# Clinical Features of Central Nervous System Complications Caused by the SARS‐CoV‐2 Omicron Variant

## TL;DR

This study examines how the Omicron variant of SARS-CoV-2 affects the central nervous system in adults, highlighting risk factors and cerebrospinal fluid features.

## Contribution

The study identifies specific clinical and laboratory risk factors for severe CNS complications caused by the Omicron variant.

## Key findings

- Older age, comorbidities, and elevated creatine kinase and d-dimer levels are risk factors for severe CNS complications.
- SARS-CoV-2 was not detected in the CSF of most patients with CNS complications.
- Abnormal CSF findings were observed in nearly half of the patients with CNS complications.

## Abstract

This study investigated clinical characteristics and cerebrospinal fluid (CSF) features of central nervous system (CNS) complications in adults caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) Omicron variant.

We retrospectively examined adult patients with coronavirus disease‐2019 (COVID‐19), with or without CNS complications, hospitalized in China from December 2022 to August 2023.

Twenty‐five patients with CNS complications (9 severe, 16 non‐severe) and 50 patients without CNS complications were examined. The percentage of patients with severe/critical COVID‐19 was relatively higher in the CNS complications group (24% [6/25] vs. 12% [6/50]). Procalcitonin and creatine kinase levels, and leukocyte and neutrophil counts were significantly higher in patients with CNS complications. Having severe CNS complications was associated with older age, comorbidities, and elevated creatine kinase and d‐dimer levels. Among 22 patients with CNS complications who underwent CSF testing, 10 (45%) had abnormal CSF cytology or biochemistry—including 9 (41%) with elevated protein levels—and 2 (9%) had increased white blood cell counts. Among the CSF samples tested, 2 (12%) and 3 (18%) tested positive for SARS‐CoV‐2 and autoantibodies respectively.

Older age, comorbidities, and elevated serum creatine kinase and d‐dimer levels were risk factors for severe CNS complications in adult patients with COVID‐19. SARS‐CoV‐2 was not detected in the CSF of most patients with CNS complications.