The craniometric linear dimensions of the posterior fossa have been relatively well studied, but angular craniometry has been poorly studied and may reveal differences in the several types of craniocervical junction malformation. The objectives of this study were to evaluate craniometric angles compared with normal subjects and elucidate the main angular differences among the types of craniocervical junction malformation and the correlation between craniocervical and cervical angles. Angular craniometries were studied using primary cranial angles (basal and Boogard’s) and secondary craniocervical angles (clivus canal and cervical spine lordosis). Patients with basilar invagination had significantly wider basal angles, sharper clivus canal angles, larger Boogard’s angles, and greater cervical lordosis than the Chiari malformation and control groups. The Chiari malformation group does not show significant differences when compared with normal controls. Platybasia occurred only in basilar invagination and is suggested to be more prevalent in type II than in type I. Platybasic patients have a more acute clivus canal angle and show greater cervical lordosis than non-platybasics. The Chiari group does not show significant differences when compared with the control, but the basilar invagination groups had craniometric variables significantly different from normal controls. Hyperlordosis observed in the basilar inavagination group was associated with craniocervical kyphosis conditioned by acute clivus canal angles.

Object. Craniovertebral junction malformation (CVJM) or Chiari malformation in adults, with or without syringomyelia and basilar invagination, produces neuronal dysfunction of the brainstem, cerebellum, cranial nerves, and upper spinal cord. The respiratory center and some of its afferent and efferent components can be altered in these diseases. The authors studied patients with and without CVJM to determine whether this physical feature contributed to sleep disturbances. Methods. Respiratory manifestations during sleep were studied prospectively, by using whole-night polysomnography, in 32 symptomatic patients (CVJM group) and 16 healthy volunteers (control group). Patients with CVJM presented with more sleep disturbances (reports of snoring and apnea) than those in the control group. The apnea/hypopnea index values were higher in patients with CVJMs than in the control group (13 ± 15 compared with 3 ± 6; p = 0.007) and the rate of central sleep apneas was higher in the CVJM than in the control group (22 ± 30 compared with 4 ± 8%; p = 0.009). The apnea/hypopnea index was highest in the subgroup with basilar invagination than in the other subgroups. The central apneic episodes were more frequent in the patients with basilar invagination (35 ± 40%; p = 0.001) and in those with syringomyelia (17.6 ± 24.6%; p = 0.003) than in the control group (4 ± 8%). Patients with symptomatic CVJM, especially those with basilar invagination, presented with more sleep respiratory compromise than did those in the control group. Conclusions. The incidence of sleep apnea/hypopnea syndrome is significantly higher in patients with CVJM.

Patients with craniocervical disorders (CCD) show a wide variety of symptoms and signs suggesting cerebellar and/or high cervical lesion. The anatomic localization of respiratory centers and their possible injury may explain the presence of respiratory disturbances in these diseases. The aim of this preliminary study was to evaluate the polysomnographic findings in a group of patients with CCD, most of them with Arnold-Chiari malformation type I, since sleep apnea has been referred to in isolated cases in the literature. Eleven patients (seven females and four males) with CCD diagnosed by magnetic resonance imaging referred from the neurosurgery unit were submitted to clinical history, physical examination with sleep questionnaires, and scored on the Epworth Sleepiness Scale. Full night polysomnography was performed in an Oxford SAC system where EEG, electro-oculography, electrocardiography, chin and leg electromyography, chest and abdominal efforts, airflow, and oximetry were recorded continuously. Nine patients presented with Arnold-Chiari type I malformation, of whom six showed associated syringomyelia. The other two had basilar invagination. Ninety percent of these patients complained of sleep problems (snoring, choking, and witnessed apneas) and 72% presented hypersomnolence (ESS >9). The polysomnographic findings showed sleep fragmentation in 81% of the patients and a reduction of rapid eye movement sleep in 63%. The apnea/hypopnea index was above 5 in 72%, with a predominance of central apnea. Patients with craniocervical disorders present a higher probability of displaying sleep respiratory disturbances. Their sleep complaints should be assessed and patients should be submitted to an overnight sleep recording in order to identify sleep apnea.

Decompressive surgery in patients with craniovertebral junction malformations resulted in decreased respiratory events during sleep, lowered sleep fragmentation, and enhanced the sleep apnea index in a significant number of patients. The effect was more pronounced in patients with central apnea.

Object Anterior cervical discectomy and fusion had been considered a safe and effective procedure for radiculopathy and myelopathy in the cervical spine, but degeneration in adjacent spinal levels has been a problem in some patients after fusion. Since 2002, cervical disc arthroplasty has been established as an alternative to fusion. The objective of this study was to review data concerning the role of cervical arthroplasty in reducing adjacent-level degeneration. Methods A systematic review was performed using the MEDLINE, EMBASE, Cochrane, and LILACS databases, focusing on a structured question involving the population of interest, types of intervention, types of control, and outcomes studied. Results No study has specifically compared the results of arthroplasty with the results of fusion with respect to the rate of postoperative development of adjacent-segment degenerative disease. One paper described a rate for adjacent-level surgery. The level of evidence of that paper was classified 2b, and although its authors found a statistically significant between-groups difference (arthroplasty vs fusion) using log-rank analysis, re-analysis according to number needed to treat (in the current paper) did not reveal statistical significance. Conclusions Adjacent-level degeneration has not been adequately studied in a review of the available randomized controlled trials on this topic, and there is no clinical evidence of reduction in adjacent-level degeneration with the use of cervical arthroplasty.

2.

IntroductionThe stability of the atlantoaxial motion segment is unique. The lack of typical vertebral bodies and the arrangement of articular facets without protection against horizontal gliding make the articular system dependent mostly on the ligaments. Anterior C1-C2 dislocation is a rare and severe lesion in distraction caused by a predominantly ligamentous lesion, leading to displacement of the atlas on the axis [13].Vertebral displacements require reduction for neural decompression and stabilization. The most frequently used reduction mode is traction. This creates an unusual kind of stress in the craniocervical transition, called vertical distraction. Without ligamentous integrity, even a simple cranial traction can not be counterbalanced and may cause overdistraction among the vertebrae, with its consequences. Recently, traumatic vertical (longitudinal) dissociation between C1 and C2 has been described [8,15,19]. It is extremely difficult to predict which patient will develop this lesion after being subjected to the traction. Here, we describe the case of a patient with traumatic anterior atlantoaxial dislocation who developed a vertical dissociation after skull traction, studying its complications and how they are related to the skull traction. Case reportA 16-year-old female patient, E.C.S., who was run over by a vehicle on 5 May 1997, was immediately taken to the first aid clinic of Conjunto Hospitalar do Mandaqui, São Paulo, Brazil.Cardiorespiratory arrest was detected upon examination. She was submitted to resuscitation attempts. The patient was hemodynamically stabilized, and remained in a coma without opening her eyes and with no motor response, with a score of 3 on the Glasgow coma scale. She was submitted to computed axial tomography (CAT) of the skull, which permitted visualization of the high cervical column and identification of an anterior C1-C2 dislocation (scout view) (Fig. 1). The CAT scan showed a wide separation between the odontoid and the anterior C1 arch and a minimal bilateral displaced fracture of the anterior C1 arch (Fig. 2).Abstract Traumatic overdistraction between C1 and C2 may occur when all the ligaments connecting C2 to the skull are ruptured, and may be manifested when an attempt to reduce C1-C2 subluxation is made by means of traction. We describe here the case of a patient with traumatic anterior atlantoaxial dislocation, who developed atlantoaxial vertical dissociation after skull traction using a Gardner-Halo with lb 4.02 (1.5 kg) of weight. The identification of patients who are susceptible to this complication is difficult. In this case, it might have been prevented by avoiding spinal traction. The aim of this report was to show that vertical dissociation may occur in C1-C2 anterior dislocation submitted to spinal traction, and that other forms of reduction must be considered to treat these pathologies and avoid this potentially fatal complication.

Prevention remains the most effective way to reduce the burden of spinal injuries (SI). Estimating the incidence and causes of SI is essential for the development of prevention programs. To reveal the current state of Brazilian ST epidemiology. To evaluate the current state of Brazilian SI epidemiology, we performed an electronic search using the Lilacs database (Latin American and Caribbean Health Sciences Literature). Fifteen papers and one unsubmitted ongoing study (BH project) reported the epidemiologic status of ST in Brazil. The mean age of SI patients was 34,75 years, and 84% of patients were male. The most commonly affected segment was the cervical spine (36.65%). The incidence ranged from 16 to 26 patients per million per year (average 21 per million per year). The average rate of complete spinal cord injury among five papers was 34%. The average mortality in four papers was 11.58%. Analyzing published national epidemiological data enables the estimation of the current state of Brazilian SI epidemiology.