Browsing by Author "Kozic, D. (6602538657)"

There is an increase in the number of patients with systemic lupus erythematosus (SLE) reported as developing progressive multifocal leukoencephalopathy (PML) while on intensive immunosuppressive therapy. A 39-year-old HIV-negative woman with a 10-year history of SLE presented with progressive left-side weakness while on maintenance therapy with oral prednisone and mycophenolate mofetil (MMF). On several occasions low CD4+ T-lymphocyte counts were found (68/μL). Brain magnetic resonance imaging (MRI) revealed a large lesion in the right subcortical fronto-parietal region and a smaller one in the left frontal subcortex, corresponding to the PML. In cerebrospinal fluid, polymerase chain reaction (PCR) for JC virus (JCV) was negative, but anti-JCV antibodies were highly positive. Diagnosis of probable PML was made and MMF was withdrawn. The patient's condition improved with marked reduction of left-side weakness and an increase in CD4+ T-lymphocyte count (141/μL). Follow-up MRI showed regression of lesions and over the next 6 months the patient remained stable. In spite of the grave prognosis associated with PML, SLE patients can have an excellent outcome if immunosuppressants are discontinued as soon as the correct diagnosis is made. SLE patients with associated low CD4+ T-lymphocyte counts should be monitored for the development of PML during immunosuppressive therapy in particular. © The Author(s), 2011.

Aim: The aim of this study was to determine the bilateral distribution of proton metabolites along the long axis of the hippocampus. Materials and methods: Forty-one healthy volunteers were examined using a 1.5 T magnetic resonance imaging system, using proton three-dimensional spectroscopic imaging (3D CSI) of the left and the right hippocampus separately. Three dominant signals were measured: choline (Cho), total creatine (tCr), and n-acetylaspartate (NAA) and expressed as ratios of Cho:tCr, NAA:tCr, NAA:Cho and NAA:(Cho+tCr). We compared the data from three hippocampal regions: head, body and tail. Results: Lower NAA:tCr ratios were found in head compared with the body (p<0.05) and in the head compared with the tail (p<0.05) bilaterally. Lower NAA:Cho and NAA:(Cho+tCr) ratios were found in the head compared with the body (p<0.05), in the body compared with the tail (p<0.05), and in the head compared with the tail (p<0.05) bilaterally. There was no statistically significant difference between the left and the right hippocampus. Conclusion: Ratios of NAA:tCr, NAA:Cho, and NAA:(Cho+tCr) in hippocampal tissue were significantly higher posteriorly than anteriorly. As the differences are present in healthy volunteers, the appearance in patients related to approximate voxel positioning within hippocampi may result in false-positive results. © 2010 The Royal College of Radiologists.