Human prion diseases can be classified as sporadic, hereditary or acquired. The acquired forms are known to be caused by the transmission to human from human or animal, via medical appliances, oral intake or parenteral solutions. Usually, peripheral infection such as oral(Kuru) or parenteral (human pituitary hormones) transmission causes cerebellar degenerative form, and central nervous system infection such as neurosurgical treatment, dura mater grafts or corneal grafts transmission causes clinical features similar to sporadic form of Creutzfeldt-Jakob disease (CJD). The variant CJD (vCJD) is considered to be transmitted bovine spongiform encephalopathy(BSE) to human through dietary exposure. The early clinical features of vCJD are dominated by psychiatric symptoms, and minor number of patients have neurological symptoms from the onset. After about 6 months, there are frank neurological signs, including ataxia, cognitive impairment and involuntary movements.