Ricardo Vieira Botelho

Polysomnographic respiratory findings in patients with Arnold-Chiari type I malformation and basilar invagination, with or without syringomyelia: preliminary report of a series of cases.

Abstract 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.

A systematic review of randomized trials on the effect of cervical disc arthroplasty on reducing adjacent-level degeneration

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.

Adult Chiari malformation and sleep apnoea

Chiari malformation (CM) is primarily characterised by herniation of the cerebellar tonsils through the foramen magnum. Clinically, two main types of CM represent the vast majority of cases: type I (in adults) and type II (in infants). CM may result in neuronal impairment of the brainstem, upper spinal cord and cranial nerves. Part of the afferent and efferet systems and the central respiratory controlling system are located in the cranium-cervical transition and may be damaged in these pathologies, leading to respiratory disorders, such as respiratory failure and death. The ventilatory responses to exogenous and endogenous stimuli, such as responses to hypoxia and hypercapnia, are usually diminished, and apnea may be manifested and detected during sleep, allowing for the diagnosis. This study is a review of the relationship between sleep apnoea and adult CM.

The effects of posterior fossa decompressive surgery in adult patients with Chiari malformation and sleep apnea.

OBJECT One of the feared consequences of craniovertebral junction diseases is apnea. Although several cases of patients with central apnea have been described, obstructive sleep apnea has been identified as the most frequent manifestation of sleep respiratory disorder. Neuronal involvement may be responsible for both central and obstructive apneas. The objective of this work was to study the effect of posterior fossa decompressive surgery on respiratory parameters during sleep in patients with craniovertebral junction malformations and breathing-related sleep disorders. METHODS In this study, prospectively enrolled consecutive symptomatic adult patients were monitored with full-night polysomnography before and after surgical decompression of the cranial posterior fossa. RESULTS Of the 25 patients who were evaluated, 68% received a diagnosis of sleep apnea. After surgery, the mean number of respiratory events decreased from 180.70 to 69.29 (p = 0.005); the mean number of obstructive events decreased from 107.37 to 60.58 (p = 0.01); and the mean number of central events decreased from 38.45 to 8.05 (p = 0.01). The mean preoperative apnea/hypopnea index decreased from 26.68 to 12.98 (p = 0.06), and the mean central apnea index decreased from 13.81 to 1.68 (p = 0.01). CONCLUSIONS 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.

Basilar invagination: craniocervical instability treated with cervical traction and occipitocervical fixation. Case report.

The upward odontoid displacement observed in basilar invagination (BI) is generally associated with a horizontal clivus and craniocervical kyphosis, conditions that exert ventral compression at the spinomedullary junction. Ventral brainstem decompression by reduction or elimination of the odontoid invagination is part of the desired treatment. The authors describe a case of BI in an adult, who was effectively treated with the easy and safe reduction of odontoid invagination via cervical traction. Normalization of kyphosis at the craniovertebral junction and the vertical position of both a previously horizontal clivus and the cerebellar tentorium demonstrated that these conditions were not part of the original malformation but instead were caused by a reducible craniovertebral instability.

Angular craniometry in craniocervical junction malformation

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.

Traumatic vertical atlantoaxial instability: the risk associated with skull traction. Case report and literature review.

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.

Efetividade da metilprednisolona na fase aguda do trauma raquimedular: revisão sistemática dos ensaios clínicos randomizados

Steroid therapy has been tested as a protector in spinal cord injury. Multicenter studies evaluating the methylprednisolone (MP) in post traumatic neurological recovery have shown promising results according to NASCIS. A large number of critical studies related to the NASCIS results have been published. OBJECTIVE: To review literature related to use of methylprednisolone compared with placebo. METHODS: This analysis added the average improvement achieved in groups of patients who used MP and placebo (PL) to the average scores of groups at baseline, before treatment, resulting in the final neurological outcome for both groups. RESULTS: The motor score of the MP group was only 2.5 points higher than the PL in a one year follow-up. In neurologically intact patients, the total score is 70 points. Improvement in sensitive scores was also discrete (1.1 and 1.7 points for the pinprick and light touch respectively). A high rate of complications was observed in a group of patients about 60 years old who used MP. CONCLUSION: Differences in the clinical magnitude of benefit obtained (not confirmed by other studies) with the use of MP or PL are not significant, in comparison with the potential for complications when using methylprednisolone.

Revisiting hydrocephalus as a model to study brain resilience

Hydrocephalus is an entity which embraces a variety of diseases whose final result is the enlarged size of cerebral ventricular system, partially or completely. The physiopathology of hydrocephalus lies in the dynamics of circulation of cerebrospinal fluid (CSF). The consequent CSF stasis in hydrocephalus interferes with cerebral and ventricular system development. Children and adults who sustain congenital or acquired brain injury typically experience a diffuse insult that impacts many areas of the brain. Development and recovery after such injuries reflects both restoration and reorganization of cognitive functions. Classic examples were already reported in literature. This suggests the presence of biological mechanisms associated with resilient adaptation of brain networks. We will settle a link between the notable modifications to neurophysiology secondary to hydrocephalus and the ability of neuronal tissue to reassume and reorganize its functions.

The Choice of the Best Surgery After Single Level Anterior Cervical Spine Discectomy: A Systematic Review

Background: The anterior cervical discectomy (ACD) is often used to treat spinal cord and nerve root compressions and the frequent use of interbody fusion (ACDF) has popularized it as a common practice associated or not with cages or plates for maintaining the intervertebral disc height. Objective: The aim of this study is to clarify the effectiveness of ACD compared with ACDF, with or without the use of anterior cervical spacer (Cage) or instrumentation with plate fixation (ACDFI). Methods: randomized controlled trials or quasi-randomized trials were selected for analysis in one segmental level. The comparison criteria were the rates of success and failure with surgery (Odom’s’ criteria), fusion rates and kyphosis rates. Electronic search was made in the MEDLINE database (Pubmed), in the Central Registry of randomized trials of Cochrane database and EMBASE. Results: Seven studies were selected for analysis. Conclusion: Implications for practice: There is moderate evidence that clinical results of ACD and ACDF are not significant different. There is moderate evidence that addition of intervertebral cage enhance clinical results.There is moderate evidence that anterior cervical plate does not change the clinical results of ACD. There is moderate evidence that ACD produce more segmental kyphosis than ACDF and ACDFI, with use of cage or plate.There is moderate evidence that ACD produce lower rate of fusion than ACDF and than the cages. There is limited evidence of the lower capacity of PMMA to produce fusion. There is limited evidence that fused patients have better outcome than non fused patients.