Background:The coronavirus disease 2019 (COVID-19) pandemic has unveiled a wide array of clinical biomarkers, and neurological manifestations in affected patients, necessitating further exploration.Methods:This single-center retrospective study evaluated clinical and neurological sequelae, demographics, as well as laboratory markers, in hospitalized COVID-19 patients from January to September 2020.Results:Among 1248 inpatients (median age: 68 years; 651 women), 387 (31%) were admitted to the ICU. Central nervous system (CNS) manifestations were present in 521 (41.74%) patients, while peripheral nervous system manifestations were observed in 84 (6.73%). COVID-19-related mortality occurred in 314 (25.16%) cases. ICU-admitted patients were predominantly male (P<0.0001), older (age≥60;P=0.037) and had more comorbidities such as diabetes (P=0.001), hyperlipidemia (P=0.043), and coronary artery disease (P=0.015). ICU patients exhibited more CNS manifestations (P=0.001), including impaired consciousness (P<0.0001) and acute cerebrovascular disease (P=0.023). Biomarkers linked to admission to the ICU included elevated white blood cell count, ferritin, lactate dehydrogenase, creatine kinase, blood urea nitrogen, creatinine, and acute phase reactants (e.g. erythrocyte sedimentation rate and C-reactive protein). ICU patients demonstrated lower lymphocyte and platelet counts compared to non-ICU patients. Those with CNS involvement in the ICU often exhibited elevated blood urea nitrogen, creatinine, and creatine kinase levels. Higher mortality from COVID-19 was observed in ICU patients (P<0.0001).Conclusions:Multiple serum biomarkers, comorbidities, and neurological manifestations in COVID-19 patients have been consistently documented and may be linked to increased morbidity, ICU admission, and mortality. Recognizing and addressing these clinical and laboratory markers is essential for effective COVID-19 management.