RESUMO
Preterm birth represents a high risk of neurodevelopmental disabilities when associated with white-matter damage. Recent studies have reported cognitive deficits in children born preterm without brain injury on MRI at term-equivalent age. Understanding the microstructural and metabolic underpinnings of these deficits is essential for their early detection. Here, we used diffusion-weighted imaging and single-voxel 1H magnetic resonance spectroscopy (MRS) to compare brain maturation at term-equivalent age in premature neonates with no evidence of white matter injury on conventional MRI except diffuse excessive high-signal intensity, and normal term neonates. Thirty-two infants, 16 term neonates (mean post-conceptional age at scan: 39.8±1 weeks) and 16 premature neonates (mean gestational age at birth: 29.1±2 weeks, mean post-conceptional age at scan: 39.2±1 weeks) were investigated. The MRI/MRS protocol performed at 1.5T involved diffusion-weighted MRI and localized 1H-MRS with the Point RESolved Spectroscopy (PRESS) sequence. Preterm neonates showed significantly higher ADC values in the temporal white matter (P<0.05), the occipital white matter (P<0.005) and the thalamus (P<0.05). The proton spectrum of the centrum semiovale was characterized by significantly lower taurine/H2O and macromolecules/H2O ratios (P<0.05) at a TE of 30 ms, and reduced (creatine+phosphocreatine)/H2O and (glutamine+glutamate)/H2O ratios (P<0.05) at a TE of 135 ms in the preterm neonates than in full-term neonates. Our findings indicate that premature neonates with normal conventional MRI present a delay in brain maturation affecting the white matter and the thalamus. Their brain metabolic profile is characterized by lower levels of creatine, glutamine plus glutamate, and macromolecules in the centrum semiovale, a finding suggesting altered energy metabolism and protein synthesis.
Assuntos
Disfunção Cognitiva/metabolismo , Recém-Nascido Prematuro , Lobo Occipital/metabolismo , Lobo Temporal/metabolismo , Tálamo/metabolismo , Substância Branca/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , Creatina/metabolismo , Imagem de Difusão por Ressonância Magnética , Feminino , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Lactente , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Masculino , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/fisiopatologia , Espectroscopia de Prótons por Ressonância Magnética , Estudos Retrospectivos , Taurina/metabolismo , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Nascimento a Termo , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia , Substância Branca/diagnóstico por imagem , Substância Branca/fisiopatologiaRESUMO
BACKGROUND: Ultrasonography is a well-established efficient diagnostic tool for ileocolic intussusceptions in children. It can also be used to control hydrostatic reduction by saline enemas. This reduction method presents the advantage of avoiding radiations. Parents can even stay with their children during the procedure, which is comforting for both. The purpose of this study was to present our 20 years' experience in intussusception reductions using saline enema under ultrasound control and to assess its efficiency and safety. MATERIAL AND METHODS: This retrospective single center study included patients with ileocolic intussusceptions diagnosed by ultrasound between June 1993 and July 2013. We excluded the data of patients with spontaneous reduction or who underwent primary surgery because of contraindications to hydrostatic reduction (peritonitis, medium or huge abdominal effusion, ischemia on Doppler, bowel perforation). A saline enema was infused into the colon until the reduction was sonographically confirmed. The procedure was repeated if not efficient. Light sedation was practiced in some children. RESULTS: Eighty-tree percent of the reductions were successful with a median of 1 attempt. Reduction success decreased with the number of attempts but was still by 16% after 4 attempts. The early recurrence rates were 14.5%, and 61.2% of those had a successful second complete reduction. Forty-six patients needed surgery (11 of them had a secondary intussusception). Sedation multiplies success by 10. In this period, only one complication is described. CONCLUSION: Ultrasound guided intussusception reduction by saline enema is an efficient and safe procedure. It prevents exposure of a young child to a significant amount of radiation, with similar success rate. We had very low complication rate (1/270 cases or 3). The success rate could be increased by standardized procedures including: systematic sedation, trained radiologists, accurate pressure measurement, and number and duration of attempts.