This special issue focuses on innovative approaches to diagnosing post-concussion syndrome (PCS) and functional neurological disorders (FNDs). PCS is a condition that can occur following a concussion, where individuals experience a range of symptoms that can persist for weeks, months or even years after the initial injury. FNDs are a group of conditions that are characterized by neurological symptoms but without a clear underlying neurological cause. The special issue explores new diagnostic tools and techniques that can aid in identifying and diagnosing PCS and FNDs. This includes studies on the use of biomarkers, imaging techniques, and other objective measures to help identify individuals with these conditions. The issue also includes research on how technology, such as virtual reality or wearable sensors, can aid in the diagnosis of PCS and FNDs. In addition, this issue explores new approaches to understanding the underlying mechanisms of PCS and FNDs. This includes studies on the role of genetics, inflammation, and other biological factors in the development of these conditions. The issue also explores how psychological factors, such as stress and trauma, can contribute to the development and persistence of PCS and FNDs. The present journal issue highlights the importance of innovative approaches to diagnosing PCS and FNDs, to improve outcomes for individuals with these conditions.