RESUMO

We aimed to analyse cardiac autonomic control by assessing the post-exercise heart rate recovery (HRR) and physical fitness in children and adolescents with spina bifida (SB), compared to participants with typical development. A total of 124 participants, 42 with spina bifida (SB group) and 82 typical developmental controls (CO group) performed the arm cranking exercise test with a gas analysis system. HRR was determined at the first (HRR_1) and second (HRR_2) minute at recovery phase. Data are shown as [mean difference (95% CI)]. The SB group showed reduced HR reserve [14.5 (7.1-22.0) bmp, P<0.01], slower HRR_1 [12.4 (7.4-17.5) bpm, P<0.01] and HRR_2 [16.3 (10.6-21.9) bpm; P<0.01], lower VO2peak [VO2peak relative: 7.3 (4.2-10.3) mL·min-1·kg-1, P<0.01; VO2peak absolute: 0.42 (0.30-0.54) L·min-1, P<0.01], and lower O2 pulse [2.5 (1.8-3.2) mL·bpm, P<0.01] and ventilatory responses [13.5 (8.8-18.1) L·min-1, P<0.01] than the CO group. VE/VO2 was not different between groups [-2.82 (-5.77- -0.12); P=0.06], but the VE/VCO2 [-2.59 (-4.40-0.78); P<0.01] and the values of the anaerobic threshold corrected by body mass [-3.2 (-5.8- -0.6) mL·min-1·kg-1, P=0.01] were higher in the SB group than in the CO group. We concluded that children and adolescents with SB have reduced physical fitness and a slower HRR response after maximal effort.

Assuntos

RESUMO

UNLABELLED: Dysraphism is a defect in neural tube development, leading to dysplastic growth of the spinal cord and meninges. Myelomeningocele (MM) is just one of its forms. Hydrocephalus is among the most important alterations in MM and occurs as a consequence of Arnold-Chiari malformation (AC). Experimental models have been developed in sheep, rabbits and rats to study MM physiopathology, allowing a more detailed evaluation of clinical parameters involved in this anomaly. OBJECTIVE: Using the experimental model of dysraphism in fetal rats, the aim of this study was to evaluate the relevance of AC malformations, clinical parameters and grade of histological lesions. MATERIALS AND METHODS: Three groups with 16 fetuses in each were compared, MM, Control and Sham, after intrauterine surgical creation of MM on day 18.5 of gestation (term = 22 days). AC was evaluated by photographic comparison of sagittal cuts of fetal heads. Clinical and histological evaluations were also made. RESULTS: 88% of AC (14/16) in MM fetuses were obtained, besides 100% of clinical alterations. Necrosis and erosion of the spinal cord exposed to amniotic fluid were verified in histology. CONCLUSION: The presence of AC in the dysraphism rat model was high. These results allowed the use of this model to study alterations and intrauterine evolution of MM in a fashion similar to those observed in humans.

Assuntos

RESUMO

OBJECTIVE: The objective of this study was to assess respiratory responses of newborn infants with myelomeningocele through pneumograms and carbon dioxide challenge, and to evaluate the possibility of predicting which patients with myelomeningocele acquired respiratory symptoms related to the Arnold-Chiari deformity and brain-stem dysfunction. METHODS: All surviving infants with spina bifida who were born at the University of Iowa Hospitals and Clinics (UIHC) or were transferred there on the first day of life between January 1987 and January 1991 were assessed with a pneumogram and CO2 challenge once they were medically stable, and were followed for a mean of 30 months (10 to 53 months). RESULTS: Thirty patients met the inclusion criteria for this study; four died before being studied. Of the 26 remaining patients, 12 were born at the UIHC and 14 were transferred to the UIHC on the first day of life. Of the 26 infants studied, 12 (46%) had abnormalities on the pneumogram, including 2 with significant periodic breathing and 10 with episodes of desaturation below 87%. Of the 26 infants studied, 4 had no detectable response to an increasing fraction of CO2 in inspired air on the CO2 challenge and 12 had an increase in exhaled minute ventilation per increase in the alveolar fraction of CO2 in exhaled air more than 2 SD below the mean. Only 10 patients (38.5%) had normal ventilatory responses to the increasing fraction of CO2 in inspired air. On follow-up, only one study patient had symptoms related to Arnold-Chiari deformity and brain-stem dysfunction (bilateral vocal cord paralysis). His neonatal CO2 challenge results and his pneumogram were normal. CONCLUSION: We conclude that these two tests are not useful in predicting which patients will have symptoms related to Arnold-Chiari deformity. Specificity for the pneumogram and the CO2 challenge was 0.52 and 0.36, respectively. Sensitivity was zero for both tests, although this result is limited by the low incidence of symptomatic Arnold-Chiari deformity in this sample. As previous investigators have found, a significant number of patients with meningomyelocele had abnormal ventilatory patterns. These ventilatory abnormalities indicate that even in the absence of severe symptoms, the control of the ventilatory response is somewhat impaired in many patients with meningomyelocele. This alteration in ventilatory control is probably related to abnormalities in the development of the brain stem.

Assuntos

RESUMO

Dentro do espectro de defeitos de fechamento do tubo neural, a mielomeningocele é a principal responsável pelas repercussöes do aparelho locomotor. Säo revisados conceitos fundamentais, métodos diagnóstico, medidas terapêuticas gerais e alguns fatores relacionados com o prognóstico, dentro do campo da ortopedia

Assuntos

Assuntos

Assuntos

Assuntos