Mild traumatic brain injury at older age:Patterns in clinical and neuroimaging data

With the global population growing and getting older, the number of older adults sustaining a mild traumatic brain injury (mTBI) increases. In this population, which is at higher risk of developing persistent post-traumatic complaints, complex interactions between brain injury, age-related neurological changes and other pre-injury factors are likely involved in determining recovery.In this thesis, we employed neuroimaging techniques and machine learning methods to answer clinical questions such as: “Which (combination of) self-reported complaints indicates increased risk for incomplete recovery in older adults who suffered an mTBI?” and “How can effects of sustaining mTBI at older age on brain functioning be disentangled from those of ageing?”. By analyzing clinical data, we identified post-injury neck pain, irritability and forgetfulness as potential prognostic markers for incomplete recovery after mTBI at older age.By analyzing neuroimaging data at rest and during a working memory task, we found altered brain activity in this population, in areas involved in the integration of multisensorial inputs (e.g. left-middle temporal gyrus, cerebellum). Despite (cognitive) complaints, working memory performance of older patients with mTBI was unimpaired. However, we observed hypoconnectivity between their bilateral insula, while activity in these regions was not associated with task performance. Perhaps sustaining an mTBI affects regions that are indirectly involved in cognitive processes, such as sustained attention, self-motivation and integration of sensorial inputs for visuomotor control or visual-auditory perception. The observed changes in brain functioning could act as stressors on more vulnerable, older brains, and partly explain the development of persistent post-traumatic complaints