Serial cranial MR imaging and single voxel proton MR spectroscopy in paraneoplastic limbic encephalitis

Abstract

We report the serial cranial MR imaging (MRI) and single voxel proton magnetic resonance spectroscopy ( 1 H -MRS) findings of the brain, at 3 and 11 weeks after the onset of symptoms in a patient with paraneoplastic limbic encephalitis (PLE) in association with anti-Hu antibodies. There was a suspiciously detectable hyperintensity in temporal lobes on initial MRI and increased myoinositol (mI) and minimally decreased N-acetylaspartate (NAA) levels were seen in 1 H -MRS from the right superior temporal neocortex. Follow-up cranial MRIs showed more striking hyperintensity in bilateral medial temporal regions on T2-weighted images. Repeat single voxel 1 H -MRS from the bilateral medial temporal region showed the lactate peak, prominent NAA decrease, both choline and mI increase. These findings provided suggestive evidence in vivo for neuronal loss and gliosis, even there may be inflammatory cell infiltration in the PLE brain. To our knowledge, this is the first description of single voxel 1 H -MRS findings associated with PLE.