Type I atlanto-occipital dislocation complicated by non-communicating hydrocephalus – A case report

Hydrocephalus, an extremely rare complication of craniocervical junction injuries, is postulated to result from compression of the fourth ventricular cerebrospinal fluid (CSF) outlets by fractured and displaced bone fragments, a swollen upper spinal cord or adhesions formed after a traumatic subarachnoid haemorrhage. We present the case of a 21-year-old woman for whom an injury to the cervical spine complicated by a type I atlanto-occipital dislocation contributed to the development of non-communicating hydrocephalus. The hydrocephalus was probably a consequence of impaired CSF circulation at the fourth ventricular outlets (the foramina of Luschka and Magendie), caused by post-haemorrhagic adhesions formed after severe injury to the craniocervical junction. (AU)

La hidrocefalia, una complicación extremadamente rara de las lesiones de la unión craneocervical se considera resultado del bloqueo de las salidas del líquido cefalorraquídeo (LCR) del cuarto ventrículo por los fragmentos óseos fracturados y desplazados, la inflamación de la médula espinal superior o las adherencias formadas después de una hemorragia subaracnoidea traumática. Se reporta caso clínico de una mujer de 21 años en el que la lesión de la columna cervical complicada por una luxación atlanto-occipital de tipo I contribuyó al desarrollo de una hidrocefalia no comunicante. La hidrocefalia probablemente fue consecuencia de una obstrucción del flujo del LCR fuera del cuarto ventrículo (agujeros de Luschka y Magendie), debida a las adherencias post-hemorrágicas formadas después de la grave lesión de la unión craneocervical. (AU)

Type I atlanto-occipital dislocation complicated by non-communicating hydrocephalus - A case report.

Hydrocephalus, an extremely rare complication of craniocervical junction injuries, is postulated to result from compression of the fourth ventricular cerebrospinal fluid (CSF) outlets by fractured and displaced bone fragments, a swollen upper spinal cord or adhesions formed after a traumatic subarachnoid haemorrhage. We present the case of a 21-year-old woman for whom an injury to the cervical spine complicated by a type I atlanto-occipital dislocation contributed to the development of non-communicating hydrocephalus. The hydrocephalus was probably a consequence of impaired CSF circulation at the fourth ventricular outlets (the foramina of Luschka and Magendie), caused by post-haemorrhagic adhesions formed after severe injury to the craniocervical junction.

[Atlanto-occipital dislocation-A challenge with respect to making the diagnosis and treatment]. / Atlantookzipitale Dislokation ­ eine Herausforderung hinsichtlich der Diagnosestellung und Therapie.

BACKGROUND: The correct diagnosis and treatment of the atlanto-occipital dislocation (AOD) remains a major challenge. OBJECTIVE: To evaluate the different radiological diagnostic criteria for AOD and discuss potential treatment strategies based on a case with AOD and additional fracture of the atlas. MATERIAL AND METHODS: A 29-year-old male patient is presented who suffered from AOD with concomitant fracture of the anterior and posterior arches of the atlas with rotational atlantoaxial dislocation following an accident in forestry. The following parameters were evaluated for the diagnosis and assessment of postoperative reduction: Powers ratio, the X­lines-method, Wackenheim line, basion-dens interval (BDI), basion-axial interval (BAI) and occipital condyle-C1 interval (CCI). RESULTS: Stabilization was performed by occipitocervical spondylodesis from C0 to C2/3. For final reduction it was necessary to reduce the malrotation of the atlas. In the presented case, the revised CCI proved to be a sensitive and valid yet practical parameter. Powers' ratio and the BDI were less suited for assessing the diagnosis. The X­lines-method, Wackenheim line and the BAI did not adequately detect the pathological situation. DISCUSSION: The AOD is a severe injury requiring immediate correct diagnosis for later adequate treatment results. Among the published parameters, the revised CCI proved to be a practical and valid parameter to detect AOD. For definitive treatment, the operative occipitocervical stabilization is regarded as the method of choice.

Reduction of Atlanto-Occipital Dislocation After Cervical Collar Removal.

A 39-year-old male pedestrian-hit-by-car was transferred to our institution with atlantooccipital dislocation (AOD) on outside computed tomography (CT) imaging. On arrival he had a rigid cervical collar in place. Given the reported AOD, we placed the patient flat, removed the cervical collar, and supported the head in neutral alignment with sandbags. Due to a technical issue uploading his prior imaging to our system, the patient underwent repeat CTs at our center. Subsequently, after the outside images were uploaded, we were able to compare his cervical spine CT images before and after removing his cervical collar. On comparison, we noted a substantial reduction in AOD after collar removal. We hope this serves as a reminder of this key step in managing a rare but deadly clinical entity and a small demonstration of the efficacy of this intervention.

Our experiences in patients with atlanto-occipital dislocation: A case series with literature review.

Atlanto-occipital dislocation (AOD) is an injury to the upper cervical spine that occurs after trauma. This injury is associated with a high mortality rate. According to studies, 8%-31% of deaths caused by accidents are due to AOD. Due to the improvement in medical care and diagnosis, the rate of related mortality has decreased. Five patients with AOD were evaluated. Two cases had type 1, one case had type 2, and two other patients had type 3 AOD. All patients had weakness in the upper and lower limbs and underwent surgery to fix the occipitocervical junction. Other complications in patients were hydrocephalus, 6 nerve palsy, and cerebellar infarction. All patients improved in follow-up examinations. AOD damage is divided into four groups: anterior, vertical, posterior, and lateral. The most common type of AOD is type 1 and the most instability is type 2. There are neurological and vascular injuries due to pressure on regional components; vascular injuries are associated with high mortality rate. In most patients, their symptoms improved after surgery. AOD requires early diagnosis and immobilization of the cervical spine along with maintaining the airway to save the patient's life. It is necessary to consider AOD in cases with neurological deficits or loss of consciousness in the emergency unit because earlier diagnosis could cause a wonderful improvement of the patient's prognosis.

Congenital atlanto-occipital dislocation in a patient with Down syndrome: a case report.

Down syndrome, also known as trisomy 21, is associated with congenital cervical spine abnormalities, including atlantoaxial instability with or without os odontoideum, atlanto-occipital instability, and hypoplasia of the atlas. Herein, we report a case of Down syndrome complicated by congenital atlanto-occipital dislocation. The patient presented with severe cervical myelopathy at 13 years of age after a 10-year follow-up. Radiography and computed tomography revealed os odontoideum protruding into the foramen magnum and congenital anterior atlanto-occipital dislocation. Additionally, a bifurcated internal occipital crest with a thinned central portion of the occipital bone was noted. Magnetic resonance imaging revealed kyphotic alignment of the spinal cord with severe compression at the foramen magnum level. As the neurological impairment was partially improved by halo vest immobilization, we performed in situ O-C2 fusion with an iliac autograft and decompression of the foramen magnum and posterior arch of C1. An improvement was observed immediately after surgery. Two years after surgery, radiography and computed tomography showed solid O-C2 segment fusion. The accumulation of similar cases is essential for determining the prognosis or optimal treatment for this rare congenital condition.

Atlanto-occipital dislocation with concomitant severe traumatic brain injury: A retrospective study at a level 1 trauma center / Luxación atlantooccipital con traumatismo craneoencefálico grave concomitante: estudio retrospectivo en un centro de trauma de nivel 1

Background: Traumatic atlanto-occipital dislocation (AOD) is a life-threatening injury. Although traumatic brain injury (TBI) is associated with increased mortality in AOD patients, a detailed individual analysis of these patients is lacking in the literature. Methods: Patients ≥16 years old who were diagnosed of AOD with concomitant severe TBI from 2010 to 2020 were included in this retrospective study. We examined the epidemiology, injury mechanisms, associated injuries, and outcomes of these patients. Results: Eight patients were included. Six patients died before any intervention could be performed, and two patients underwent an occipito-cervical fixation, showing a notorious neurologic improvement on follow-up. Cardiorespiratory arrest (CRA) was a strong predictor of subsequent death. CT signs of diffuse axonal injury (DAI) were present in most patients and were confirmed by magnetic resonance imaging (MRI) in survivors. Although TBI was not the main cause of death, it was responsible for the delayed neurological improvement and deferred stabilization. The average sensitivity of the different used methodologies for AOD diagnosis ranged from 0.50 to 1.00, being the Basion Dens Interval (BDI) and the Condyle-C1 interval (CCI) sum the most reliable criteria. Non-survivors tended to show greater distraction measurements. The high incidence of condylar avulsion fractures suggests that their visualization on the initial CT study should heighten the suspicion for AOD. Conclusions: Our data suggest that patients with AOD and concomitant severe TBI might be salvageable patients. In those who survive beyond the first hospital days and show neurological improvement, surgical treatment should be performed as they can achieve an important neurologic recovery. (AU)

Antecedentes: La luxación atlantooccipital (AOD) traumática es una lesión potencialmente mortal. Aunque el traumatismo craneoencefálico (TCE) se asocia con un aumento de la mortalidad en los pacientes con AOD, no existe en la literatura un análisis individual detallado de estos pacientes. Métodos: En este estudio retrospectivo se incluyeron pacientes mayores de 16 años que fueron diagnosticados de AOD con TCE grave concomitante durante el periodo 2010-2020. Estudiamos la epidemiología, los mecanismos lesionales, así como las lesiones asociadas y los resultados de estos pacientes. Resultados: Se incluyeron ocho pacientes. Seis pacientes fallecieron antes de que se pudiera realizar cualquier intervención y dos pacientes fueron sometidos a una fijación occipitocervical, mostrando una notoria mejoría neurológica durante el seguimiento. La parada cardiorrespiratoria fue un predictor de muerte. En la TC inicial, signos de lesión axonal difusa estaban presentes en la mayoría de los pacientes y se confirmaron mediante imágenes de resonancia magnética en los supervivientes. Aunque el TCE no fue la principal causa de muerte, fue responsable de una mejoría neurológica tardía y por ello una estabilización diferida. La sensibilidad de las diferentes metodologías utilizadas para el diagnóstico de AOD osciló entre 0,50 y 1,00, siendo el intervalo Basion Dens y la suma del intervalo Condylo-C1 los criterios más fiables. Además, los no supervivientes presentaban mayores medidas de distracción. La alta incidencia de fracturas de cóndilo por avulsión sugiere que su visualización en el estudio de TC inicial debería aumentar la sospecha de AOD. Conclusiones: Nuestros datos sugieren que los pacientes con AOD y TCE grave concomitante podrían ser pacientes salvables. En aquellos que sobreviven más allá de los primeros días de...(AU)Palabras clave:Luxación atlantooccipitalColumna cervicalUnión craneocervicalFusión occipitocervicalTraumatismo craneoencefálico

Atlanto-occipital dislocation with concomitant severe traumatic brain injury: A retrospective study at a level 1 trauma center.

BACKGROUND: Traumatic atlanto-occipital dislocation (AOD) is a life-threatening injury. Although traumatic brain injury (TBI) is associated with increased mortality in AOD patients, a detailed individual analysis of these patients is lacking in the literature. METHODS: Patients ≥16 years old who were diagnosed of AOD with concomitant severe TBI from 2010 to 2020 were included in this retrospective study. We examined the epidemiology, injury mechanisms, associated injuries, and outcomes of these patients. RESULTS: Eight patients were included. Six patients died before any intervention could be performed, and two patients underwent an occipito-cervical fixation, showing a notorious neurologic improvement on follow-up. Cardiorespiratory arrest (CRA) was a strong predictor of subsequent death. CT signs of diffuse axonal injury (DAI) were present in most patients and were confirmed by magnetic resonance imaging (MRI) in survivors. Although TBI was not the main cause of death, it was responsible for the delayed neurological improvement and deferred stabilization. The average sensitivity of the different used methodologies for AOD diagnosis ranged from 0.50 to 1.00, being the Basion Dens Interval (BDI) and the Condyle-C1 interval (CCI) sum the most reliable criteria. Non-survivors tended to show greater distraction measurements. The high incidence of condylar avulsion fractures suggests that their visualization on the initial CT study should heighten the suspicion for AOD. CONCLUSIONS: Our data suggest that patients with AOD and concomitant severe TBI might be salvageable patients. In those who survive beyond the first hospital days and show neurological improvement, surgical treatment should be performed as they can achieve an important neurologic recovery.

A Novel Treatment of Pediatric Atlanto-Occipital Dislocation with Nonfusion Using Muscle-Preserving Temporary Internal Fixation of C0-C2: Case Series and Technical Note.

Study Design Case series with surgical technical note. Objectives This article reports experiences and results of muscle-preserving temporary C0-C2 fixation for the treatment of atlanto-occipital dislocation (AOD). Methods AOD is a rare injury caused by high-energy trauma, occurring in less than 1% of pediatric trauma patients. Recommended treatment is C0-C2 fusion which, however, will result in significant loss of mobility in the craniocervical junction (CCJ), especially C1-C2 rotation. An alternative approach, with the ability of preserving mobility in the C1-C2 segment, is a temporary fixation that allows the ligaments to heal, after which the implants can be removed to regain function in the CCJ joints. By using a muscle-preserving approach and navigation for the C2 screws, a relatively atraumatic fixation of the CCJ can be achieved with motion recovery after implant removal. Results We present two cases of AOD treated with temporary fixation. A 12-year-old boy involved in a frontal car collision, as a strapped back seat passenger, was treated with temporary C0-C2 fixation for 10 months. Follow-up at 11 months after implant removal included clinical evaluation, computed tomography, magnetic resonance imaging (MRI), and flexion-extension X-rays. He was free of symptoms at follow-up. The CCJ was radiographically stable and he had 45 degrees of C1-C2 rotation. A 7-year-old girl was hit by a car as she got off a bus. She was treated with temporary fixation for 4 months after which the implant was removed. Follow-up at 8 years included clinical evaluation and MRI in rotation. She was free of symptoms. The ligaments of the CCJ appeared normal and her C1-C2 rotation was 30 degrees. Conclusion C0-C2 fixation without fusion allows the CCJ ligaments to heal in pediatric AOD. By removing the implants after ligament healing, rotation in the C1-C2 segment can be regained without subsequent instability. Both our patients tolerated the treatment well and were free of symptoms at follow-up. By using minimally invasive muscle-preserving technique and navigation, temporary fixation of the CCJ can be achieved with minimal damage to the soft tissues allowing recovery of almost normal function after implant removal.

Atlanto-occipital dislocation in a child: a challenging diagnosis. Illustrative case.

BACKGROUND: Atlanto-occipital dislocation (AOD) is a highly unstable injury of the osseoligamentous complex at the craniocervical junction that is more common in children. Its diagnosis remains a challenging process that must integrate clinical presentation and radiological criteria. OBSERVATIONS: A 9-year-old child presented with severe craniocervical trauma (Glasgow Coma Scale score 6) and cardiorespiratory arrest on-site. Prompt resuscitation on-site and transfer to the university hospital were performed, and a computed tomography (CT) scan showed a subarachnoid hemorrhage around the brainstem and a retroclival hematoma. Most of the radiological criteria on CT scans for AOD were negative, except for the occipital condyle-C1 interval, and further imaging with magnetic resonance imaging permitted the diagnosis of AOD with rupture of both the tectorial membrane and the transverse ligament. Occipital-cervical Oc-C1-2 fixation was performed. The neurological outcome was excellent, with full recovery 6 months after the trauma. LESSONS: AOD should be suspected in all high-intensity trauma in children, especially if the clinical presentation includes cardiorespiratory arrest and other brainstem and/or upper cervical cord symptoms along with premedullary subarachnoid hemorrhage. Understanding the ligamentous nature of the injury resulting in "normal" radiographs or CT scans is important to avoid underdiagnosing AOD, which can have detrimental consequences.

Management of traumatic atlanto-occipital dislocation in a 10-year-old with noninvasive halo immobilization: A case report.

Background: Traumatic atlanto-occipital dislocation is an unstable injury of the craniocervical junction. For pediatric patients, surgical arthrodesis of the occipitocervical junction is the recommended management. While having a high success rate for stabilization, the fusion comes with obvious morbidity of limitation in cervical spine flexion, extension, and rotation. An alternative is external immobilization with a conventional halo. Case Description: We describe the case of a 10-year-old boy who was treated successfully for traumatic AOD with a noninvasive pinless halo. Following initial brain trauma management, we immobilized the craniocervical junction with a pinless halo after reducing the atlanto-occipital dislocation. The pinless halo was kept on at all times for the next 3 months. The craniocervical junction alignment was monitored with weekly cervical spine X-rays and CT craniocervical junction on day 15th, day 30th, and day 70th. A follow-up MRI C-spine 3 months from presentation confirmed resolution of the soft-tissue injury and the pinless halo was removed. Dynamic cervical spine X-rays revealed satisfactory alignment in both flexion and extension views. The patient has been followed up for 2 years postinjury and no issues were identified. Conclusion: Noninvasive pinless halo is a potential treatment option for traumatic pediatric atlanto-occipital dislocation. This should be considered bearing in mind multiple factors including age and weight of the patient, severity of the atlanto-occipital dislocation (Grade I vs. Grade II and incomplete vs. complete), concomitant skull and scalp injury, and patient's ability to tolerate the halo. It is vital to emphasize that this necessitates close clinicoradiological monitoring.

Factors Affecting the Outcomes of Traumatic Atlanto-Occipital Dislocations in Adults: A Systematic Review.

OBJECTIVE: The objectives of this study were to conduct a systematic review of the literature to determine the optimal treatment method for patients with atlanto-occipital dislocation (AOD) and to identify possible factors influencing their outcomes. METHODS: We conducted a systematic review of the PubMed database between January 1966 and December 2020. The main inclusion criterion was articles that discussed AOD treatment methods, and outcome descriptions were selected for analysis. Intergroup differences were assessed using nonparametric statistical methods. RESULTS: Of the 657 articles identified initially, only 54 met the inclusion criteria, resulting in data from 139 patients. Type I or II AODs were more frequent in patients injured in road traffic accidents, whereas type III AODs were more frequent in patients with catatrauma (P = 0.027). Spinal cord injury was more frequently observed in patients with types I and II AODs than in those with type III AOD (P = 0.026). Improved outcomes were more common in the surgical treatment group (P < 0.001). Significant differences in treatment outcomes between the halo device and orthosis groups were not observed (P = 0.32). CONCLUSIONS: Prognosis of AOD is unfavorable in adults with dislocations resulting from road traffic accidents, those with types I and II AOD, and patients younger than 22 years and older than 47 years. Surgical treatment was optimal for adult patients with an AOD, and treatment outcomes did not depend on the number of occipitocervical fusion levels. Immobilization with the halo device showed no advantages over use of an external orthosis.

Traumatic Atlanto-Occipital Dislocation-A Comprehensive Analysis of All Case Series Found in the Spinal Trauma Literature.

BACKGROUND: Traumatic atlanto-occipital dislocation (TAOD) is one of the most devastating traumatic injuries, generally associated with immediate death after high-energy trauma. The aim of this study was to perform a systematic literature review of all cases series of TAOD and present the current state of this entity. METHODS: A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only case series with at least 5 cases were included in the analysis. We focused on survival rates, diagnostic methods, delays in diagnosis, outcomes, and cases successfully treated nonoperatively. RESULTS: A total of 17 articles were included (16 retrospective and 1 prospective study) with 341 patients. Six studies included pediatric patients only. The mean Glasgow Coma Scale at admission was ≤8 in all studies. Many different diagnostic criteria were used, but none of them had high accuracy. The overall mortality rate was 34.8%, but the studies' designs were heterogeneous (some included only survivors). A high rate of concomitant traumatic brain injury was documented in some studies. We found it interesting that some patients were treated with cervical immobilization (37/341; 10.8%), which was generally used in less unstable injuries; however, the majority of patients were managed with an occipito-cervical fusion (193/341; 56.5%). CONCLUSIONS: TAOD is a devastating traumatic injury, with a high mortality rate. An MRI may be recommended when there are subtle findings of TAOD and a normal computed tomography scan, such as subarachnoid hemorrhage in the posterior fossa, upper cervical injuries, or consistent neurological findings. Further studies are necessary to identify patients with mild MRI findings and TAOD that may be managed nonoperatively.

Concomitant atlantoaxial and atlanto-occipital rotatory dislocation in children: Radiological features, diagnostic pitfalls, and long-term outcome.

While the pathological manifestation of atlantoaxial rotatory dislocation has been well described in the medical literature, the combined dislocation of the atlantoaxial and atlanto-occipital joints, or OAARD - short for occipital-atlantoaxial rotatory dislocation - is a condition which has been poorly elucidated and probably underdiagnosed. We believe that the pathogenesis of combined atlantoaxial and atlanto-occipital dislocation is most likely a result of untreated atlantoaxial rotatory dislocation leading to chronic secondary compensation measures occurring at the occiput-C1 joints. Unique clinical and radiological features lead to difficulty in diagnosis, and conventional treatment algorithms may not apply. This paper describes a combination of clinical and radiological features which can help clinicians correctly diagnose and treat OAARD.

Radiological and clinical features of traumatic atlanto-occipital dislocation.

PURPOSE: We aimed to describe the findings of traumatic atlanto-occipital dislocation (AOD) on cervical spine CTs and differences leading to varying treatment of these patients. METHODS: We retrospectively identified 20 adult patients with AOD from cervical spine CTs demonstrating fracture or fracture dislocations over 19 years at 2 major trauma centers. Medical records were reviewed and craniovertebral junction (CVJ) metrics measured on CT. Intubation, Glasgow Coma Scale (GCS), additional injuries, occiput/atlas/axis fracture, concurrent atlantoaxial subluxation, vascular injury on CT angiography, and ligamentous injury on MRI were noted. RESULTS: Using the Traynelis Classification, eight patients had type 2 and eight patients type 3 AOD. Four of 5 patients who died within 14 days of CT had type 2 AOD. Three patients had medial/lateral AOD. Of the patients who survived initial injuries, a greater percentage who underwent surgical or halo fixation versus non-operatively treated patients had abnormal CVJ measurements including BDI (62.5% vs 0%), atlantoaxial subluxation (75% vs 14.3%), ligamentous injury (80% vs 66.7%), intubation (62.5% vs 28.6%), GCS<8 (62.5% vs 14.3%), and additional injuries (75% vs 71.4%) on presentation. MRI helped identify 2 cases of type 2 AOD and surgical decision making in 8 cases. CONCLUSIONS: Types 2 and 3 were the most common, and type 2 is the deadliest type of AOD. A greater proportion of patients who undergo surgical or halo fixation have abnormal CT/MR findings with neurologic impairment at presentation. MRI aided detection of potentially missed type 2 AOD and was critical for surgical decision making.

Occipitocervical fusion of traumatic atlanto-occipital dissociation in a patient with autofused cervical facet joints: illustrative case.

BACKGROUND: Patients who survive traumatic atlanto-occipital dissociation (AOD) may present with normal neurological examinations and near-normal-appearing diagnostic images, such as cervical radiographs and computed tomography (CT) scans. OBSERVATIONS: The authors described a neurologically intact 64-year-old female patient with a degenerative autofusion of her right C4-5 facet joints who presented to their center after a motor vehicle collision. Prevertebral soft tissue swelling and craniocervical subarachnoid hemorrhage prompted awareness and consideration for traumatic AOD. An abnormal occipital condyle-C1 interval (4.67 mm) on CT and craniocervical junction ligamentous injury on magnetic resonance imaging (MRI) confirmed the diagnosis of AOD. Her autofused right C4-5 facet joints were incorporated into the occipitocervical fusion construct. LESSONS: Traumatic AOD can be easily overlooked in patients with a normal neurological examination and no associated upper cervical spine fractures. A high index of suspicion is needed when evaluating CT scans because normal values for craniocervical parameters are significantly different from the accepted ranges of normal on radiographs in the adult population. MRI of the cervical spine is helpful to evaluate for atlanto-occipital ligamentous injury and confirm the diagnosis. Occipitocervical fusion construct may need to be extended to incorporate spinal levels with degenerative autofusion to prevent adjacent level degeneration.

Successful non-operative management for atlanto-occipital dislocation resulting in spinal cord contusion in a patient with atlanto-occipital assimilation and severe Chiari I malformation.

BACKGROUND: Atlanto-occipital dislocation (AOD) is a rare, highly morbid, and highly lethal injury that results from high-energy trauma and almost universally requires operative management for satisfactory outcomes. It can be difficult to identify the severity of injury at the time of presentation, and when diagnosis is delayed outcomes worsen significantly. Anatomic anomalies of the craniovertebral junction may further complicate its detection. When such anomalies are present either singly or in combination, they are known to cause space constraints which may increase the likelihood of spinal cord injury. Given that such anomalies and AOD are rare, few examples of patients with both are reported in the literature. Furthermore, it is not clear in what way patient management may be impacted in this context. CASE DESCRIPTION: We will present a unique case of an 18-year-old patient with traumatic AOD and an intact neurologic examination who was found to have atlanto-occipital assimilation (AOA), platybasia, basilar invagination, and severe Chiari I malformation, who was treated effectively with non-operative management. CONCLUSION: Our case demonstrates the successful application of a non-operative treatment strategy in a carefully selected patient with AOD in the context of AOA.

Surgical management of a retropharyngeal pseudomeningocele: Case report.

INTRODUCTION: Retropharyngeal pseudomeningocele is a very rare form of pseudomeningocele, that is known to be associated with cervical trauma. Identifying such pathology can be challenging leading to delayed management. CASE PRESENTATION: We report a case of post-traumatic retropharyngeal pseudomeningocele that was managed surgically in a 21-year-old gentleman with poly-trauma injuries due to a motor vehicle accident. After 10 weeks since the traumatic event, magnetic resonance imaging (MRI) and computerised tomography (CT) scan showed evidence of bilateral atlanto-occipital dislocation and a fluid collection of 8 × 4 × 2 cm in the retropharyngeal space. The patient was found to have dysphagia and muffled voice with difficult visualisation of the vocal cords upon examination. After a multidisciplinary team decision, the patient underwent cerebrospinal fluid (CSF) leak management, pseudomeningocele resection and dural defect repair with shunting conducted by the Neurosurgery and Otolaryngology. Postoperative assessments and patient's symptoms, at 9 months follow-up, were satisfactory and reassuring. DISCUSSION: It's believed that conservative management with bed rest, elevation of bed head and acetazolamide is the initial step in management. As an alternative measure, shunting of the CSF had led to resolution of the collection. However, surgical removal of the collection and direct dural defect repair have been suggested in the literature but needed to be properly studied. CONCLUSION: Early recognition of this condition is important to avoid management delay. With a multidisciplinary approach, surgical management can be safe and an acceptable option for retropharyngeal pseudomeningocele.

Integrity of the tectorial membrane is a favorable prognostic factor in atlanto-occipital dislocation.

Objective: Atlanto-occipital dislocation is usually considered to be a fatal injury or one that leaves the victim with serious neurological deficits. The aim of this study is to illustrate a novel positive prognostic factor for atlanto-occipital dislocation, based on cervical MRI studies of patients who suffered this injury.Methods: Over the course of the past year, the authors have treated three consecutive patients with atlanto-occipital dislocation who attained an excellent clinical outcome. We retrospectively evaluated clinical, surgical and radiographic parameters in search of a common denominator to explain the excellent outcome of these patients.Results: All patients presented with severe polytrauma that required urgent surgical intervention including two laparotomies and a thoracotomy. The patients were subsequently treated with an occipitocervical fusion. No patient developed neurological deficits on long-term follow-up. The cervical MRI studies of all patients were notable for a having a preserved tectorial membrane, while other primary stabilizers of the craniocervical junction such as the apical, alar and cruciate ligaments were shown to be severely disrupted. We consider this anatomical distinction to account for their benign clinical course.Conclusion: A preserved tectorial membrane appears to be an important favorable prognostic factor in atlanto-occipital dislocation and may serve to mitigate neurological outcome in such injuries. To determine the integrity of the ligament and consequently affect clinical management, expeditious MRI of the cranio-cervical junction should be considered routinely in such injuries in addition to cervical CT scans.

A Novel Instrumentation Approach in a Pediatric Patient with Atlanto-Occipital Dislocation and Cervical Fracture: Case Report.

BACKGROUND: Although instrumented stabilization of pediatric atlanto-occipital dislocation (AOD) has been described in the literature, there is little evidence regarding instrumentation techniques in pediatric patients presenting with both AOD and a cervical fracture. We present a case of a 2-year-old male involved in a motor vehicle collision with an unstable C2 fracture and AOD, treated with an occiput-C4 posterior arthrodesis using a rod, crosslink, and cable construct. CASE DESCRIPTION: This patient suffered a type III C2 fracture and AOD with 4 mm craniocaudal and 3 mm anterior displacement. In the operating room, 2 cobalt chrome connecting rods (3.5 mm) were connected to 1 another with crosslinks at C2 and C4. These were affixed with suboccipital and sublaminar cables at C1, C2, and C4. At 14 months postoperatively, his spine is clinically and radiographically stable. He has spontaneous movement in all 4 extremities, and remains in a persistent vegetative state because of his underlying central nervous system injury. CONCLUSIONS: Although there is a breadth of literature investigating instrumentation approaches to pediatric AOD, there is minimal evidence on outcomes of patients presenting with both AOD and cervical fracture. The technique we describe has proven safe and effective for this patient.