This study demonstrates significant differences in mean diffusional kurtosis (DK) between World Health Organization glioma grades II through IV, thereby showing a better separation between the tumor grades by mean DK than by conventional diffusion tensor imaging measurements such as apparent diffusion coefficient and fractional anisotropy. PurposeTo characterize the non-Gaussian diffusion patterns of cerebral glioma microstructure with respect to the different glioma grades by using a new method called diffusional kurtosis (DK) imaging.Materials and MethodsIn this study with institutional review board approval and patient consent, diffusional measures of mean kurtosis (MK), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were compared prospectively. Data were normalized to the contralateral white matter. A Mann-Whitney test was used to compare each histologic glioma subtype regarding the diffusion measurements. Receiver operating characteristic curves were used to test for the parameter with the best sensitivity and specificity for glioma grade discrimination.ResultsIn 34 patients with cerebral gliomas (five World Health Organization [WHO] grade II astrocytomas, 13 WHO grade III astrocytomas, and 16 WHO grade IV glioblastomas multiforme), significantly different diffusion patterns were found among the three glioma group...

Pathogenic autoantibodies targeting the recently identified leucine rich glioma inactivated 1 protein and the subunit 1 of the N-methyl-D-aspartate receptor induce autoimmune encephalitis. A comparison of brain metabolic patterns in 18F-fluoro-2-deoxy-d-glucose positron emission tomography of anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis patients has not been performed yet and shall be helpful in differentiating these two most common forms of autoimmune encephalitis.

Background and Purpose—: Knowledge about cytotoxic edema (CE) in intracerebral hemorrhage is still limited. We aimed to analyze its presence, temporal pattern, and prognostic meaning. Methods—: Twenty-one patients with primary intracerebral hemorrhage underwent magnetic resonance imaging at days 1, 3, and 7 after symptom onset. CE was identified using diffusion-weighted imaging. Hematoma and perihematomal edema volumes were measured on fluid-attenuated inversion recovery images. National Institutes of Health Stroke Scale score was assessed at admission and with each magnetic resonance imaging. Clinical outcome was assessed by modified Rankin scale at 90 days. Results—: CE appeared in half of the patients within the first 24 hours. The apparent diffusion coefficient values decreased until day 3 and were significantly reversed from days 3 through 7 ( P <0.01). Patients with CE showed significantly faster perihematomal edema growth from day 0 to 1 ( P =0.036) than those without. Larger 3-day perihematomal edema volume ( P =0.02) and presence of CE on day 3 ( P =0.07) were associated with poor clinical outcome. Conclusions—: CE is associated with stroke severity, perihematomal edema volume, and poor outcome. It is considered to indicate ongoing neuronal injury and, thus, might emerge as new treatment target.

The 2010 McDonald criteria were developed to allow a more rapid diagnosis of relapsing-remitting multiple sclerosis (MS) by only one MRI of the brain. Although cerebrospinal fluid (CSF) is not a mandatory part of the latest criteria, the evidence of an intrathecal humoral immunoreaction in the form of oligoclonal bands (OCB) is crucial in the diagnostic workup. To date, the impact of the 2010 McDonald criteria on the prevalence of OCB has not been investigated. We retrospectively evaluated data of 325 patients with a clinical relapse suggestive of demyelination that were treated in a German university hospital between 2010 and 2015. One hundred thirty-six patients (42%) were diagnosed with MS and 189 patients with CIS when the criteria of 2010 were applied. The criteria of 2005 allowed only 70 patients (22%) to be designated as MS. In contrast, the prevalence of OCB was marginal affected in MS patients with 96% for the criteria of 2010 and 98.5% for the criteria of 2005. In conclusion, OCB are prevalent in most MS patients and reflect the chronic inflammatory nature of the disease. We recommend CSF examination to exclude alternative diagnoses and reevaluation of the diagnosis MS in patients with negative OCB.

Acute hemorrhagic leukoencephalitis is a fulminant demyelinating disease and commonly considered as a rare and severe variant of acute disseminated encephalomyelitis. Here, we report the clinical, magnetic resonance imaging, and brain biopsy findings of a 35-year-old female with relapsing-remitting multiple sclerosis, who developed acute hemorrhagic leukoencephalitis. Magnetic resonance imaging revealed symmetrical hemorrhagic lesions in the basal ganglia including the thalami. Disease progression was consistent with acute hemorrhagic leukoencephalitis with rapid deterioration of consciousness and seizures. Besides hemorrhage, infiltration of neutrophils was detected in brain biopsy. Acute hemorrhagic leukoencephalitis, also known as Weston-Hurst syndrome, is an excessive immunological response of unknown etiology. So far, an association with multiple sclerosis has not been reported. The present case raises the question, whether acute hemorrhagic leukoencephalitis is a specific hyperacute form of acute disseminated encephalomyelitis, a severe and unspecific form of an immune response in the central nervous system, or belongs to the spectrum of tumefactive multiple sclerosis.

We conducted a two-center retrospective survey on standard MRI features including apparent diffusion coefficient mapping (ADC) of diffuse midline gliomas H3 K27M-mutant (DMG) compared to midline glioblastomas H3 K27M-wildtype (midGBM-H3wt). We identified 39 intracranial DMG and 18 midGBM-H3wt tumors. Samples were microscopically re-evaluated for microvascular proliferations and necrosis. Image analysis focused on location, peritumoral edema, degree of contrast enhancement and DWI features. Within DMG, MRI features between tumors with or without histomorphological GBM features were compared. DMG occurred in 15/39 samples from the thalamus (38%), in 23/39 samples from the brainstem (59%) and in 1/39 tumors involving primarily the cerebellum (2%). Edema was present in 3/39 DMG cases (8%) versus 78% in the control (midGBM-H3wt) group (p < 0.001). Contrast enhancement at the tumor rim was detected in 17/39 DMG (44%) versus 67% in control (p = 0.155), and necrosis in 24/39 (62%) versus 89% in control (p = 0.060). Strong contrast enhancement was observed in 15/39 DMG (38%) versus 56% in control (p = 0.262). Apparent diffusion coefficient (ADC) histogram analysis showed significantly higher skewness and kurtosis values in the DMG group compared to the controls (p = 0.0016/p = 0.002). Minimum relative ADC (rADC) values, as well as the 10th and 25th rADC-percentiles, were lower in DMGs with GBM features within the DMG group (p < 0.001/p = 0.012/p = 0.027). In conclusion, DMG cases exhibited markedly less edema than midGBM-H3wt, even if histomorphological malignancy was present. Histologically malignant DMGs and midGBM-H3wt more often displayed strong enhancement, as well as rim enhancement, than DMGs without histomorphological malignancy. DMGs showed higher skewness and kurtosis values on ADC-histogram analysis compared to midGBM-H3wt. Lower minimum rADC values in DMGs indicated malignant histomorphological features, likely representing a more complex tissue microstructure.