Causes And Risk Factors Of Traumatic Brain Injury
Recently, large epidemiological studies have additionally identified mild TBI (mTBI) as a risk factor for dementia. However, the role of mTBI in risk of PD and chronic traumatic encephalopathy (CTE) is less established (Sundman et al., 2015). Therefore, this review will summarize the current literature regarding the correlation between mTBI and neurodegenerative diseases. Having a better understanding of the causes and risk factors of mTBI may limit their prevalence.
Traumatic Brain Injury
Traumatic brain injury is a closed head injury as a result of external physical forces (Sundman et al., 2014). It can be caused by a bump, blow, or jolt to the head that can change the way the brain normally functions (Carroll et al., 2004). During an initial TBI, there is brain swelling and disruption of autoregulation of cerebral blood flow. If a person suffers a second TBI before completely healing from the initial injury, known as second impact syndrome, then there is an increasing chance the injury will be fatal (Wetjen et al., 2010). TBI is separated into three categories (severe, moderate, and mild), which are classified using the Glasgow Coma Scale. This …show more content…
CTE is a form of neurodegeneration that is believed to result from repeated head injuries. The concept of CTE was first introduced by Martland in 1928, and was long recognized as dementia pugilistica due to its association with boxing. CTE has several symptoms. There are psychological changes, which include “disordered memory and executive function, behavioral and personality disturbances, and parkinsonism” (Gavett et al., 2011), and speech and gait abnormalities (McKee et al., 2009). CTE include pathological changes in the brain such as atrophy of the cerebral hemispheres, medial temporal lobe, thalamus, mammillary bodies, and brainstem, with ventricular dilatation and a fenestrated cavum septum pellucidum. Microscopically, there are extensive tau-immunoreactive neurofibrillary tangles, astrocytic tangles, and spindle-shaped and threadlike neurites throughout the brain. The onset of CTE is often mid-life, usually after the athlete has retired from the sport (Gavett et al., 2011). The mean age for CTE is 42.8 years, and normally appears approximately 8 years after retirement (McKee et al.,