The Impact of Traumatic Brain Injury in the Elderly: a Prospective Study

In order to achieve the goals of the project, a cohort of 50 patients and 50 volunteers is expected, and the following evaluations will be performed:

For the patients group, after signing the informed consent form, a clinical data collection, a serum-based injury biomarkers study, a brain damage assessment, a cognitive and motor assessment, a sleep quality and a quality of life evaluation will be performed.

• Data collection: injury patterns, injury severity, co-morbidities and post-traumatic history will be prospectively registered in our cohort of patients in order to study which types of accidents are risky to result in poor outcome. This will be done through the data collection in medical records of the patients. Advanced statistical methods, such as Gaussian models, will be applied in order to find relations between input and outcome to the best extent possible. In addition, injury mechanisms will be categorized into classes with more or less similar magnitudes of force and acceleration inputs.
• Serum based injury biomarkers study: blood samples from our cohort, taken by UZ Leuven nurses in the context of routine-clinical practice will be studied by the Laboratory for Molecular Neurobiomarker Research in UZ Leuven, through Enzyme-Linked Immunosorbent Assay (ELISA). No data will be available for the control group. The results will be compared to results previously obtained in the Laboratory for Molecular Neurobiomarker Research from healthy patients with similar demographic characteristics.
• CT imaging: CT images performed in the context of routine clinical practice at admission and follow up will be obtained from the hospital's database. The scans will be carefully studied, using automated reports created by Icometrix and the Marshall Head Injury Scale, in order to quantify brain damage. No data will be available for the control group, so results will not be compared between both groups. These findings will be related with the results obtained in the serum-based injury biomarkers study and cognitive and motor assessments.
• Economic impact prospective analysis: hospital costs for the clinical management in our cohort will be extracted from the financial database of UZ Leuven, in order to know what is the economic impact that TBI in the elderly has on society.

1st evaluation session with the patient: 6 months after the injury, the patient will be called back to UZ Leuven for evaluation.The protocol for this session will be done in 1 or 2 sessions, depending on the preferences of the patient, and will consist of:

• MRI: High-resolution T1 and T2 weighted imaging sequences will be used to study volumetric and morphological changes in the brain. Moreover, Diffusion Tractography Imaging (DTI) will be used to study changes in white matter. Susceptibility Weighted Imaging (SWI) sequences will also be included in order to study axonal injuries and microbleeds. One MRI scan will be obtained from each patient and the results will be interpreted with the Icobrain TBI report, provided by Icometrix.
• Cognitive assessment: the CANTAB test will be used to study cognitive functions after TBI, as it is a validated and reliable computerized neuropsychological battery, consisting of memory, learning, attention, problem solving and executive function test. Moreover, the patients' level of education will be asked, registered and correlated with the results obtained in our evaluations.
• Motor assessment: it will be performed using the Berg Balance Scale (BBS), Timed Up an Go (TUG) test, Timed Up and Go with cognitive dual task (TUGcog) test, Box-and-block test and a cycling test performed with a bicycle simulator created by the IMPAct group (KU Leuven).
• Sleep quality assessment: the sleep quality in our cohort will be assessed using the Pittsburgh Sleep Quality Index, in order to understand how TBI can affect the patients' sleep patterns.
• Quality of life evaluation: the quality of life in our cohort will be assessed with the Quality of Life after Brain Injury (QOLIBRI) tool, in the same session as cognitive and motor outcomes, in order to understand how the quality of life is affected in the elderly population after TBI.

All the results will be compared with the results obtained in the control group.