Delirium in Head Trauma: Looking for a Culprit

Head trauma and delirium are two common conditions in the elderly population. They both carry a heavy burden in terms of mortality and morbidity and are associated with one another through several environmental and clinical factors, such as comorbidities, age, and sex. One factor that may play a role in both these conditions is inflammation, which might also represent a link between them. In particular, head trauma can cause both systemic and neuroinflammation, while delirium appears to be precipitated by inflammatory conditions, while also involving a number of inflammatory pathways in its pathogenesis. Interleukin 6 and tumor necrosis factor alpha are only two of the main actors in this crosstalk, which also involves microglia and immune cells. An indirect proof is that anti-inflammatory drugs have proven effective in reducing post-traumatic delirium, thus demonstrating the importance of inflammation in the pathophysiology of this disease. In this paper, we have revised the available literature exploring the links between inflammation, head trauma and delirium and we will discuss the mechanisms of this relationship, paying particular attention to the possible future implications.