The purpose of this study to investigate if cases of Creutzfeldt-Jakob Disease (CJD) and other forms of prion disease are being missed in older adults living within Lothian.

The study involves patients aged 65 years or over who have been seen by a neurologist or psycho-geriatrician and identified as having features that are atypical for the known types of dementia. All patients will be invited to an initial meeting with the research team to discuss the study and, if they agree to participate, for clinical assessment and epidemiological review. Participants will be asked to donate blood or a buccal sample for codon-129 polymorphism genotyping and may be offered a MRI brain scan if no such imaging has been previously undertaken. Participants will also be asked to consider if, in the event of their death, they would donate samples of brain tissue to the Edinburgh Brain Bank for use in this and future research. Telephone follow up will be offered within 1 month of joining the study and at 3 monthly intervals thereafter, with further clinical review offered if deemed appropriate.

Inclusion Criteria:

• Patients aged 65 years or above
• Patients accessing NHS Lothian neurology and psychogeriatric services
• Patients who have features atypical for the recognised forms of dementia
• Appropriate informed consent

Exclusion Criteria:

• Patients aged below 65 at time of recruitment
• Patients diagnosed with a clear alternative demonstrable pathology

Patients aged 65+ accessing NHS Lothian neurology/psychogeriatric services with atypical features of the recognised forms of dementia. Eligible patients will be identified by the local clinical team by screening their existing patient lists, as they see patients as they attend their clinic or are visited in the community. The clinic staff are asked to consult the study team to confirm the patient's eligibility.