Evolution of Neuroimaging Findings in Severe COVID-19 Patients with Initial Neurological Impairment: An Observational Study

Abstract

Background and objectives: Cerebral complications related to the COVID-19 were documented by brain MRIs during the acute phase. The purpose of the present study was to describe the evolution of these neuroimaging findings (MRI and FDG-PET/CT) and describe the neurocognitive outcomes of these patients.

Methods: During the first wave of the COVID-19 outbreak between 1 March and 31 May 2020, 112 consecutive COVID-19 patients with neurologic manifestations underwent a brain MRI at Strasbourg University hospitals. After recovery, during follow-up, of these 112 patients, 31 (initially hospitalized in intensive care units) underwent additional imaging studies (at least one brain MRI).

Results: Twenty-three men (74%) and eight women (26%) with a mean age of 61 years (range: 18-79) were included. Leptomeningeal enhancement, diffuse brain microhemorrhages, acute ischemic strokes, suspicion of cerebral vasculitis, and acute inflammatory demyelinating lesions were described on the initial brain MRIs. During follow-up, the evolution of the leptomeningeal enhancement was discordant, and the cerebral microhemorrhages were stable. We observed normalization of the vessel walls in all patients suspected of cerebral vasculitis. Four patients (13%) demonstrated new complications during follow-up (ischemic strokes, hypoglossal neuritis, marked increase in the white matter FLAIR hyperintensities with presumed vascular origin, and one suspected case of cerebral vasculitis). Concerning the grey matter volumetry, we observed a loss of volume of 3.2% during an average period of approximately five months. During follow-up, the more frequent FDG-PET/CT findings were hypometabolism in temporal and insular regions.

Conclusion: A minority of initially severe COVID-19 patients demonstrated new complications on their brain MRIs during follow-up after recovery.

Keywords: COVID-19; follow-up; neuroimaging.

Figure 1

Flow diagram.

Figure 2

A 79-year-old man (#21) initially hospitalized (ICU) (A,B), who underwent a second MRI during follow-up 112 days later (C,D). Sagittal post-contrast three-dimensional T1-weighted spin-echo MR imaging (A,C) and sagittal FLAIR MR images (B,D). Basilar artery wall enhancement (A) with normalization of the vessel wall imaging during follow-up (C), and appearance of white matter FLAIR hyperintensities, presumed of a vascular origin (D).

Figure 3

A 67-year-old man (#20) (A,C) and a 61-year-old man (#7) (B,D), both initially hospitalized (ICU), who each underwent a second MRI during follow-up 112 (A,C) and 99 (B,D) days later, respectively. Axial (A,C) and sagittal (B,D) post-contrast three-dimensional T1 weighted spin-echo MR imaging. Appearance of contrast enhancement affecting the right hypoglossal nerve (C) (neuritis), and the wall of the posterior cerebral arteries suggestive of cerebral vasculitis.

Figure 4

A 46-year-old man (#6) initially hospitalized in the ICU (A,B), who underwent a second MRI during follow-up 92 days later (C,D). Axial arterial spin labeling (ASL) brain perfusion imaging (A–D). Abnormal brain perfusion on initial imaging with frontotemporal hypoperfusion (A,B) and normalization during follow-up (C,D).

Figure 5

Patient #5: colliculus’s hypermetabolism and left medial temporal hypometabolism at subacute phase. These abnormalities worsened over time.