Zombie

You live in Papua New Guinea. You meet a patient who was normal up to a year ago when he developed tremors, ataxia, and postural instability. You remember him well; he was shaking so hard that he looked like he was shivering. Because of worsening tremors and ataxia, he became nonambulatory six months ago. At that time, he was noted to have myoclonus, choreoathetosis, and fasciculations. Unfortunately, you are unable to diagnose the disease, and he progresses to dementia. Exam shows frontal release signs and dysarthria. He ultimately succumbs to pneumonia.

Challenge: What's the diagnosis? Happy Halloween!