The corticospinal tract in Sturge-Weber syndrome: a diffusion tensor tractography study

Area of Science:

• Neuroimaging
• Pediatric Neurology
• Radiology

Background:

• Sturge-Weber syndrome (SWS) is a congenital disorder characterized by a facial birthmark, neurological abnormalities, and often seizures.
• Motor deficits are common in SWS, but the underlying white matter tract integrity, particularly the corticospinal tract, is not fully understood in early stages.
• Early detection of corticospinal tract abnormalities may allow for timely intervention to mitigate motor dysfunction progression.

Purpose of the Study:

• To investigate the integrity of the corticospinal tract (CST) in children diagnosed with unilateral Sturge-Weber syndrome (SWS) using diffusion tensor tractography.
• To correlate diffusion tensor imaging (DTI) metrics of the CST with the degree of motor deficits in affected children.
• To evaluate the potential of DTI as a clinical tool for assessing CST integrity in pediatric SWS.

Main Methods:

• A prospective study included sixteen children (ages 1.5-12.3 years) with unilateral SWS and varying motor deficits.
• Magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI) was performed to acquire data for fiber tracking of the corticospinal tract.
• Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for the CST, comparing affected and unaffected hemispheres and correlating with motor deficit severity, adjusted for age.

Main Results:

• Lower fractional anisotropy (FA) and higher apparent diffusion coefficient (ADC) values were observed in the corticospinal tract of the affected hemisphere compared to the unaffected side (p=0.008 and p=0.011, respectively).
• The corticospinal tract on the SWS-affected side exhibited atypical age-related variations in FA and ADC values, unlike the contralateral pathway.
• Increased ADC values in the CST were associated with moderate motor deficits, compared to mild or no motor deficits (p=0.009 and p=0.045).

Conclusions:

• Diffusion tensor imaging (DTI) effectively detects corticospinal tract abnormalities in children with Sturge-Weber syndrome (SWS), even in the absence of severe motor impairment.
• DTI demonstrates potential as a valuable clinical tool for evaluating corticospinal tract integrity in young children with SWS who are susceptible to progressive motor dysfunction.
• These findings suggest that DTI can aid in the early identification of neurological involvement and guide management strategies for motor deficits in pediatric SWS.