From the Guidelines
Blood tests for dementia should include a comprehensive panel to rule out treatable causes of cognitive decline, as recommended by the most recent guidelines 1. When evaluating patients with suspected dementia, it is essential to order a range of laboratory tests to identify potential underlying causes of cognitive impairment. These tests typically include:
- Complete blood count
- Comprehensive metabolic panel
- Thyroid function tests (TSH, T3, T4)
- Vitamin B12 and folate levels
- Syphilis screening
- Homocysteine levels
- Inflammatory markers like C-reactive protein
- Lipid profiles The results of these tests can help identify conditions such as thyroid disorders, vitamin deficiencies, infections, or metabolic problems that can mimic dementia symptoms but are treatable. While blood tests cannot definitively diagnose Alzheimer's or other forms of dementia, they are an essential part of the diagnostic process to exclude other causes of cognitive impairment. According to the most recent study 1, blood biomarker tests for the detection of AD pathology have been developed and are now widely used in AD research studies and clinical trials. However, the performance of these tests varies widely, and there is a need for standardization of collection, processing, and storage procedures, as well as agreed-upon procedures to monitor and maintain long-term stability in the biomarker measurements 1. In clinical practice, blood tests are typically ordered during the initial evaluation of memory concerns, and some may be repeated periodically to monitor treatment effectiveness or disease progression. It is crucial to note that the diagnosis of dementia requires a comprehensive assessment, including a thorough medical history, physical examination, cognitive testing, and structural brain imaging, in addition to laboratory tests. By following the recommended guidelines and using the most recent evidence, healthcare providers can ensure that patients with suspected dementia receive an accurate diagnosis and appropriate treatment.
From the Research
Blood Work for Dementia
- Blood work is an essential component of the diagnostic evaluation for dementia, as it can help identify underlying causes of cognitive decline 2, 3, 4.
- The initial laboratory evaluation for dementia typically includes tests for:
- These tests can help identify reversible causes of dementia, such as vitamin B12 deficiency or hypothyroidism 3, 4.
- Additional laboratory tests, such as cerebrospinal fluid assays or genetic testing, may be considered in atypical dementia cases, such as age of onset younger than 65 years, rapid symptom onset, and/or impairment in multiple cognitive domains but not episodic memory 2, 5.
- Serum biomarkers are also being researched as a potential tool for earlier and more accurate diagnosis of dementia 6.
Diagnostic Evaluation
- A comprehensive evaluation for dementia includes a thorough medical history and physical examination, which may reveal important clues about the potential underlying causes of cognitive decline 2, 5, 6.
- Validated cognitive assessment tools, such as the Mini-Mental State Examination, can help clinicians identify the extent and nature of cognitive deficits, and track disease progression over time 3, 6.
- Brain imaging, such as noncontrast computed tomography or magnetic resonance imaging, is also recommended as part of the diagnostic evaluation for dementia 3, 5.