The corticospinal tract in Sturge–Weber syndrome: A diffusion tensor tractography study

Abstract

OBJECTIVE-To utilize diffusion tensor tractography and evaluate the integrity of the corticospinal tract in children with unilateral Sturge-Weber syndrome (SWS).METHODS-Sixteen children (age: 1.5-12.3 years) with SWS involving one hemisphere and varying degrees of motor deficit, underwent magnetic resonance imaging (MRI) as part of a prospective clinical research study. Diffusion tensor imaging (DTI) was obtained and fiber tracking of the corticospinal tract was performed yielding average FA and ADC values along the pathway. These values were compared between the two hemispheres (affected vs. unaffected) and also correlated with the degree of motor deficits, after correction for age.RESULTS-Cortico-spinal tract FA values on the side of the affected hemisphere were lower (p=0.008) and ADC values were higher (p=0.011) compared to the normal side. Furthermore, FA and ADC values on the side of the angioma did not show the normal age-related variations, which the contralateral corticospinal pathway values did demonstrate. Although none of the patients had severe hemipares, those with moderate motor deficit had increased ADC values, as compared to those with mild (p= 0.009) or no motor deficit (p= 0.045).CONCLUSION-MRI with DTI shows abnormalities of the corticospinal tract in children with SWS even before severe motor impairment develops. Thus, DTI can be a clinically useful method to evaluate the integrity of the corticospinal tract in young children who are at risk for progressive motor dysfunction.

Focal White Matter Abnormalities Related to Neurocognitive Dysfunction: An Objective Diffusion Tensor Imaging Study of Children With Sturge-Weber Syndrome

“…Concordantly, our previous tractography study evaluating the corticospinal tract demonstrated increased MD values in SWS patients with more severe motor deficit (33). Lower N-acetyl-aspartate (NAA) levels in frontal lobe WM as well as GM are also associated with impaired motor function (8).…”

Updates and future horizons on the understanding, diagnosis, and treatment of Sturge–Weber syndrome brain involvement

“…45 Diffusion tensor imaging can provide further information by allowing the study of white matter tract integrity and enabling the detection of early changes in specific cerebral pathways (such as the corticospinal tract) prior to the onset of neurological symptoms. 46 In one case, transient abnormal diffusion was identified concurrent with repeated complex partial seizures. 31 Such diffusion changes may indicate focal brain ischemia and/or seizure-induced abnormalities, typically after prolonged or frequent seizures; since seizure control may result in resolution of seizure-induced MRI abnormalities, serial MRI is important to differentiate peri-ictal diffusion from permanent brain ischemia.…”

Atlasing location, asymmetry and inter-subject variability of white matter tracts in the human brain with MR diffusion tractography

“…number of streamlines, volume, and fractional anisotropy) and a lateralization index calculated (Parker et al, 2005;Powell et al, 2006;Catani et al, 2007;Vernooij et al, 2007;Makris et al, 2008;Matsumoto et al, 2008;Rodrigo et al, 2008;Sivaswamy et al, 2008;Lebel and Beaulieu, 2009) according to the following formula (for example for the number (N.) of streamlines):…”