RPD, CJD

Question 1

How is rapidly progressive dementia defined?

Answer 1

Dementia which develops within 12 months after appearance of first cognitive symptoms

Question 2

What are 4 recommendations of CCCDTD regarding investigations and management for RPD?

Answer 2

1. Refer to experienced physician for diagnosis
2. Exclude delirium and underlying causes, then base diagnostic strategy on prevalence of causes of RPD in case series
3. Emphasize detection of curable conditions (infectious, immune, toxic)
4. CSF biomarkers can be of benefit

Question 3

What lab work would you include for RPD work up?

Answer 3

Routine: CBC, lytes, Cr, LFTs, TSH, B12, glucose
Blood film
Syphilis, HIV
Rheum - RF, ANA, ESR/CRP, ENA, ANCA, C3/4
Infectious panel (Lyme)

Question 4

What special tests would you send for RPD work up?

Answer 4

CSF for:
- 14-3-3 protein for CJD
- Cell count and diff, glucose, protein
- Oligoclonal bands, IgG

Question 5

What imaging would you order for RPD?

Answer 5

MRI>CT
EEG

Question 6

What are the main causes for rapidly progressive dementia?

Answer 6

1. CJD
2. Neurodegenerative
3. Secondary
   a. Autoimmune
   b. Vascular
   c. Toxic/metabolic
   d. Neoplastic
   e. Psychiatric
   f. Infectious
   g. NPH

Question 7

What are clinical features of CJD?

Answer 7

1. Neuropsychiatric - dementia, behavioural changes, aphasia, apraxia, frontal lobe
2. Myoclonus
3. Cerebellar - nystagmus, ataxia
4. Corticospinal tract involvement - hyperreflexia, positive Babinski, spasticity
5. Extrapyramidal signs - hypokinesia, bradykinesia, dystonia, rigidity

Question 8

What are the diagnostic criteria for sporadic CJD?

Answer 8

1. Progressive dementia
   AND
2. At least 2/4 of:
   a. Myoclonus
   b. Visual or cerebellar disturbance
   c. Pyramidal or extrapyramidal dysfunction
   d. Akinetic Mutism
   AND
3. Supportive findings on one or more of:
   a. Typical EEG - periodic sharp wave complexes
   b. Positive 14-3-3 CSF
   c. MRI - hyper intensity in caudate nucleus/putamen and/or at least 2 cortical regions on DWI or FLAIR

Question 9

What investigations can confirm diagnosis of CJD?

Answer 9

1. Biopsy on autopsy
2. Positive RT-QuIC on CSF

Question 10

What is the underlying pathology of CJD?

Answer 10

Accumulation of prion protein (proteinaceous infectious particles)

Develop transmissible spongiform encephalopathy due to neuronal degeneration from accumulation of protease resistant pathologic isomer of prion protein