—COVID-19神経合併症（1）—脳炎と脳症update

Neurological Manifestations of COVID-19: Meningoencephalitis and Encephalopathy

COVID-19では高率に神経症状を呈し，以下の3つの機序で種々の脳炎・脳症を合併する。①SARS-CoV-2は極めて稀に中枢神経系へ直接感染し髄膜脳炎を起こす。②COVID-19に伴う高サイトカイン血症が血管内皮細胞障害，血液脳関門の破綻，微小血管症とそれらによる脳症を起こす。③COVID-19では急性期および感染後に，または神経症状を初発として自己免疫性脳炎を合併する。その他の経過・画像が特徴的な病型として急性壊死性脳症，ADEM，PRES，MERSを合併し得る。

Abstract

Coronavirus disease (COVID-19) causes neurological symptoms in a high percentage of patients and is associated with various types of encephalitides and encephalopathies, which are etiologically classified into (a)direct infection of the central nervous system with severe acute respiratory syndrome coronavirus 2 and resultant meningoencephalitis (this is a rare presentation), (b)COVID-19-induced cytokine storms, which trigger endothelial cell injury, blood-brain barrier disruption, and microangiopathy and consequent encephalopathy and, (c)autoimmune encephalitis secondary to para- or post-infectious mechanisms that play a key role during the acute or post-COVID-19 phase. Notably, some patients present with neurological symptoms as the first manifestation. Radiologically characteristic encephalitides and encephalopathies, such as acute necrotizing encephalopathy, acute disseminated encephalomyelitis, posterior reversible encephalopathy syndrome, and clinically mild encephalitis/encephalopathy with a reversible splenial lesion are also complicated by COVID-19. Further investigations and appropriate treatments are warranted in patients with COVID-19, who develop new neurological symptoms.