Neurocognitive disorders
BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.
Neurocognitive disorders
Fasting laboratory tests
- FBC
- CRP
- Serum electrolytes
- Serum calcium
- Serum albumin
- Serum creatinine with eGFR
- Fasting plasma glucose
- TSH
- Vitamin B12if neededDepending on the clinical context, or from the outset if the symptoms start before age 65: the HAS (2011, 2018) reserves them for the clinical context [2,3], and the 2026 recommendations of the memory centres also request them routinely in young patients [4]. In Quebec (B12) and Switzerland (B12, folate, transaminases, GGT), they are part of the baseline tests [5,6].
- Vitamin B9 (folate)if neededDepending on the clinical context, or from the outset if the symptoms start before age 65: the HAS (2011, 2018) reserves them for the clinical context [2,3], and the 2026 recommendations of the memory centres also request them routinely in young patients [4]. In Quebec (B12) and Switzerland (B12, folate, transaminases, GGT), they are part of the baseline tests [5,6].
- ASTif neededDepending on the clinical context, or from the outset if the symptoms start before age 65: the HAS (2011, 2018) reserves them for the clinical context [2,3], and the 2026 recommendations of the memory centres also request them routinely in young patients [4]. In Quebec (B12) and Switzerland (B12, folate, transaminases, GGT), they are part of the baseline tests [5,6].
- ALTif neededDepending on the clinical context, or from the outset if the symptoms start before age 65: the HAS (2011, 2018) reserves them for the clinical context [2,3], and the 2026 recommendations of the memory centres also request them routinely in young patients [4]. In Quebec (B12) and Switzerland (B12, folate, transaminases, GGT), they are part of the baseline tests [5,6].
- GGT (liver function tests)if neededDepending on the clinical context, or from the outset if the symptoms start before age 65: the HAS (2011, 2018) reserves them for the clinical context [2,3], and the 2026 recommendations of the memory centres also request them routinely in young patients [4]. In Quebec (B12) and Switzerland (B12, folate, transaminases, GGT), they are part of the baseline tests [5,6].
- syphilis serologyif neededDepending on the clinical context, and from the outset if the symptoms started before age 65.
- HIV serologyif neededDepending on the clinical context, and from the outset if the symptoms started before age 65.
- Lyme serologyif neededDepending on the clinical context, and from the outset if the symptoms started before age 65.
Do not order
- Repeating laboratory tests done recently for another reason: “it is pointless to prescribe them again” [3].
- Repeating recent brain imaging in the absence of any new element: “it is not recommended to repeat it” [3].
- Measuring plasma pTau217 (or another blood biomarker of Alzheimer's disease): not indicated for screening, even with a family history, nor when the cognitive examination is normal; prescribing it is a matter for a memory clinic doctor or one trained in cognitive disorders, and none of these tests is listed in the French laboratory fee schedule (NABM) [4].
- Genotyping APOE to make the diagnosis: “it is not recommended to perform a specific APOE gene analysis for diagnostic purposes” [4].
Sources (13)
- [Epidemiology of neurocognitive disorders in France] (Rochoy M, Chazard E, Bordet R)
- Guide parcours de soins des patients présentant un trouble neurocognitif associé à la maladie d’Alzheimer ou à une maladie apparentée (HAS, 2018)
- Haute Autorité de santé. Maladie d'Alzheimer et maladies apparentées : diagnostic et prise en charge. Recommandation de bonne pratique, décembre 2011.
- Fédération des centres mémoire (avec la SFGG, la SF3PA, la SFNR, la SFMN et la SFBC). Recommandations pour le diagnostic de la maladie d'Alzheimer. Juin 2026 (version française actualisée de : Dumurgier J et al. Rev Neurol (Paris) 2025;181:1021-1029, PMID 41033931).
- Institut national d'excellence en santé et en services sociaux (INESSS, Québec). Protocole médical national n° 628013 : Initier un bilan sanguin à la suite du repérage de symptômes et signes suggestifs d'un trouble neurocognitif léger ou majeur. Mars 2020.
- Swiss Memory Clinics (Popp J, Meyer-Heim T, Bürge M, Ehrensperger MM et al.). Recommandations de SMC pour le diagnostic des troubles cognitifs – mise à jour 2024 (Alzheimer Suisse).
- Guideline Adaptation Committee (Australie). Clinical Practice Guidelines and Principles of Care for People with Dementia. NHMRC Partnership Centre for Dealing with Cognitive and Related Functional Decline in Older People, Sydney, 2016.
- Kramer ES, Johnson MN, Winslow B. Evaluation of Suspected Dementia. Am Fam Physician. 2025;112(6):657-667.
- Falk N, Cole A, Meredith TJ. Evaluation of Suspected Dementia. Am Fam Physician. 2018;97(6):398-405.
- Atri A, Dickerson BC, Clevenger C, Karlawish J, et al. Alzheimer's Association clinical practice guideline for the Diagnostic Evaluation, Testing, Counseling, and Disclosure of Suspected Alzheimer's Disease and Related Disorders (DETeCD-ADRD): Executive summary of recommendations for primary care. Alzheimers Dement. 2025;21(6):e14333.
- National Institute for Health and Care Excellence (NICE). Dementia: assessment, management and support for people living with dementia and their carers. Guideline NG97, juin 2018.
- U.S. Preventive Services Task Force (USPSTF). Cognitive Impairment in Older Adults: Screening. Recommandation, février 2020 (I).
- Assurance maladie. Nomenclature des actes de biologie médicale (NABM), version 105 : actes 0388 (VIH, B40), 1256 (syphilis, B20), 1301 (Lyme, B59).