In plain English
UK memory clinics follow NICE NG97 to investigate suspected dementia systematically. This section covers each test, what it does, what to expect, what the result means, and how the tests fit together to support a diagnosis.
The standard UK dementia work-up
NICE NG97 sets out the recommended sequence of investigations:
- Clinical history, ideally with input from a close family member;
- Structured cognitive testing: the Addenbrooke's Cognitive Examination (ACE-III) is the UK standard, with the Mini-ACE as a shorter alternative;
- Blood tests to rule out reversible causes (see blood tests);
- An Electrocardiogram if anti-dementia medication is being considered (see ECG);
- Structural brain imaging: Magnetic Resonance Imaging preferred, Computed Tomography where MRI is not possible;
- Advanced imaging only when subtype is uncertain and would change management: FDG-PET, SPECT or DAT Scan;
- Lumbar Puncture for Cerebrospinal Fluid biomarkers in selected cases (see Lumbar Puncture);
- Neuropsychometric assessment where the cognitive picture is complex or atypical (see neuropsychometric testing);
- Genetic testing in selected cases, particularly young-onset or with strong family history (see genetic testing);
- Capacity assessment where a specific decision (Will, LPA, residence, treatment) is in question (see capacity assessment).
What to expect at assessment
A typical first appointment in a memory clinic lasts 60 to 90 minutes. It includes a detailed history, a structured cognitive test, and a discussion of next steps. Blood tests, the ECG and the brain scan are usually arranged separately. The findings are explained at a follow-up appointment, usually 4 to 8 weeks later.
If you would value an assessment sooner, The Dementia Service, the leading UK Private Memory Clinic, typically offers an appointment within a few weeks. The structured letter is sent to your GP.
What each test contributes
- ACE-III: the core cognitive screen, scored out of 100.
- Mini-ACE: a shorter five-minute version, useful when the full ACE-III is not possible.
- Blood tests: rule out Vitamin B12 and folate deficiency, thyroid disease, kidney impairment, calcium disturbance, glucose dysregulation, liver dysfunction.
- Electrocardiogram: required before Cholinesterase Inhibitor prescribing to check for slow heart rate or conduction problems.
- MRI brain scan: structural imaging with visual rating scales (MTA, GCA, Fazekas).
- CT brain scan: alternative to MRI where MRI is not possible.
- FDG-PET: brain metabolism imaging for atypical or uncertain cases (NICE NG97 1.2.15).
- SPECT and DAT Scan: dopamine transporter imaging in suspected Dementia with Lewy Bodies (NICE NG97 1.2.20).
- Lumbar Puncture and CSF biomarkers: amyloid and tau measurement, particularly relevant for the new antibody therapies.
- Neuropsychometric testing: detailed cognitive profile by a clinical psychologist.
- Visual rating scales: MTA (Scheltens), GCA (Pasquier), Fazekas explained.
- Genetic testing: APOE, PSEN, GRN, C9orf72 and others, with counselling.
- Capacity assessment: structured assessment of capacity for a specific decision (Will, LPA, residence, treatment).
The principles
Three NICE principles guide UK practice:
- 1.2.13: Offer structural imaging to rule out reversible causes and to assist with subtype diagnosis.
- 1.2.14: Only consider advanced testing where it would change management.
- 1.2.17: Do not rule out Alzheimer's Disease on imaging alone.
Private versus NHS testing
The NHS provides the full diagnostic pathway at no cost, with waiting times that vary by region. Private memory clinics can offer faster access, structured, ICD-11 aligned reporting, and can arrange any tests needed directly. The two routes can be combined. See private versus NHS pathways.
Frequently asked questions
Do I need every test?
No. The standard work-up is history, cognitive test, blood tests, ECG and structural scan. Advanced imaging, Lumbar Puncture and neuropsychometric assessment are reserved for cases where they would change management.
How long does the work-up take?
Typically 8 to 16 weeks from referral to follow-up appointment in the NHS; 2 to 6 weeks privately. The tests themselves take an hour or two of contact time, spread over a few visits.
Can the tests rule out dementia?
No single test rules out dementia. The diagnosis rests on the clinical picture combined with investigation findings. A normal MRI does not exclude Alzheimer's Disease.
Will I get a copy of my results?
Yes. You are entitled to a copy of the assessment letter and the investigation reports. Ask at the appointment.
What if a test is abnormal but I do not have dementia?
Many findings on brain imaging (age-related involutional change, mild Small Vessel Disease) are common and do not indicate dementia. Interpretation is always in the context of the clinical picture.
References
- NICE NG97: Dementia, assessment, management and support.
- Royal College of Psychiatrists. Memory Services National Accreditation Programme.
- British Geriatrics Society. Comprehensive geriatric assessment.
- Royal College of Radiologists. Imaging guidance for dementia.
