Table 1.

CNS features and diseases in SARS-CoV, MERS-CoV, and SARS-CoV-2 infections

Pathogen	CNS features	CNS diseases	References
SARS-CoV	Direct viral invasion into the CNS through ACE-2 receptors leading to olfactory bulb involvement and resultant anosmia Immune-mediated CNS damage through SIRS, cytokine storm, cross-reactivity, and WBC infiltration	Stroke Guillain-Barre syndrome Encephalopathy Seizure Brainstem involvement	[14] [17] [13] [39] [16]
MERS-CoV	Direct viral invasion into the CNS Immune-mediated CNS damage through SIRS, cytokine storm, and cross-reactivity	Stroke Guillain-Barre syndrome Encephalopathy Seizure Brainstem involvement	[17] [13] [39] [16]
SARS-CoV-2	Direct viral invasion into the CNS through ACE-2 receptors leading to olfactory bulb involvement and resultant anosmia Immune-mediated CNS damage through SIRS, cytokine storm, cross-reactivity, and WBC infiltration Neural degeneration Disruption of synaptic plasticity Impairment in neurotransmitter metabolism Demyelination Disruption in the integrity of the blood-brain barrier Secretion of glucocorticoids through manipulation of the hypothalamic-pituitary-adrenocortical axis	Alzheimer’s disease Parkinson’s disease Stroke Multiple sclerosis Guillain-Barre syndrome Encephalopathy Seizure Brainstem involvement	[4] [15] [12] [25] [40] [41] [13] [39] [16]