Intact Brain Network Function in an Unresponsive Patient with COVID-19

Abstract

Many patients with severe coronavirus disease 2019 (COVID-19) remain unresponsive after surviving critical illness. Although several structural brain abnormalities have been described, their impact on brain function and implications for prognosis are unknown. Functional neuroimaging, which has prognostic significance, has yet to be explored in this population. Here we describe a patient with severe COVID-19 who, despite prolonged unresponsiveness and structural brain abnormalities, demonstrated intact functional network connectivity, and weeks later recovered the ability to follow commands. When prognosticating for survivors of severe COVID-19, clinicians should consider that brain networks may remain functionally intact despite structural injury and prolonged unresponsiveness. ANN NEUROL 2020;88:851-854.

FIGURE 1

(A) The patient's hospital course is depicted relative to days since admission. The patient's partial pressure of oxygen (PaO₂) is depicted in dark blue (with the oxygenation goal of >55mmHg proposed by the Acute Respiratory Distress Syndrome Network depicted as a light blue dotted line), and his mean arterial pressure (MAP) is depicted in dark red (with the goal of >65mmHg depicted as a pink dotted line). The timing of paralytics is depicted in purple, sedatives in blue, stimulants in green, and vasopressors in red. The patient's level of consciousness is depicted over time; he was in a coma when not opening his eyes, in a vegetative state (VS; also known as the unresponsive wakefulness syndrome) when opening his eyes but not showing purposeful responses, in a minimally conscious state minus (MCS−) when demonstrating visual pursuit, and in a minimally conscious state plus (MCS+) when demonstrating visual pursuit and following commands. (B) Electroencephalographic (EEG) results are shown from a representative 12‐second recording. (C) Structural magnetic resonance imaging (MRI) results are shown, including T2‐weighted fluid‐attenuated inversion recovery (FLAIR), diffusion‐weighted imaging (DWI), and apparent diffusion coefficient (ADC) sequences. Basal ganglia and thalamic T2 hyperintensities are indicated by arrows. (D) Resting‐state fMRI results are shown for the patient, a representative healthy control, and another patient with diminished default mode network (DMN) connectivity (ie, a negative control). DMN nodes, used as seeds in the analysis, are shown in red. Overall DMN connectivity, defined as the average correlation values within the DMN nodes, is compared across subjects; the patient is represented in red, the healthy controls in black, and the negative control in purple. fMRI = functional MRI.