Early identification of cerebral visual impairments in infants born extremely preterm.

AIM: Children born extremely preterm are at risk of visual processing problems related to brain damage. Damage in visual pathways can remain undetected by conventional magnetic resonance imaging (MRI) and functional consequences cannot always be predicted. The aim of this study was to assess the efficacy of processing visual information in infants born extremely preterm at a corrected age of 1 year using a communication-free visual function test based on eye tracking. METHOD: Infants born extremely preterm (<29wks' gestation) without apparent white and grey matter damage on conventional MRI at 30 weeks' postmenstrual age were included (19 males, 1.01y [0.96-1.24] (median [25th-75th centiles]); 11 females, 0.99y [0.98-1.01]). At the corrected age of 1 year, reaction times to fixation (RTF) of specific visual properties displayed on an eye-tracker monitor were quantified and compared with results from a comparison group (eight males, 1.28y [1.01-1.33]; nine females, 1.10y [0.90-1.20]). RESULTS: The infants in the preterm group had longer response times in detecting colour patterns (red-green) and motion compared with infants in the comparison group. No impairments were detected in oculomotor functions (saccades, pursuit, and fixations). INTERPRETATION: The data suggest that delays in processing visual information can be identified in children born extremely preterm. The delays might be ascribed to deficits in neuronal connectivity in visual pathways at a microstructural level.

Data quality in diffusion tensor imaging studies of the preterm brain: a systematic review.

BACKGROUND: To study early neurodevelopment in preterm infants, evaluation of brain maturation and injury is increasingly performed using diffusion tensor imaging, for which the reliability of underlying data is paramount. OBJECTIVE: To review the literature to evaluate acquisition and processing methodology in diffusion tensor imaging studies of preterm infants. MATERIALS AND METHODS: We searched the Embase, Medline, Web of Science and Cochrane databases for relevant papers published between 2003 and 2013. The following keywords were included in our search: prematurity, neuroimaging, brain, and diffusion tensor imaging. RESULTS: We found 74 diffusion tensor imaging studies in preterm infants meeting our inclusion criteria. There was wide variation in acquisition and processing methodology, and we found incomplete reporting of these settings. Nineteen studies (26%) reported the use of neonatal hardware. Data quality assessment was not reported in 13 (18%) studies. Artefacts-correction and data-exclusion was not reported in 33 (45%) and 18 (24%) studies, respectively. Tensor estimation algorithms were reported in 56 (76%) studies but were often suboptimal. CONCLUSION: Diffusion tensor imaging acquisition and processing settings are incompletely described in current literature, vary considerably, and frequently do not meet the highest standards.

Serial cranial ultrasonography or early MRI for detecting preterm brain injury?

OBJECTIVE: To investigate detection ability and feasibility of serial cranial ultrasonography (CUS) and early MRI in preterm brain injury. DESIGN: Prospective cohort study. SETTING: Level III neonatal intensive care unit. PATIENTS: 307 infants, born below 29 weeks of gestation. METHODS: Serial CUS and MRI were performed according to standard clinical protocol. In case of instability, MRI was postponed or cancelled. Brain images were assessed by independent experts and compared between modalities. MAIN OUTCOME MEASURES: Presence of preterm brain injury on either CUS or MRI and discrepant imaging findings on CUS and MRI. RESULTS: Serial CUS was performed in all infants; early MRI was often postponed (n=59) or cancelled (n=126). Injury was found in 146 infants (47.6%). Clinical characteristics differed significantly between groups that were subdivided according to timing of MRI. 61 discrepant imaging findings were found. MRI was superior in identifying cerebellar haemorrhage; CUS in detection of acute intraventricular haemorrhage, perforator stroke and cerebral sinovenous thrombosis. CONCLUSIONS: Advanced serial CUS seems highly effective in diagnosing preterm brain injury, but may miss cerebellar abnormalities. Although MRI does identify these lesions, feasibility is limited. Improved safety, better availability and tailored procedures are essential for MRI to increase its value in clinical care.

Incidental sonographic diagnosis of neonatal carotid occlusion.

UNLABELLED: Cranial ultrasonography including colour Doppler can detect neonatal carotid flow problems at an early stage, even before symptoms occur. Different pathogeneses can be identified. The condition is more frequent than previously reported. If the circle of Willis is fully developed, this can prevent brain injury even in case of total carotid flow obstruction CONCLUSION: Screening of the carotid artery in critically ill neonates may detect complications of treatment at an early stage.

Safety of routine early MRI in preterm infants.

BACKGROUND: Cerebral MRI performed on preterm infants at term-equivalent 30 weeks' gestational age (GA) is increasingly performed as part of standard clinical care. OBJECTIVE: We evaluated safety of these early MRI procedures. MATERIALS AND METHODS: We retrospectively collected data on patient safety of preterm infants who underwent early MRI scans. Data were collected at fixed times before and after the MRI scan. MRI procedures were carried out according to a comprehensive guideline. RESULTS: A total of 52 infants underwent an MRI scan at 30 weeks' GA. Although no serious adverse events occurred and vital parameters remained stable during the procedure, minor adverse events were encountered in 26 infants (50%). The MRI was terminated in three infants (5.8%) because of respiratory instability. Increased respiratory support within 24 h after the MRI was necessary for 12 infants (23.1%) and was significantly associated with GA, birth weight and the mode of respiratory support. Hypothermia (core temperature < 36°C) occurred in nine infants (17.3%). Temperature dropped significantly after the MRI scan. CONCLUSION: Minor adverse events after MRI procedures at 30 weeks GA were common and should not be underestimated. A dedicated and comprehensive guideline for MRI procedures in preterm infants is essential.

Plasma water as a diagnostic tool in the assessment of dehydration in children with acute gastroenteritis.

Acute gastroenteritis is common in childhood. The estimation of the degree of dehydration is essential for management of acute gastroenteritis. Plasma water was assessed as a diagnostic tool in children with acute gastroenteritis and dehydration admitted to hospital. In a prospective cohort study, 101 patients presenting at the emergency department with dehydration were included. Clinical assessment, routine laboratory tests, and plasma water measurement were performed. Plasma water was measured as a percentage of water content using dry weight method. During admission, patients were rehydrated in 12 h. Weight gain at the end of the rehydration period and 2 weeks thereafter was used to determine the percentage of weight loss as a gold standard for the severity of dehydration. Clinical assessment of dehydration was not significantly associated with the percentage of weight loss. Blood urea nitrogen (r = 0.3, p = 0.03), base excess (r =-0.31, p = 0.03), and serum bicarbonate (r = 0.32, p = 0.02) were significantly correlated with the percentage of weight loss. Plasma water did not correlate with the percentage of weight loss. On the basis of the presented data, plasma water should not be used as a diagnostic tool in the assessment of dehydration in children with acute gastroenteritis.