RT Journal Article
SR Electronic
T1 Infratentorial MRI Findings in Rasmussen Encephalitis Suggest Primary Cerebellar Involvement
JF Neurology - Neuroimmunology Neuroinflammation
JO Neurol Neuroimmunol Neuroinflamm
FD Lippincott Williams & Wilkins
SP e1058
DO 10.1212/NXI.0000000000001058
VO 8
IS 6
A1 Johannes T. Reiter
A1 Bastian David
A1 Selma Enders
A1 Conrad C. Prillwitz
A1 Tobias Bauer
A1 Deniz Atalay
A1 Anna Tietze
A1 Angela M. Kaindl
A1 Vera Keil
A1 Alexander Radbruch
A1 Bernd Weber
A1 Albert J. Becker
A1 Christian E. Elger
A1 Rainer Surges
A1 Theodor Rüber
YR 2021
UL http://nn.neurology.org/content/8/6/e1058.abstract
AB Background and Objective Rasmussen encephalitis (RE) is characterized by its unilateral cerebral involvement. However, both ipsi- and contralesional cerebellar atrophy have been anecdotally reported raising questions about the nature and extent of infratentorial findings. Using MRI, we morphometrically investigated the cerebellum and hypothesized abnormalities beyond the effects of secondary atrophy, implicating a primary involvement of the cerebellum by RE.Methods Voxel-based morphometry of the cerebellum and brainstem was conducted in 57 patients with RE and in 57 matched controls. Furthermore, patient-specific asymmetry indices (AIs) of cerebellar morphometry and fluid-attenuated inversion recovery (FLAIR) intensity were calculated. Using diffusion tensor imaging, the integrity of the cortico-ponto-cerebellar (CPC) tract was assessed. Finally, a spatial independent component analysis (ICA) was used to compare atrophy patterns between groups.Results Patients with RE showed bilateral cerebellar and predominantly ipsilesional mesencephalic atrophy (p < 0.01). Morphometric AIs revealed ipsilesional < contralesional asymmetry in 27 and ipsilesional > contralesional asymmetry in 30 patients. In patients with predominant ipsilesional atrophy, morphometric AIs strongly correlated with FLAIR intensity AIs (r = 0.86, p < 0.0001). Fractional anisotropy was lower for ipsilesional-to-contralesional CPC tracts than opposite tracts (T = 2.30, p < 0.05). ICA revealed bilateral and strictly ipsi- and contralesional atrophy components in patients with RE (p < 0.05).Discussion We demonstrated atrophy of the ipsilesional-to-contralesional CPC pathway and, consequently, interpret the loss of contralesional gray matter as secondary crossed cerebellar atrophy. The ipsilesional cerebellar atrophy, however, defies this explanation. Based on FLAIR hyperintensities, we interpret ipsilesional atrophy to be due to inflammation in the scope of a primary involvement of the cerebellum by RE.AI=asymmetry index; CON=controls; CPC=cortico-ponto-cerebellar; DTI=diffusion tensor imaging; FA=fractional anisotropy; FDR=false discovery rate; FLAIR=fluid-attenuated inversion recovery; FOD=fiber orientation distribution; FSL=FMRIB Software Library 6.0; FWE=family-wise error; GM=gray matter; ICA=independent component analysis; RE=Rasmussen encephalitis; SUIT=spatially unbiased infratentorial atlas template; VBM=voxel-based morphometry; WM=white matter