These domestic reports follow similar observations by doctors in Italy and other parts of the world, of Covid-19 patients having strokes, seizures, encephalitis-like symptoms and blood clots, as well as tingling or numbness in the extremities, called acroparesthesia. In some cases, patients were delirious even before developing fever or respiratory illness, according to Dr. Alessandro Padovani, whose hospital at University of Brescia in Italy opened a separate NeuroCovid unit to care for patients with neurological conditions.
The patients who come in with encephalopathy are confused and lethargic and may appear dazed, exhibiting strange behavior or staring off into space. They may be having seizures that require immediate medical care, and experts are warning health care providers who treat such patients to recognize that they may have Covid-19 and to take precautions to protect themselves from infection.
Much is still unknown about the neurological symptoms, but efforts are underway to study the phenomena, said Dr. Sherry H-Y. Chou, a neurologist at the University of Pittsburgh School of Medicine, who is leading a team of investigators for the Neurocritical Care Society.
“We absolutely need to have an information finding mission, otherwise we’re flying blind,” Dr. Chou said. “There’s no ventilator for the brain. If the lungs are broken we can put the patient on a ventilator and hope for recovery. We don’t have that luxury with the brain.”
Experts have emphasized that most Covid-19 patients appear to be normal neurologically.
“Most people are showing up awake and alert, and neurologically appear to be normal,” said Dr. Robert Stevens, a neurologist at the Johns Hopkins School of Medicine in Baltimore who is tracking neurological observations.
Neurological specialists also say that it is too early to make definitive statements or identify the specific mechanisms by which the new coronavirus is affecting the neurological system.
In one recent paper, Chinese scientists noted that there was some evidence that other coronaviruses were not confined to the respiratory tract and invaded the central nervous system, and the authors speculated that this may potentially play a role in acute respiratory failure in Covid-19.
Dr. Stevens emphasized that all mechanistic explanations at this point are hypotheses because so little is known: “It could be as simple as low levels of oxygen in the bloodstream,” resulting from respiratory failure, along with an increase in carbon dioxide, which “can have significant impact on the function of the brain, and lead to states of confusion and lethargy,” he said.
“We are still in the early days of this, and we don’t really know for sure.”