Sample Solution

executive function (Bennett et al., 2016). Studies have demonstrated BDNF’s importance in cognition following brain injury as it has been shown to increase in the hippocampus following brain injury and influence repair (McAllister et al., 2012). These genes play a critical role in the emergence of vegetative and minimally conscious states following brain trauma. By modulating the repair processes and inflammation following brain injuries, these genes can have a significant effect on the outcomes of these injuries by offering neuroprotective benefits that reduce the chances of entering a vegetative or minimally conscious state. Thus, polymorphisms or mutations in these genes can negatively impact the repair process following a brain injury and increase the chance of entering a vegetative or minimally conscious state.

Mutations

Polymorphisms in TNF, specifically -238 A/G and -308 A/G, have been implicated in the outcome of inflammatory conditions. Studies have demonstrated that unfavorable outcomes following traumatic brain injury such as death and vegetative state were more likely in individuals with the -308 A allele. It is suggested that this may be due to the effect this allele has on the expression of TNF, as those with the -308 A allele have increased expression of TNF after injury. Studies investigating polymorphisms in IL-1 suggest that they are associated with unfavorable outcomes following brain injuries. The APOE4 allele has been linked to the development of Alzheimer’s Disease due to its influence in the development of amyloid beta in the brain. Additionally, individuals with this allele have an increase risk of developing Alzheimer’s Disease if they have a history of brain injury. It has also been suggested that this allele can result in poorer outcomes following brain injury and a higher chance of experiencing loss of consciousness (Bennett et al., 2016). However, due to the differences between individuals in the severity of brain, age, and health, there are conflicting studies that imply that there is little to no association between APOE polymorphisms and unfavorable outcomes following brain injury (Liberman et al., 2002).

Polymorphisms in BDNF has been associated with cognitive function following brain injuries. Studies have demonstrated that in healthy patients, stroke patients, and psychiatric pat