Neurological symptoms as a clinical manifestation of coronavirus disease 2019: implications for internists.

Numerous experimental and clinical studies have proven that the new severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) has a tropism for the nervous system. The infection of the nervous system by SARS‑CoV‑2 can occur via the nasal route through trans‑synaptic pathways. Coronaviruses can infect neurons and glial cells through angiotensin‑converting enzyme 2 receptors or by endocytosis. The infection of the central nervous system accompanied by coronavirus disease 2019-related systemic inflammation leads to the impairment of the blood-brain barrier and triggers a neuroinflammatory response with reactive astrogliosis and microglial activation. In addition, brain stem cells are being damaged, which results in respiratory distress. Apart from typical symptoms of COVID‑19 associated with the involvement of the respiratory system, neurological manifestations such as headache, dizziness, myalgia, anosmia, ageusia, encephalopathy, encephalitis, stroke, epileptic seizures, rhabdomyolysis, and Guillain-Barré syndrome are related to SARS‑CoV‑2 infection. In this review, we focused on the currently known neurological manifestations of COVID‑19, which could be considered mainly in asymptomatic patients with COVID‑19 and, if noted, may limit the transmission of coronavirus infection.