Progressive multifocal leukoencephalopathy after liver transplantation can have favorable or unfavorable outcome.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyomavirus (JCPyV) in immunocompromised patients, including solid organ transplant recipients. We report 2 cases of PML late after liver transplantation (144 and 204 months) and review the few other published cases. The clinical course of PML is characterized by a rapid progressive neurological decline coinciding with the presence of white matter lesions on magnetic resonance images. No direct antiviral therapy is available against the JCPyV. The prognosis is therefore extremely poor. Restoration of the immune response achieved by tapering or ending the immunosuppressive therapy is the basis of treatment in transplanted patients. One of our patients is alive 3 years after diagnosis after total withdrawal of immunosuppressive therapy. The other presented severe rejection when tapering immunosuppression and died 26 months after diagnosis.

[Sequential MRI imaging of progressive bilateral rostro-caudal medullary infarction]. / Infarctus bulbaire paramédian bilatéral d'évolution progressive: à propos de deux cas documentés en imagerie par résonance magnétique séquentielle.

Bilateral medial medullary infarction is exceptional. Initial symptoms can be misleading, even for a trained neurologist. We report two patients who presented progressive quadriplegia, anarthia and dysphagia. Sequential MRI showed progressive constitution of the characteristic "heart appearance" sign.

Reliability of longitudinal brain volume loss measurements between 2 sites in patients with multiple sclerosis: comparison of 7 quantification techniques.

BACKGROUND AND PURPOSE: Brain volume loss is currently a MR imaging marker of neurodegeneration in MS. Available quantification algorithms perform either direct (segmentation-based techniques) or indirect (registration-based techniques) measurements. Because there is no reference standard technique, the assessment of their accuracy and reliability remains a difficult goal. Therefore, the purpose of this work was to assess the robustness of 7 different postprocessing algorithms applied to images acquired from different MR imaging systems. MATERIALS AND METHODS: Nine patients with MS were followed longitudinally over 1 year (3 time points) on two 1.5T MR imaging systems. Brain volume change measures were assessed using 7 segmentation algorithms: a segmentation-classification algorithm, FreeSurfer, BBSI, KN-BSI, SIENA, SIENAX, and JI algorithm. RESULTS: Intersite variability showed that segmentation-based techniques and SIENAX provided large and heterogeneous values of brain volume changes. A Bland-Altman analysis showed a mean difference of 1.8%, 0.07%, and 0.79% between the 2 sites, and a wide length agreement interval of 11.66%, 7.92%, and 11.94% for the segmentation-classification algorithm, FreeSurfer, and SIENAX, respectively. In contrast, registration-based algorithms showed better reproducibility, with a low mean difference of 0.45% for BBSI, KN-BSI and JI, and a mean length agreement interval of 1.55%. If SIENA obtained a lower mean difference of 0.12%, its agreement interval of 3.29% was wider. CONCLUSIONS: If brain atrophy estimation remains an open issue, future investigations of the accuracy and reliability of the brain volume quantification algorithms are needed to measure the slow and small brain volume changes occurring in MS.