Atlanto-occipital Instability Research Articles

Subclinical Chronic Atlanto-Occipital Rotatory Fixation: A Case Report.

Cases of symptomatic atlanto-occipital rotatory subluxation and dislocation caused by trauma, tumor, inflammatory disease, or congenital anomaly have been previously reported1-3. These conditions can be highly unstable and result from osteoligamentous disruption between the occipital bone (Oc) and the axis (C2)4,5. To the best of our knowledge, there have been no reports of cases of asymptomatic chronic atlanto-occipital rotatory fixation (AORF). While there are patients who may be asymptomatic neurologically and only present with neck pain, we report an extremely rare case of subclinical chronic AORF with previous symptomatic atlantoaxial rotatory fixation (AARF). The patient and her parents were informed that data concerning the case would be submitted for publication, and they provided consent. A previously healthy eleven-year-old girl presented to our clinic with a two- month history of neck pain and torticollis without any traumatic history or prodromal symptoms (e.g., fever). She had torticollis with a tilt of the head to the right (Fig. 1-a). Physical examination revealed restricted neck motion; lateral cervical spine bending was limited to 30° to the right and 0° to the left, and rotation was limited to 30° to the right and 40° to the left. She had no excessive ligamentous laxity. Neurologic examination revealed no abnormalities. Computed tomography (CT) showed 12° rotation to the left of C1 on C2, and 32° rotation to the right of the occipital bone on the atlas (C1) (Fig. 2-a). The diagnosis of concomitant AARF and AORF was made after CT scanning. Lateral dynamic radiographs of the cervical spine showed neither atlantoaxial nor atlanto-occipital instability (Figs. 3-a, 3-b, and 3-c). Fig. 1 At presentation, the patient exhibited torticollis ( Fig. 1-a) . After a sequence of conservative treatments, she showed no cervical abnormality ( Fig. 1-b ). Fig. 2 CT axial images of the occipitoatlantoaxial …

Expert's comment concerning Grand Rounds case entitled "Temporary occipito-cervical stabilization of an unilateral occipital condyle fracture" (by Klaus John Schnake, Andreas Pingel, Matti Scholz and Frank Kandziora).

Expert's comment concerning Grand Rounds case entitled "Temporary occipito-cervical stabilization of an unilateral occipital condyle fracture" (by Klaus John Schnake, Andreas Pingel, Matti Scholz and Frank Kandziora).

Equivalence of fusion rates after rigid internal fixation of the occiput to C-2 with or without C-1 instrumentation

The object of this study was to assess a multiinstitutional experience with pediatric occipitocervical constructs to determine whether a difference exists between the fusion and complication rates of constructs with or without direct C-1 instrumentation. Seventy-seven cases of occiput-C2 instrumentation and fusion, performed at 9 children's hospitals, were retrospectively analyzed. Entry criteria included atlantooccipital instability with or without atlantoaxial instability. Any case involving subaxial instability was excluded. Constructs were divided into 3 groups based on the characteristics of the anchoring spinal instrumentation: Group 1, C-2 instrumentation; Group 2, C-1 and C-2 instrumentation without transarticular screw (TAS) placement; and Group 3, any TAS placement. Groups were compared based on rates of fusion and perioperative complications. Group 1 consisted of 16 patients (20.8%) and had a 100% rate of radiographically demonstrated fusion. Group 2 included 22 patients (28.6%), and a 100% fusion rate was achieved, although 2 cases were lost to follow-up before documented fusion. Group 3 included 39 patients (50.6%) and demonstrated a 100% radiographic fusion rate. Complication rates were 12.5, 13.7, and 5.1%, respectively. There were 3 vertebral artery injuries, 1 (4.5%) in Group 2 and 2 (5.1%) in Group 3. High fusion rates and low complication rates were achieved with each configuration examined. There was no difference in fusion rates between the group without (Group 1) and those with (Groups 2 and 3) C-1 instrumentation. These findings indicated that in the pediatric population, excellent occipitocervical fusion rates can be accomplished without directly instrumenting C-1.

Treatment of chronic musculoskeletal pain with opioids

Dear Editor, Our letter is inspired by the article of D Choquette, TG McCarthy, JFN Rodrigues, and coauthors [1]. We read it with great interest as it discusses important issues encountered by physicians who deal with chronic nonmalignant pain (CNMP) in the course of musculoskeletal disease. The article specifically relates to the use of opioids in patients with CNMP, with underlying musculoskeletal disease, who do not benefit fully from firstand second-step drugs of the World Health Organization (WHO) pain relief ladder. We have no intention to debate the mentioned article. We write in reference to the commonly expressed opinion that climbing the pain relief ladder in CNMP treatment is often done in a schematic way. In other words, it is believed that the lack of analgesic effect of step 1 and 2 drugs, in a patient whose pain intensity equals to 5 on the numerical pain scale, justifies the introduction of strong opioids. This is an approach which assumes that every kind of chronic pain is similar. It does not differentiate between malignant and osteoarthritic pain. The WHO pain relief ladder, initially created for cancer pain, was also adopted in practice for nonmalignant pain treatment. However, causes and sources of pain should not be ignored in relation to analgesic treatment. A priority in malignancy is to suppress pain and this does not interfere with the treatment of the underlying disease. In CNMP caused by musculoskeletal disease, treatment aims to maximize preservation of motor organ functions. In these patients, the intention to decrease pain is very important but it can sometimes be incompatible with maintaining maximal possible efficiency of motor organs after the termination of treatment. As an example, we show the case of our patient with hip joint pain and high-grade subchondral cysts in the femoral head and iliac acetabulum, awaiting an operation. Pain occurred mainly during movement and applying load to the joint. We may therefore ask whether it is prudent to remove pain and enable activity and loading of the joint, increasing the risk of femoral head fracture. Clinically, we all encounter many such examples. It should be remembered that opioids improve the quality of life but deprive the patient of the warning function of pain. Opioids also have adverse effects. They were discussed by the authors in their article. We would also remark on another adverse effect of opioids, important in treatment planning, which is their sedative potential. The risk of femoral neck fracture among persons taking opioids is increased 1.6-fold [2]. It results from the ability of opioids to impair balance and increase the risk of falls. This risk seems to be even higher among elderly people with advanced musculoskeletal disease. In persons with concomitant osteoporosis and/or atlantooccipital junction instability due to rheumatoid arthritis, falls can have serious consequences [3]. These factors should always be considered by a physician estimating risks and benefits for the patient. Opioids are an important class of drugs in the treatment of CNMP caused by musculoskeletal diseases. Their inclusion in the treatment of CNMP significantly improved the effectiveness of analgesia. They also counteract with mechanisms of pain chronification. Nevertheless, decisions concerning their introduction into CNMP treatment should not be schematic. Thus, as recommended by the American Clin Rheumatol (2008) 27:1473–1474 DOI 10.1007/s10067-008-0987-9

Stabilization of Complex Traumatic Lesions of the Occipitocervical Junction with a Tapered Rod-Plate Construct

Background/Objective: Occipitocervical fusion is an accepted surgical procedure for the management of atlanto-occipital instability, including traumatic etiologies. Various types of instrumentation have been used to promote fusion. We report experience with the use of a rod-plate construct. Method: 7 patients with traumatic atlanto-occipitial instability underwent occipitocervical fusion. There were 5 men and 2 women (age range, 34-53 years). 4 patients had an atlanto-occipital dislocation, and 3 had complex upper cervical spine fractures. 2 patients with atlanto-occipital dislocation had severe spinal cord injuries as well as a closed head injury. Outcome measures included fusion rates, complications, and functional neurologic status. Results: All patients achieved fusion. No patient experienced neurologic deterioration, and all 5 patients with neurologic injury experienced varying degrees of recovery. 1 patient required re-operation following back-out of his skull screws on one side. Conclusion: In individuals requiring occipitocervical fixation and fusion, an instrumentation system employing a screw-rod construct is a safe, efficacious method for achieving these goals.

β2-Microglobulin amyloidosis caused spinal cord compression in a long-term haemodialysis patient

A case report of cervical myelopathy caused by epidural beta (2)-microglobulin (beta2m) amyloid deposits in a 50-year-old woman with haemodialysis treatment. Long-term haemodialysis in patients with end-stage renal disease leads to several complications based on beta2m deposits, which can affect, in the cervical spine, the intervertebral disk, and in rare cases, they may compress the spinal cord and nerves. The objective of this report is to describe the clinical and radiological follow-up preceding the indispensable surgical excision of an amyloid mass in a 50-year-old woman with haemodialysis treatment. Long-term postoperative cervicalgia owing to subcondylian bone cyst-associated atlanto-occipital instability is also described and discussed. Department of Neurosurgery A, Hop Pellegrin, Bordeaux, France. We present a clinical case of a patient with spinal cord compression. The patient was treated by surgical excision of an amyloid mass subsequent to a C2-C3 laminectomy. The patient experienced clinical improvement with a regression of all of her neurological symptoms. Histological findings confirm the diagnosis of beta2m amyloid deposition. However, 5 years after surgery the subcondylian bone cysts were still observed and atlanto-occipital instability required her to wear a minerva. Our case report confirms that surgical excision of beta2m epidural deposits is necessary and relevant when neurological prognosis is discussed, and that pain is still the major symptom of disease evolution. The use of high-flux synthetic membranes could decrease the beta2m blood level and early renal graft is the only method to prevent such complications.

Atlanto-occipital Assimilation Associated with Basilar Invagination, C1-2 Instability, C2-3 Block Vertebra,and C3-4 Retrolisthesis: A Case Report

Congenital atlanto-occipital assimilation is frequently accompanied by basilar invagination and C1-2 instability. Occipitocervical fusion is required if these conditions cause neurological symptoms. Recently posterior fusion using occipitocervical screw fixation in the extension position has been introduced for the simultaneous decompression of the cervicomedullary junction compressed by basilar invagination, a reduction of atlantoaxial subluxation, and rigid fixation. However, it is a technically demanding procedure, and there is no domestic report of an experience with this procedure. We report a case of a patient with C2-3 block vertebra and C3-4 retrolisthesis in addition to congenital atlanto-occipital assimilation, basilar invagination and C1-2 instability. The patient underwent posterior fusion using occipitocervical screw fixation in the extension position.

Cervical Spine Considerations When Anesthetizing Patients with Down Syndrome

It is characterized by mental retardation, as well as craniofacial, upper airway, cardiovascular, and gastrointestinal anomalies. One manifestation of DS relevant to anesthesiologists is upper cervical spine instability produced by ligamentous laxity, skeletal anomalies, or both. This instability can result in neurologic impairment, including quadriplegia. However, there are no evidencebased practical guidelines to aid anesthesiologists in caring for these patients. The risk of spinal cord injury during anesthesia is unknown, as are the preoperative factors that might aid in accurately defining the risk in specific patients. Review of Normal Upper Cervical Spine Anatomy The structures relevant to this discussion include the base of the skull, the atlas (C1), and the axis (C2). The articulations between these structures are complex but are designed to facilitate maximal movement without compressing the spinal cord. The motions are flexion extension and rotation; little lateral bending occurs in this area.

Posterior Instrumentation Surgery for Craniocervical Junction Instabilities: an Update

The surgical treatment of craniocervical junction (CCJ) instability has recently undergone significant development and change. Posterior instrumentation surgery has been the mainstay of treatment of CCJ instability, and is the focus of this review. For the treatment of atlantoaxial instability, C1-2 transarticular screw fixation has shown good stability, and has been regarded as the "gold standard" procedure. Because of potentially hazardous complications including vertebral artery injury, however, C-1 lateral mass-C-2 pedicle screw fixation is gaining popularity. For treatment of atlantooccipital instability, occipitocervical fixation using screw constructs (combined with either rods or plates) has shown more stability than sublaminar wiring techniques, and has been utilized more frequently. Both innovation in material engineering and in vitro biomechanical studies have contributed significantly to the development of more rigid internal fixation devices, and as a result, many patients who would have been treated conservatively with external orthosis are treated nowadays with instrumentation surgery, resulting in earlier ambulation, shortened hospital stay, and earlier recovery into social activities. New surgical techniques and instruments, however, need to stand the test of time to see whether they are free from long-term adverse events. The rapid turnover of new surgical techniques and hardware has made it difficult for less experienced surgeons to keep up with the latest developments. Conventional techniques can be safer and less technically demanding than newer techniques for those who are not familiar with them.

Traumatic Atlanto-Occipital Dislocation in Children

Traumatic atlanto-occipital dislocation is seen in approximately 25% of fatal pediatric trauma. This was previously considered to be a rare and fatal entity, however with improvements in resuscitation in the field, many patients who previously might have died are now evaluated in the hospital. Treatment of atlanto-occipital instability is internal fixation. Many authors have advocated supplemental external immobilization with a halo vest. However, there are several circumstances where the application of a halo vest is undesirable. Thus a method of internal fixation and fusion that is rigid enough not to require supplemental external orthosis is necessary. We present 2 cases of atlanto-occipital dislocation which were treated with Locksley intersegmental tie bar occipital cervical fusion. Both patients achieved solid fusion without supplemental halo bracing, and made complete neurologic recoveries. Traumatic atlanto-occipital dislocation is a potentially survivable injury that requires aggressive resuscitation in the field, a high index of suspicion and early definitive surgical stabilization.

Down syndrome: imaging of multiorgan involvement.

Down syndrome (trisomy 21) has many manifestations that affect multiple organ systems, and we describe the wide array of imaging findings. Common cardiovascular and gastrointestinal entities are congenital heart disease (atrioventricular canal), bowel atresias (duodenal and anal), and Hirschsprungs disease. Children with Down syndrome have an 18-20 fold increased incidence of leukemia. Pulmonary hypoplasia, lung cysts, and pig bronchus (origin of the right upper lobe bronchus from the trachea) have been described. Neurologic findings include mineralizing vasculopathy of the basal ganglia, Moyamoya disease, and cerebellar/vermian hypoplasia. Musculoskeletal manifestations are numerous and include eleven ribs, hypersegmented sternum, abnormal pelvis, joint laxity/dislocations, and DDH (developmental dysplasia of the hip). Of special importance is the "triple jeopardy" of the upper cervical spine (atlanoaxial subluxation, hypoplastic posterior arch of C1, and atlantooccipital instability) and the resulting controversial cervical spine radiographic screening of children with Down syndrome. Knowledge of the many anomalies associated with Down syndrome can aid the clinician, not only in diagnosing abnormalities in these patients, but also in counseling families for potential problems that can occur in these children.

Health care concerns and guidelines for adults with Down syndrome

Down syndrome (DS) is the most common cause of mental retardation in North America, yet little information is available on the natural history of DS in adults. We report on significant medical problems of adults with DS (DS adults) residing in a British Columbia provincial residential center, Woodlands, over the 12-year period from 1981 through 1992. Prospective, yearly health care reviews on 38 DS adults are summarized according to age. Group 1 consists of 18 middle-aged DS adults less than 50 years old, and group 2 comprises 20 elderly DS adults 50 years and older. Significant health problems in all DS adults include untreated congenital heart anomalies (15. 8%), acquired cardiac disease (15.8%), pulmonary hypertension (7.8%), recurrent respiratory infections/aspiration leading to chronic pulmonary interstitial changes (30%), complications from presenile dementia/Alzheimer-type disease (42%), adult-onset epilepsy (36.8%), osteoarthritic degeneration of the spine (31.6%), osteoporosis with resultant fractures of the long bones (55%) or vertebral bodies (30%), and untreated atlantooccipital instability (7.9%). Acquired sensory deficits are significant problems including loss of vision due to early onset of adult cataracts (50%), recurrent keratitis (21%) or keratoconus (15.8%), and significant hearing loss (25%). Behavioral problems (50%), loss of cognitive abilities, and onset of symptoms of Alzheimer disease (group 1: 5.5%; group 2: 75%) pose ongoing challenges for care. In conclusion, the quality of life for adults with DS can be improved by routine, systematic health care screening to identify treatable diseases that may be missed because of poor communication or confusion due to Alzheimer disease.

Health care concerns and guidelines for adults with Down syndrome

Down syndrome (DS) is the most common cause of mental retardation in North America, yet little information is available on the natural history of DS in adults. We report on significant medical problems of adults with DS (DS adults) residing in a British Columbia provincial residential center, Woodlands, over the 12-year period from 1981 through 1992. Prospective, yearly health care reviews on 38 DS adults are summarized according to age. Group 1 consists of 18 middle-aged DS adults less than 50 years old, and group 2 comprises 20 elderly DS adults 50 years and older. Significant health problems in all DS adults include untreated congenital heart anomalies (15.8%), acquired cardiac disease (15.8%), pulmonary hypertension (7.8%), recurrent respiratory infections/aspiration leading to chronic pulmonary interstitial changes (30%), complications from presenile dementia/Alzheimer-type disease (42%), adult-onset epilepsy (36.8%), osteoarthritic degeneration of the spine (31.6%), osteoporosis with resultant fractures of the long bones (55%) or vertebral bodies (30%), and untreated atlantooccipital instability (7.9%). Acquired sensory deficits are significant problems including loss of vision due to early onset of adult cataracts (50%), recurrent keratitis (21%) or keratoconus (15.8%), and significant hearing loss (25%). Behavioral problems (50%), loss of cognitive abilities, and onset of symptoms of Alzheimer disease (group 1: 5.5%; group 2: 75%) pose ongoing challenges for care. In conclusion, the quality of life for adults with DS can be improved by routine, systematic health care screening to identify treatable diseases that may be missed because of poor communication or confusion due to Alzheimer disease. Am. J. Med. Gent. (Semin Med. Genet.) 89:100–110, 1999. © 1999 Wiley-Liss, Inc.

Instability of the craniovertebral junction and treatment outcomes in patients with Down's syndrome

Operative intervention for the treatment of instability at the craniovertebral junction in patients with Down's syndrome has become somewhat controversial because some authors have reported high surgery-related complication rates and suggested that the incidence of neurological abnormality associated with this abnormal motion may be low. In this report, the authors describe the clinical and radiographic findings in 33 patients treated at their institution. Common presenting symptoms included neck pain (14 patients), torticollis (12 patients), and myelopathy manifested as hyperreflexia (21 patients), or varying degrees of quadriparesis (11 patients). Four patients suffered acute neurological insults, two after receiving routine general anesthetics for minor surgical procedures and two other patients following minor falls. Atlantoaxial instability was the most common abnormality documented on radiography (22 patients). Atlantooccipital instability (15 patients) was also frequently observed and was coexistent with the presence of atlantoaxial luxations in 14 patients. A rotary component of the atlantoaxial luxation was present in 13 cases. In 17 patients bony anomalies were present, the most frequent of which was os odontoideum (10 patients). Twenty-four patients underwent operative intervention, and successful fusion was achieved in 23. In six of nine patients with basilar invagination, reduction was achieved with preoperative traction and thus avoided the need for ventral decompressive procedures. There were no cases of postoperative deterioration, and 22 patients made excellent or good recoveries. The results of this series highlight the clinicopathological phenomena of craniovertebral instability in patients with Down's syndrome and suggest that satisfactory outcomes can be achieved with a low rate of surgical morbidity.

Point of View: Reproducibility is the Measurement of Atlanto-occipital Instability in Children With Down Syndrome

Point of View: Reproducibility is the Measurement of Atlanto-occipital Instability in Children With Down Syndrome

Reproducibility in the measurement of atlanto-occipital instability in children with Down syndrome.

This study compared the reproducibility of three techniques used to measure translation between the occiput and C1 in children with Down syndrome. Intraobserver and interobserver variability were computed to determine if there is a reliable way to measure occiput-C1 instability. No studies have been performed comparing measurement techniques in children with Dow syndrome. Powers ratios, basion-axial intervals, and translational anteroposterior motion as described by Wiesel and Rothman were calculated for 50 pairs of flexion-extension lateral cervical radiographs from children with Down syndrome. Calculations were made on two occasions by four reviewers. Mean differences between measurements for two observers were 0.14 for the Powers ratio, 1.3 mm for the Wiesel technique, and 1.8 mm for the basion-axial interval. The 95th percentiles of the differences between measurements for two observers were 0.38 for Powers ratios, 3.5 mm for the Wiesel technique, and 5.3 mm for the basion-axial interval. Measurement of atlanto-occipital translation by any of these methods is not reproducible. Although the technique by Wiesel and Rothman is the easiest to apply, confirmation of instability with magnetic resonance imaging should guide management.

Atlanto-Occipital and Atlanto-Axial Instability in Children with Down Syndrome

Thirty-six children with Down syndrome, between two-and-ne-half and 13 years of age, were evaluated for instability of the cervical spine, in order to determine the prevalence of upper cervical spine instability in Saudi children with this condition. Nine patients exhibited abnormal cervical spine movement. Eight patients had atlanto-occipital instability and three had atlanto-axial instability. None of the nine patients with abnormal cervical spine movements developed any neurological deficit. Our survey confirms the data from the literature that there is a high incidence of cervical spine instability in children with Down syndrome.

Traumatic Atlanto-Occipital Instability A Case Report With Follow-up and A New Diagnostic Technique

Traumatic Atlanto-Occipital Instability A Case Report With Follow-up and A New Diagnostic Technique

Type I fractures of the odontoid process: implications for atlanto-occipital instability

Only four cases of Type I odontoid fracture have been previously described in the English literature. Most authors consider this lesion to be stable, although the mechanism(s) of injury has not been clearly elucidated. A case of Type I odontoid fracture in association with atlanto-occipital and atlantoaxial dislocation resulting in death is presented. The normal ligamentous anatomy is reviewed and proposed mechanisms for this injury are discussed. The radiographic features of all reported cases of this type are reviewed. It is proposed that the Type I odontoid fracture is a likely manifestation of atlanto-occipital instability and rarely occurs as an isolated or stable injury.

Atlanto‐occipital instability in Down's syndrome

A patient with Down's syndrome and asymptomatic atlanto-occipital instability is described. The relationship between atlanto-occipital instability, atlanto-axial instability and generalized ligamentous laxity, is discussed.