Garg RK. Neurol India 2020 - Review.
COVID-19, in most patients, presents with mild flu-like illness. Elderly patients with comorbidities, like hypertension, diabetes, or lung and cardiac disease, are more likely to have severe disease and deaths. Neurological complications are frequently reported in severely or critically ill patients with comorbidities. In COVID-19, both central and peripheral nervous systems can be affected. The SARS-CoV-2 virus causes the disease COVID-19 and has the potential to invade the brain. The SARS-CoV-2 virus enters the brain either via a hematogenous route or olfactory system. Angiotensin-converting enzyme two receptors, present on endothelial cells of cerebral vessels, are a possible viral entry point. The most severe neurological manifestations, altered sensorium (agitation, delirium, and coma), are because of hypoxic and metabolic abnormalities. Characteristic cytokine storm incites severe metabolic changes and multiple organ failure. Profound coagulopathies may manifest with ischemic or hemorrhagic stroke. Rarely, SARS-CoV-2 virus encephalitis or pictures like acute disseminated encephalomyelitis or acute necrotizing encephalopathy have been reported. Nonspecific headache is a commonly experienced neurological symptom. A new type of headache "personal protection equipment-related headache" has been described. Complete or partial anosmia and ageusia are common peripheral nervous system manifestations. Recently, many cases of Guillain-Barré syndrome in COVID-19 patients have been observed, and a postinfectious immune-mediated inflammatory process was held responsible for this. Guillain-Barré syndrome does respond to intravenous immunoglobulin. Myalgia/fatigue is also common, and elevated creatine kinase levels indicate muscle injury. Most of the reports about neurological complications are currently from China. COVID-19 pandemic is spreading to other parts of the world; the spectrum of neurological complications is likely to widen further.