Creutzfeldt-Jakob disease is a very rare, progressive neurodegenerative disorder that is incurable and always fatal. It is one of the transmissible spongiform encephalopathies caused by prions. Multiple vacuoles in neuropil and neuronal loss in the gray matter gives the classical sponge–like appearance of brain and are responsible for the typical clinical symptoms.

In this report, we present 4 cases referred to the neurology department of Uludağ University with neurological symptoms. Patients were evaluated with electroencephalogram and magnetic resonance imaging, and performed brain biopsies for further investigation. For definitive diagnosis of Creutzfeldt-Jakob disease, accumulation of prion protein in brain was detected immunohistochemically. Patients died within weeks in consequence of rapid progression of the disease.

Although Creutzfeldt-Jakob disease is an infrequent disorder, when a patient presents with characteristic clinical symptoms such as rapidly progressive dementia with myoclonus, the diagnosis of Creutzfeldt-Jakob disease should be taken into consideration.