PhD defence C.L. (Crispijn) van den Brand

Each year millions of people die or become disabled as a result of traumatic brain injury (TBI). The incidence of TBI is increasing worldwide, including the Netherlands. 

The first part of this thesis focusses on epidemiological trends in TBI during a period of 15 years in the Netherlands. We observed an increase in emergency department (ED) visits and hospitalizations for TBI with 75% and 95% respectively. Remarkable is the shift in age groups. The number of ED visits by elderly (65+ years) for TBI increased almost fivefold during the study period. Meanwhile the number of ‘young’ (<65 years) TBI patients decreased. Expressed in mortality: at the beginning of the study period 34% of the patients that died because of TBI was 65 years or older; 15 years later this figure had increased to 63%. This increase cannot solely be explained by ageing of the population. Other important factors are that the elderly live independent and remain active until a higher age than in the past. 

Research presented in this thesis shows that the number of CT-scans for TBI increases rapidly. Research in 10 ED and more than 5000 patients shows that all frequently used existing decision rules for selective CT-scanning in TBI have their shortcomings. Therefore, an existing decision rule was updated to perform better in the current population of TBI patients. 

We also studied which factors increase, or decrease the risk of (severe) TBI. The use of anti-platelet therapy, drugs often used in cardiovascular disease, increases the risk of traumatic intracranial hemorrhages. Therefore, it seems sensible to have a low threshold for performing a CT-scan in this group of patients in case of a head injury. Whether bicycle helmets do offer effective protection for TBI is an subject of discussion and has not been studied before in the Netherlands. Our study demonstrates that the use of a bicycle helmet decreases the risk of TBI substantially. Bicycle helmets offer most protection for one-sided accidents.

Due to corona, the PhD defences do not take place publicly in the usual way in the Senate Hall or in the Professor Andries Querido Room. The candidates will defend their dissertation either in a small group or online.