Creutzfeldt-Jakob disease (CJD) is a rare and fatal human neurodegenerative disorder characterized by a rapidly progressive dementia, myoclonus, cerebellar, pyramidal, extrapyramidal, visual symptoms, and psychiatric manifestations. CJD occur sporadically in about 85% of cases, 10%-15% are inherited, <1% are iatrogenic, and <1% are variant. 1,2 Normal cellular prion protein (PrPC) is found on cell membranes throughout the mammalian body. Disease-causing form of prion (PrPSc) multiplies by binding to the normal cellular isoform PrP and converts it into an abnormal, structurally altered disease-causing PrPSc, which then spreads and accumulates throughout the brain leading to spongiform neurodegeneration. 1 CJD occurs worldwide, but as systematic surveillance has only been undertaken in a minority of countries, the incidence in much of the world is currently unknown. 3,4 Usually, initial diagnosis of CJD may be obscured by its variable presentation. We herein present a case of a 66-year-old female who was admitted to our university hospital for a rapidly progressive cognitive decline followed by ataxia and myoclonus. She was diagnosed with sporadic CJD, based on her clinical features, cerebrospinal fluid (CSF) studies, electroencephalogram (EEG), and brain magnetic resonance imaging (MRI) imaging sequences. 2 | CASE DESCRIPTION A 66-year-old female was referred to our hospital with 4-month history of progressive cognitive decline, behavioral, and personality changes. She was in her usual state of health until four months ago when she was noted by her family members to have easy forgetfulness and worsening functional impairment. She was initially noted to be aggressive and stopped taking care of herself. As per the husband, she would have sudden outbursts of agitation and delusional behavior followed by paranoid behavior. She initially presented