A tract-based spatial statistics study of white matter integrity in Rasmussen's encephalitis

To investigate the alterations in cerebral white matter diffusion tensor metrics in individuals with Rasmussen's encephalitis (RE).

This retrospective study utilized diffusion tensor imaging (DTI) to assess cerebral white matter integrity. We included ten patients diagnosed with RE and ten healthy control subjects, matched for sex, age, and handedness. Employing tract-based spatial statistics (TBSS), we conducted a comprehensive analysis of DTI parameter indices in the cerebral white matter of all participants. The parameters measured included fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD).

Compared to the control group, patients with RE exhibited significantly elevated MD and RD values in several white matter tracts. Specifically, these differences were observed in the anterior thalamic radiation, corticospinal tract, cingulate gyrus, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, uncinate fasciculus, and the temporal part of the superior longitudinal fasciculus within the ipsilesional hemisphere. Additionally, increased MD and AD values were found in the anterior thalamic radiation, cingulate gyrus, inferior fronto-occipital fasciculus, and uncinate fasciculus in the contralateral hemisphere.

Our findings indicate that RE is not confined to the cortical regions of the affected hemisphere. There is evidence of extensive white matter integrity compromise in patients with RE, which could potentially serve as the structural foundation for the emergence of affective disorders, cognitive impairments, and motor dysfunctions.