Os odontoideum with vertebral artery occlusion

Vertebral Artery Dissection in Sport: A Systematic Review

BACKGROUND

Vertebral artery dissection (VAD) is a potentially catastrophic injury that may occur during sports participation. A comprehensive review is needed to collate documented cases to improve understanding and inform future preventative approaches.

OBJECTIVE

This review aimed to understand the extent of VAD in sport and characterise trends suggestive of mechanisms of injury.

METHODS

Electronic databases were searched using terms related to VAD and sport. Records were included if they described one or more cases of VAD attributed to sport.

RESULTS

A total of 79 records described 128 individual cases of VAD in sport, of which 118 were confirmed by imaging or autopsy and included in analyses. Cases were attributed to 43 contact and non-contact sports. The median age of cases was 33 years (IQR 22-44), and 75% were male. There were 22 cases of fatal injury, of which ten involved an impact to the mastoid region and seven involved an impact to the head or neck. Non-fatal cases of VAD were attributed to impact to the head or neck (not mastoid region), movement or held position without impact, and in some cases no reported incident.

CONCLUSIONS

VAD attributed to sports participation is uncommonly reported and the mechanisms are varied. Impact to the mastoid region is consistently implicated in fatal cases and should be the focus of injury prevention strategies in sport. Efforts may also be directed at improving the prognosis of cases with delayed presentation through clinical recognition and imaging. The review was registered on the international prospective register for systematic reviews ( http://www.crd.york.ac.uk/PROSPERO ) (CRD42018090543).

Profiles of Vertebral Artery Dissection with Congenital Craniovertebral Junction Malformation: Four New Cases and a Literature Review

OBJECTIVE

Vertebral artery dissection (VAD) combined with congenital craniovertebral junction malformation (CVJM) is rare. This study aimed to analyze the etiology, clinical and imaging features, treatment, and prognosis of VAD with CVJM.

METHODS

Four new cases of VAD with congenital CVJM and 28 similar cases found in the literature were included. Detailed clinical data from all cases were retrospectively analyzed.

RESULTS

A total of 32 patients (28 men, four women; mean age 19.01±12.53 years) were included. Seventeen of 32 cases (53.1%) had had multiple ischemic episodes. The most common neurological symptoms were limb numbness/weakness (20/32), ataxia (15/32), and dizziness/vertigo (12/32). In sum, 31 of 32 cases had multiple infarcts scattered throughout the posterior circulation area on cranial computed tomography or resonance imaging. Dissection had occurred in the V3 segment of the VA in 29/31 cases (93.5%). The most common congenital CVJMs were atlantoaxial dislocation and atlantoaxial subluxation (found in 20/32 cases [62.5%]), while 27/32 cases (84.3%) had multiple combined abnormalities. Seven of eleven cases (63.6%) with initial antiplatelet treatment and one of eleven (9.1%) with initial anticoagulation treatment experienced stoke recurrence. Fusion or vertebral fixation was performed in 16 patients and aneurysm resection in one patient. There was no reported recurrence after surgery in 13 patients with follow-up data.

CONCLUSION

Underlying CVJM is a rare but overlooked etiology in VAD, and is prone to induce recurrent ischemic stroke. Patients with VAD, especially that localized in the V3 segment, should be examined for CVJM. Timely assessment is critical for determining the specific cause and to provide targeted intervention.

Post-traumatic os odontoideum - case presentation and literature review

Os odontoideum is a rare condition. Nevertheless this condition was described by Giacomini in 1886. It is defined radiologicaly as an oval or round-shaped ossicle of variable size with smooth circumferential cortical margins representing the odontoid process that has no continuity with the body of C2. It is important to review this topic since the upper cervical spinal region is complex from anatomical point of view and has many vital structures passing in close relation to each other. If a person suffers from hyper mobile dens due to insufficiency of its ligamentous complex, it may cause translation of the atlas on the axis and may compress the cervical cord or vertebral arteries. There are cases where patients suffering from Os odontoideum became quadriplegic after a minor trauma. This lesion usually present in pediatric population and its cause is widely debatable today. In our paper we present a review of Os odontoideum in general and present a specific case of a young woman that was diagnosed with Os odontoideum together with the methods that were used to examine, stabilize and finally treat her.

A rare case of os odontoideum from an Early Intermediate period tomb at the Huacas de Moche, Peru

Os odontoideum is an uncommon vertebral anomaly where there is a smoothly corticated ossicle independent from a shortened odontoid peg. An example of os odontoideum was observed in an Early Intermediate period skeleton excavated from the Huacas de Moche (Moche IV, AD 400-700), Peru. The affected individual is a middle adult male who presents additional minor developmental anomalies of the axial skeleton. This individual was interred with a middle adult female who also has developmental anomalies of the axial skeleton, including block cervical vertebra (Klippel-Feil). Os odontoideum is infrequently reported in the medical literature and there continues to be debate about whether it is acquired or congenital. Unlike clinical cases, archaeological cases present an opportunity to examine the entirety of the skeleton. In the present case, there does not appear to be macroscopic or radiographic evidence for a healed fracture, and since the individual has multiple minor axial developmental anomalies, a congenital etiology is plausible. This case is the first to be described from the archaeological context of South America and one of few paleopathological examples worldwide.

Atlantoaxial Subluxation due to an Os Odontoideum in an Achondroplastic Adult: Report of a Case and Review of the Literature

The authors report the first example of an adult achondroplastic dwarf with progressive quadriparesis secondary to atlantoaxial subluxation as a consequence of an os odontoideum. Actually, craniocervical region is a frequent site of compression and myelopathy in achondroplasia particularly in children as a result of small foramen magnum and hypertrophied opisthion. Moreover, very rarely in achondroplastic patients, coexistence of atlantoaxial instability as the sequel of os odontoideum can result in further compression of the already compromised cervicomedullary neural tissues, the scenario that has been reported only in five achondroplastic children. Herein, a 39-year-old achondroplastic male suffering such an extremely rare combination is presented. With C1-C2 screw rod instrumentation, atlas arch laminectomy, limited suboccipital craniectomy, and release of dural fibrous bands, reduction, decompression, and stabilization could be achieved properly resulting in steady but progressive recovery.

Profile of patients with craniovertebral junction anomalies with posterior circulation strokes

BACKGROUND

Craniovertebral junction (CVJ) anomalies are rare and treatable risk factors for posterior circulation strokes (PCSs). Most of the literature comprises case reports and from varied specialities.

METHODS

Chart review of patients with PCS with CVJ anomalies admitted in a single tertiary stroke care unit. We describe their clinical profile, investigative findings, and therapeutic outcomes.

RESULTS

We saw 7 patients (6 males, mean age 20.1 ± 12.0 years), all previously undiagnosed during the 6-year period. Three patients had a combination of atlantoaxial dislocation (AAD), basilar invagination (BI) and Klippel-Feil anomalies, 2 patients had os odontoideum with AAD, and 1 patient each had isolated AAD and BI. Clinically, they presented with first or recurrent episodes of stroke with neck pain. Examination revealed noticeable skeletal markers and neurologic deficits involving the arterial territory. Routine stroke risk factors were absent. X-ray of CVJ was abnormal and diagnostic in all the patients. Other imaging modalities had their own contributions for identifying associated defects, demonstrating pathophysiology, and management of these patients. Acute care with anticoagulation and supportive measures helped in recovery of all of them. Posterior fusion was done in 4 patients, and 2 patients are awaiting the surgery. During follow-up all patients have improved and none had recurrences.

CONCLUSIONS

In case of a young patient with PCS (first/recurrent) in the absence of routine risk factors for stroke, careful physical examination and imaging with basic X-ray may help in the diagnosis CVJ abnormalities, which may be effectively managed by a multidisciplinary team to prevent recurrences.

Os odontoideum syndrome: pathogenesis, clinical patterns and indication for surgical strategies in childhood

Os odontoideum is a rare condition with a controversial pathogenesis and poorly understood natural history. Hypoplasia of the odontoid associated with an independent oval ossicle, with smooth margins widely separated from C2 and well above the superior facets of the axis, is termed "os odontoideum". The neurological manifestations arise from bulbospinal compression both at rest and during motion, due to the craniovertebral junction (CVJ) instability itself. Consequently, the surgical management of os odontoideum should aim at achieving both neural decompression and stabilization of the CVJ. The aims of this paper are to introduce the embryological steps involved in the CVJ development, to underline the updated theories propounded to interpret developmental and congenital disorders of the os odontoideum, to introduce the most updated surgical techniques and to discuss some exemplary cases selected from our personal experience.

Incidental os odontoideum: current management strategies

Os odontoideum was first described in the late 1880s and still remains a mystery in many respects. The genesis of os odontoideum is thought to be prior bone injury to the odontoid, but a developmental cause probably also exists. The spectrum of presentation is striking and ranges from patients who are asymptomatic or have only neck pain to those with acute quadriplegia, chronic myelopathy, or even sudden death. By definition, the presence of an os odontoideum renders the C1-2 region unstable, even under physiological loads in some patients. The consequences of this instability are exemplified by numerous cases in the literature in which a patient with os odontoideum has suffered a spinal cord injury after minor trauma. Although there is little debate that patients with os odontoideum and clinical or radiographic evidence of neurological injury or spinal cord compression should undergo surgery, the dispute continues regarding the care of asymptomatic patients whose os odontoideum is discovered incidentally. The authors' clinical experience leads them to believe that certain subgroups of asymptomatic patients should be strongly considered for surgery. These subgroups include those who are young, have anatomy favorable for surgical intervention, and show evidence of instability on flexion-extension cervical spine x-rays. This recommendation is bolstered by the fact that surgical fusion of the C1-2 region has evolved greatly and can now be done with considerable safety and success. When atlantoaxial instrumentation is used, fusion rates for os odontoideum should approach 100%.

Tumours of the atlas and axis: a 37-year experience with diagnosis and management

PURPOSE

This paper presents a single institution's longterm experience regarding the incidence and management of tumours of the atlas and axis and discusses clinical and imaging findings and treatment options.

MATERIALS AND METHODS

We searched the registry of the Istituto Ortopedico Rizzoli for patients admitted and treated for tumours of the upper cervical spine. We identified 62 patients over 37 years, from July 1973 to October 2010. There were 39 male and 23 female patients, with a mean age of 39.5 (range 5-77) years. For each patient, we collected data on clinical presentation, imaging and treatment. Mean follow-up was 10 years.

RESULTS

Benign bone tumours were diagnosed in 24 (39%) and malignant tumours in 38 (61%) patients. The most common tumours were bone metastases, followed by osteoid osteomas and chordomas. The atlas was involved in six and the axis in 52 patients; in four patients, both the atlas and axis were involved. The most common clinical presentation was pain, torticollis, dysphagia and neurological deficits. Surgical treatment was performed in 35 patients and conservative treatment, including intralesional methylprednisolone injections and halo-vest immobilisation with or without radiation therapy, chemotherapy or embolisation, in the remaining patients. One patient with osteoblastoma of the atlas had local recurrence. All patients with metastatic bone disease had local recurrence; four of the eight patients with plasmacytoma progressed to multiple myeloma within 1-4 years. All patients with chordomas had two to four local recurrences. Patients with osteosarcomas and chondrosarcoma died owing to local and distant disease progression.

CONCLUSIONS

Bone tumours of the cervical spine are rare. However, they should be kept in mind when examining patients with neck pain or neurological symptoms at the extremities. In most cases, only intralesional surgery can be administered. Combined radiation therapy and chemotherapy is indicated for certain tumour histologies.

Os odontoideum: etiology and surgical management

OBJECTIVE

Os odontoideum is an independent ossicle of variable size with smooth circumferential cortical margins separated from the foreshortened odontoid peg. The etiology of os odontoideum remains controversial, but there is now emerging consensus on the traumatic etiology of os odontoideum rather than a congenital source.

RESULTS

We reviewed the literature of os odontoideum. Patients with this condition can be asymptomatic or present with wide range of neurological dysfunctions. Although the diagnosis of os odontoideum can be made with plain x-rays, further imaging modalities including magnetic resonance imaging and computed tomography angiography have improved the preoperative planning.

CONCLUSION

There is a role for conservative treatment of an asymptomatic incidentally found, radiologically stable, and noncompressive os odontoideum. Conversely, surgery has a definite role in symptomatic cases. The main method of surgical treatment today is posterior decompression after reduction and fusion via independent C1 and C2 instrumentation. Irreducible, persistent anterior compression from os odontoideum can be approached by a transoral route with good results in experienced hands.

Upper cervical ligament testing in a patient with os odontoideum presenting with headaches

STUDY DESIGN

Resident's case problem.

BACKGROUND

The role of premanipulative testing of the cervical spine is an area of controversy, and there are very few data to inform and guide practitioners on the use of ligamentous stability tests when assessing the upper cervical spine.

DIAGNOSIS

A 23-year-old female was referred to physical therapy by a neurologist for the management of intractable headaches of possible musculoskeletal origin. Her Neck Disability Index score was 54% and she rated her headache pain from 3/10 to 9/10 on a Numerical Pain Rating Scale. She reported a 2-year history of intermittent lower extremity paresthesias without a known mechanism or current symptoms. She was treated in physical therapy for 11 visits with improvements in cervical range of motion, strength, and intensity of her headaches, but noted no change in the frequency of headaches. She was subsequently referred to the primary author for a second opinion and potential manual therapy interventions. Initial neurological screening examination for upper and lower motor neuron lesions was unremarkable. Assessment of the transverse ligament, using the anterior shear test in supine, brought on paresthesias in both feet and her toes. The paresthesias continued after the cessation of the test. The Sharp-Purser test performed in sitting, immediately after the transverse ligament test, abolished the paresthesias. She was then referred back to her primary care physician for further evaluation. Subsequent radiographs and magnetic resonance imaging revealed that the patient had a C2-C3 Klippel-Feil congenital fusion and os odontoideum. The patient was examined by a neurosurgeon who concluded that she was not a surgical candidate. Her neurological symptoms completely resolved, but she continued to have headaches.

DISCUSSION

Os odontoideum is a clinically important condition, given that the mobile dens may render the transverse ligament incompetent, leading to atlantoaxial instability. Both the role and sequencing of upper cervical ligamentous testing is controversial. The results of this case report suggest that physical therapists should be cognizant of this condition and consider screening the upper cervical ligaments prior to manual or mechanical interventions to this region.

LEVEL OF EVIDENCE

Differential diagnosis, level 4.

“Stretched loop sign” of the vertebral artery: a predictor of vertebrobasilar insufficiency in atlantoaxial dislocation

BACKGROUND

Vertebrobasilar territory infarction is one of the rarer presentations of CVJ anomalies. A new radiologic sign due to stretching of the short third segment of VA detected on MRA/DSA may identify patients of AAD at risk of developing VBI.

METHODS

Seven patients who presented with VBI were found to have a coexisting mobile (n = 6) or fixed (n = 1) AAD. None of these patients had the presence of any of the known risk factors for cerebrovascular disease. On identification of VBI on CT/MRI, DSA (n = 7) and MRA (n = 1) were performed to assess bilateral vertebral arteries. The course of normal VA was also studied in 5 control patients without AAD or VBI.

RESULTS

Digital subtraction angiography/MRA showed obstruction of VA at the C1 through C2 level on one side in each of these cases. The third segment of the contralateral VA showed a shortened and straighter loop termed as the stretched loop sign of the VA. On DSA, the latter manifested as (a) opening of the distal loop of the VA as it emerges from the foramen transversarium of the atlas and traverses on the dorsum of the posterior arch of atlas (n = 3), (b) shortened and stretched VA that runs laterally and posteriorly forming the proximal loop after emerging from the foramen transversarium of the axis (n = 2), or (c) both (n = 2). All patients presented with the clinical manifestations of VBI. Only 2 of these had preexisting myelopathy and long tract signs conventionally attributable to AAD.

CONCLUSION

Vertebrobasilar territory infarction in AAD may occur because of the obstruction of the third segment of VA. A shorter and straighter loop of the third segment of VA coexisting with an abnormal translational mobility between the atlas and the axis may be the etiopathogenetic factor.

Cerebellar infarction secondary to os odontoideum

A 43-year-old man developed cerebellar infarction due to atlantoaxial dislocation associated with os odontoideum. Cervical X-ray films confirmed os odontoideum, and conventional angiography revealed irregular narrowing of the right vertebral artery at the axis level. A correlation between the vertebral artery lesion and atlantoaxial instability was shown with 3-dimensional (3-D) computed tomographic (CT) angiography. This is the first case of atlantoaxial dislocation with vertebral artery stenosis demonstrated 3-D CT angiography. 3-D CT angiography can support the conventional angiography with respect to the diagnosis and management of vertebral artery insufficiency associated with occipitocervical deformity.

Contraindications to the Dix-Hallpike manoeuvre: a multidisciplinary review

The Dix-Hallpike manoeuvre is widely used in the diagnosis of positional vertigo and is regarded as safe. The manoeuvre involves a degree of neck rotation and extension, and consequently one might expect there to be some patients, particularly those with neck problems, in whom the manoeuvre is contraindicated. The term 'neck problem', however, encompasses a whole range of conditions, including soft tissue disorders, cervical spondylosis, prolapsed intervertebral disk, and severe rheumatoid arthritis with cervical instability. These in turn will give rise to a variety of symptoms, which will vary from minimal pain or stiffness to severe pain or complete immobility, and, in some cases, neurological deficit. Clarification is therefore needed to establish the point at which any neck pain or stiffness ceases to be a minor problem and becomes a contraindication to performing the Dix-Hallpike manoeuvre. This paper clarifies this issue by discussing the issue of absolute contraindications and proposing a simple functional assessment of neck mobility which can be performed prior to performing the Dix-Hallpike manoeuvre. Relative contraindications such as back pathology, vertebrobasilar ischaemia (posterior circulation ischaemic disease), nerve root compression and medical fitness are also discussed.

Os odontoideum in a patient with cervical vertigo: a case report

Cervical vertebral anomalies are often associated with malformations or traumas, they may be completely asymptomatic and represent an occasional finding in vertigo or can cause severe neurologic complications (ie, compression of the upper cervical spine with myelopathy, epilepsy, or respiratory failure). This clinical case is a patient who came to us for observation for a peripheral harmonic vestibular syndrome, and in whom a malformation of the cervical vertebral joint (os odontoideum) was occasionally found on magnetic resonance imaging.

Complete reduction of retro-odontoid soft tissue mass in os odontoideum following the posterior C1-C2 tranarticular screw fixation

STUDY DESIGN

A case report of os odontoideum with retro-odontoid soft tissue hypertrophy treated by the transarticular screw fixation.

OBJECTIVES

To present a case of os odontoideum that showed complete reduction of retro-odontoid soft tissue mass caused by atlantoaxial subluxation after the C1-C2 transarticular screw fixation.

SUMMARY OF BACKGROUND DATA

Hypertrophy of the periodontoid soft tissue has been reported to be associated with chronic atlantoaxial subluxation and progressive myelopathy. While the rheumatoid pannus has been reported to become reduced of disappear after fixation of the unstable segment, the reduction of the hypertrophied soft tissue mass has never been reported in atlantoaxial subluxation of nonrheumatoid origin, especially in the case of os odontoideum.

METHODS

Posterior C1-C2 transarticular screw fixation was performed in a patient with os odontoideum, who showed signs of progressive myelopathy by the compression of retro-odontoid soft tissue mass and atlantoaxial subluxation.

RESULTS

The fixation of atlantoaxial subluxation achieved not only the complete reduction of the retro-odontoid soft tissue mass, but also clinical improvement of the myelopathy.

CONCLUSIONS

Posterior atlantoaxial fixation is worth trying in slow progressing myelopathy by the compression of hypertrophy of the soft tissue even in nonrheumatoid atlantoaxial subluxation, thereby obviating the need for direct removal of the mass via the transoral route.

Rotational obstruction of nondominant vertebral artery and ischemia. Case report

A 70-year-old man presented with repeated vertebrobasilar insufficiency for 3 years. Four-vessel angiography revealed complete occlusion of the nondominant left vertebral artery on head turning to the right. Three-dimensional computerized tomography angiography demonstrated atlantoaxial joint dislocation when the head was turned to the right, in accordance with simultaneous occlusion of the left vertebral artery caused by stretching of the artery at C1-2. After posterior fixation of C1-2 by a Halifax interlaminar fixation system, the patient had no further episodes. Hemodynamic function associated with nondominant vertebral artery occlusion contributed to the symptoms in this case.

A report on the safety of unilateral vertebral artery ligation during cervical spine surgery

STUDY DESIGN

This study retrospectively analyzed the outcome of unilateral vertebral artery ligation during cervical spine surgery.

OBJECTIVES

To examine the influence of unilateral vertebral artery ligation on the function of brain and spinal cord.

SUMMARY OF BACKGROUND DATA

There was little published information about the outcome of a vertebral artery ligation except for several reports from the field of neurosurgery.

METHODS

Unilateral vertebral artery ligation was used in 15 patients with cervical tumors of the spine or the spinal cord (age range, 13-71 years; nine male patients and six female). The authors ligated the involved vertebral artery only when the tumor appeared on the minor or equal diameter artery side measured by pre-operative angiogram. The patient's condition was examined regarding signs of dysfunction of the brain stem, the cerebellum, or the spinal cord.

RESULTS

Preoperative angiogram showed that the involved vertebral artery had a smaller diameter in four patients and had an equal diameter in 11 patients compared with the one not involved. The involved vertebral artery was severed at single site in four patients and was resected between two distant sites of ligation in 11 patients. Examination after surgery of the patient's condition (follow-up periods ranged from 10 months to 7 years) revealed that unilateral vertebral artery ligation did not provoke any symptoms of damage resulting from ischemia of the brain stem, the cerebellum, or the spinal cord.

CONCLUSION

A vertebral artery could be ligated uneventfully when the diameter of the vertebral artery was not larger than the one not involved. Where vertebral artery ligation could not be avoided, it should be confirmed by preoperative angiogram that the other vertebral artery is large enough and that simultaneous occlusion testing of the involved vertebral artery is uneventful.