Diffusion tensor imaging of periventricular leukomalacia shows affected sensory cortex white matter pathways

Abstract

The authors used diffusion-tensor imaging to examine central white matter pathways in two children with spastic quadriplegic cerebral palsy. Corticospinal tracts projecting from cortex to brainstem resembled controls. In contrast, posterior regions of the corpus callosum, internal capsule, and corona radiata were markedly reduced, primarily in white matter fibers connected to sensory cortex. These findings suggest that the motor impairment in periventricular leukomalacia may, in part, reflect disruption of sensory connections outside classic pyramidal motor pathways.

Diffusion Tensor Imaging in Children with Periventricular Leukomalacia: Variability of Injuries to White Matter Tracts

“…In our previous publication, 28 we reported 2 patients with PVL whose corticospinal tracts and fibers penetrating the posterior limb of the internal capsule were relatively well preserved, whereas the posterior thalamic radiation was severely affected. This was an unexpected observation because the fibers in the corticospinal tract and fibers penetrating the posterior limb of the internal capsule, which are related to motor functions, were expected to be one of the most affected tracts, whereas the posterior thalamic radiation, which connects the thalamus and parietal/occipital lobes and is mostly related to sensory function, was believed to be relatively preserved.…”

“…Findings in this study demonstrate the utility of DTI in characterizing injury in specific white matter tracts in children with PVL, a capability beyond that possible on conventional MR imaging. 23,28,29,47 In this study, we used the DT-generated color-coded maps to classify the status of major white matter tracts by using a 3-grade system based on a qualitative visual assessment of each individual white matter tract. The color-coded map, combined with conventional T1-weighted images, allowed detailed assessment of white matter anatomy of the patients.…”

“…[19][20][21] Results have provided further understanding of pathogenesis and treatment in a range of neurologic disorders by providing visualization of specific white matter fiber tracts (see review by Horsfield and Jones 22 ). [23][24][25][26][27] Although injury to the corticospinal tracts is thought to be the major determinant of motor impairment in children with PVL, recent studies have shown that sensory pathways, including the posterior thalamic radiation, may be affected instead or, concurrently, 28 indicative of the complexity of white matter involvement in PVL. 29,30 Criteria for DTI-based identification of various white matter tracts at 26 locations were established and applied to 24 children with CP associated with PVL as well as in a group of 35 unaffected controls to further elucidate the diversity of white matter tract injury involvement in PVL.…”

Relation between neuroradiological findings and upper limb function in hemiplegic cerebral palsy

“…On the other hand, some authors showed by diffusion tensor MRI that apart from corticospinal tract damage, children with a periventricular lesion also had involvement of thalamocortical pathways. 32,33 Interestingly, recent imaging studies suggest that motor and sensory reorganization may be mediated by different forms of neuroplasticity. 30,34 Interhemispheric reorganization differences may account for the different levels of sensory and motor outcomes.…”

Transcranial magnetic stimulation in children

“…Altered cortical maps-Periventricular leukomalacia (PVL) arising from ischemia of the central white matter (especially the motor and sensory fibers of the lower extremities (Hoon et al, 2002;Volpe, 1998)) is not uncommon in prematurely born infants. As children with PVL get older, they may manifest a bilateral, spastic type of cerebral palsy (quadriplegia or diplegia).…”