After written consent from next-of-kin patients with severe traumatic brain injury was included from the neurointensive care unit (NICU) at Sahlgrenska university hospital, Gothenburg. Blood and CSF samples were collected during the initial 3 weeks after trauma. 1 year after trauma patients were assessed according to Glasgow outcome scale (GOS), NIHSS and Barthels. 10-15 years after trauma a repeated evaluation according to GOS was performed by telephone. Different biomarkers such as Neurofilament light, Glial fibrillary acidic protein and Tau among others, was analyzed from serum and CSF samples. Further patients were explored Apolipoprotein-E genetype (APOE). The investigators hypothesize that higher biomarkers concentrations and positive test for this gene relate to worse outcome 1-year and 10-15 years after trauma. Further that these biomarkers and genetic marker further have prognostic value on outcome 1-year and 10-15 years after trauma. Finally, the investigators want to explore the concentrations dynamics of these biomarkers in serum and CSF in the acute phase after trauma.

Patients with a severe traumatic brain injury (sTBI) were included after written consent from next-to kin. The injury was considered as severe if having a Glasgow coma scale of 8 or less. Within 48h of trauma patients were included from the neurointensive care unit at Sahlgrenska university hospital, Gothenburg during 2000-2004. Patients were intubated and had a ventricular catheter. All patients were treated in accordance with the Lund Concept. Samples from ventricular cerebrospinal fluid (CSF) and blood was collected, during the first 3 weeks, then prepared for storage and later analyzed. Samples were stored in -70 degrees Celsius until analyzed. 1 year after trauma patients were assessed according to Glasgow outcome scale (GOS), NIHSS and Barthels Index. 10-15 years after trauma an evaluation of GOS by phone was repeated. Biomarkers such as Neurofilament light, Glial fibrillary acidic protein, Tau among others is analyzed in serum and CSF. Further, patients APOE genotype was explored. The investigators hypothesizes that higher concentrations of these biomarkers both in serum and CSF relate to worse 1-year and 10-15 year outcome after a severe traumatic brain injury. Further, patients that have the gene APOE4 is predisposed to worse 1 year and 10-15 year outcome after a sTBI. The investigators further want to explore the dynamics of these biomarkers in serum and CSF in the acute phase after trauma and if these biomarkers gave any prognostic value to on outcome (mortality and functional) 1-year and 10-15 years after trauma.

Inclusion Criteria:

• Reaction level scale >3, corresponding to a Glasgow coma scale <9
• A therapeutic indication for intracranial pressure monitoring
• Need for ventilator treatment

Exclusion Criteria:

• Not residing in Sweden

Patient with severe traumatic brain injury, defined by our inclusion criteria, where enrolled from the Neurointensive care unit at Sahlgrenska university hospital, Gothenburg. Sahlgrenska University hospital is a tertiary hospital admitting patients from the whole south west part of Sweden.