Coronavirus Infections; Critical Care/methods; Magnetic Resonance Imaging/methods; Multiple Organ Failure; Myelitis, Transverse; Neuromyelitis Optica; Pandemics; Paresis; Pneumonia, Viral; Spinal Cord/diagnostic imaging; Aged; Antibodies/blood; Aquaporin 4/immunology; Betacoronavirus/isolation & purification; COVID-19; Clinical Deterioration; Coronavirus Infections/complications; Coronavirus Infections/physiopathology; Coronavirus Infections/therapy; Diagnosis, Differential; Fatal Outcome; Humans; Male; Multiple Organ Failure/diagnosis; Multiple Organ Failure/etiology; Myelitis, Transverse/diagnosis; Myelitis, Transverse/etiology; Myelitis, Transverse/physiopathology; Neurologic Examination/methods; Neuromyelitis Optica/diagnosis; Neuromyelitis Optica/etiology; Neuromyelitis Optica/physiopathology; Neuromyelitis Optica/therapy; Paresis/diagnosis; Paresis/etiology; Paresis/physiopathology; Pneumonia, Viral/complications; Pneumonia, Viral/physiopathology; Pneumonia, Viral/therapy; SARS-CoV-2; Sepsis/etiology; Sepsis/therapy