Symptoms associated with CTE are currently classified according to whether problems or changes are observed in cognitive processing, mood, or behaviour. Symptoms in these areas are usually diagnosed years or even decades after repetitive brain trauma when the neurodegeneration progresses to the point that changes in cognition, mood, or behaviour begins to interfere with daily functioning. Changes in these three symptom areas can be mild at first but progress over time to a more severe form of the disease, usually with dementia evident in all advanced cases of CTE. Problems with thinking or cognition involve difficulties with complex attention, which incorporates sustained, divided, selective attention and processing speed; executive functioning, which includes planning, decision making, working memory, responding to feedback, inhibition and mental flexibility; learning and memory; perceptual-motor; and recognition in different contexts (McKee et …show more content…
This includes mental health issues as being characteristics of CTE, and assert or imply that the predominant underlying cause of these clinical features is delayed-onset, progressive, degenerative neuropathology. CTE is hard to diagnose in the living because it manifests in behavioral changes that mimic other brain disorders such as Alzheimer’s disease, progressive supranuclear palsy, post-encephalitic parkinsonism, amyotrophic lateral sclerosis or ALS, and Parkinson’s-dementia complex of Guam, or PDC (McKee et al., 2009). However, CTE is a neuropathologically distinct, progressive tauopathic disorder with a clear environmental etiology that differentiates from these other disorders (McKee et. al, 2009). Currently, this distinct neurodegenerative disease can only be diagnosed with certainty by post-mortem through neuropathological