Traumatic brain injury (TBI) has been the subject of many studies while a variety of attempts have been conducted. Many guidelines and clinical studies have reported the incidence. The pathogenesis and outcome of these injuries differ from study to study, but all could conclude to the importance of management and categorization. However, neither of them reports the fact that reevaluation of the health care system and tight gun control is extremely necessary.

One of the various kinds of TBI is the injury from a gunshot. The first appearance of the gun took place around 1000 AD in China, but its further evolution is multidimensional and eventful.4) Since then, the incidence of gun brain trauma has been increasing, reaching nowadays the level of mortality12)

In this study, the authors present an effort to categorize the traumatic brain injuries due to gunshot in cadavers, comparing the data from Greece and Bulgaria. The main purpose of the study is to observe and thereafter to evaluate important clinical and autopsy findings of subjects suffering from the same pathology- penetrating brain injury, for which there are no similar reports.

The records are collected from 2 laboratories of forensic science and toxicology. The first is located in hospital “Stamen Iliev,” in Montana, Bulgaria, while the second in the university hospital of Alexandroupolis, Greece.

The laboratory of forensic science in Bulgaria examines patients and cadavers from the western half of North-West Bulgaria, including 2 regions—Montana and Vidin with a few municipalities (Vidin, Lom and Montana). The university hospital, on the other hand, examines patients and cadavers from the region of East Macedonia and Thrace that include 5 regions—Evros, Rhodope, Xanthi, Kavala, and Drama.

The law in both countries stipulates that an individual might own a weapon, based on solid grounds (reasoning), after proper psychiatric evaluation has been conducted and a license from the police has been issued. Many of the subjects had licenses for weapon ownership, while few of them had an access to such. The fact that all of them were victims of suicide and all of them had an access to gunshot weapon, despite their psychological condition, suggest that better weapon control or healthcare is highly required.

The study is based on the retrospective analysis of the archived protocols from 1 January 2007 to 31 December 2016 from both centers, therefore an informed consent was not needed. The total number of fatal TBI collected from the laboratories of forensic science and toxicology for this period is 233 in Montana/Vidin and 228 in North Greece. The basic concept of the study is the analysis and comparison between both countries on the subject of gunshot brain injury in cadavers. Due to that we excluded every other cause of TBI, as well as cases of living patients. Subsequently, the authors compared three basic categories—demographic, anatomical localization and cadaveric findings.

Under the term “demographic” we included data based on the age, sex, location of the incident and toxicological result.

Under the term “anatomical localization” we concluded anatomical landmarks of the skull, number of skull injuries, open or closed trauma and morphology of the head trauma. Finally, under the term “cadaveric findings” we concluded autopsy findings, such as brain edema, atherosclerosis of the vessels, old scar tissue etc.

Afterwards, the data is analyzed on Jeffreys's Amazing Statistics Program (JASP) statistical program, including Correlation analysis and t-paired tests.

To summarize, our study shows that despite the fact that PBI has the same cause—gunshot, while the guidelines suggest similar therapeutical approaches, the difference between the subjects should be taken under consideration for further investigation and prevention.

Alcohol consumption, age, extended injury of the skull and brain tissue and high rate of co-morbidities are all factors increasing the mortality rate. All of the subjects of the current study had more than one of those factors contributing to the fatal result of the PBIs. More important, due to the cause of the PBIs in the current study, it could be suggested that better healthcare is highly required to prevent and cure this type of brain trauma, including better psychiatric evaluation and post-traumatic management.

The study reports very important facts, but has the limitation that it is conducted for only a small region from each country and more detailed national investigations are highly required. Despite that fact, it observes an important issue regarding gun control, health care system, the current criminal code and most significant—the importance of personalized therapeutical approaches, including also preventative measures.

Penetrating brain trauma is a serious issue not only because of its origin but also due to its high mortality rate and post-traumatic complications. The basic factor behind this, is the trajectory of the gunshot through the skull.2^,11) The more domains being injured, the worse the outcome becomes. Hence, the bihemispheric and transventricular trajectory seem to be linked to poorer results.2^,11) Other factors for the outcome and the mortality are the existing or post-traumatic co-morbidities2) and the cause of the wound (suicide attempts are linked to higher mortality).6) Our study shows primarily results for poorer outcome—mainly suicide attempts with bihemisphreric brain trauma—covering more than one anatomical structure and bone and plenty of co-morbidities.

As far the demographics are concerned, according to a study made by Izci et al.,5) who examined only male patients, the average age of the participants in the study is 22. Another study, conducted by Liebenberg et al.7) with 125 participating patients, shows male predominance with an average age of 24.9. Solmaz et al.,9) investigating 442 patients, concludes male prevalence in gunshot TBI with an average age of the patients being 23.2 years. On the contrary, the authors of this study observed higher numbers of the average age (45.62 and 50.54) in both nationality groups, but also a definite male dominance (96.72%). According to Esposito and Walker,3) higher numbers of age are linked to poorer results. Finally, regarding the topic of toxic substances and alcohol, Tien et al.10) revealed that patients with brain trauma and alcohol consumption had worse results compared to those who had consumed any of the above. On the other hand, cocaine seems not to play a role in the results and the mortality.13) Our study showed that 44.26% had drunk alcohol and 22.22% combined it with opiates and/or benzodiazepines. The conclusion whether the drugs lead to a poorer outcome will not be reliable because of the existence of other factors and the additional use of alcohol.

It seems that as far as the topic of open/closed trauma is concerned, all of the studies include open traumas.1^,5^,7^,9) Regarding the anatomical localization, the results vary. Andrade et al.1) showed in his study that the most frequently involved parts of the skull are frontal (38%), temporal (28%) and parietal (12.5%). Lin et al.8) in his case-series shows that common localizations are parietal, occipital, temporal bones and skull base. Solmaz et al.9) on the same subject reaches the conclusion that frontal, temporal and parietal bone are the most frequently injured parts, but the trauma of the posterior fossa and the multiple injuries lead almost certainly to death. In the current study we observed that the most commonly injured region is the face, followed by the skull base. These findings are very important not only to determine the trajectory of the gunshot and the cause of death, but also for management planning, including hospital administration and hospital staff organization.

Other findings after/due to penetrating TBI are derived to be subarachnoid hemorrhage, ventricular hemorrhage, subdural hemorrhage, and hematoma, linked to the trajectory of the bullet.1^,8) Results with prognostic significance, however, are brain swelling, lesions and vascular events.1) As it is depicted in TABLE 3 & 4, our study also reports a great number of hematomas, subdural hemorrhages and brain swelling. At this point it should be mentioned that, no other study has revealed similar findings after the autopsy in addition to the number of head injuries as the ones derived from this particular which is thoroughly described above.

In conclusion, brain trauma due to gunshot is one of the most dangerous kinds of brain injuries. Tracking the 10-year cadaveric findings among 2 nations suggests that indeed there are differences among the nations, including trajectory, age and alcohol consumption, but also there is a common fact that there should be present better preventative measures, including gun control and healthcare system.