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Aim: To examine the diagnostic ability of early magnetic resonance imaging (MRI; <36wks postmenstrual age) to detect later adverse motor outcomes or cerebral palsy (CP) in infants born preterm., Method: Studies of infants born preterm with MRI earlier than 36 weeks postmenstrual age and quantitative motor data or a diagnosis of CP at or beyond 1 year corrected age were identified. Study details were extracted and meta-analyses performed where possible. Quality of included studies was evaluated with the QUADAS-2 (a revised tool for the quality assessment of diagnostic accuracy studies)., Results: Thirty-one articles met the inclusion criteria, five of which reported diagnostic accuracy and five reported data sufficient for calculation of diagnostic accuracy. Early structural MRI global scores detected a later diagnosis of CP with a pooled sensitivity of 100% (95% confidence interval [CI] 86-100) and a specificity of 93% (95% CI 59-100). Global structural MRI scores determined adverse motor outcomes with a pooled sensitivity of 89% (95% CI 44-100) and a specificity of 98% (95% CI 90-100). White matter scores determined adverse motor outcomes with a pooled sensitivity of 33% (95% CI 20-48) and a specificity of 83% (95% CI 78-88)., Interpretation: Early structural MRI has reasonable sensitivity and specificity to determine adverse motor outcomes and CP in infants born preterm. Greater reporting of diagnostic accuracy in studies examining relationships with motor outcomes and CP is required to facilitate clinical utility of early MRI., What This Paper Adds: Early magnetic resonance imaging (MRI) has reasonable sensitivity and specificity to determine later adverse motor outcomes and cerebral palsy (CP). Detection of infants who progressed to CP was stronger than motor outcomes. Global MRI scores determined adverse motor outcomes more accurately than white matter scores. Few studies report diagnostic accuracy of early MRI findings. Diagnostic accuracy is required to draw clinically meaningful conclusions from early MRI studies., (© 2017 Mac Keith Press.)

We report on a patient with mirror movements sustained by a mono-hemispheric fast control of bilateral hand muscles and normal hand function. Transcranial magnetic stimulation of the right motor cortex evoked contractions of muscles in both hands while no responses were observed from the left hemisphere. Somatosensory-evoked potentials, functional magnetic resonance, and diffusion tractography showed evidence of sensorimotor dissociation and asymmetry of corticospinal projections, suggestive of reorganization after early unilateral left brain lesion. This is the first evidence that, in certain rare conditions, good hand function is possible with ipsilateral corticospinal reorganization, supporting the role of unexplored mechanisms of motor recovery., (© 2015 Mac Keith Press.)

Aim: The aim of this study was to quantify grey matter changes in children with unilateral cerebral palsy (UCP), differentiating between cortical or deep grey matter (CDGM) lesions, periventricular white matter (PWM) lesions, and unilateral and bilateral lesions., Method: In a cross-sectional study we obtained high resolution structural magnetic resonance images from 72 children (41 males, 31 females, mean age 10y 9mo [SD 3y 1mo], range 5y 1mo-17y 1mo) with UCP (33 left, 39 right hemiplegia; Manual Ability Classification System level I n=29, II n=43; Gross Motor Function Classification System level I n=46, II n=26), and 19 children with typical development (CTD; eight males, 11 females, mean age 11y 2mo [SD 2y 7mo], range 7y 8mo-16y 4mo). Images were classified by lesion type and analyzed using voxel-based morphometry (VBM) and subcortical volumetric analysis., Results: Deep grey matter volumes were not significantly different between children with CDGM and PWM lesions, with the thalamus, putamen, and globus pallidus being reduced unilaterally in both groups compared with CTD (p≤0.001). Children with CDGM lesions additionally showed widespread cortical changes involving all lobes using VBM (p<0.01). Children with bilateral lesions had reduced thalamus and putamen volumes bilaterally (p<0.001). The thalamic volume was reduced bilaterally in children with unilateral lesions (p=0.004)., Interpretation: Lesions to the PWM cause secondary changes to the deep grey matter structures similar to primary changes seen in CDGM lesions. Despite having a unilateral phenotype, grey matter changes are observed bilaterally, even in children with unilateral lesions., (© 2014 Mac Keith Press.)

Aim: Preterm birth is associated with an increased risk of adverse neurodevelopmental outcomes. Diffusion magnetic resonance imaging (dMRI) combined with tractography can be used to assess non-invasively white matter microstructure and brain development in preterm infants. Our aim was to conduct a systematic review of the current evidence obtained from tractography studies of preterm infants in whom MRI was performed up to term-equivalent age., Method: Databases were searched for dMRI tractography studies of preterm infants., Results: Twenty-two studies were assessed. The most frequently assessed tracts included the corticospinal tract, the corpus callosum, and the optic radiations. The superior longitudinal fasciculus, and the anterior and superior thalamic radiations were investigated less frequently. A clear relationship exists between diffusion metrics and postmenstrual age at the time of scanning, although the evidence of an effect of gestational age at birth and white matter injury is conflicting. Sex and laterality may play an important role in the relationship between diffusion metrics, early clinical assessment, and outcomes., Interpretation: Studies involving infants of all gestational ages are required to elucidate the relationship between gestational age and diffusion metrics, and to establish the utility of tractography as a predictive tool. There is a need for more robust acquisition and analysis methods to improve the accuracy of assessing development of white matter pathways., (© 2013 Mac Keith Press.)