COVID-19 and the Brain: The Neuropathological Italian Experience on 33 Adult Autopsies

Abstract

Neurological symptoms are increasingly recognized in SARS-CoV-2 infected individuals. However, the neuropathogenesis remains unclear and it is not possible to define a specific damage pattern due to brain virus infection. In the present study, 33 cases of brain autopsies performed during the first (February–April 2020) and the second/third (November 2020–April 2021) pandemic waves are described. In all the cases, SARS-CoV-2 RNA was searched. Pathological findings are described and compared with those presently published.

What Can We Still Learn from Brain Autopsies in COVID-19?

“…One report from Italy identified microthrombi with acute or subacute ischemic damage in a greater proportion of cases in the first wave from February to April 2020 compared with the combined second and third waves from November 2020 to April 2021, with leptomeningeal chronic inflammation most commonly identified in the third wave. 15 Fewer cerebral microhemorrhages were noted in autopsies from Switzerland in the second wave from October 2020 to April 2021 compared with the first wave from March to May 2020. 44 The SARS-CoV-2 B.1.1.7 (Alpha) variant was detected at similar viral loads to prior variants in a German case series.…”

“…Several large studies in the United States, [3][4][5][6][7][8][9] Europe, [10][11][12][13][14][15][16][17][18][19] Russia, 20 Turkey, 21 Zambia, 22 Ghana, 23 and Brazil 24 have identified cerebrovascular pathology and microglialpredominant inflammation as the primary COVID-19-associated findings. His topathological features variably include acute to subacute infarcts and hypoxic-ischemic injury, microthrombi, acute hemorrhages or microhemorrhages, occasional microglial nodules, and sparse lymphocytic perivascular inflammation (►Fig.…”

“…Overt cerebrovascular events that contributed to death from COVID-19 and have been described in adult brain autopsy studies typically occurred in patients with preexisting vascular conditions or patients vulnerable to vascular insult (advanced age, obesity, hypertension, atrial fibrillation). 6,8,9,15,58,83 Early autopsy studies reported the presence of SARS-CoV-2 spike protein or RNA in the endothelial cells of cerebral blood vessels of COVID-19 decedents. 6,17 More subtle forms of endothelial disruption and microvascular damage were identified in ex vivo imaging and autopsy studies, including evidence of perivascular leakage of fibrinogen and immunoglobulin G. 8,9,58 In studies using CD-1 mice, spike 1 protein had the capacity to cross the BBB through absorptive transcytosis following an inflammatory state induced by lipopolysaccharide injection.…”

Manifestaciones neurológicas en pacientes con diagnóstico de COVID-19

“…Sin embargo, los casos se pueden acompañar de una sola manifestación o de las dos al momento de la evaluación. Además se debe mencionar que la evaluación gustativa y olfatoria generalmente no es valorada, lo cual (26,35) podría subestimar la incidencia de dichas manifestaciones . La anosmia y la ageusia son comunes incluso en casos leves a moderados, Mao y colaboradores analizaron las manifestaciones neurológica de 214 pacientes con infección de SARS CoV2 de los cuales el 5,6% presentaron ageusia y el 5,1% (23) anosmia .…”

“…La enfermedad cerebrovascular, tanto en sus dos formas isquémica y hemorrágica, son manifestaciones relacionadas al coronavirus. Los pacientes con mayor susceptibilidad a estas complicaciones, son aquellos con enfermedades crónicas o comorbilidades como la hipertensión arterial, la diabetes mellitus y las enfermedades cardiovasculares compartiendo estos factores de (35) riesgo con COVID-19 .Hay una fuerte evidencia que la gravedad de la infección por está directamente relacionada con la presencia de comorbilidades cardiovasculares y así una mayor probabilidad de tener (28) algún tipo de complicación encefálica .…”