 ± 4.5 mm), and hyoid-sella (108.1 ± 9.8; 111.3 ± 9.2; 109.7 ± 10 mm); clivus-canal angle (152.3 ± 13; 150.3 ± 10; 150.7 ± 10°) and Torg-Pavlov index (1.0 ± 0.2; 1.0 ± 0.1; 1.1 ± 0.2). Potentially unstable anomalies and malformations were more prevalent in the UCLP group (34,4%). Conclusion: Subjects with UCLP presented compressive or unstable anomalies on upper cervical spine, more frequently than controls and BCLP, despite the lack of statistically significant differences among groups. Future studies could increase the safety of patients and healthcare professionals specialized in craniofacial anomalies. [ABSTRACT FROM AUTHOR]

Introduction: Chiari II malformation (CM-II) is a congenital malformation characterized by the caudal displacement of the cerebellar tonsils, inferior cerebellar vermis, and fourth ventricle through the foramen magnum. Although rare, the association between CM-II and the development of a variety of mass lesions within the fourth ventricle and craniocervical junction has been described in the literature. Case Presentation: We present the case of a 9-year-old boy with a history of mid-lumbar myelomeningocele, CM-II, and ventriculoperitoneal shunt-dependent hydrocephalus who was discovered to have a syringomyelia and numerous spherical/ovoid masses within the caudal fourth ventricle and dorsal cervicomedullary subarachnoid space on a surveillance brain MRI. On questioning, the patient endorsed a longstanding history of poor bilateral hand dexterity and grip strength. After further imaging workup, the patient underwent suboccipital craniectomy and C1 laminectomy for resection of the mass lesions arising from the fourth ventricular choroid plexus (CP) and performance of an expansile pericranial duraplasty. The patient tolerated surgery well and had progressive improvement in hand dexterity/strength as well as radiographic improvement in the cervical cord syrinx after surgery. Pathologic analysis of the resected mass lesions demonstrated the lesions to be predominantly characterized by dense nodular fibrosis of the CP stromal cores which we are describing as choroid plexus papillary fibrosis. A minority of the lesional stromal cores were noted to be edematous, imparting a more “reticular” appearance. There were no features to suggest a neoplastic or infectious process. Conclusion: This combination of dysplastic/reactive CP histologic findings has not been previously reported in an extramedullary location. The unique pathology of this patient’s CP lesions will be discussed, and previously reported fourth ventricular mass lesions seen in association with CM-II will be reviewed. [ABSTRACT FROM AUTHOR]

Background: The management for craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) remains controversial and clinically challenging. We systemically summarized the clinical and angiographic outcomes of microsurgery, embolization, and conservative management. Methods: Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane, following PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management approaches, and clinical and angiographic outcomes. Results: We included 13 articles (166 patients). The weighted mean age was 58.9 years (95%CI: 53.2–64.5), 58.8 years (95%CI: 48.4–69.2), and 63.8 years (95%CI: 60.1–67.5), in microsurgery, embolization, and conservative groups respectively, with an overall male sex predominance (microsurgery [n = 51/77, 66.2%], embolization [n = 44/56, 78.6%], and conservative management [n = 6/8, 75.0%]). Patients were managed with microsurgery (n = 80/172, 46.5%), embolization (n = 79/172, 45.9%), and conservative treatment (n = 13/172, 7.6%). Foramen magnum was the most common location (microsurgery [n = 34/77, 44.2%], embolization [n = 31/56, 55.4%], and conservative treatment [n = 3/8, 37.5%]). Vertebral artery was the primary feeder (microsurgery [n = 58/84, 69.1%], embolization [n = 41/86, 47.6%], and conservative treatment [n = 4/7, 57.1%]). Complete fistula obliteration rates were 74.1% (95%CI:52.3–88.2%) in the microsurgery group and 54.9% (95%CI:30.7–77.0%) in the embolization group. Complications rates were 16.2% (95%CI:6.7–34.5%) in the embolization group, 11.6% (95%CI:3.8–30.4%) in the microsurgery group, and 7.7% (95%CI:1.1–39.1%) in the conservative group. Different rates of good clinical outcomes were observed [microsurgery: 66.4% (95%CI:48.1–80.8%), embolization: 51.9% (95%CI:30.8–72.4%), and conservative: 11.6% (95%CI:4.4–27.4%)]. Conclusions: In patients with CCJ-DAVFs, each management approach has its own merits based on the fistula and patient characteristics. [ABSTRACT FROM AUTHOR]

Background: Spontaneous subarachnoid hemorrhage (SAH) often results in altered cerebrospinal fluid (CSF) flow and secondary hydrocephalus, yet the mechanisms behind these phenomena remain poorly understood. This study aimed to elucidate the impact of SAH on individual CSF flow patterns and their association with secondary hydrocephalus. Methods: In patients who had experienced SAH, changes in CSF flow were assessed using cardiac-gated phase-contrast magnetic resonance imaging (PC-MRI) at the Sylvian aqueduct and cranio-cervical junction (CCJ). Within these regions of interest, volumetric CSF flow was determined for every pixel and net CSF flow volume and direction calculated. The presence of acute or chronic hydrocephalus was deemed from ventriculomegaly and need of CSF diversion. For comparison, we included healthy subjects and patients examined for different CSF diseases. Results: Twenty-four SAH patients were enrolled, revealing a heterogeneous array of CSF flow alterations at the Sylvian aqueduct. The cardiac-cycle-linked CSF net flow in Sylvian aqueduct differed from the traditional figures of ventricular CSF production about 0.30–0.40 mL/min. In 15 out of 24 patients (62.5%), net CSF flow was retrograde from the fourth to the third and lateral ventricles, while it was upward at the cranio-cervical junction in 2 out of 2 patients (100%). The diverse CSF flow metrics did not distinguish between individuals with acute or chronic secondary hydrocephalus. In comparison, 4/4 healthy subjects showed antegrade net CSF flow in the Sylvian aqueduct and net upward CSF flow in CCJ. These net CSF flow measures also showed interindividual variability among other patients with CSF diseases. Conclusions: There is considerable inter-individual variation in net CSF flow rates following SAH. Net CSF flow in the Sylvian aqueduct differs markedly from the traditional ventricular CSF production rates of 0.30–0.40 mL/min in SAH patients, but less so in healthy subjects. Furthermore, the cardiac-cycle-linked net CSF flow rates in Sylvian aqueduct and CCJ suggest an important role of extra-ventricular CSF production. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion The objective of this study was to analyze failed posterior fossa decompression (PFD) in patients with basilar invagination and atlantoaxial dislocation (BI‐AAD). Revision surgery in these patients is challenging and has been rarely reported. In addition, the anatomical variations of the vertebral artery increase the risk of revision surgery. Here, we introduce the implementation of a new type of one‐stage posterior revision surgery, whose difficulties and effects are summarized.A total of 21 patients with BI‐AAD who underwent PFD were retrospectively analyzed in our center from November 2017 to April 2021. The revision surgery in all patients was performed through the posterior approach. The Japanese Orthopaedic Association (JOA) score and the Short Term 12 (SF‐12) score were employed to evaluate the clinical symptoms and health status. The distance from the tip of the odontoid to Chamberlain's line (DCL), the atlantodental interval (ADI), the clivus‐canal angle (CCA), the diameter of the subarachnoid space (DSS), and the craniovertebral junction triangular area (CTA) were assessed radiographically. The pre‐ and postoperative results were compared by paired t test.The data of 21 consecutive patients were reviewed, with an average follow‐up period of 28 ± 14 months. Postoperative imaging showed effectively reduced compression of BI‐AAD. No implant failure or neurovascular injury occurred. Eleven patients had vertebral artery abnormalities, but none had vertebral artery injury. All patients had evidence of bone fusion on the CT scan images within a 12‐month follow‐up period. The JOA and SF‐12 scores were significantly improved 1 year postoperatively (p < 0.001).Posterior surgery using the technique of interarticular distraction, fusion with cage grafting, and fixation is a safe and effective revision surgery to treat patients with basilar invagination and atlantoaxial dislocation who failed PFD, which will result in good outcome. [ABSTRACT FROM AUTHOR]

Case: A 47-year-old man presented with neck pain, restricted neck movements, along with involvement of facial and hypoglossal nerve. On the basis of clinico-radiological correlation, the patient was diagnosed with craniovertebral junction tuberculosis and was started on antitubercular therapy (ATT). Failing the conservative trial, the patient was operated and occipitocervical fusion was done with bone grafting. After 12 months of ATT intake, he showed complete recovery of the facial and hypoglossal nerve, with complete resolution of instability pain. Conclusion: Craniovertebral junction tuberculosis is uncommon, and its manifestation with cranial nerves involvement is even more rare. Meticulous clinico-radiological assessment should be done to diagnose and plan the treatment. Early recognition and prompt initiation of ATT, along with timely surgical intervention, when necessary, are crucial for optimal management and outcomes. [ABSTRACT FROM AUTHOR]

Background: Chiari malformation type 1 (CM1) remains a complex neurosurgical condition with ongoing debate regarding its optimal management. Methods: This narrative review examines key controversies surrounding the pathophysiology, surgical indications, and treatment strategies for CM1. Results: We highlight the challenges posed by the wide spectrum of CM variants and the evolving understanding of its association with syringomyelia, basilar invagination, and craniovertebral instability. Emerging surgical techniques, including minimally invasive approaches and the use of new technologies such as endoscopes and exoscopes, are evaluated for their potential to improve outcomes. Recent consensus guidelines are also discussed. Conclusions: The need for individualized treatment plans for CM1 is emphasized, with special focus put on the connection between novel pathophysiological insights, technological advancements and opportunities for a more nuanced surgical management. Further research is necessary to establish solid foundations for more individualized treatments. [ABSTRACT FROM AUTHOR]

Background: The shape and morphology of the foramen magnum play a crucial role in identifying the cause and formulating the treatment approach for neurological conditions such as Arnold Chiari malformation. Transcondylar approach enables neurosurgeons to access the brainstem and cervico medullary junction region with minimum retraction and it requires thorough knowledge of different parameters of foramen magnum. Aim: To study the morphometric characteristics of foramen magnum in dry human skulls. Material and method: This study was conducted on hundred skulls, obtained from Department of Anatomy from various teaching Institutions of Mumbai. Result: Most common shape of foramen magnum found in this study was oval shape followed by tetragonal shape. The mean Anterior-Posterior Diameter (APD) and Transverse Diameter (TD) of foramen magnum calculated were 33.8 ± 3.5 mm and 28.8 ± 3.1 mm respectively. Fifty-five skulls (out of hundred) were having FM index more than 1.2, while forty-five skulls (out of hundred) were having FM index less than or equal to 1.2. Mean of foramen magnum areas calculated by method of Routalet al and by Teixeira's method were 770.56 ± 143.06 mm2 and 777.83 ± 143.77 mm2 respectively. Conclusion: The data collected in this study will be valuable for neurosurgeons in examining the Craniovertebral junction's anatomy for preoperative planning and skull base surgery management. These results will also provide insights for Radiologists, Orthopedicians, Anthropologists, Anatomists, anesthesiologist and forensic specialists. [ABSTRACT FROM AUTHOR]

In the present study, the most commonly observed types of occipital condyles were oval, followed by circular and two-portioned shapes. Occipital condyles are small bilateral extensions of the occipital bone that hold crucial implications for neurosurgical practice due to their association with various disease processes affecting the craniovertebral junction. A comprehensive understanding of the bony anatomy and variations in occipital condyles is imperative for optimising neurosurgical approaches. The primary objective of this study is to conduct an in-depth investigation of occipital condyles. We examined 40 dry human skulls, meticulously measuring various parameters such as length, breadth, anterior, and posterior intercondylar distances. The shapes of occipital condyles were classified into distinct types: oval, circular, eight-shaped, kidney-shaped, deformed, two-portioned, oval convex, and pyramid. The documented parameters of occipital condyles and their variations are poised to serve as invaluable guidelines for future surgeons. Possessing a thorough understanding of occipital condyle morphometry can significantly facilitate the instrumentation process, mitigating the risk of neurovascular damage. We firmly believe that the outcomes of our research will establish a comprehensive reference database, aiding in the development of implants and the formulation of optimal surgical approaches tailored to the intricacies of occipital condyles. [ABSTRACT FROM AUTHOR]

Background: This study aimed to elucidate the specificity of the radiological features of Dropped head syndrome (DHS) from both reginal and global aspects. Methods: We enrolled 53 patients with DHS (8 men, 45 women; mean age 73.5 years), and captured their lateral spinopelvic radiographs in standing position. We also selected 21 age- and sex-matched controls with cervical spondylosis. Radiological parameters were measured and compared between two groups. Compensatory and decompensatory sites were also listed for each patient. Results: Radiological factors such as sagittal vertical axis (SVA), clivo-axial angle (CAA), C2–7 angle, C2–7 SVA, anterior slippage of the vertebra, alignment. C1, C2, C3, C4, C5, C6 slopes, and T1 slope-C2–7 angle showed statistically significant differences between the groups. Multivariate logistic regression showed that SVA, C2–7 SVA, T1-slope-C2–7 angle, and C1 slope were the most important factors specific to DHS. Sole cervical spine and involvement of both cervical and thoracic spine accounted for 22% and 29% of the decompensatory sites in DHS respectively. Notably, 24% of the patients did not show decompensation of the cervical spine. While, 93% exhibited compensation at the craniovertebral junction. The thoracic spine contributed 70% to DHS compensation. Conclusions: This study indicated the radiological features of DHS from both regional and global aspects. Compensatory and decompensatory DHS mechanisms varied among individuals. Compensation was likely to be developed at the neighboring sites, with the craniovertebral and thoracic junctions as the proximal and distal parts for DHS, respectively. [ABSTRACT FROM AUTHOR]

Surgery to expose the anterior occiptocervical junction (OCJ) is exacting, and optimal approaches are debatable. The close proximity of vital structures and difficult surgical access present a unique challenge to treat lesions in this area. Routine access to the upper anterior cervical spine remains limited. The authors present a modified retropharyngeal approach and instrumentation in order to resect an exceptionally rare atypical rhabdoid teratoid tumor involving the craniovertebral junction. The technical aspects of this approach in anatomical perspectives are discussed in this article. [ABSTRACT FROM AUTHOR]

Introduction The clival, paraclival, and craniocervical junction regions are challenging surgical targets. To approach these areas, endoscopic endonasal transclival approaches (EETCAs) and their extensions (far-medial approach and odontoidectomy) have gained popularity as they obviate manipulating and working between neurovascular structures. Although several cadaveric studies have further refined these contemporary approaches, few provide a detailed step-by-step description. Thus, we aim to didactically describe the steps of the EETCAs and their extensions for trainees. Methods Six formalin-fixed cadaveric head specimens were dissected. All specimens were latex-injected using a six-vessel technique. Endoscopic endonasal middle and inferior clivectomies, far-medial approaches, and odontoidectomy were performed. Results Using angled endoscopes and surgical instruments, an endoscopic endonasal midclivectomy and partial inferior clivectomy were performed without nasopharyngeal tissue disruption. To complete the inferior clivectomy, far-medial approach, and partially remove the anterior arch of C1 and odontoid process, anteroinferior transposition of the Eustachian–nasopharynx complex was required by transecting pterygosphenoidal fissure tissue, but incision in the nasopharynx was not necessary. Full exposure of the craniocervical junction necessitated bilateral sharp incision and additional inferior mobilization of the posterior nasopharynx. Unobstructed access to neurovascular anatomy of the ventral posterior fossa and craniocervical junction was provided. Conclusion EETCAs are a powerful tool for the skull-base surgeon as they offer a direct corridor to the ventral posterior fossa and craniocervical junction unobstructed by eloquent neurovasculature. To facilitate easier understanding of the EETCAs and their extensions for trainees, we described the anatomy and surgical nuances in a didactic and step-by-step fashion. [ABSTRACT FROM AUTHOR]

The upper cervical spine is responsible for a significant portion of the flexion, extension and rotation movements of the whole cervical spine. It is a complex region with anatomical and biomechanical relationships between the occipital condyles, atlas, axis and their joints. These make this a region of special interest in the context of trauma. In this article we review the anatomy of the cranio-vertebral junction, the clinical patterns of injury, and the options in their clinical management. [ABSTRACT FROM AUTHOR]

Purpose: Proper posture is essential for maintaining musculoskeletal health. The stability of the spine depends largely on the curvature of the human upright spine, and deviations in sagittal arches may signify a displacement in the body's center of gravity. This study aims to investigate the relationship between spinal curvature and postural... [ABSTRACT FROM AUTHOR]

Background: Forward head posture (FHP) leads to the anterior excursion of the center of gravity, which can affect a person's standing balance. Evaluating the balance in different degrees of severity of FHP can help design and plan appropriate balance exercises for people with FHP. Objectives: This study aimed to evaluate the changes in the limits of stability (LOS) in people with mild and moderate-to-severe grades of FHP. Methods: The participants in this study were 70 individuals suffering from FHP, aged between 17 - 45. They were divided into two groups based on their craniovertebral angle: Mild (> 45.5 degrees) and moderate-to-severe (< 45.5 degrees). The LOS test was performed using a posturography device (NeuroCom, Equitest, USA). Five indices—movement reaction time (RCT), movement velocity (MVL), endpoint excursion (EPE), maximum excursion (MXE), and directional control (DCL)—were evaluated. Results: Based on the results of the LOS test, RCT, MVL, EPE, MXE, and DCL were significantly different between the mild and moderate-to-severe FHP groups in both anterior and posterior directions (P < 0.05). However, in other directions, no significant difference was observed in these variables based on the LOS test (P > 0.05). Conclusions: It can be concluded that individuals with moderate-to-severe FHP are more likely to have postural control deficits. Therefore, it is necessary to design appropriate targeted interventions to prevent falls in these individuals. Specifically, they should receive balance exercises in dynamic situations. [ABSTRACT FROM AUTHOR]

This paper presents the anatomical and biomechanical aspects of chronic instability of the craniocervical junction (CCJ) with a discussion on clinical diagnostics based on mobility tests and provocative tests related to ligamentous system injuries, as well as radiological criteria for CCJ instability. In addition to the structural instability of the CCJ, the hypothesis of its functional form resulting from cervical proprioceptive system (CPS) damage is discussed. Clinical and neurophysiological studies have shown that functional disorders or organic changes in the CPS cause symptoms similar to those of vestibular system diseases: dizziness, nystagmus, and balance disorders. The underlying cause of the functional form of CCJ instability may be the increased activity of mechanoreceptors, leading to "informational noise" which causes vestibular system disorientation. Due to the disharmony of mutual stimulation and the inhibition of impulses between the centers controlling eye movements, the cerebellum, spinal motoneurons, and the vestibular system, inadequate vestibulospinal and vestibulo-ocular reactions occur, manifesting as postural instability, dizziness, and nystagmus. The hyperactivity of craniocervical mechanoreceptors also leads to disturbances in the reflex regulation of postural muscle tone, manifesting as "general instability". Understanding this form of CCJ instability as a distinct clinical entity is important both diagnostically and therapeutically as it requires different management strategies compared to true instability. Chronic CCJ instability significantly impacts the quality of life (QOL) of affected patients, contributing to chronic pain, psychological distress, and functional impairments. Addressing both structural and functional instability is essential for improving patient outcomes and enhancing their overall QOL. [ABSTRACT FROM AUTHOR]

Purpose: Instrumentation of the C1 vertebra requires either mobilization or transection of the C2 nerve root. This study investigates clinical and radiological outcomes and incidences of C2 neuropathic pain after posterior instrumented fusion in the cranio-cervical junction with or without division of the C2 nerve roots. Methods: This retrospective study compared two cohorts of patients who underwent instrumented fusion in the cranio-cervical junction. Fifty patients (22 males and 28 females) were operated with complete resection of C2 nerve root ganglion (Ex group), and fifty-one patients (30 men, 21 women) with C2 nerve roots preservation (No group). Results: The incidence of postoperative C2 neuropathy was eight times lower in the Ex group compared to the No group that was statistical significant, p = 0.039. Surgical time was significantly shorter in the No group (p = 0.001). The fusion rates were very high for both groups, without difference between groups (p = 1.0). Autografting from the iliac crest (p = 0.001) as well as postoperative immobilisation with a hard collar (p < 0.001) were required in fewer patients in the Ex group. Also, patients in the Ex group were mobilised faster after surgery (p = 0.49). Overall, complication rates were similar between groups, but the Ex group demonstrated fewer major medical complications (16% vs 31%). Male sex and iliac bone harvesting demonstrated significantly higher OR for development of postoperative complications (p = 0.023 and p = 0.034 respectively) and postoperative mobilization demonstrated significant higher OR for development of postoperative major complications (p = 0.042). Conclusions: Resection of the C2 nerve root ganglion during posterior instrumented fusion of the cranio-cervical junction is safe and rarely leads to C2 neuropathy. The technique tends to mitigate the odds of developing postoperative complications. [ABSTRACT FROM AUTHOR]

This study aims to discuss the identification of the C1 nerve root as an effective surgical approach to successfully locate the shunting point of craniocervical junction spinal dural arteriovenous fistula (CCJ-SDAVF) intraoperatively. This study included all patients with CCJ-SDAVF who underwent surgical treatment using the far-lateral transcondylar approach at a single institution from January 2017 to June 2023. Data on patient demographics, clinical and angiographic characteristics of CCJ-SDAVF, surgical details, and treatment outcomes were collected. Follow-up assessments were conducted for all patients until December 31, 2023. The study included a total of 7 patients, comprising 5 men(71.4%) and 2 women (28.6%), with an average age of 57.6 years. Among them, 4 patients (57.1%) developed diffuse subarachnoid hemorrhage(SAH), while 2 patients (28.6%) experienced progressive cervical myelopathy. The shunting points of all CCJ-SDAVFs, which exhibited engorged veins, were identified next to the C1 root. Complete obliteration of CCJ-SDAVFs was successfully achieved in all patients, as confirmed by postoperative angiography one month later. No recurrent CCJ-SDAVFs were observed two years after the operation. Among the patients, 5 (71.4%) experienced good functional recovery, as indicated by an mRS score ranging from 0 to 1, while the remaining 2 patients (28.6%) showed incomplete functional recovery. The surgical interruption of CCJ-SDAVFs is the preferred treatment option, given its high obliteration rate and favorable functional recovery outcomes. We advocate the identification of C1 spinal nerve root as a crucial surgical step to identify the shunting points of CCJ- SDAVFs. [ABSTRACT FROM AUTHOR]

In this report, atlantooccipital assimilation (AS), anterior arch defect (AAD), and posterior arch defect (PAD) of the atlas, and several variations around the craniocervical junction were identified on computed tomography (CT) of a patient of unknown sex and age. Coronal and sagittal CT scans showed AS and bilateral fusion of the atlas and the base of occipital bone. Axial CT scan at the atlas revealed PAD type B on the left side and midline AAD. Morphometric measurements indicated a potential ventral spinal cord compression. In addition, mid-sagittal CT revealed the presence of fossa navicularis magna and incomplete formation of the transverse foramen on the right side. This study reports an extremely rare AS associated with AAD, PAD, and other variations of the clivus and the atlas. To our knowledge, no similar case has been reported in the literature. [ABSTRACT FROM AUTHOR]

Objective: Recent studies indicate that 3 morphological types of atlanto-occipital joint (AOJ) exist in the craniovertebral junction and are associated with type II basilar invagination (BI) and atlanto-occipital instability. However, the actual biomechanical effects remain unclear. This study aims to investigate biomechanical differences among AOJ types I, II, and III, and provide further evidence of atlanto-occipital instability in type II BI. Methods: Models of bilateral AOJ containing various AOJ types were created, including I-I, I-II, II-II, II-III, and III-III models, with increasing AOJ dysplasia across models. Then, 1.5 Nm torque simulated cervical motions. The range of motion (ROM), ligament and joint stress, and basion-dental interval (BDI) were analyzed. Results: The C0–1 ROM and accompanying rotational ROM increased progressively from model I-I to model III-III, with the ROM of model III-III showing increases between 27.3% and 123.8% indicating ultra-mobility and instability. In contrast, the C1–2 ROM changes were minimal. Meanwhile, the stress distribution pattern was disrupted; in particular, the C1 superior facet stress was concentrated centrally and decreased substantially across the models. The stress on the C0–1 capsule ligament decreased during cervical flexion and increased during bending and rotating loading. In addition, BDI gradually decreased across the models. Further analysis revealed that the dens showed an increase of 110.1% superiorly and 11.4% posteriorly, indicating an increased risk of spinal cord impingement. Conclusion: Progressive AOJ incongruity critically disrupts supportive tissue loading, enabling incremental atlanto-occipital instability. AOJ dysplasia plays a key biomechanical role in the pathogenesis of type II BI. [ABSTRACT FROM AUTHOR]

Introduction. Clival chordomas represent a rare but clinically significant subset of skull base tumors, characterized by a locally aggressive nature and a location in proximity to vital neurovascular structures. Surgical resection, often combined with adjuvant therapies, remains the cornerstone of clival chordoma treatment, and various approaches and techniques have evolved to maximize tumor removal while preserving neurological function. Recent advancements in skull base surgery, imaging, and adjuvant therapies have improved outcomes by reducing morbidity and thus enhancing long-term survival. Methods and Results. We have conducted a systematic review on PubMed/Medline following PRISMA guidelines regarding indications, the extent of resection (EOR), and complication rates. Then, we present three illustrative cases from our personal experience, which started 25 years ago with CVJ instrumentation procedures and 15 years ago with anterior decompressive transmucosal procedures performed with the aid of an operative microscope, an endoscope, and neuroradiological monitoring. Conclusions. Traditionally, the transoral approach (TOA) is the most frequently used corridor for accessing the lower clivus and the anterior craniovertebral junction (CVJ), without the need to mobilize or retract neural structures; however, it is associated with a high rate of complications. The endonasal approach (EEA) provides access to the anterior CVJ as well as to the lower, middle, and superior clivus, decreasing airway and swallowing morbidity, preserving palatal function, decreasing postoperative pain, and reducing the incidence of tracheostomy. The submandibular retropharyngeal approach (SRA) allows unique access to certain cervical chordomas, which is better suited when the lesion is located below the clivus and in the midline. [ABSTRACT FROM AUTHOR]

Objective: Pediatric athletes with concussion present with a variety of impairments on clinical assessment and require individualized treatment. The Buffalo Concussion Physical Examination is a brief, pertinent clinical assessment for individuals with concussion. The purpose of this study was to identify physical examination subtypes in pediatric athletes with concussion within 2 weeks of injury that are relevant to diagnosis and treatment. Design: Secondary analysis of a published cohort study and clinician consensus. Setting: Three university-affiliated sports medicine centers. Participants: Two hundred seventy children (14.961.9 years). Independent Variables: Orthostatic intolerance, horizontal and vertical saccades, smooth pursuits, vestibulo-ocular reflex, near-point convergence, complex tandemgait, neck range of motion, neck tenderness, and neck spasm. Main Outcome Measures: Correlations between independent variables were calculated, and network graphs were made. k-means and hierarchical clustering were used to identify clusters of impairments. Optimal number of clusters was assessed. Results were reviewed by experienced clinicians and consensus was reached on proposed subtypes. Results: Physical examination clusters overlapped with each other, and no optimal number of clusters was identified. Clinician consensus suggested 3 possible subtypes: (1) visio-vestibular (horizontal and vertical saccades, smooth pursuits, and vestibulo-ocular reflex), (2) cervicogenic (neck range of motion and spasm), and (3) autonomic/balance (orthostatic intolerance and complex tandemgait). Conclusions: Although we identified 3 physical examination subtypes, it seemed that physical examination findings alone are not enough to define subtypes that are both statistically supported and clinically relevant, likely because they do not include symptoms, assessment of mood or cognitive problems, or graded exertion testing. [ABSTRACT FROM AUTHOR]

To evaluate the feasibility of a novel method for occipitocervical fixation (OCF) through the endonasal corridor. Thin-cut computed tomography scans were obtained for 5 cadaveric specimens. Image segmentation was used to reconstruct 3D models of each O-C1 joint complex. Using computer-aided design software, plates were custom-designed to span each O-C1 joint, sit flush onto the bony surface, and accommodate screws. The final models were 3D-printed in titanium. For implantation, specimens were held in pin-fixation and registered to neuronavigation. A rigid 0º endoscope was used for endonasal visualization. An inverted U-shaped nasopharyngeal flap was raised to expose the occipital condyles and C1. The plates were introduced and fixed with bone screws. Computed tomography scans were obtained to assess screw accuracy and proximity to critical neurovascular structures. Screw entry points and trajectories were recorded. Endonasal OCF was performed on 5 cadaveric specimens. The mean starting point for occipital condyle screws was 6.17 mm lateral and 5.38 mm rostral to the medial O-C1 joint. Mean axial and sagittal trajectories were 7.98° and 6.71°, respectively. The mean starting point for C1 screws was 16.11 mm lateral to the C1 anterior tubercle and 6.39 mm caudal to the medial O-C1 joint. Mean axial and sagittal trajectories were 10.97° and −9.91°, respectively. Endonasal OCF is technically and anatomically feasible. The application of this technique may allow for same-stage endonasal decompression and fixation, offering a minimally invasive alternative to current methods of fixation and advancing surgeons' ability to treat pathology of the craniovertebral junction. Next steps will focus on biomechanical testing. [ABSTRACT FROM AUTHOR]

We designed this study to introduce the surgical strategy cerebrospinal fluid (CSF) decompression in treatment of Chiari malformation type I and compared CSF decompression with other surgical strategies to provide a solid basis for patient counseling. The study enrolled 528 consecutive patients with CMI who underwent surgical interventions from 2012 to 2022. The surgical strategy for these patients was bony and dural decompression, anatomical reduction of herniated tonsils, or CSF decompression. Short-term results were determined after 3 months; long-term outcomes were evaluated at last follow-up (at least 18 months). CSF decompression was independently associated with better long- or short-term primary outcomes than anatomical reduction of herniated tonsils or bony and dural decompression (P < 0.001). Compared with short-term, the long-term outcomes were better in patients who underwent CSF decompression (P = 0.035), but were worse in patients with bony and dural decompression (P = 0.03). Specific surgical techniques cannot affect the long- and short-term outcomes of patients with Chiari malformation type I. CSF decompression provided better long-term syringomyelia improvement than short-term (181/218, 83% vs. 169/218, 77.5%; P < 0.001). CSF decompression, but not a specific surgical technique or operative method, was associated with favorable neurological outcomes in ADULT patients with Chiari malformation type I. The surgical technique and operative method should be selected according to the characteristics of each patient and the intraoperative condition to normalize CSF circulation at the craniovertebral junction area. The intraoperative target, smooth CSF flow out from the fourth ventricle and in to the bilateral Luschka foramina, could be observed. [ABSTRACT FROM AUTHOR]

Short-lasting cough-associated headache (CAH) in patients with Chiari I malformation (CMI) is believed to be due to transient worsening of cerebrospinal flow (CSF) obstruction at the foramen magnum. We assessed changes in CSF flow in response to coughing in CMI patients with CAH and compared with those without CAH and healthy participants (HPs) using real-time magnetic resonance imaging. Seventeen CMI patients (12 with CAH, 5 without CAH) and 6 HPs were prospectively assessed using real-time pencil-beam imaging magnetic resonance sequence. A 64-mm length pencil-beam imaging cylinder was placed at the craniocervical junction. CSF stroke volume (SV CSF) was assessed during resting, postcoughing, and relaxation phases via a 90-second scan. SV CSF was measured at 6 levels at 5-mm intervals between 10 and 35 mm below the foramen magnum. During each phase, SV CSF was compared between CMI with and without CAH and HPs and corrected for multiple comparisons. At multiple consecutive levels, postcoughing SV CSF was significantly lower in CMI with CAH compared with both CMI without CAH and HP (P < 0.05). No differences in postcoughing SV CSF were seen between CMI without CAH and HP. At rest or relaxation phase, no differences in SV CSF were seen between patients with and without CAH but minimal differences were seen between CMI with CAH and HP. A decrease in CSF flow after coughing in CMI patients with CAH supports the notion that CAH is caused by transient worsening of CSF flow obstruction at the foramen magnum. [ABSTRACT FROM AUTHOR]

Craniovertebral junction (CVJ) tumors are challenging due to their unique anatomical location. This study aimed to evaluate the complexities in dealing with such precarious CVJ extradural lesions over the decade. Twenty-seven patients of extradural CVJ tumors operated between 2009 and 2018 were included. The demographic details, neurological status, surgical approach, extent of resection, type of fixation, complications, and outcome at final follow-up were recorded for each patient. The mean age of the patients was 39.5 ± 20 years. Most (17/27) of the patients had involvement of a single level. Clivus was the most common (9/17) involved region followed by atlas (7/17) vertebrae. Majority of the patients (13/27) were operated through the posterior-only approach. About 15 patients (55.5%) had instability or extensive lesions that necessitated posterior fixation. None of the patients underwent anterior fixation. Gross and near total excision were achieved in 10 patients (37%) and 3 patients (11%) respectively while 14 patients underwent subtotal excision of tumor. On histopathological analysis, clival chordoma (8/27) was found to be the most common pathology followed by giant cell tumor (6/27), plasmacytoma (4/27), and multiple myeloma (2/27). Most patients (13 out of 27) had the same neurological status after the surgery. Six patients (22%) improved post-operatively with decreased weakness and spasticity. Thirteen (48%) patients underwent adjuvant radiotherapy. This retrospective study provides valuable insights into managing extradural CVJ tumors and highlights the importance of individualized approaches for optimal outcome. [ABSTRACT FROM AUTHOR]

Bow Hunter's syndrome (BHS) is a very rare condition in which there is rotational vertebral artery (VA) insufficiency. The association of BHS with rotational atlantoaxial instability is extremely rare. We are reporting a case of pediatric BHS who presented with features of VA insufficiency on neck rotation. Careful evaluation revealed rotational C1-C2 instability. Provocative digital subtraction angiography and dynamic neck computed tomography were the mainstay of our diagnostic armamentarium. Our case emphasizes the fact that VA abnormalities need special consideration in young patients with craniovertebral junction instability and a high degree of suspicion is necessary in most instances for accurate diagnosis. [ABSTRACT FROM AUTHOR]

Fibrous dysplasia (FD) is a rare skeletal disorder characterized by the replacement of normal bone with fibrous connective tissue, leading to abnormal bone formation. This case report details the successful treatment of a 61-year-old woman with FD at the craniovertebral junction (CVJ). The patient, who had a history of intracranial meningioma and had already been diagnosed with FD, experienced worsening gait disturbance and muscle weakness following a fall. Imaging studies revealed extensive polyostotic FD lesions in the skull and cervical spine, along with a C2 odontoid fracture causing spinal cord compression. The patient underwent occipitocervical fixation and decompression surgery. Intraoperative O-arm navigation was used to ensure accurate screw placement and effective decompression. This procedure allowed for proper positioning of the C2 and C3 pedicle screws, resection of the hyperplastic occipital bone and C1 posterior arch, and placement of the occipital plate with avoiding the cyst components. At a 2-year follow-up, there were no signs of screw loosening, and the patient showed marked clinical improvement. This case emphasizes the importance of tailored surgical strategies and the use of advanced navigational technologies in managing complex FD cases, particularly those involving the CVJ. It also highlights the challenges of treating polyostotic FD, where complete resection is often unfeasible. The successful outcome in this case supports the use of decompressive surgery combined with stabilization to relieve symptoms and prevent further complications.

The craniocervical junction (CCJ) forms the bridge between the skull and the spine, a highly mobile group of joints that allows the mobility of the head in every direction. The CCJ plays a major role in protecting the inferior brainstem (bulb) and spinal cord, therefore also requiring some stability. Children are subjected to multiple constitutive or acquired diseases involving the CCJ: primary bone diseases such as in FGFR‐related craniosynostoses or acquired conditions such as congenital torticollis, cervical spine luxation, and neurological disorders. To design efficient treatment plans, it is crucial to understand the relationship between abnormalities of the craniofacial region and abnormalities of the CCJ. This can be approached by the study of control and abnormal growth patterns. Here we report a model of normal skull base growth by compiling a collection of geometric models in control children. Focused analyses highlighted specific developmental patterns for each CCJ bone, emphasizing rapid growth during infancy, followed by varying rates of growth and maturation during childhood and adolescence until reaching stability by 18 years of age. The focus was on the closure patterns of synchondroses and sutures in the occipital bone, revealing distinct closure trajectories for the anterior intra‐occipital synchondroses and the occipitomastoid suture. The findings, although based on a limited dataset, showcased specific age‐related changes in width and closure percentages, providing valuable insights into growth dynamics within the first 2 years of life. Integration analyses revealed intricate relationships between skull and neck structures, emphasizing coordinated growth at different stages. Specific bone covariation patterns, as found between the first and second cervical vertebrae (C1 and C2), indicated synchronized morphological changes. Our results provide initial data for designing inclusive CCJ geometric models to predict normal and abnormal growth dynamics. [ABSTRACT FROM AUTHOR]

Introduction The transbasal approach traditionally uses a bicoronal scalp incision with bifrontal craniotomy to establish an extradural midline skull base working corridor. Depending on additional craniofacial osteotomies, this approach can expand its reach to the nasal cavity and paranasal sinuses and may be employed for the resection of particularly complex sinonasal and midline skull base tumors. Given its discrepancy in nomenclature and differences in interoperator technique, we propose a practical, operatively oriented guide for trainees performing this approach. Methods Three formalin-fixed, latex-injected specimens were dissected under microscopic magnification and endoscopic-assisted visualization. Stepwise dissections of the transcranial-transbasal approach with common modifications were performed, documented with three-dimensional photography, and supplemented with representative case applications. Results The traditional transbasal approach via bifrontal craniotomy affords wide extradural access to the anterior cranial fossa and central skull base. The addition of craniofacial osteotomies further expands access into the sinonasal cavities, clivus, and craniocervical junction. Key steps described include patient positioning, bicoronal skin incision, pericranial graft harvest, bifrontal craniotomy, orbital rim osteotomy, sphenoidotomy, bilateral ethmoidectomies, and microsurgical dissection of the sellar region. Basal superior sagittal sinus ligation and durotomy allow for intradural exposure. Reconstruction techniques are also discussed. Conclusion While the transbasal approach is rich with historical descriptions, illustrations, and modifications, its stepwise performance may be relatively unknown and unclear to younger generations of trainees. We present a comprehensive guide to optimize familiarity with the transbasal approach and its indications in the surgical anatomy laboratory, mastery of the relevant microsurgical anatomy, and simultaneous preparation for learning and participation in the operating room. [ABSTRACT FROM AUTHOR]

Simple Summary: Tumor-like lesions at the craniovertebral junction, including epidermoids, dermoids, and neurenteric cysts present significant treatment challenges. Our review of several cases, combined with a meta-analysis of numerous patients, aimed to identify recurrence predictors to improve treatment and follow-up accuracy. Neurenteric cysts were the most common, generally presenting with gradual symptom onset over several months and commonly located in the anterior part of the CVJ. Recurrence in neurenteric cyst cases was linked to factors such as older age, subtotal resection, complications, rim enhancement, and poor outcomes. Recognizing these predictors is essential for enhancing treatment strategies and patient management. By understanding the key factors influencing recurrence, healthcare professionals can better tailor their approaches to ensure optimal outcomes for patients with CVJ lesions. Background: Tumor-like lesions at the craniovertebral junction mimic tumors in clinical presentation and imaging. Our study focuses on three common developmental pathologies—epidermoids, dermoids and neurenteric cysts. Methods: We conducted a retrospective analysis of a case series and a meta-analysis of 170 patients from 119 reports. Results: Neurenteric cysts predominated (81.2%). Anterior cysts were linked to neurenteric cysts, while posterior ones correlated with dermoid/epidermoid cysts (p < 0.001). Complications occurred in 27.2% of cases, with cranial nerve paresis being the most common. Most patients had excellent outcomes (75.2%) with low recurrence rates (12%). Dermoid cysts were more associated with anomalies (p < 0.001). Among 138 neurenteric cyst cases, 15 experienced recurrence, with predictors including ages 51–60 and over 70, subtotal resection, complications, and poor outcomes (p < 0.001). Cysts with total resection were significantly less likely to adhere to surrounding brain tissue (p < 0.001). CSF diversion was correlated with older age (p = 0.010) and various complications (p < 0.001). Age affected outcomes, and the hydrocephalus was linked to poor outcomes (p = 0.002). Conclusions: This meta-analysis underscores the importance of total resection in minimizing recurrence rates and emphasizes meticulous preoperative planning and imaging. Our results indicate that rim enhancement (p = 0.047) and poor outcome (p = 0.007) are significant factors associated with recurrence. Additionally, associated anomalies, as well as the patient's age and overall health, significantly influence the surgical outcomes and the likelihood of recurrence. [ABSTRACT FROM AUTHOR]

Achondroplasia is the most common skeletal dysplasia and is associated with serious complications such as foramen magnum stenosis (FMS). This case report describes an infant with achondroplasia who presented with a syndrome of inappropriate antidiuretic hormone secretion (SIADH), secondary to significant FMS and myelocompression. A 2-month-old boy with prenatally diagnosed achondroplasia was referred due to disordered breathing and altered consciousness. On admission, apathy, hypotonus, and hypothermia with typical features of achondroplasia were noticed. Laboratory investigations revealed severe hyponatremia and hypochloridaemia with normal glucose and urea levels. The diagnosis of SIADH was made based on low serum osmolality in the presence of high urine osmolality, along with an elevated copeptin level. An emergency computerized tomography showed a high-grade stenosis at the cranio-cervical junction; subsequent magnetic resonance imaging demonstrated myelocompression. The patient underwent decompression surgery the next day; serum osmolality increased after the operation. Spontaneous breathing after extubation was sufficient whereas tetraplegia persisted despite intensive physiotherapy. Clinicians should be aware of SIADH as a presenting sign of FMS in children with achondroplasia. Further discussion is warranted regarding improving parental education and timing of screening recommendations. [ABSTRACT FROM AUTHOR]

The paper discusses a case of a 58-year-old male suffering from a destructive process affecting the cranial bone and craniovertebral junction. A pathological fracture of the axial vertebrae led to a progressing atlantoaxial dislocation combined with pain syndrome and orthopedic disturbances. After symptom assessment, he was diagnosed to have developed the Gorham-Stout disease (GSD), a rare syndrome accompanied by massive osteolysis. The paper considers GSD etiology and observes the main pathogenetic theories. [ABSTRACT FROM AUTHOR]

This case study presents a 47-year-old male who was diagnosed with Gorham-Stout syndrome (GSS) 10 years ago in the occipitocervical junction. The pathology caused the resorption of the suboccipital bone, clivus, foramen magnum, and C1–C3 laminae. After his first fusion attempt in 2010 using occipital plate-cervical lateral mass screws, he needed many revision surgeries either for the progression of the pathology or for instrumentation failure and wound healing problems. Eventually, a new occipital plate and cervical pedicle screws were applied to obtain the exact solution. The involvement of the craniovertebral junction in GSS may be challenging for spinal surgeons due to the inadequate bone reserve for stabilization. As lateral mass screws cannot provide a strong pull-out force, cervical pedicular screws may be used as the first choice for unstable cervical GSS cases. [ABSTRACT FROM AUTHOR]

Purpose: The topic of osseous variations of the craniocervical junction is a complex morphological and embryological chapter of human anatomy, with a possible impact on neurogical and vascular functionality in this morphological variable region. Material & methods: An until now undescribed anatomical variation of the exoccipital part of the occipital bone has been observed after maceration at the outer skull base of a West-European 68-year-old male body donor. Results: On both sites of the foramen magnum accessory osseous processes were observed that arise from the jugular process and point towards the lateral margin of the foramen magnum. On the left site this process forms a full arc that bridges the condylar fossa completely. Conclusion: The observed osseous bridge over the condylar fossa has not been reported on before and can be explained by the partial persistence of a primordial vertebra between atlas and occipital bone: the Proatlas. The resulting accessory structure may affect due to its topographic conditions the V3-Segment of the vertebral artery and its accompanying nerves, and thus, play a role in diagnosis and therapy of vascular and/or neurological symptoms of head and neck. [ABSTRACT FROM AUTHOR]

Objective While the transcondylar approach is technically challenging, it provides generous ventral and caudal exposure to the craniovertebral junction. This approach requires navigation around multiple eloquent neurovascular structures including the lower cranial nerves, vertebral artery and its branches, and the brainstem. Superficial exposure, including incision location and muscle dissection, can dramatically affect the surgical angle and maneuverability at depth. Methods We demonstrate the transcondylar approach in a step-by-step fashion in a formalin-embalmed, latex-injected cadaver head. Dissection within each layer of the suboccipital muscles was performed. A small cohort with an illustrative case is also included herein. Results The sternocleidomastoid (SCM) muscle was retracted anteriorly; the splenium capitis, semispinalis capitis, and longissimus capitis muscles were disconnected from the superior nuchal line and reflected inferomedially. The suboccipital muscle group was fully exposed. The superior and inferior oblique muscles were disconnected from the transverse process of C1. The superior oblique and the rectus capitis posterior major muscles were then dissected off the inferior nuchal line, and the suboccipital muscle group was retracted inferomedially en bloc. The greater auricular nerve was retracted laterally with the SCM, and the greater occipital nerve was retracted inferomedially with the suboccipital muscle group. Conclusion This technique avoids the obstructive muscle bulk that results from a myocutaneous approach while maximizing deep exposure. Understanding the detailed muscular anatomical relationship with the insertion location and suboccipital nerves is key to complete and safe extracranial dissection. Diligent dissection helps minimize postoperative pain and muscle spasm while optimizing the closure technique. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of calvarial graft (CG) in craniovertebral fusion procedures in children at a single single center. Methods: Paediatric patients in whom CG had been used as the sole construct, or to augment a semi-rigid construct were identified from a prospective operative database. Age, underlying diagnosis and clinical presentation were obtained from review of the electronic patient record. The primary outcome was bony fusion confirmed on CT. Additional outcome measures were donor site morbidity and need for further surgery. Results: From 82 paediatric CVJ procedures, CG was used in 15 patients with a mean age of 4.1 (± 3.52) years. Aetiology comprised skeletal dysplasia (n = 12), congenital anomaly of segmentation (n = 1) and cervical trauma (n = 2). Myelopathy was the most common clinical finding (9/15), followed by cervical pain (3/15). The indications for surgery comprised atlanto-axial subluxation (8/15), basilar invagination with compression (2/15), and cervicomedullary compression without instability but deemed at risk of instability following decompression (4/15). CG was used in three scenarios: (i) CG + wire only (n = 10); (ii) CG + semirigid instrumentation (n = 3); (iii) CG to augment rigid instrumented fixation (n = 2). In 13 patients a Halo-body Jacket was used peri-operatively. At a mean time of 4.4 months following surgery, 80% of cases had radiological evidence of fusion. Conclusion: Full thickness calvarial bone graft is readily available, has good structural integrity and is associated with minimal donor site morbidity. CG should be considered for use as a sole construct, or to augment semi-rigid constructs when instrumented fixation is precluded. [ABSTRACT FROM AUTHOR]

This review highlights the need for therapeutic guidelines for syringomyelia associated with tethered cord syndrome (TCS) caused by spinal dysraphism (SD). A comprehensive literature review was conducted, selecting twelve articles to analyze common therapeutic strategies. Surgical cord untethering alone has recently become a preferred treatment, with 45 ± 21.1% of patients experiencing remission or improvement, 47 ± 20.4% unchanged and asymptomatic, and 4 ± 8% worsened. Untethering with direct surgical drainage for the syrinx had better outcomes than untethering alone (78% vs. 45%, p = 0.05). Terminal syringostomy was beneficial for syrinxes extending to the filum terminale but not for asymptomatic small syrinxes with a syrinx index < 0.4. Syrinx shunting was recommended for symptomatic large syrinxes (>2 cm in length and syrinx index > 0.5). Various shunt procedures for syrinxes are still advocated, mainly for refractory syringomyelia in Chiari malformation, posttraumatic cases, SD, or other causes. Personalized surgical methods that address the root cause of syringomyelia, particularly those improving cerebrospinal fluid flow, offer promising results with minimized complications. Ongoing studies are required to enhance management strategies for syringomyelia associated with TCS, optimize patient outcomes, and reduce the risk of recurrent symptoms. [ABSTRACT FROM AUTHOR]

The Ehlers-Danlos Syndromes (EDS) represent a group of hereditary connective tissue disorders, with the hypermobile subtype (hEDS) being the most prevalent. hEDS manifests with a diverse array of clinical symptoms and associated comorbidities spanning the musculoskeletal, neurological, gastrointestinal, cardiovascular, and immunological systems. hEDS patients may experience spinal neurological complications, including cervico-medullary symptoms arising from cranio-cervical and/or cervical instability/hypermobility, as well as tethered cord syndrome (TCS). TCS is often radiographically occult in nature, not always detectable on standard imaging and presents with lower back pain, balance issues, weakness in the lower extremities, sensory loss, and bowel or bladder dysfunction. Cervical instability due to ligament laxity can lead to headaches, vertigo, tinnitus, vision changes, syncope, radiculopathy, pain, and dysphagia. TCS and cervical instability not only share clinical features but can also co-occur in hEDS patients, posing challenges in diagnostics and clinical management. We present a review of the literature and a case study of a 20-year-old female with hEDS, who underwent surgical interventions for these conditions, highlighting the challenges in diagnosing and managing these complexities and underscoring the importance of tailored treatment strategies to improve patient outcomes. [ABSTRACT FROM AUTHOR]

Objective: Forward head posture (FHP) is a common postural disorder that alters shoulder function. This study examined the efficacy of a corrective program involving postural correction exercises (PCEs), scapular stabilization exercises (SSEs), and kinesiotaping (KT) on improving craniovertebral angle (CVA), scapular position, and dominant hand grip strength (HGS) in individuals with FHP. Methods: Sixty subjects (8 males and 52 females, 18–40 years old) were randomly allocated into four equal groups: Group A: received PCEs only, Group B: received PCEs and SSEs, Group C: received PCEs and KT, Group D: received PCEs, SSEs and KT. All subjects received treatment for 4 weeks (4 times/week) and postural advice. Outcome measures included cranio‐vertebral angle (CVA), scapular position using Lateral Scapular Slide Test and dominant HGS using a CAMRY dynamometer that were assessed at baseline and 4 weeks post intervention. Results: Comparing all groups post training revealed that there were statistically significant increases (p < 0.05) in all measured variables (CVA, scapular position and dominant HGS) in favor of group (D). Conclusion: Combination of PCEs, SSEs and KT interventions has achieved the best gains in terms of CVA, dominant HGS and regaining optimal scapular position in FHP subjects. [ABSTRACT FROM AUTHOR]

We compared the diameter of the jugular foramen (JF) between normal individuals and those with a diagnosis of craniovertebral junction abnormalities, such as Chiari malformation type I (CMI) and/or basilar invagination (BI). This cross-sectional analytical study measured the diameter of the right and left JF on magnetic resonance imaging scans of patients divided into 4 groups: 68 with combined CMI and BI (CMI+BI), 42 with isolated BI, 45 with isolated CMI, and 102 control cases. The t test determined sex differences, and univariate analysis of variance with Tukey's post hoc test assessed JF differences between groups. Considering all combinations of laterality and sex, the CMI+BI group had a JF narrower than their respective control groups. The JF was bilaterally narrower in the BI group than in the control group only in the women. Regardless of laterality, the CMI group had a wider JF than did the CMI+BI group in men and did not differ from that of the control group. In the female patients with CMI, the right JF did not differ from that of the controls and was wider than that in the CMI+BI group. Also, the left JF was narrower than that in the control group and did not differ from that in the CMI+BI group. JF narrowing is associated with CMI and BI when combined in the same patient. When CMI or BI are detected separately, they do not imply evident changes in JF morphometry. It is expected that these findings could bring empiric substrate to support theories that claim a possible role of intracranial pressure disturbances as a triggering factor for CMI. [ABSTRACT FROM AUTHOR]

Vertebral artery (VA) injury poses a significant risk in cervical spine surgery, necessitating accurate preoperative assessment. This study aims to introduce and validate a novel approach that combines the Fast field echo that resembles a computed tomography using restricted echo spacing (FRACTURE) sequence with Time of Flight (TOF) Magnetic Resonance Angiography (MRA) for comprehensive evaluation of VA courses in the cervical spine. A total of eight healthy volunteers and two patients participated in this study. The FRACTURE sequence provided high-resolution bone images of the cervical spine, while TOF MRA offered non-invasive vascular imaging. Fusion images were created by merging FRACTURE and MRA modalities to simultaneously visualize cervical spine structures and VA courses. Board-certified orthopedic spine surgeons independently evaluated images to assess the visibility of anatomical characteristics of the VA course by Likert-scale. The FRACTURE-MRA fusion images effectively depicted the extraosseous course of the VA at the craniovertebral junction, the intraosseous course of the VA at the craniovertebral junction, the VA entrance level to the transverse foramen, and the side-to-side asymmetry of bilateral VAs. Additionally, clinical cases demonstrated the utility of the proposed technique in identifying anomalies and guiding surgical interventions. The integration of the FRACTURE sequence and TOF MRA presents a promising methodology for the precise evaluation of VA courses in the cervical spine. This approach improves preoperative planning for cervical spine surgery with detailed anatomy and is a valuable alternative to conventional methods without contrast agents. [ABSTRACT FROM AUTHOR]

Purpose: Surgical treatment for atlantoaxial instability in pediatric patients is challenging. We report our experience with posterior intra-articular distraction technique in treating this disorder. Methods: This is a retrospective descriptive study which included 15 patients of atlantoaxial instability whose age was less than 16 years at the time of clinical presentation. All patients underwent anterior soft tissue released through a posterior-only approach, followed by intra-facet cage implantation, cantilever correction, and instrumentation. Clinical results were measured using the Japanese Orthopedic Association (JOA) scale and radiographic measurements including the atlantodental interval (ADI), posterior atlantodental interval (pADI), the distance of odontoid tip above Chamberlain's line, clivuscanal angle (CCA), and triangular area (TA) of craniovertebral junction. Results: The follow-up period ranged from 18 to 72 months, with an average of 41.2 ± 15.2 months. The JOA score increased from 13.6 ± 2.3 to 16.6 ± 0.8. ADI decreased from 4.31 ± 2.37 to 1.85 ± 1.09 mm, and TA decreased from 261.96 ± 107.99 to 197.12 ± 72.37 mm2. pADI increased from 12.89 ± 3.52 to 18.25 ± 3.89 mm, and CCA improved from 132.19 ± 16.34 to 144.35 ± 13.91°. All changes in measurements showed statistically significant. There were no evidence of surgery-related complications or iatrogenic secondary cervical deformity during follow-up. Radiological evaluation showed satisfactory corrections and bony fusions of C1–2 facet joint in all cases. Conclusion: Posterior intra-articular distraction followed by cage implantation and cantilever correction can be one of the safe and effective ways to solve atlantoaxial instability in pediatric patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cranio-cervico-mandibular (CCM) malalignment is associated with forward head posture (FHP) and temporomandibular joint (TMJ) disorders and affects masticatory muscles. OBJECTIVE: This randomized, double-blind controlled trial aimed to compare the efficacy of scapula-thoracic (ST) exercises on temporomandibular and cervical joint position sense and postural stability in individuals with CCM malalignment. METHODS: Forty-nine participants with CCM malalignment were randomly assigned to the ST exercise group (STEG, n = 24) or the control group (CG, n = 25). STEG included progressive strengthening, proprioceptive, and stabilization exercises. All participants were assessed before treatment, at the end of the 8th week treatment period and at the 12th week post-treatment follow-up. Cranio-vertebral angle measurement, Fonseca's Questionnaire, Helkimo Clinical Dysfunction Index, TMJ position test, cervical joint position error test and postural stability assessment were used. RESULTS: The TMJ and cervical joint position sense, total sway degree, area gap percentage, sway velocity and antero-posterior body sway results showed significant improvement in the STEG compared to the CG (p < 0.05), however medio-lateral body sway did not differ between groups (p > 0.05). CONCLUSIONS: Postural stability, TMJ and cervical joint position sense appear to be affected in individuals with CCM malalignment. Our results showed that an exercise program including ST stabilization, proprioception and strengthening of the scapular muscles may be effective in the management of CCM malalignment and will allow clinicians to plan holistic treatment. [ABSTRACT FROM AUTHOR]

This review aims to enrich our understanding of Chiari-like malformation (CLM) by combining human and veterinary insights, and providing a detailed cross-species overview. CLM is a developmental abnormality characterised by caudal displacement of the hindbrain into the foramen magnum due to an entire brain parenchymal shift caused by insufficient skull volume. This malformation leads to a progressive obstruction at the craniocervical junction, which disrupts the normal cerebrospinal fluid flow, leading to secondary syringomyelia. The clinical signs of CLM and syringomyelia include phantom scratching, head tilt, head tremor, ataxia, tetraparesis, pain, muscle atrophy, and scoliosis or torticollis. Magnetic resonance imaging remains the gold standard for diagnosing CLM, since it allows the visualisation of abnormal findings such as the caudal cerebellar herniation, caudal cerebellar compression from occipital dysplasia, and attenuated cerebrospinal fluid cisternae. Although various medical and surgical interventions, including foramen magnum decompression, can provide temporary symptomatic/ clinical sign relief, current literature shows a lack of sustained long-term efficacy. Therefore, additional research is needed to evaluate the long-term effects of existing treatment strategies and to compare different techniques utilised in conjunction with foramen magnum decompression. [ABSTRACT FROM AUTHOR]

Extracranial vascular pathology uncommonly causes intracranial subarachnoid hemorrhage (SAH). Among possible lesions are aneurysms at the craniocervical junction arising from a posterior inferior cerebellar artery (PICA) with an extradural origin. We describe a case of a 55-year-old female presenting with a sudden and severe headache. A computed tomography scan revealed a SAH within the fourth ventricle and cervical spinal canal, and a ruptured saccular aneurysm on a PICA with extradural C2-origin. Despite difficult access anatomy, endovascular treatment was feasible and resulted in subtotal initial occlusion and preservation of distal PICA flow. Upon 3-month follow-up, the aneurysm was completely occluded with a patent PICA. The patient's clinical status remained stable at the 1.5-year follow-up. In conclusion, we present a rare case of an aneurysm originating from a PICA with extradural C2-origin that was treated endovascularly with preservation of the PICA. [ABSTRACT FROM AUTHOR]

Atlanto-occipital assimilation is a congenital craniovertebral junction malformation where the partial or complete fusion of the atlas and occiput occurs. Atlanto-occipital assimilation can be associated with numerous complications, including basilar invagination, atlantoaxial subluxation, Chiari malformation, congenital vertebral bodies fusion, and cord compression. As a result, vigilant identification and accurate reporting of atlanto-occipital assimilation are essential. The purpose of this review article is to discuss the numerous complications and associations of atlanto-occipital assimilation, such that an accurate diagnosis could be made for this commonly missed pathology. [ABSTRACT FROM AUTHOR]