Retrospective Observational Study of Brain MRI Findings in Patients with Acute SARS-CoV-2 Infection and Neurologic Manifestations

Abstract

Background This study provides a detailed imaging assessment in a large series of patients infected with coronavirus disease 2019 (COVID-19) and presenting with neurologic manifestations. Purpose To review the MRI findings associated with acute neurologic manifestations in patients with COVID-19. Materials and Methods This was a cross-sectional study conducted between March 23 and May 7, 2020, at the Pitié-Salpêtrière Hospital, a reference center for COVID-19 in the Paris area. Adult patients were included if they had a diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with acute neurologic manifestations and referral for brain MRI. Patients with a prior history of neurologic disease were excluded. The characteristics and frequency of different MRI features were investigated. The findings were analyzed separately in patients in intensive care units (ICUs) and other departments (non-ICU). Results During the inclusion period, 1176 patients suspected of having COVID-19 were hospitalized. Of 308 patients with acute neurologic symptoms, 73 met the inclusion criteria and were included (23.7%): thirty-five patients were in the ICU (47.9%) and 38 were not (52.1%). The mean age was 58.5 years ± 15.6 [standard deviation], with a male predominance (65.8% vs 34.2%). Forty-three patients had abnormal MRI findings 2-4 weeks after symptom onset (58.9%), including 17 with acute ischemic infarct (23.3%), one with a deep venous thrombosis (1.4%), eight with multiple microhemorrhages (11.3%), 22 with perfusion abnormalities (47.7%), and three with restricted diffusion foci within the corpus callosum consistent with cytotoxic lesions of the corpus callosum (4.1%). Multifocal white matter-enhancing lesions were seen in four patients in the ICU (5%). Basal ganglia abnormalities were seen in four other patients (5%). Cerebrospinal fluid analyses were negative for SARS-CoV-2 in all patients tested (n = 39). Conclusion In addition to cerebrovascular lesions, perfusion abnormalities, cytotoxic lesions of the corpus callosum, and intensive care unit-related complications, we identified two patterns including white matter-enhancing lesions and basal ganglia abnormalities that could be related to severe acute respiratory syndrome coronavirus 2 infection. © RSNA, 2020 Online supplemental material is available for this article.

Figure 1:

Flowchart of patient inclusion. Abbreviations: CNS: central nervous system; COVID-19: coronavirus disease 2019; CSF: cerebrospinal fluid; CT: computed tomography; ICU: intensive care unit; RT-PCR: reverse-transcriptase–polymerase-chain-reaction.

Figure 2:

Microhemorrhages. Diffuse microhemorrhages involving the corpus callosum in two patients in intensive care on extracorporeal membrane oxygenation (EMCO, A, arrows) and without ECMO (B, arrows) Abbreviations: ECMO: extracorporeal membrane oxygenation.

Figure 3:

White matter enhancing lesions. A 37-year-old obese male with no medical history, admitted to ICU for SARS-CoV-2-associated pneumonia ten days after the onset of flu-like symptoms, who developed severe acute respiratory syndrome, recurrent venous thrombo-embolism with negative thrombophilia tests, and multiple organ failure. MRI is performed for late awakening following withdrawal of sedation after 38 days of intensive care. The patient did not recover consciousness and died 42 days after the brain MRI. There were symmetrical multifocal periventricular and deep white matter lesions, hyperintense on axial FLAIR images with a vacuolated appearance (A, arrows), without diffusion restriction (B, arrows), hypointense on T1-weighted images (C, arrows), and with a perivascular enhancement on post-contrast T1-weighted images (D E, F, arrows). These lesions were associated with white matter FLAIR hyperintensities (A, arrowhead) with decreased apparent coefficient diffusion (B, arrowhead). Abbreviations: SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.

Figure 4:

White matter enhancing lesions. A 50-year-old man with a history of kidney transplantation (A-D) and a 50-year-old ICU man with type 2 diabetes (E-H), who presented with late awakening following sedation withdrawal after 39 and 65 days of intensive care for severe hypoxic SARS-CoV-2-associated pneumonia complicated with severe acute respiratory syndrome, respectively. Both patients progressively recovered consciousness and were able to respond to orders. A similar imaging pattern than that in Figure 4 was seen, but with fewer white matter lesions appearing hyperintense on FLAIR images (A, E, arrows) and diffusion-weighted images (B, F, arrows), without apparent diffusion coefficient decrease (C, G, arrows), with a perivascular enhancement on post-contrast T1-weighted images (D, H, arrows). Abbreviation: SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.

Figure 5:

Basal ganglia abnormalities. Basal ganglia abnormalities in three patients who experienced late awakening after sedation withdrawal in a context of SARS-CoV-2 hypoxic pneumonia with severe acute respiratory syndrome: 1) A 42-year-old male with untreated chronic lymphocytic leukemia who had tetraparesis upon awakening after 47 days of intensive care (A-C). Hyperintensity on DWI within the substantia nigra (A, arrows) with decreased apparent diffusion coefficient (B, arrows) and hyperintensity on axial FLAIR images (C, arrows) were seen. The follow-up neurological examination showed complete consciousness recovery with persistent peripheral motor deficit consistent and mild parkinsonian symptoms. 2) A 62-year-old diabetic female with chronic cardiovascular disease, who suffered cardiorespiratory arrest after 54 days of intensive care (D-F). Hyperintensity on pre-contrast MPRAGE axial T1-weighted images in the globus pallidus (D, arrows), with no enhancement on post-contrast T1-weighted images (E, arrows) or hypointensity on susceptibility-weighted images (F, arrows). The follow-up neurological examination also showed complete consciousness recovery with a persistent motor deficit. 3) A 56-year-old diabetic and obese female who experienced late awakening after 48 days of intensive care (G-I). Bilateral enhancement within the globus pallidus on coronal post-contrast T1-weighted images (G, arrows), with hyperintensity on diffusion-weighted images (G, arrows) and decreased apparent diffusion coefficient (H, arrows). No follow-up was available. Abbreviation: SARS-CoV-2: severe acute respiratory syndrome coronavirus 2

Figure 6:

Posterior reversible encephalopathy syndrome (PRES). A 66-year-old male infected with SARS-CoV-2 presenting with status epilepticus in a context of pneumonia and severe hyponatremia. There were cortico-subcortical signal abnormalities in the parieto-occipital and superior frontal regions on FLAIR images (A and D, arrows), with no diffusion restriction (B and E). Follow-up MRI performed ten days later showed complete disappearance of the lesions (C, F).