A 57 year-old male complains of a mild weakness and numbness in his legs. He reports that symptoms have slowly been getting worse over the course of the last several years. Upon testing, it is determined that his muscle coordination is poor, some reflexes are absent, he has problems with his vision, and he "walks like a drunk" although he reports he is sober. When asked, he recalls that some ten years earlier he had experienced small lesions on his scrotum that developed into a rash and finally cleared up on their own. Please define and describe each disorder listed below. Then, indicate disorder you believe is the cause of the described symptoms. Explain your choice, including why the other disorder were eliminated. Subdural hemorrhage Amyotrophic lateral sclerosis (ALS) Tabes dorsalis Cerebral palsy