Prediction of Outcome in Children with Congenital Hemiplegia: A Magnetic Resonance Imaging Study

Abstract

The degree of Wallerian degeneration (WD) in the corticospinal tracts seen with magnetic resonance imaging (MRI) was correlated with the distribution and severity of congenital hemiplegia in 20 children aged nine months to nine years. All the children had hemispheric lesions diagnosed with ultrasound in the neonatal period: MRI and clinical assessment were performed from nine months to nine years of age. Hemiplegia was graded as mild, moderate or severe and into predominantly upper or lower limb distribution. WD was assessed by the presence or absence of signal intensity changes in the internal capsule on inversion recovery and spin echo sequences and by the asymmetry of the upper brainstem. The degree of asymmetry was estimated by measuring the cross sectional area (CSA) of the brainstem at three levels and calculating the ratio of the measurements between the side of the lesion and the unaffected side. Infarct size was estimated from the CSA of the infarct at the maximum site of the lesion. Both measurements were correlated with the severity of outcome and the site of involvement. There was a better correlation between severity of outcome and brainstem asymmetry (p = 0.003) than severity of outcome and infarct size (p = 0.02). There was also a significant correlation between upper limb involvement and brainstem asymmetry (p = 0.01). As WD estimated by brainstem asymmetry appears early and is easy to measure, it may be a good marker to estimate later impairment in infants with predominantly unilateral hemispheric haemorrhagic/ischaemic lesions diagnosed in the neonatal period.

Poststroke Cerebral Peduncular Atrophy Correlates with a Measure of Corticospinal Tract Injury in the Cerebral Hemisphere

“…The significant relationship that has been demonstrated to occur between acute ischemic lesion extent and infarction extent later in the first year after stroke onset (rs ϭ 0.68 -0.84) 1,2 suggests that the acute ischemic lesion extent could also reliably predict the amount of subsequent poststroke loss in the remote CST due to wallerian degeneration, at least in the affected cerebral peduncle. Our findings also suggest that the significant relationship between infarction extent in chronic stroke and concurrent motor findings 18,21 may be entirely due to local infarction effects and is not additionally affected by the extent of remote tissue loss.…”

“…The patients in our study were specifically recruited for mildto-moderate chronic hemiparesis and, thus, were likely to have CST injury. [20][21][22][23] We hypothesized that in such patients the hemispheric extent of lesion to the CST would significantly correlate with the extent of cerebral peduncular atrophy and to a greater extent than would the volume of the infarction. Such a finding would suggest that a simple, predictable relationship exists between the amount of postinfarction structural injury at discrete and widely separated portions of the same fiber tract.…”

Activity- and use-dependent plasticity of the developing corticospinal system☆

“…These findings are consistent with the hypothesis that the impaired side is rendered much less competitive in securing and maintaining spinal synaptic space than the normal or less impaired side. Cerebral palsy is a condition in which the child "grows into" the impairment because spastic hemiplegia is not expressed immediately after the perinatal traumatic event (Bouza et al 1994). Eyre and colleagues propose that the damaged side progressively looses capacity to control motor circuits during development (Eyre, 2003).…”

Injury to the Cerebellum in Term Asphyxiated Newborns Treated with Hypothermia

“…14,15,29,31 Transneuronal degeneration has been described as the anterograde and retrograde degeneration of neurons synapsing with neurons injured in the initial lesion, related to a disruption of electrical inputs and outputs. 29,[32][33][34] This process can lead to the disappearance of entire white matter tracts. [32][33][34] The 3 cerebellar peduncles manage the fibers that connect the basal ganglia and widespread cortical areas to the cerebellum.…”

“…29,[32][33][34] This process can lead to the disappearance of entire white matter tracts. [32][33][34] The 3 cerebellar peduncles manage the fibers that connect the basal ganglia and widespread cortical areas to the cerebellum. 35,36 An injury to one of these above-mentioned structures can lead to transneuronal degeneration and programmed cell death through the cerebellar peduncles by way of disruption of these pathways.…”