Efficacy of steroid therapy in the acute stage of anti-NMDAR and anti-MOG antibody overlapping encephalitis: a case report and literature review.

Background: Recently, cases of overlapping encephalitis caused by anti-N-methyl-D-aspartate receptor (anti-NMDAR) and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies have been reported, and their clinical characteristics are gradually becoming clear. Acute-phase treatment typically involves the use of steroids, and although some studies have suggested that steroids can be effective, the extent of their efficacy has not yet been fully explored. Case presentation: We present the case of a 25-year-old man with anti-NMDAR and anti-MOG antibody overlapping encephalitis who showed considerable improvement after steroid treatment. To gain a deeper understanding of the efficacy of steroids in managing this condition, we conducted a literature review of cases of anti-NMDAR and anti-MOG antibody double-positive encephalitis that were treated with steroids during the acute phase. Thirteen cases were analyzed, including a new case diagnosed at our hospital. All patients showed improvement after receiving steroid treatment in the acute phase. Ten patients did not have any sequelae, and nine of them showed a rapid or major response during the acute phase. In contrast, three patients experienced sequelae (mild cognitive decline, visual impairment, and memory impairment, respectively), with their response to steroids in the acute phase being slow or limited. Relapses occurred in five patients, in one patient during steroid tapering, and in another two patients after cessation of steroids. Conclusion: Steroid therapy can be effective in the acute stage of anti-NMDAR and anti-MOG antibody overlapping encephalitis. A positive prognosis may be expected in patients who experience substantial improvement with steroid therapy during the acute phase.

[Symmetrical lesions of the cerebral peduncles and internal capsules on MRI in a patient with extranodal NK/T cell lymphoma].

A 72-year-old man was admitted to our hospital because of subacute progressive consciousness disturbance. FLAIR images showed diffuse high intensity areas in the bilateral thalamus, basal ganglia, and white matter. Chest CT revealed a mass in the right lung. The patient was diagnosed with extranodal natural killer/T cell lymphoma (ENKL) according to the results of a biopsy of the right pulmonary mass. The FLAIR images showed diffuse white matter lesions, without a mass such as lymphomatosis cerebri. On diffusion-weighted images, symmetrical high-intensity lesions of the cerebral peduncle and the internal capsule suggested high-density lymphoma cells around neurons. ENKL of the central nervous system and lung is a very rare neoplasm, and this case showed characteristic images.

Progressive and widespread brain damage in ALS: MRI voxel-based morphometry and diffusion tensor imaging study.

We investigated 17 patients with sporadic amyotrophic lateral sclerosis (ALS) using voxel-based morphometry (VBM) and voxel-based analysis of diffusion tensor images (DTI) at baseline and after a six-month follow-up. Compared with 17 healthy controls, ALS patients at baseline showed only minimal white matter volume decreases in the inferior frontal gyrus but marked decreases in the gray matter of several regions, especially in the bilateral paracentral lobule of the premotor cortex. DTI revealed reduced fractional anisotropy in the bilateral corticospinal tracts, insula, ventrolateral premotor cortex, and parietal cortex. Increased mean diffusivity was noted bilaterally in the motor cortex, ventrolateral premotor cortex, insula, hippocampal formation, and temporal gyrus. At the six-month follow-up, ALS patients showed widespread volume decreases in gray matter, and DTI abnormalities extended mainly into the bilateral frontal lobes, while volume changes in the white matter remained minimal but more distinct. Our combined VBM and DTI techniques revealed extra-corticospinal tract neuronal degeneration mainly in the frontotemporal lobe of ALS patients. In particular, follow-up examinations in these patients showed that whole-brain DTI changes occurred predominantly in the regions of brain atrophy. These objective analyses can be used to assess the disease condition of the ALS brain.

Putaminal magnetic resonance imaging features at various magnetic field strengths in multiple system atrophy.

We delineated the effects of magnetic field strength on signal intensities to facilitate the specific findings of multiple system atrophy (MSA). Fifteen patients with probable MSA were imaged by 0.35T fast spin-echo (FSE), 1.5T FSE, and 3.0T FSE using a consistent protocol, testing all field strengths on the same day. Sixty patients with probable Parkinson's disease (PD) also underwent imaging. Moderate or marked hyperintensity at the dorsolateral outer putaminal margin, hyperintensity of the putaminal body, hypointensity relative to the globus pallidus at the dorsolateral putaminal margin, and infratentorial signal changes were evaluated as specific findings for MSA. As the field strength increased, the occurrence of hyperintensity both at the dorsolateral outer putaminal margin and of the putaminal body decreased, while the occurrence of hypointensity at the dorsolateral putaminal margin increased in MSA. The occurrence of uniform mild hyperintensity of the outer putaminal margin was evident in 7% at 0.35T, 40% at 1.5T, and 47% at 3.0T in MSA and in 5% at 0.35T, 60% at 1.5T, and 75% at 3.0T in PD. However, no PD patients showed hyperintensity at the dorsolateral outer putaminal margin and that of the putaminal body. Putaminal magnetic resonance imaging (MRI) findings in MSA were altered considerably by magnetic field strength. The severity and distribution of signal changes are important for assessing putaminal MRI findings in MSA.