CHICAGO, June 12 (Xinhua) -- A review of neurological symptoms of COVID-19 patients in current scientific literature reveals the disease poses a global threat to the entire nervous system, said a Northwestern Medicine study posted on the website of Northwestern University (NU) on Thursday.

About half of hospitalized patients have neurological manifestations of COVID-19, which include headache, dizziness, decreased alertness, difficulty concentrating, disorders of smell and taste, seizures, strokes, weakness and muscle pain.

The disease may affect the entire nervous system, including the brain, spinal cord and nerves as well as the muscles. As the disease may affect multiple organs, such as lung, kidney and heart, the brain may also suffer from lack of oxygenation or from clotting disorders that may lead to ischemic or hemorrhagic strokes.

Moreover, the virus may cause direct infection of the brain and meninges. The reaction of the immune system to the infection may cause inflammation that can damage the brain and nerves.

"It's important for the general public and physicians to be aware of this, because a SARS-COV-2 infection may present with neurologic symptoms initially, before any fever, cough or respiratory problems occur," said lead author Igor Koralnik, Northwestern Medicine chief of neuro-infectious diseases and global neurology and a professor of neurology at NU Feinberg School of Medicine.

Koralnik and colleagues have formed a Neuro-COVID research team and started a retrospective analysis of all COVID-19 patients hospitalized at Northwestern Medicine to determine the frequency and type of neurological complications, as well as response to treatment.

The study has been published this week in Annals of Neurology.

Northwestern Medicine is the collaboration between Northwestern Memorial HealthCare and Northwestern University Feinberg School of Medicine, which includes research, teaching and patient care. Enditem