FC conceived of the study, and participated in its design and coordination. ADP conceived of the study, and participated in its design and coordination. EEM conceived of the study, and participated in its design and coordination. All authors read and approved the final manuscript.”
“We read with great interest the recent review article by Veenith et al. published in the World Journal of Emergency Surgery [1]. In this paper, see more the authors provide an overview on the epidemiology and pathophysiology of traumatic brain injury (TBI), and present an update on TBI-induced apoptosis, intracranial gene regulation

and pharmacological approaches to ameliorate secondary brain injury. The authors are to be congratulated for outlining this important and constantly evolving topic of global importance. Unfortunately, our initial excitement about this paper, which promised to disclose the “”missing link”" between molecular pathology and new treatment concepts for TBI [1], was not justified. We believe that important pathways in the pathophysiology of TBI and resulting therapeutic concepts were not addressed in the review article. We would therefore like to comment on the missing aspects in the

article by Veenith and colleagues R428 [1], in order to provide a more balanced and comprehensive perspective on the topic. Beyond a doubt, a detailed description of the molecular neuropathology of TBI represents a challenging task, which is difficult to describe in just a few paragraphs. However, the authors could have expanded their article to include some of what we consider “”key”" pathways in

the cellular and molecular pathophysiology of TBI (Figure 1). For example, the role of neurotoxic proteases, nitric oxide and phospholipases released by damaged tissue, the impact on blood-brain-barrier breakdown by recruited and local inflammatory AZD9291 in vitro cells, and the activation of the innate immune system, e.g. the complement system, as a crucial mediator of posttraumatic neuroinflammation, are not mentioned or discussed in the paper. The section devoted to apoptosis provides the reader with some basic textbook information and definitions, but may have benefited from an additional update on the current literature in the field of neuronal apoptosis in TBI. Similarly, the paragraph on gene regulation appears to represent a random selection of candidate genes without a rationale being provided on how alterations in gene regulation may relate to the pathophysiology of TBI. Several references cited refer to studies related to cardiovascular disease, rather than head injury. Most importantly, this section of the manuscript fails to stress the clinical relevance of pathological alterations in gene expression. Figure 1 Simplified schematic of the complex neuroinflammatory response following traumatic brain injury.