Faculty Bibliography

Coronavirus disease 2019 (COVID-19) has been reported in association with a variety of brain imaging findings such as ischemic infarct, hemorrhage, and acute hemorrhagic necrotizing encephalopathy. Here, we report brain imaging features in 11 critically ill COVID-19 patients with persistently depressed mental status who underwent MRI between April 5-25, 2020 at our institution. These features include, 1) Confluent T2 hyperintensity and mild restricted diffusion in bilateral supratentorial deep and subcortical white matter (in 10 of 11 patients), and 2) multiple punctate microhemorrhages in juxtacortical and callosal white matter (in 7 of 11 patients). We also discuss potential pathogeneses.

Spinal dural fistulas (SDAVFs) occasionally arise from the same segmental artery as the radiculomedullary branch to the anterior spinal artery. In such cases, selective fistula embolization that does not endanger the anterior spinal artery is not possible, and surgical fistula disconnection is recommended. We present an exceptional case in which rational embolization strategy of SDAVF was feasible because of separate origins from a common segmental artery pedicle of the ventral radiculomedullary artery and the dorsal radicular artery branch supplying the fistula.

BACKGROUND: There is substantial overlap between MRI of acute spinal cord lesions from neuromyelitis optica (NMO) and spinal cord infarct (SCI) in clinical practice. However, early differentiation is important since management approaches to minimize morbidity from NMO or SCI differ significantly. OBJECTIVE: To identify MRI features at initial presentation that may help to differentiate NMO acute myelitis from SCI. METHODS: 2 board-certified neuroradiologists, blinded to final diagnosis, retrospectively characterized MRI features at symptom onset for subjects with serologically-proven NMO (N=13) or SCI (N=11) from a single institution. Univariate and multivariate analyses were used to identify factors associated with NMO or SCI. RESULTS: SCI was more common in men and Caucasians, while NMO was more common in non-Caucasian women (P<0.05). MRI features associated with NMO acute myelitis (P<0.05) included location within 7-cm of cervicomedullary junction; lesion extending to pial surface; 'bright spotty lesions' on axial T2 MRI; and gadolinium enhancement. Patient's age, lesion length and cross-sectional area, cord expansion, and the "owl's eyes" sign did not differ between the two groups (P>0.05). CONCLUSION: Along with patient demographic characteristics, lesion features on MRI, including lesion location, extension to pial border and presence of 'bright spotty lesion' can help differentiate acute myelitis of NMO from SCI in the acute setting.

Objective. To compare periventricular lesions in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOsd). Materials and Methods. Sagittal and axial fluid attenuated inversion recovery (FLAIR) sequences of 20 NMOsd and 40 group frequency-matched MS patients were evaluated by two neuroradiologists. On axial FLAIR, periventricular area was characterized as free of lesions/smooth-bordered ("type A") or jagged-bordered ("type B") pattern. On sagittal FLAIR, the images were evaluated for presence of "Dawson's fingers." Results. Type A pattern was observed in 80% of NMOsd patients by Reader 1 and 85% by Reader 2 but only in 5% MS patients by either Reader. Type B was seen in 15% NMOsd patients by Reader 1 and 20% by Reader 2 and in 95% MS patients by either Reader. Dawson's fingers were observed in no NMOsd patients by Reader 1 and 5% by Reader 2. In MS, Dawson's fingers were seen in 92.5% patients by Reader 1 and 77.5% by Reader 2. The differences in periventricular patterns and Dawson's finger detection between NMOsd and MS were highly significant (P < 0.001). Conclusions. Dawson's fingers and "jagged-bordered" periventricular hyperintensities are typical of MS and almost never seen in NMOsd, which suggests a practical method for differentiating the two diseases.

AQP4 water channels are thought to be the target of autoimmune attack in neuromyelitis optica-spectrum disorders (NMOsd). AQP4 are highly expressed on ventricular ependyma. The objective of this study was to describe a novel pattern of linear, 'pencil-thin' enhancement of ventricular ependyma in NMOsd. We report two NMOsd patients with pencil-thin ependymal enhancement along the frontal and occipital horns of lateral ventricles. Differential diagnosis of ependymal enhancement should include NMOsd alongside with infectious and neoplastic etiologies. Pencil-thin ependymal enhancement may be a helpful radiological marker of NMOsd that can be used to differentiate this condition from multiple sclerosis.