Acute necrotizing encephalopathy with SARS-CoV-2 RNA confirmed in cerebrospinal fluid.

Here, we report a case of COVID-19-related acute necrotizing encephalopathy where SARS-CoV-2 RNA was found in CSF 19 days after symptom onset after testing negative twice. Although monocytes and protein levels in CSF were only marginally increased, and our patient never experienced a hyperinflammatory state, her neurologic function deteriorated into coma. MRI of the brain showed pathologic signal symmetrically in central thalami, subinsular regions, medial temporal lobes, and brain stem. Extremely high concentrations of the neuronal injury markers neurofilament light and tau, as well as an astrocytic activation marker, glial fibrillary acidic protein, were measured in CSF. Neuronal rescue proteins and other pathways were elevated in the in-depth proteomics analysis. The patient received IV immunoglobulins and plasma exchange. Her neurologic status improved, and she was extubated 4 weeks after symptom onset. This case report highlights the neurotropism of SARS-CoV-2 in selected patients and emphasizes the importance of repeated lumbar punctures and CSF analyses in patients with suspected COVID-19 and neurologic symptoms.

Acute Hemorrhagic Leukoencephalopathy: Pathological Features and Cerebrospinal Fluid Cytokine Profiles.

BACKGROUND: Acute hemorrhagic leukoencephalopathy is a rare encephalopathy of unknown etiology, causing fulminant, hemorrhagic central nervous system demyelination with high mortality. It is unclear whether acute hemorrhagic leukoencephalopathy is an entirely distinct entity from acute disseminated encephalomyelitis. PATIENTS AND METHODS: We report two patients with rapidly progressive neurological illness resulting in raised intracranial pressure and coma, with biopsy-proven acute hemorrhagic leukoencephalopathy (perivascular hemorrhages and demyelination, predominantly neutrophil infiltrates). RESULTS: Acute cerebrospinal fluid showed pronounced T cell-associated cytokine elevation (interleukins 6, 8, and 17A) and CCL2 or CCL3, higher than in patients with acute disseminated encephalomyelitis, but no B cell-associated cytokine elevation. CONCLUSION: Improved understanding of the immune process may provide rationale for use of anticytokine biologic agents.

Impaired expression of excitatory amino acid transporter 2 (EAAT2) and glutamate homeostasis in canine necrotizing meningoencephalitis.

To clarify the involvement of excitatory and inhibitory amino acids in canine necrotizing meningoencephalitis (NME), glutamate, aspartate, taurine and gamma-aminobutylic acid (GABA) were determined in the cerebrospinal fluids (CSF) from eight NME cases and ten healthy controls. NME dogs exhibited significantly higher concentrations of glutamate and aspartate than those in controls (p<0.001 and p<0.001, respectively), while there was no difference in taurine or GABA between the two groups. When fetal canine astrocytes were cultured for 24 hr in the presence of NME-CSF, supernatant concentrations of glutamate, aspartate and taurine were significantly elevated. Simultaneously, expression of excitatory amino acid transporter 2 (EAAT2) mRNA was significantly reduced in the astrocytes without change in EAAT1 mRNA. Hence, reduced expression of EAAT2 and impaired glutamate homeostasis may contribute to the pathogenesis of NME.