Skip to main content
Quest Diagnostics

Dementia, Secondary Causes

Test code(s) 91410

This panel is designed to evaluate patients for the presence of potentially reversible (ie, secondary) causes of dementia such as vitamin B12 deficiency, hypothyroidism, hypoparathyroidism, anemia, hypoxia or hypercapnia, hepatic and renal encephalopathies, diabetes, and dehydration.

The panel includes a complete blood count (including differential and platelets; test code 6399), TSH, vitamin B12, folate, and a comprehensive metabolic panel (test code 10231). It is modeled after the recommendations of the American Academy of Neurology (AAN), a National Institutes of Health Consensus Panel, the European Federation of Neurological Societies (EFNS), and others.1-5

Guidelines recommend screening for syphilis and HIV in patients with suggestive clinical features.1,2,4 Urinalysis, urine culture, and heavy metal screening may also be added as needed based on clinical suspicion.4 Finally, cerebrospinal fluid testing may be helpful in patients highly suspicious for neurosyphilis, HIV, cerebral Lyme disease, or vasculitis.2,3  

Simmons et al suggest ordering blood testing at the time of the initial assessment if cognitive impairment screening test results are abnormal or if there is clinical suspicion of another disease (Figure 1).4

At this time, dementia diagnosis is primarily based on clinical observation. Biomarker tests, however, may enhance the specificity of the diagnosis in research settings.5 Genetic tests may also enhance the specificity in such settings.

Athena Diagnostics, a Quest Diagnostics company, offers testing for total tau (T-tau), β-amyloid1-42 (Aβ42), and phosphorylated tau 181 (P-tau) protein biomarkers. Athena Diagnostics also offers mutation testing of the APOE, PSEN1, PSEN2, and APP genes. For more information, visit AthenaDiagnostics.com or call 1-800-394-4493.

References

  1. Knopman DS, DeKosky ST, Cummings JL, et al. Practice parameter: diagnosis of dementia (an evidence-based review). Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2001;56:1143-1153.
  2. Consensus conference. Differential diagnosis of dementing diseases. JAMA. 1987;258:3411-3416.
  3. Sorbi S, Hort J, Erkinjuntti T, et al. EFNS-ENS Guidelines on the diagnosis and management of disorders associated with dementia. Eur J Neurol. 2012;19:1159-1179.
  4. Simmons BB, Hartmann B, DeJoseph D. Evaluation of suspected dementia. Am Fam Physician. 2011;84:895-902.
  5. McKhann GM, Knopman DS, Chertkow H, et al. The diagnosis of dementia due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement. 2011;7:263-269.

 

This FAQ is provided for informational purposes only and is not intended as medical advice. A clinician’s test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

Document FAQS.88 Revision: 0

Our company

Quest® is the brand name used for services offered by Quest Diagnostics Incorporated and its affiliated companies. Quest Diagnostics Incorporated and certain affiliates are CLIA certified laboratories that provide HIPAA covered services.  Other affiliates operated under the Quest® brand, such as Quest Consumer Inc., do not provide HIPAA covered services. 

 

Quest®, Quest Diagnostics®, any associated logos, and all associated Quest Diagnostics registered or unregistered trademarks are the property of Quest Diagnostics. All third-party marks—® and ™—are the property of their respective owners. © 2024 Quest Diagnostics Incorporated. All rights reserved. Image content features models and is intended for illustrative purposes only.