Post-COVID Neurological Syndrome (PCNS) has emerged as one of the most significant and disabling long-term consequences of the COVID-19 pandemic. Epidemiological evidence indicates that between 5% and 50% of individuals recovering from SARS-CoV-2 infection develop persistent neurological and systemic symptoms that may last for months or years. These include cognitive impairment, autonomic dysfunction, chronic fatigue, sensory disturbances, and mood changes. PCNS affects individuals across all age groups and degrees of initial illness severity, including those with mild or asymptomatic infections. However, true prevalence estimates remain difficult to standardize due to methodological differences in case definitions, study designs, and follow-up periods. Global health surveillance systems—particularly in low- and middle-income countries (LMICs)—often fail to capture post-acute outcomes, leading to significant underreporting. Emerging data suggest that women, older adults, and individuals with certain pre-existing conditions are at increased risk, though younger populations are also affected. Given the scale of the pandemic, PCNS represents a global public health burden with broad social, economic, and healthcare implications. This volume brings together multidisciplinary expertise and draws on the Global Burden of Disease (GBD) 2022 framework to better understand the epidemiology, pathophysiology, and policy responses required to address PCNS at scale.