title: Diffusion tensor imaging in a child with hypertrophic olivary degeneration.
abstract: Hypertrophic olivary degeneration (HOD) is caused by disruptive lesions affecting components of the Guillain-Mollaret triangle (GMT). We present conventional magnetic resonance and diffusion tensor imaging (DTI) findings in a 6-year-old girl with HOD after surgery for a midbrain pilocytic astrocytoma. To our knowledge, this is the first dedicated DTI analysis of GMT in a child with HOD in the literature. In our patient, we found higher fractional anisotropy (FA) and axial diffusivity values of the inferior olivary nucleus (ION) and lower FA, but higher radial diffusivity (RD) values of all other GMT components compared to age-matched controls. Increased FA values of the ION may be explained by increased packing of white matter fibers. However, associated hyperintense T2 signal is contradictory and the association between increased FA values and hyperintense T2 signal remains unclear. Low FA and high RD values of the other GMT components likely reflect demyelination with axonal degeneration and correlate well with histopathological findings.
authors: Division of Pediatric Radiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-0842, USA.
authors: Avner
authors: A
authors: Meoded
authors: Andrea
authors: A
authors: Poretti
authors: A Turan
authors: AT
authors: Ilica
authors: Randall
authors: R
authors: Perez
authors: George
authors: G
authors: Jallo
authors: Peter C
authors: PC
authors: Burger
authors: Thierry A G M
authors: TA
authors: Huisman
authors: Izlem
authors: I
authors: Izbudak
mesh_terms: D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000175:diagnosis / Q000378:metabolism; D009410:Nerve Degeneration / Q000378:metabolism* / Q000473:pathology*; D009847:Olivary Nucleus / Q000378:metabolism* / Q000473:pathology*