A 42 year-old caucasian male presents to your office for the evaluation of his loss of fine manual skills, diminished work performance, inability to manage household responsibilities and disturbances of sleep. For the last 10 months, he has been experiencing repeated, irregular movements of his eyebrows and the muscles in his forehead. His hands and legs feel rigid. He has developed uncontrolled jerking movements of face, arms, and trunk, which he cannot control. He has trouble speaking. He developed loss of balance and had trouble walking. He hears, sees, smells and feels things that others do not. He is having problems with his memory. He is becoming increasingly suspicious of others, even his wife. He is having difficulty figuring out where he is, what time, date or day it is. He is no more interested in doing things he used to enjoy. He reports some of his relatives in his extended family also developed similar symptoms around his age. You ordered some laboratory work up and genetic testing. His head CT showed cerebral and caudate nucleus atrophy. Genetic testing revealed CAG trinucleotides with defective genes localized on chromosome 4. Of the following, what is the most likely diagnosis in this patient?
