Lumbar nerve root "walled" by a calcified herniated mass in a young patient.

INTRODUCTION: Discal calcification in childhood is rare. Calcifications are occasionally discovered during routine examinations, especially in the cervical spine. Generally, the calcification process is confined to the nucleus pulposus of the intervertebral disc. CASE REPORT: In this report, we describe the case of a 16-year-old girl who presented with acute low back pain, right S1 radiculopathy and a history of increasing paresthesia. The patient underwent a CT scan, which demonstrated a postero-lateral calcified disc hernia at the L5-S1 level. The surgical decompression of the lumbar nerve root was carried out; at the operation it was observed that the nerve root was "walled" into the calcified hernia. DISCUSSION: Only a few cases with evidence of calcification of the herniated portion of the disc have been previously described. In none of them was the phenomenon was so pronounced that it sealed the nerve root completely.

Biomechanics of the conservative treatment in idiopathic scoliotic curves in surgical "grey-area".

The biomechanical behaviour of the spine significantly varies in relation to the age of the spine. Particularly, the elastic behaviour of the intervertebral discs has been proved to change during the spine growth, which changes the disc reaction to externally imparted forces. The biomechanical analysis of the G modulus of torsion rigidity of the intervertebral disc shows that the G values progressively increase through growth, which favours the progression of early scoliotic curves. At the same time, however, early structural scoliosis is more amenable to conservative treatment owing to the residual growth potential of the spine. Whereas indications to surgical treatment of scoliotic curves has been based upon the magnitude of the curves as measured according to the Cobb method, two additional factors affect the chance of correcting a scoliotic curve, The first is the residual growth potential of the vertebrae. In fact, a longer residual growth allows for external forces to be applied so as to change the growth model of the scoliotic spine, which ensures a stable correction of the deformity when these external forces are removed. The second is the magnitude of the elastic deformation of the intervertebral discs. It has been suggested that a deformation beyond the disc elastic behaviour, by producing hysteresis of the disc, renders the disc less susceptible to transferring the load to the neighbouring vertebral bodies, thus impairing remodelling. It ensues that both the age and the magnitude of rotation affects the success of conservative treatment and not only the magnitude in Cobb degrees. The curve localization adds to these two parameters, thoracic curves being stiffer than thoracolumbar and lumbar curves.

Biomechanical factors affecting progression of structural scoliotic curves of the spine.

The development of the spine is affected by both biological and mechanical factors. As the geometry of the motion segment changes throughout growth, so does the mechanical behaviour of the spine owing to changing vectors acting on a variable geometry system. The biomechanical analysis of the growing spine enables the assessment of the role played by biological and mechanical factors in the pathogenesis of progressive scoliosis to be assessed and its comparison with factors acting on an adult scoliotic spine. The knowledge of these principles is instrumental to setting the right parameters for treatment and to design braces that may be capable of obtaining correction of the deformity. The elastic behaviour of child and adult spine differs because of both physiologic and pathologic conditions. In child scoliosis an abnormal geometry causes a persistent stress concentration in crucial areas of the motion segment. This induces a progressive elasto-plastic strain which modifies the geometry of the motion segment, thus worsening the stress concentration and the excessive strain through a vicious cycle. In adult scoliosis, on the other hand, deformation primarily affects the viscous-elastic structures, namely the intervertebral disc and the capsulo-ligamentous structures. This produces instabilty of the motion segments and slow deformation of the vertebrae through remodelling. It therefore ensues that the aim of the treatment differs in both conditions. In the child spine the aim is to prevent the motion segment deformity by means of braces which adequately modifies the stress distribution acting on the spine, thus enabling the spine to grow according to a quasi-physiological model. In adult scoliosis a stable equilibrium is required in order to prevent further deformation of the motion segment.

Spondylolysis and spondylolisthesis in the pediatric and adolescent population.

This article is a review of spondylolysis and spondylolisthesis in younger age groups. Since Herbinaux first described the pathology (1782), many classifications and theories of etiopathogenesis have been proposed. The congenital and isthmic types, as classified by Wiltse, are the most frequent in younger age groups, but the postsurgical progressive forms (3-5%) have been described as increasing in frequency secondary to neoplastic surgery in children. The general incidence is 4-5% at the age of 6 years, and in 30-50% of cases these types do not progress to spondylolisthesis. Most cases are asymptomatic (80%). Standard radiographic examinations (A-P, L, Oblique) are helpful in diagnosis and can suggest what the prognosis will be in terms of the evolution, and also what treatment is indicated (degree of slippage, slip angle, lumbar and lumbosacral index, SPTI). A bone scan (PBS and SPECT) is useful in the early stages of spondylolysis (pre-spondylosis). Although the CT scan is the most accurate examination, MRI is becoming important for diagnosis because of the frequency with which it is used as a primary investigation method. Depending on patient age, progression, degree of slippage, and symptoms, different therapeutic approaches have been proposed and are described in this paper.

A rare cause of lumbar radiculopathy: spinal gas collection.

The presence of gas in the intervertebral disk space, known as the vacuum phenomenon, is a relatively common radiologic finding, especially on computed tomographic investigation. In a few cases, the gas can be collected into the lumbar spinal canal and can also compress the nerve root. To date only seven cases of symptomatic lumbar radiculopathy caused by a bubble of gas are reported in the literature. The presence of gas inside a narrowed disk and the collection of gas in the spinal canal suggest a communication between the two structures. A case of lumbar radiculopathy caused by a collection of gas in the spinal canal provided the authors the opportunity to study this rare condition by magnetic resonance imaging. Magnetic resonance imaging had not been used before in the referred cases and proved conclusively the discal origin of the gas.

Biomechanics of the spine.

Instability is one of the pathologic conditions of the spine for which surgical treatment is increasingly indicated, even if to-date the definition of instability is controversial. Some aspects of the biomechanics of the spine with particular reference to the viscoelastic characteristics of its elements and the involved loads, are reported. The elasticity of the spine is analyzed with an in-depth consideration of the concept of stability and instability from the biomechanical, clinical and radiographic viewpoint.

Surgical management of instability of the lumbar spine.

The surgical management of clinical spinal instability is for many aspects controversial since the lack of a precise clinical and instrumental definition of instability complicates the implementation of a therapeutic protocol. Both the indications and the surgical procedure are not always well defined. Some of the most common surgical techniques used in the most frequent causes of instability of the lumbar spine: fractures, degenerative disease and spondylolisthesis, are described.

[Guided anti-arrhythmia therapy by programmed ventricular stimulation. A case of arrhythmogenic dysplasia of the right ventricle]. / Terapêutica antiarrítmica guiada por estimulação ventricular programada. Um caso de displasia arritmogénica do ventrículo direito.

Right ventricle dysplasia (RVD) is a rare clinical entity, described in young people, and a known cause of ventricular arrhythmias and sudden death. A genetic transmission has been suggested from the study of familial cases. The disease is characterized by a dilated right ventricle, cardiac infiltration with fatty tissue and focal fibrosis. Lymphoplasmocyte infiltrates are documented. The diagnosis is based on electrocardiography, echocardiography, magnetic resonance imaging and right ventricular endomyocardial biopsy. The authors report a case of a young woman with symptomatic ventricular tachycardia (VT) in whom the diagnosis of RVD was established. Programmed ventricular stimulation was used to reproduce the clinical VT and to test the efficacy of the anti-arrhythmic drug therapy. The diagnosis criteria and therapeutic options are discussed.

[Diagnosis of coronary disease using echocardiography with inotropic dobutamine stimulation]. / Diagnóstico de doença coronária através da ecocardiografia com estimulação inotrópica com dobutamina.

PURPOSE: To evaluate dobutamine echocardiography capacity to diagnose coronary artery disease. STUDY DESIGN: Prospective clinical study. SETTING: Cardiology Department of Hospital Santa Marta. PATIENTS: 32 patients with suspected coronary artery disease, without myocardial infarction, have been studied. METHODS: An intravenous perfusion of dobutamine with gradual doses, from 5 to 40 micrograms/kg/min, and increments of 5 to 10 micrograms/kg/min, in 3 minute stages, except the last stage which lasted only 1 minute with 40 micrograms/kg, was performed. Twelve-lead ECG were registered to detect ST changes and symptoms, namely chest pain. Basal and dobutamine bidimensional echocardiograms, in the end of each stage and during recovery, were registered in video. The segmental analysis was performed considering the left ventricle divided in 16 segments. It was considered positive the occurrence or aggravation of the contractility asynergy of the left ventricle with inotropic stress. All the patients were submitted to coronary arteriography. RESULTS: Due to the bad quality of the echocardiographic images 2 patients were excluded. The stress dobutamine echocardiograms were positive in 14 P and negative in 16 P. The coronary arteriography showed coronary disease in 18 cases and absence of significant lesions in 12 cases. The values for sensitivity, specificity positive predictive value and negative predictive value obtained with dobutamine echocardiography were, 78% and 100% and 75% respectively. In Dobutamine-ECG, 7P had ST segment changes, 2 of them with chest pain values for sensitivity, specificity, positive and negative predictive value with dobutamine-ECG were, 39%, 100% and 52%, respectively. The occurrence of side-effects was observed in 8 P (27%): ventricular tachycardia (2 P-7%), complex ventricular ectopy (4 P-13%), chest pain (2 P-7%), headache (1 P-3%), nausea (1 P-3%) and palpitations (2 P-7%). There was no significant difference in the occurrence of side-effects in the two groups of patients, with and without coronary artery disease (33% vs 17%, respectively; p = ns). The reasons for early discontinuation of dobutamine infusion were: ventricular tachycardia (2 P), complex ventricular ectopy (2 P) and chest pain (1 P). Heart rate, systolic blood pressure and double-product did not differ significantly in patients with and without coronary artery disease. In dobutamine electrocardiography 7 P had ST segment changes, 2 of them with chest pain. CONCLUSION: Dobutamine echocardiography showed in this study elevated values for sensitivity and specificity, however sensitivity can be increased with better technical conditions.

[Acute aortic dissection. Therapeutic strategies and results]. / Dissecção aguda da aorta. Estratégias terapêuticas e resultados.

OBJECTIVE: To analyse early and medium-term results of patients (pts) with acute aortic dissection (DAO) regarding the importance of the different therapeutic modalities adopted. DESIGN: Retrospective study of the cases with DAO admitted in the cardiology intensive care unit of Santa Marta Hospital. POPULATION: 46 pts (aged 25 to 80 years) with the diagnosis of DAO from January/1989 throughout December/1993. RESULTS: early mortality rate (30 days) was 36%. DAO type A Two cases were treated only with medical therapy for they suffer from severe associated pathology. Twenty eight pts were treated surgically. In this group mortality concerning time passed from the beginning of the symptoms throughout the surgery was: < 24 h-31%, 24-72 h-40%, > 72 h-63%. Among 17 discharged pts mortality occurred in 7% during the first year. DAO type B In pts with uncomplicated Stanford type B DAO survival was 90%. Emergency surgery was performed in pts who developed complications such as rupture of the aorta, occlusion of major arteries or extension of dissection. In this particular group mortality was 66%. Among 11 discharged pts with type B DAO 9% died within one year. During the follow-up period of 17.4 +/- 14.8 months one third of the pts discharged from hospital had clinical events. CONCLUSION: despite new advances in diagnostic and therapeutic approaches, DAO still's reported as a relatively high hospital mortality situation. Remove pts to an institution with ability to perform quickly the correct diagnosis and treatment becomes essential. Clinical presentation, type of DAO, surgery timing when indicated and major complications were of particular importance in the prognosis of pts with DAO. The frequency of cardiovascular events in pts who left the hospital alive emphasized the need to maintain blood pressure within normal limits.