The above described damages to the central, peripheral, and autonomic nervous systems lead to a multitude of neuropsychological symptoms. In the beginning stages of PDD, simple attention is usually preserved; however, complex sustained attention is moderately impaired. In contrast, individuals with PDD struggle with working memory tasks early on in the disease process. Executive functioning deficits in areas such as planning, conceptualization, maintenance, and ability to shift sets are forerunners of PDD (Trosten & Brower, 2013). Language comprehension and repetition are usually intact until later in the progression of disease; however, verbal fluency is impaired early in the client’s experience of PDD. Memory and learning show mild to severe
