Primary progressive aphasia with focal periodic sharp wave complexes: An unusual manifestation of Creutzfeldt-Jakob disease.

Background: Creutzfeldt-Jakob disease (CJD) is a devastating degenerative brain disorder caused by an abnormal isoform of a cellular glycoprotein which is known as the prion protein. A diagnosis of CJD is usually based on specific clinical signs, EEG and MRI findings, as well as the presence of the 14-3-3 protein in the cerebrospinal fluid. Although end-stage CJD usually has a typical clinical presentation, early symptoms may be variable. Case presentation: We present an uncommon case of CJD which manifested with primary progressive aphasia, leading to an incorrect diagnosis of frontotemporal dementia. EEG performed eight months after symptom onset revealed focal periodic sharp wave complexes that later evolved into diffuse EEG abnormalities characteristic of CJD. Brain MRI also suggested the diagnosis of CJD. Later, the patient developed rapidly progressive dementia, visual symptoms, ataxia, extrapyramidal symptoms, followed by dysphagia and mutism, and died 34 months after disease onset. Discussion and conclusion: PPA is a relatively uncommon first manifestation of CJD, occurring only in about 1% of all CJD cases. Our case is also remarkable because we were able to capture focal periodic sharp wave complexes at the stage of the CJD when aphasia was the only clinical manifestation. We demonstrate that both brain MRI and wake and sleep EEG should be a mandatory part of the diagnostic workup for patients presenting with primary progressive aphasia.