SHM Converge Scientific Abstract ePoster Gallery-A Cognitive Conundrum: Unmasking a Rapidly Progressive Dementia

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This case describes a 75-year-old woman with known dementia, hypertension, hypothyroidism, and a prior meningioma who developed acute-on-chronic altered mental status with rapidly worsening cognition, gait disturbance, visual hallucinations, poor depth perception, dysphagia, and decreased appetite. Her presentation raised concern for rapidly progressive dementia (RPD).<br /><br />The key teaching point is that even when common explanations exist, clinicians must keep a broad differential for RPD. Important causes include metabolic and nutritional deficiencies, CNS infections, medication toxicity, structural lesions such as masses or hydrocephalus, autoimmune/paraneoplastic disease, and prion disorders such as Creutzfeldt-Jakob disease (CJD). The case highlights diagnostic pitfalls such as anchoring bias, premature closure, and false reassurance from stable imaging or a prior dementia diagnosis.<br /><br />Despite stable MRI and EEG findings, the patient’s persistent decline prompted cerebrospinal fluid testing for prion disease. RT-QuIC was positive, providing the definitive diagnosis of sporadic CJD. She also met WHO/CDC probable CJD criteria based on progressive dementia, visual/cerebellar features, EEG periodic sharp wave complexes, and markedly elevated 14-3-3 protein.<br /><br />The take-home messages are:<br />1. Always broaden the RPD differential; a patient with established dementia can still develop a new neurologic disease.<br />2. Stable MRI/EEG does not exclude prion disease—ongoing clinical decline should trigger CSF prion biomarker testing, especially RT-QuIC, which can be decisive.<br /><br />Overall, the case emphasizes careful reconsideration of rapidly progressive neurologic symptoms and the importance of testing for prion disease even when more common diagnoses seem plausible.

Asset Subtitle

Angelina Piryani

Meta Tag

Author List Angelina Piryani, Anish Kumar, Manisha Piryani

Category Clinical Vignettes

Concept Rapidly Progressive Dementia

Concept Prion Disease

Concept Sporadic Creutzfeldt-Jakob Disease

Concept RT-QuIC

Concept Neuropathologic Confirmation

Distinguished Non-Finalist

Presenter Organization Ross University School of Medicine

Presenting Author Angelina Piryani

Track Adult

Keywords

rapidly progressive dementia

Creutzfeldt-Jakob disease

RT-QuIC

prion disease

altered mental status

visual hallucinations

gait disturbance

cerebrospinal fluid

anchoring bias

neurologic decline

Rapidly Progressive Dementia

Prion Disease

Sporadic Creutzfeldt-Jakob Disease

RT-QuIC

Neuropathologic Confirmation