What are the clinical manifestations of Creutzfeldt-Jakob disease (CJD) presenting as dementia?

From the Guidelines

Prion disease presenting as dementia is a rapidly progressive and fatal condition, and the most recent and highest quality study recommends a diagnostic approach that includes MRI brain imaging, EEG, cerebrospinal fluid testing for 14-3-3 protein or RT-QuIC assay, and genetic testing for familial forms 1. When prion disease manifests as dementia, it typically progresses much faster than other forms of dementia like Alzheimer's disease, with patients often showing a rapid cognitive decline over weeks to months rather than years, accompanied by myoclonus, ataxia, visual disturbances, and psychiatric symptoms.

Key Diagnostic Features

• MRI brain imaging may show characteristic cortical ribboning or basal ganglia hyperintensities
• EEG may show periodic sharp wave complexes
• Cerebrospinal fluid testing for 14-3-3 protein or RT-QuIC assay can support the diagnosis
• Genetic testing for familial forms can help identify the underlying cause

Management and Prognosis

• Unfortunately, there is no effective treatment to halt or reverse prion diseases
• Management focuses on supportive care, symptom control, and palliative measures
• Medications like clonazepam may help control myoclonus, while antipsychotics might be needed for psychiatric symptoms
• The prognosis is poor, with most patients surviving only 6-12 months after symptom onset, as reported in a study published in The Lancet Neurology 1

Importance of Early Recognition

• Early recognition is important for appropriate counseling of patients and families
• Infection control measures can help prevent the spread of the disease
• Avoiding unnecessary interventions can improve the quality of life for patients and their families, as highlighted in a study published in the Journal of the American College of Radiology 1

From the Research

Prion Disease Presenting as Dementia

• Prion diseases are rapidly progressive neurodegenerative diseases that frequently mimic other forms of dementia, making them difficult to diagnose 2.
• The majority of cases do not receive an initial diagnosis of prion disease, with the plurality of subjects receiving an initial diagnosis of a non-prion disease related dementia 2.
• Prion diseases can present as a rapidly progressive dementia (RPD) with behavioral, cerebellar, extrapyramidal, and some pyramidal features, with a median survival from symptom onset to death of just a few months 3.
• Creutzfeldt-Jakob disease (CJD) is a rare cause of dementia and typically manifests as a rapidly progressive dementia, where symptom onset to dementia most often occurs over the course of months 4.

Clinical Features and Diagnosis

• Several clinical features are associated with initial diagnoses of prion disease, including survival time, onset of specific symptoms, and times to 14-3-3 analyses and electroencephalogram 2.
• New diagnostic methods are improving premortem and earlier diagnosis of prion diseases 5.
• Expanding our knowledge of the various clinical presentations of prion disease, especially dementia, may aid in the earlier diagnoses of these rapidly progressive diseases 2.

Differential Diagnosis

• Prion diseases can be difficult to diagnose as they can mimic many other conditions that present as RPD, and some of those conditions can present similarly to prion disease 3.
• A mnemonic used for remembering the various categories of RPDs is VITAMINS-D, for vascular, infectious, toxic-metabolic, autoimmune, mitochondrial/metastases, iatrogenic, neurodegenerative, system/seizures/sarcoid, and demyelinating 3.
• Prion disease can also be the cause of terminal decline in chronic mixed dementia, highlighting a rare but epidemiologically important cause of sudden decline in well-established neurodegenerative dementias 4.