Craniovertebral Junction Anomalies Research Articles

A Staged Approach for Surgical Management of Basilar Invagination

BACKGROUND AND OBJECTIVES: Patients with basilar invagination (BI) can be treated with several surgical options, ranging from simple posterior decompression to circumferential decompression and fusion. Here, we aimed at examining the indications and outcomes associated with these surgical strategies to devise a staged algorithm for managing BI. METHODS: We conducted a retrospective cohort study in 2 neurosurgical centers and included patients with a BI, as defined by a position of the dens tip at least 5 mm above the Chamberlain line. Other craniovertebral junction anomalies, such as atlas assimilation, platybasia, and Chiari malformations, were documented. C1-C2 stability was assessed with a dynamic computed tomography scan. RESULTS: We included 30 patients with BI with a mean follow-up of 56 months (min = 12, max = 166). Posterior decompression and fusion (n = 8) was only performed in cases of obvious atlanto-axial instability (eg, increased atlanto-dental interval or hypermobility on flexion/extension), while anterior decompression (transoral or transnasal) was reserved to patients with lower cranial nerves deficits (eg, swallowing dysfunction) and irreducible anterior compression (n = 9). Patients with posterior signs (eg, Valsalva headaches) or myelopathy but without C1-C2 instability nor anterior signs were managed with an isolated foramen magnum decompression, with or without duraplasty (n = 13). Complications were more frequent for combined procedures, including neurological deterioriation (n = 4) and tracheostomy (n = 2), but reinterventions were more likely in patients undergoing posterior decompression alone (n = 3). CONCLUSION: Patient selection is key to determine the appropriate surgical strategy for BI: In our experience, combined approaches are only needed for patients with irreducible and symptomatic anterior compression, while fusion should be restricted to patient with obvious signs of atlanto-axial instability. Other BI patients can be managed by foramen magnum decompression alone to minimize surgical morbidity.

Kimmerle anomaly as a cause of vertebrobasillary insufficiency and vertebral pain syndrome (modern principles of diagnosis, treatment and routing of patients)

Kimmerli anomaly is one of the varieties of craniovertebral junction anomalies. Currently, it is one of the main causes of the development of vertebrobasilar insufficiency, vertebral pain and vegetative syndromes. Despite a sufficient number of publications about this problem, the Kimmerle anomaly still remains not fully understood. Insufficient awareness of primary care physicians about this pathology, a wide variety of clinical manifestations, the absence of pathognomonic neurological syndromes, the complexity of the analysis of imaging data cause difficulties in identifying this anomaly. The article describes the epidemiology, pathogenesis, and clinical picture of Kimmerle anomaly. Further, the paper presents modern methods of its diagnosis (spondylography, ultrasound, MRI, MSCT, etc.), modern methods of treatment. In conclusion, the authors presented ways to optimize the diagnosis and treatment of Kimmerle anomaly.

Functional and radiological outcomes following craniovertebral junction surgery.

Craniovertebral junction (CVJ) pathologies include atlantoaxial instability/deformities resulting in myelopathy, respiratory failure, and even death. Here, we describe the indications, preoperative planning, and intra-operative/postoperative complications following surgical management of CVJ anomalies. A prospective analysis of 34 patients with CVJ pathology was evaluated between 2015 and 2022. Their various etiologies included atlantoaxial instability, trauma, tuberculosis, Down's syndrome, Morquio syndrome, os odontoideum, and atlantoaxial abnormalities. Clinical outcomes were assessed using the American spinal injury association (ASIA) impairment scale score and Benzel's modified Japanese Orthopedic Association (mJOA) score. Surgical assessments included length of hospital stay, operative time, blood loss, and intraoperative postoperative complications. Radiological parameters included fusion (i.e., implant loosening/implant failure), preoperative/ postoperative atlanto-dens interval (ADI), clivus canal angle (CCA), and space available for cord (SAC). Five patients were managed conservatively, while 29 patients had surgery. Operations included occipitocervical fusion (14 patients), C1-2 fusion (10 patients), C1-2 transarticular screw fixation (four patients), and one patient underwent anterior corpectomy decompression/fusion. Seven patients had vertebral artery anomalies, and 13 patients had atlantoaxial abnormalities. At the final follow-up, atlantoaxial instability (i.e., mean preoperative ADI of 6.6 ± 2.3 mm) was restored to 4.2 ± 0.6 mm, significant cord compression (i.e., with mean SAC of 8.3 ± 2.9 mm) was relieved to 17.2 ± 1.6 mm, and the mean preoperative CCA (i.e., 130.2 ± 15.3) was improved to 143.3 ± 8.3°. There was also a statistically significant improvement in the ASIA scale and mJOA score. Surgical management of CVJ abnormalities requires expertise and meticulous planning to avoid devastating complications such as wound dehiscence and catastrophic vertebral artery injury.

Mobility Assessment Using Multi-Positional MRI in Children with Cranio-Vertebral Junction Anomalies.

This study aimed to assess the relevance of using multi-positional MRI (mMRI) to identify cranio-vertebral junction (CVJ) instability in pediatric patients with CVJ anomalies while determining objective mMRI criteria to detect this condition. Data from children with CVJ anomalies who underwent a mMRI between 2017 and 2021 were retrospectively reviewed. Mobility assessment using mMRI involved: (1) morphometric analysis using hierarchical clustering on principal component analysis (HCPCA) to identify clusters of patients by considering their mobility similarities, assessed through delta (Δ) values of occipito-cervical parameters measured on mMRI; and (2) morphological analysis based on dynamic geometric CVJ models and analysis of displacement vectors between flexion and extension. Receiver operating characteristics (ROC) curves were generated for occipito-cervical parameters to establish instability cut-off values. (3) Additionally, an anatomical qualitative analysis of the CVJ was performed to identify morphological criteria of instability. Forty-seven patients with CVJ anomalies were included (26 females, 21 males; mean age: 10.2 years [3-18]). HCPCA identified 2 clusters: cluster №1 (stable patients, n = 39) and cluster №2 (unstable patients, n = 8). ΔpB-C2 (pB-C2 line delta) at ≥2.5 mm (AUC 0.98) and ΔBAI (Basion-axis Interval delta) ≥ 3 mm (AUC 0.97) predicted instability with 88% sensibility and 95% specificity and 88% sensitivity and 85% specificity, respectively. Geometric CVJ shape analysis differentiated patients along a continuum, from a low to a high CVJ motion that was characterized by a subluxation of C1 in the anterior direction. Qualitative analysis found correlations between instability and C2 anomalies, including fusions with C3 (body p = 0.032; posterior arch p = 0.045; inferior articular facets p = 0.012; lateral mass p = 0.029). We identified a cluster of pediatric patients with CVJ instability among a cohort of CVJ anomalies that were characterized by morphometric parameters with corresponding cut-off values that could serve as objective mMRI criteria. These findings warrant further validation through prospective case-control studies.

A Critical Update of the Classification of Chiari and Chiari-like Malformations.

Chiari malformations are a group of craniovertebral junction anomalies characterized by the herniation of cerebellar tonsils below the foramen magnum, often accompanied by brainstem descent. The existing classification systems for Chiari malformations have expanded from the original four categories to nine, leading to debates about the need for a more descriptive and etiopathogenic terminology. This review aims to examine the various classification approaches employed and proposes a simplified scheme to differentiate between different types of tonsillar herniations. Furthermore, it explores the most appropriate terminology for acquired herniation of cerebellar tonsils and other secondary Chiari-like malformations. Recent advances in magnetic resonance imaging (MRI) have revealed a higher prevalence and incidence of Chiari malformation Type 1 (CM1) and identified similar cerebellar herniations in individuals unrelated to the classic phenotypes described by Chiari. As we reassess the existing classifications, it becomes crucial to establish a terminology that accurately reflects the diverse presentations and underlying causes of these conditions. This paper contributes to the ongoing discussion by offering insights into the evolving understanding of Chiari malformations and proposing a simplified classification and terminology system to enhance diagnosis and management.

Treatment of Chiari malformations with craniovertebral junction anomalies: Where do we stand today?

BackgroundChiari malformation type 1 (CM-1) is characterized by cerebellar tonsil herniation through the foramen magnum and can be associated with additional craniovertebral junction anomalies (CVJA). The pathophysiology and treatment for CM-1 with CVJA (CM-CVJA) is debated. ObjectiveTo evaluate the trends and outcomes of surgical interventions for patients with CM-CVJA. MethodsA systematic review of the literature was performed to obtain articles describing surgical interventions for patients with CM-CVJA. Articles included were case series describing surgical approach; reviews were excluded. Variables evaluated included patient characteristics, approach, and postoperative outcomes. ResultsThe initial query yielded 403 articles. Twelve articles, published between 1998-2020, met inclusion criteria. From these included articles, 449 patients underwent surgical interventions for CM-CVJA. The most common CVJAs included basilar invagination (BI) (338, 75.3%), atlantoaxial dislocation (68, 15.1%) odontoid process retroflexion (43, 9.6%), and medullary kink (36, 8.0%). Operations described included posterior fossa decompression (PFD), transoral (TO) decompression, and posterior arthrodesis with either occipitocervical fusion (OCF) or atlantoaxial fusion. Early studies described good results using combined ventral and posterior decompression. More recent articles described positive outcomes with PFD or posterior arthrodesis in combination or alone. Treatment failure was described in patients with PFD alone that later required posterior arthrodesis. Additionally, reports of treatment success with posterior arthrodesis without PFD was seen. ConclusionPatients with CM-CVJA appear to benefit from posterior arthrodesis with or without decompressive procedures. Further definition of the pathophysiology of craniocervical anomalies is warranted to identify patient selection criteria and ideal level of fixation.

Risk Factors of Postoperative Cerebrospinal Fluid Leak After Craniovertebral Junction Anomalies Surgery: A Case-Control Study.

To identify potential risk factors for cerebrospinal fluid (CSF) leakage after craniovertebral junction (CVJ) anomaly surgery and to provide a reference for clinical practice. Sixty-six patients who underwent elective CVJ anomaly surgery during a 6-year period (April 2013 to September 2019) were retrospectively included. Research data were collected from the patients' medical records and imaging systems. Patients were divided into CSF leak and no CSF leak groups. Univariate tests were performed to identify potential risk factors. For statistically significant variables in the univariate tests, a logistic regression test was used to identify independent risk factors for CSF leakage. The overall prevalence of CSF leakage was 13.64%. Univariate tests showed that a basion-dental interval (BDI) > 10 mm and occipitalized atlas had significant intergroup differences (p < 0.05). Multivariate analysis indicated that a BDI > 10 mm was an independent risk factor for CSF leakage, and patients with CVJ anomalies with a BDI > 10 mm were more likely to have postoperative CSF leaks (odds ratio, 14.67; 95% confidence interval, 1.48-30.88; p = 0.004). It is necessary to maintain vigilance during CVJ anomaly surgery in patients with a preoperative BDI > 10 mm to avoid postoperative CSF leaks.

Central or axial atlantoaxial dislocation and craniovertebral junction alterations: a review of 393 patients treated over 12 years.

The authors reviewed their scientific publications and updated their clinical material obtained over the last 12 years for cases of central or axial atlantoaxial dislocation (CAAD) identified in the presence of craniovertebral musculoskeletal and/or neural alteration(s). The management implications of diagnosing and treating CAAD are highlighted. During a 12-year period, CAAD was diagnosed in 393 patients with craniovertebral junction-related musculoskeletal and neural alterations who underwent atlantoaxial fixation. No bone decompression was done. All CAAD-related craniovertebral junction structural changes were identified to have a naturally protective role. Hence, in this paper the term "craniovertebral alterations" is used for "craniovertebral junction anomalies" and the term "Chiari formation" is used instead of the commonly used term "Chiari malformation." The major radiological diagnosis was determined either singly or in cohort with one or more of other so-called pathological entities that included Chiari formation (367 cases), syringomyelia with Chiari (306 cases), idiopathic syringomyelia (12 cases), type B basilar invagination (147 cases), bifid arch of the atlas (9 cases), assimilation of the atlas (119 cases), C2-3 fusion (65 cases), Klippel-Feil alteration (4 cases), and dorsal kyphoscoliosis (15 cases). The follow-up period ranged from 6 to 155 months. Clinical improvement was observed in all patients. Understanding and treating CAAD may have significant implications in the surgical treatment of a number of clinical entities. The gratifying clinical outcomes obtained in patients after atlantoaxial fixation, without any type of decompression involving bone or soft-tissue resection, consolidate the concept that atlantoaxial instability has a defining role in the pathogenesis.

Single-institution comparative analysis for odontoid resection: posterior transaxis versus anterior transnasal approach.

The resection of an upwardly migrated odontoid is most widely performed via an anterior endoscopic endonasal approach after the addition of posterior occipitocervical instrumentation. In patients with craniovertebral junction (CVJ) anomalies like basilar invagination (BI), surgery is usually achieved in two separate stages. However, the authors have recently introduced a novel posterior transaxis approach in which all the therapeutic goals of the surgery can be safely and effectively accomplished in a single-stage procedure. The aim of the current study was to compare the widely used anterior and the recently introduced posterior approaches on the basis of objective clinical results in patients who underwent odontoid resection for BI. Patients with BI who had undergone odontoid resection were retrospectively reviewed in two groups. The first group (n = 7) consisted of patients who underwent anterior odontoidectomy via the standard anterior transnasal route, and the second group (n = 6) included patients in whom the novel transaxis approach was performed. Patient characteristics, neurological conditions, and modified Rankin Scale (mRS) scores at admission were evaluated. Operative time, changes in intraoperative neurophysiological monitoring, blood loss during surgery, odontoid resection rate, postoperative complications, and mortality were compared between the patient groups. Data were retrospectively reviewed for 13 patients who underwent odontoid resection, posterior CVJ decompression, and occipitocervical instrumentation at the Ankara University School of Medicine Department of Neurosurgery between 2009 and 2022. In the first group (n = 7), patients who underwent anterior odontoidectomy via the standard endonasal route, two serious complications were observed, pneumocephaly and basilar artery injury. In the second group (n = 6), patients in whom the novel transaxis approach was performed, only one complication was observed, occipital plate malposition. This study represents the results of what is to the authors' knowledge the first comparison of a novel approach with a widely used surgical approach to odontoid resection in patients with BI. The preliminary data support the successful utility of the transaxis approach for odontoid resection that meets all the operative therapeutic demands in a single-stage operation. Considering the diminished surgical risks and operative time, the transaxis approach may be regarded as a primary approach for the treatment of BI.

[Research Progress on the Application of Goel Technique in Craniovertebral Junction Anomalies].

Craniovertebral junction anomalies are a group of diseases characterized by the pathological changes of occipital bone,atlantoaxial bone,cerebellar tonsil,surrounding soft tissue,and nervous system,which are caused by a variety of factors.Chiari malformation is a common type of craniovertebral junction anomalies,the conventional surgical therapy of which is posterior fossa decompression.Currently,scholars represented by Goel have proposed a new theory on the classification,pathogenesis,and treatment of Chiari malformation based on posterior atlantoaxial fixation (Goel technique).This article introduces the progress in Goel technique,aiming to provide reference for the clinical work.

Comparative analysis of neurophysiological studies in the diagnosis of bulbar syndrome in patients with Chiari malformation Type 1

The incidence of bulbar syndrome in craniovertebral junction anomalies is between 12% and 35%. Although the use of evoked potentials intraoperatively and preoperatively has advanced in recent years, their use in predicting the development of neurological deficits remains a challenge. This research explores the predictive significance of evoked potentials in the diagnosis of bulbar syndrome in Chiari 1 anomaly. Data from 39 patients and 30 controls were reviewed. Standard multimodal neurophysiological investigations including Brainstem auditory evoked potentials (BAEPs), somatosensory evoked potentials (SSEPs), Nerve Conduction Studies (NCS), and Electromyogram (EMG) were performed. All studies were conducted on the 4-channel complex “Synapsis” (Neurotech, Russia) with computer data processing. The threshold Nerve conduction velocity (NCV) value was 21.5 m/s. The sensitivity and specificity were 75.5% and 71.2% respectively. The area under the ROC curve (AUC) was 0.96±0.36 (95% CI: 0.89-1.00) and p-value 0.004. The M-response amplitude threshold dividing the study group into high and low-risk groups was 1.01 microV. The sensitivity and specificity were 78.0 and 71.2%, respectively. The BAEPs interpeak intervals III-V and I-V were significantly prolonged (P˂ 0.05). SSEPs showed a decreased amplitude and reduced NCV (P ˂ 0.01). Glossopharyngeal nerve electroneuromyography is the most informative test. A decrease in M-response amplitude of bulbar muscles and NCV on efferent fibers is highly predictive of the development of bulbar disorders in patients with Chiari 1, even in subclinical cases.

Spinal and cranial morphometric features of chiari malformation patients undergoing decompression surgery

Chiari malformation (CM) is characterized by herniation of the cerebellar tonsil(s) and/or medulla oblongata into the spinal canal, resulting in various morphometric abnormalities. The current study aimed to evaluate the magnetic resonance imaging (MRI) findings and morphometric features of the craniocervical region in patients who underwent surgery for CM. Demographic and radiological data were collected from 59 patients who underwent surgery for CM and a control group of 58 randomly selected nonsurgical patients. For between-group comparisons, Continuous variables were described as the mean (±SD) or median (IQR) and categorical variables as frequency (%). The mean age of the control group participants was 33.38 years. The mean age of patients in the CM group at the time of surgery was 33.83 years. The diameter of the foramen magnum, the maximum anteroposterior diameter of the C1 vertebra, the maximum diameter of the spinal canal at the C2 vertebra, and the atlantodental interval were all positively correlated with the total cerebellar tonsil length [r=0.54, 0.37, 0.42, 0.71]. Comparisons of total cerebellar tonsil length with other morphological and clinical variables, including contact between the brainstem and clivus, basilar invagination, preoperative hydrocephalus, remnant cartilage between the odontoid and C2 corpus, and associated craniovertebral junction anomalies, revealed no other significant correlations. CM is associated with many structural anomalies in the brain. However, there is relatively little detail in the existing literature on the morphometric parameters associated with the malformation. The findings of this study provide insights for future research and contribute to knowledge of the morphometric features of CMs in general and CMs in patients requiring surgical management in particular.

Surgical, Clinical, and Radiological Outcomes Analysis of Craniovertebral Junction Anomalies Cases: An Institutional Experience.

Objective  The aim of this study was to evaluate the clinical and radiological outcomes analysis of craniovertebral junction (CVJ) anomalies cases. Materials and Methods  Retrospective analysis of 43 CVJ anomalies cases, which were surgically managed at Uttar Pradesh University of Medical Sciences, Saifai, Etawah, Uttar Pradesh, India, from period between June 2015 and June 2019. They were analyzed for age, sex, clinical characteristics, radiological diagnosis, and treatment given. Patient's clinical and radiological status was assessed pre- and postoperatively during time of discharge and at 6 months of follow-up. For clinical assessment we used visual analogue scale (VAS) and Nurick grading system. Radiological assessment was done by atlantodental interval (ADI), craniobasal angle, and craniometric lines. Overall outcomes were depicted as favorable, stabilized, and mortality at 6 to 18 months (mean 12.69 ± 3.77) of follow-up. Results  The age range of our cases was 7 to 71 years (mean 29.93 ± 17.39). Male-to-female ratio was 2.91:1. Majority of the cases were presented with neck pain ( n  = 38; 88.37%), motor weakness ( n  = 35; 81.40%), and sensory deficits ( n  = 25; 58.14%). Congenital atlantoaxial dislocation ( n  = 31; 72.09) was the most common CVJ anomaly. Clinically, there were significant improvements in VAS ( p  = 0.001) and Nurick grade ( p  = 0.007) postoperatively. Radiologically, ADI ( p  = 0.003) had decreased, clivus canal angle ( p  = 0.005) become less acute, and odontoid process ( p  = 0.003 for McRae's line) goes downwards in postoperative period. Bony fusion was achieved in 41 (95.35%) cases. Out of 43, 73% cases had favorable outcomes, 21% were stabilized, and mortality was seen in 2.33% cases at 6 months (mean ± standard deviation = 12.69 ± 3.77) of follow-up. Conclusion  Proper preoperative evaluation and selection of individualized surgical technique was the key for excellent clinical and radiological outcomes with minimal complications.

Aberrant Vessel with Potential Catastrophic Vascular Complications in a Patient with Chiari Malformation

Craniovertebral junction anomalies are known to be associated with many bony, soft tissue, and vascular anomalies. We encountered a case of Chiari malformation type 1 with C2-D2 syrinx, in which computed tomography angiography showed an aberrant vessel (probably vein) coursing through the soft tissue along the posterior aspect of C1-C7 vertebral bodies along the right-sided joints, superiorly coursing posterior to C1-C2 joint and curving anteriorly over C1 to enter into the foramen magnum. Had this abnormality not been detected, catastrophic vascular consequences could have occurred.

C1-C2 coronal and sagittal joint angle based treatment algorithm for the need of transoral odointectomy in complex craniovertebral junction anomalies with Clinico-Radiological outcome analysis

Objective Craniovertebral junction (CVJ) pathology by virtue of its complexity is a surgical challenge in the realm of neurosurgery. We analyzed the need for transoral odointectomy in view of their C1-C2 joint coronal and sagittal angle of 58 patients with complex CVJ anomalies treated surgically. The clinical and radiological outcome of the patients was assessed and a treatment algorithm is proposed. Methods A total of 58 cases were included in the Prospective study over the period of 2 years. Patients were evaluated clinically, investigated, and operated with reduction and rigid internal fixation with screws and rod. The clinical outcome was measured by Modified Japanese orthopedic association score(mJOA) and radiologically by conventional craniometrics indices. Paired ‘t’ test used for statistical analysis. Results Mean age of patients: 30 years, with mean, follow up: 20.5 months. 46(80%) patients were operated by posterior and 12(20%) by combined approach (anterior transoral with posterior). Occipitocervial fixation was done in 15(25.8%) cases and C1-C2 fixation in 43(74.2%) cases. As compared to patients with low coronal angle, the patient with coronal angle >65° needed anterior decompression (87.5%) and all (100%) had Occipitocervical fixation. Clinical outcome analysis showed significant improvement in mean mJOA score (preop 11.9 Vs postop 14.6) after surgery. All craniometrics indices were significantly improved after surgery. The overall complication rate was 10% with a mortality of 1.7%. 6 months follow up completed in all patients with a 100% fusion rate. Conclusion Occipitocervical fixation and anterior decompression is required in increased C1-C2 joint CA (>65°) for bony realignment and adequate decompression. Measurement of C1-C2 joint coronal and sagittal angle in complex CVJ anomalies will easily anticipate the surgeon regarding the need for anterior decompression inform of transoral odointectomy.

Prediction of the functional and radiological outcome on the basis of independent factors with special emphasis on the use of 3D printed models in craniovertebral junction surgery.

Background: The aim of the study was to evaluate the advantage of performing planned surgery using customized three-dimensional (3D) printed models versus performing surgery without using 3D printed models in patients with craniovertebral junction (CVJ) anomalies and traumatic CVJ fractures and dislocations.Methods: Forty-two patients with CVJ anomalies, who were planned for operative intervention in the Department of Neurosurgery at SMS Hospital from March 2019 to February 2021, were randomly divided into two groups and analyzed. First group was operated after rehearsal on a customized 3D printed model whereas the second group underwent operative intervention without the rehearsal of surgery on the 3D printed model.Results: Forty-two patients were enrolled for the study. Twenty-five of these patients had developmental CVJ anomalies, 16 had post traumatic Atlantoaxial dislocation (AAD), and one had congenital AAD. Twenty-three patients underwent surgical intervention using 3D printed models and 19 without using 3D printed models. The outcome in the two groups was compared using modified Japanese orthopedic association score (mJOA), recovery rate, incidence of complications such as screw malposition, postoperative neurological deterioration, vertebral artery (VA) injury, and radiological improvement based on Atlanto-Dental interval, the distance of the tip of dens from Wackhenheims clivus canal line, and the distance of tip of dens from the Chamberlain’s line. The improvement in mJOA score postoperatively was found to be statistically significant in study group (P < 0.001) as compared to control group (P = 0.06). Recovery rate was better in study group than in control group (P = 0.023). In study group, the incidence of screw malposition and VA injury was lower than control group. Three patients deteriorated neurologically postoperatively in the control group and none in the study group. The average improvements in the radiological parameters were found to be better in study group as compared to control group postoperatively.Conclusion: The authors conclude that 3D printed models are extremely helpful in analyzing joints and VA anatomy preoperatively and are helpful in unmasking any abnormal bony and vascular anatomy effectively, making the surgeon confident about the placement of the screws intraoperatively. These 3D models help in intraoperative error minimization with better neurological outcomes in postoperative period. In our opinion, these models should be included as a basic investigation tool in patients of CVJ abnormalities. The models also offer other advantages such as preoperative simulation, teaching modules, and patient education.

Role of imaging in craniovertebral junction abnormalities

Background: Craniovertebral junction (CVJ) abnormalities constitute an important group of treatable neurological disorders with diagnostic dilemma. Their precise diagnosis and pre-treatment evaluation significantly affects prognosis and quality of life of patients. Aims: To localize, describe and characterize craniovertebral junction abnormalities, arrange frequently detected CVJ pathologic imaging findings and to emphasize clinical implications to improve our radiological report. Materials and methods: A Cross sectional study done for 24 months in 50 patients of all age groups with clinical suspicion of CVJ abnormalities.Results: In the acquired CVJ abnormality Trauma is the most common etiology(n=15) followed by Tuberculosis(n=4), Rheumatoid arthritis(n=3), Tumors(n=2). Most common age group involved was 2nd decade with male predominance. Most commonly presenting symptom is weakness of limbs followed by neck pain. Most common imaging abnormality is cervicomedullary junction compression and atlanto axial dislocation. ACM I and Syringomyelia are the commonest neural anomalies associated with bony CVJ anomalies. Most common congenital anomalies are atlanto axial dislocation followed by basilar invagination. Only one patient had syndromic association which was Klippel-feil syndrome. The commonest injuries involving the CVJ were odontoid fracture predominantly type II and the commonest combination of injury was C1 with odontoid fracture.

Morphological and Morphometric Analysis of Superior Articular Facet of Atlas Vertebra.

Introduction: The first cervical vertebra, also referred to as the atlas, forms a vital part of the craniovertebral junction (CVJ). The anatomy of the atlas is essential to understand the basis for CVJ anomalies and their surgical correction. The present study was undertaken to provide accurate morphometry and describe the morphological variations of the superior articular facet (SAF) of the atlas. Methods: In this observational, cross-sectional study, the length and width of the SAF of 150 atlas were measured using a digital caliper. The variations in the morphology of the SAF in the same bones were also recorded. Z-test was applied to find the statistically significant difference between the measurements of the SAF of the atlas on the right and left sides. p-value ≤ 0.05 was considered statistically significant.Results: The width of the SAF of the atlas was found to be significantly (p < 0.001) greater on the left side (8.76 mm to 14.84 mm) compared to the right (7.67 mm to 14.83 mm). The mean length of the SAF was 21.1 mm and 21.9 mm on the left and right sides, respectively. Morphologically, four variations of superior articular facets were noted: oval, bilobed, kidney, and dumbbell shaped. The most common variation was an oval-shaped facet with a prevalence of 66.7% on the left side and 57.3% on the right. The least common variation was the bilobed facet, with a prevalence of 4% on the left side and 8.7% on the right.Conclusion: The width of the SAF of the atlas was statistically significant on the left side. Morphologically, four types of variations were observed in the shape of the SAF. Knowledge of the morphological and morphometric variations of the SAF can be of help during surgical approaches at the CVJ.

Craniovertebral Junction Anomalies: An Overlooked Cause of 'Posterior Circulation Stroke'.

Vertebral artery dissection (VAD) is a treatable cause of vertebrobasilar ischemic stroke and can be spontaneous or more commonly traumatic. Craniovertebral junction (CVJ) anomalies are a rare and often overlooked cause of VAD. The objective of this study was to study cases where CVJ anomaly presented as posterior circulation infarct and to conduct a relevant literature review. The medical records of seven patients who were managed for posterior circulation infarct associated with CVJ anomaly at our center from January 2009 through August 2013 were reviewed. PubMed and MEDLINE databases were also searched for similar cases, and the published case reports/series were reviewed. Seven patients met our inclusion criteria and were included in the study. The mean age was 17.4 years (range: 10-35 years). All the patients were males. The most common symptoms were headache, vomiting, and gait ataxia. Slurring of speech was seen in one patient. One patient had repeated episodes of gait ataxia with left-sided weakness with complete recovery in between the episodes. One patient presented in unconscious state. Four patients complained of vertigo. The median duration of symptoms was 7 days (range: 3 days-12 months). CVJ anomalies can present as posterior circulation infarct. One must evaluate all patients with posterior circulation stroke, especially young patients, for possible CVJ anomalies. Dynamic lateral cervical spine X-ray is an important tool to diagnose AAD. CVJ anomalies represent a treatable cause of VAD.

A Morphometric Evaluation Together with Computed Tomography Examination of Chiari Type 1 Cases with Craniovertebral Junction Anomaly.

To compare the posterior cranial fossa (PCF) dimensions together with the measurements related to basilar invagination and platybasia of craniovertebral junction anomalies (CVJA) in CVJA (+) and CVJA (-) Chiari malformation Type 1 (CM1) patient groups with each other and with healthy control subjects. The study group was formed of 43 CM1 and 9 tonsillar ectopia (TE) patients. A decrease was determined in the PCF vertical length (clivus and supraocciput line) and PCF volume and an increase in the transverse length (McRae and Twining line) in the CM1 cases compared to the healthy control group. There was no difference between the CVJA (+) and (-) CM1 groups in respect of the vertical and transverse length and PCF volume values. An increase in the classic and modified skull base angles was observed in the CVJA (+) CM1 group compared to the CVJA (-) CM1 group. The Wackenheim clivus angle was determined to be smaller in the CVJA (+) CM1 group compared to the CVJA (-) CM1 group. The PCF is flattened and smaller in CM1 cases compared to normal control subjects. In the planning of CM1 operations, the angle parameters may be more useful than the PCF and CVJA length parameters between CVJA (+) and (-) CM1 groups. The significant decrease in postoperative recovery in the CVJA (+) CM1 group compared to the CVJA (-) CM1 group supports the need for additional operations and/or a different surgical technique in the treatment of CVJA (+) CM1 patients.