What are the key clinical features that differentiate Creutzfeldt-Jakob Disease (CJD) from other neurodegenerative disorders?

Key clinical features that differentiate Creutzfeldt-Jakob Disease (CJD) from other neurodegenerative disorders include its rapid progression, characteristic neurological signs, and distinctive diagnostic findings.

CJD typically presents with a rapidly progressive dementia over weeks to months, which is much faster than the gradual decline seen in common neurodegenerative diseases like Alzheimer's or Parkinson's disease NICE CKS Geschwind & Murray 2018. Early prominent features include myoclonus (sudden, involuntary muscle jerks), cerebellar ataxia, visual disturbances, and pyramidal/extrapyramidal signs, which are less common or appear later in other dementias NICE CKS Mastrianni & Roos 2000.

Another distinguishing clinical hallmark is the presence of periodic sharp wave complexes on electroencephalogram (EEG), which supports the diagnosis of CJD but is not typical in other neurodegenerative disorders NICE CKS Geschwind & Murray 2018. Cerebrospinal fluid (CSF) analysis may reveal 14-3-3 protein and other prion-related biomarkers, aiding differentiation from other dementias NICE CKS Mastrianni & Roos 2000.

Unlike other neurodegenerative diseases, CJD often lacks a prolonged prodromal phase and shows rapid neurological decline leading to akinetic mutism within months NICE CKS Geschwind & Murray 2018. Sporadic fatal insomnia, a prion disease variant, may present with prominent sleep disturbances, which are not typical in other dementias Barash 2025.

In summary, the rapid clinical course, early myoclonus, characteristic EEG and CSF findings, and absence of a prolonged prodrome are key features that differentiate CJD from other neurodegenerative disorders NICE CKS Mastrianni & Roos 2000Geschwind & Murray 2018Barash 2025.