Most patients who suffer impaired consciousness as a result of COVID-19 recover within six months, according to new research published in Neurology. The findings provide new insight into the outcome of neurological complications related to severe COVID-19.
“During the initial surge of the COVID-19 pandemic, it quickly became apparent that some patients with severe COVID-19 would not wake up as expected once sedating medications were discontinued. And worse, it was uncertain if and when such patients would ever wake up again. This uncertainty had profound implications,” explained researcher David Fischer (@dbfisch), a neurocritical care fellow at Massachusetts General Hospital and Harvard Medical School.
“For some patient families, who had already seen their loved ones endure weeks or months of intensive medical care, the prospects of prolonged neurologic disability was too much to bear, and life-sustaining treatment was subsequently withdrawn. Patients died as a result. Though COVID-19 has taken so many lives in so many ways, as a physician, this means of death was particularly distressing – patients were dying not only because of the virus, but because we as physicians could not tell families what to expect in terms of neurologic recovery.”
“To understand the chances of recovery from these disorders of consciousness, we launched a prospective study, screening every patient with COVID-19 at our hospital to identify those who did not wake up as expected after sedation was discontinued.
Between July 2020 and March 2021, the researchers screened 1,105 patients with COVID-19 at Massachusetts General Hospital and enrolled twelve individuals with disorders of consciousness unrelated to sedative medication. Two patients were comatose, eight were in a vegetative state, and two were in a minimally conscious state. The patients ranged in age from 33 to 82 years and were 63.5 years old on average.
One patient died of COVID-19 shortly after enrollment and another patient improved neurologically shortly after enrollment. Fischer and his colleagues used magnetic resonance imaging (MRI) to compare the remaining 10 COVID-19 patients’ brain structure and connectivity to 14 healthy controls and 18 patients with disorders of consciousness due to severe traumatic brain injury.
“Of those patients who survived, all eventually recovered consciousness, though recovery could sometimes take over a month. The recovery of consciousness was difficult to predict; no clinical variables reliably predicted when consciousness would be recovered,” Fischer told PsyPost. Half of the patients regained consciousness within a week after sedation was discontinued.
“Though all patients were disabled at hospital discharge due to prolonged critical illness, after 6 months, almost all returned home with normal cognition and minimal disability (two patients had more severe disability related to weakness),” Fischer said. “This study also taught us about the potential pathophysiology of this condition; patients with these disorders of consciousness had diminished connectivity of brain networks, though the cause of such diminution remains unclear.”
The researchers observed reduced connectivity within the default mode network along with reduced connectivity between the default mode network and salience network among the COVID-19 patients. They also observed reduced white matter integrity. Moreover, four patients had microhemorrhages, three had leukoencephalopathy, and two had both.
“The findings of this study imply that, with enough time, patients who are slow to wake up after severe COVID-19 are likely to recover consciousness, and barring further medical complications, are likely to regain significant neurologic function in the following months,” Fischer said.
“Moving forward, as the pandemic continues to affect many, we hope to better understand the cause of these disorders of consciousness. Are these disorders predictable based on patient demographics and characteristics of their illness? Can we better anticipate how long patients will take to recover, so we can counsel families more specifically? And ultimately, once we better understand the pathophysiology and cause of these disorders, we hope to develop therapeutics to assist patients in their recovery of consciousness.”
The study, “Disorders of Consciousness Associated With COVID-19: A Prospective Multimodal Study of Recovery and Brain Connectivity“, was authored by David Fischer, Samuel B. Snider, Megan E. Barra, William R. Sanders, Otto Rapalino, Pamela Schaefer, Andrea S. Foulkes, Yelena G. Bodien, and Brian L. Edlow.
