From the Guidelines
For a patient presenting with forgetfulness, I recommend a comprehensive and individualized lab workup that includes routine Tier 1 laboratory studies, such as complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid-stimulating hormone (TSH), vitamin B12, folate, and homocysteine levels, as suggested by the Alzheimer's Association clinical practice guideline 1. This approach is supported by the most recent and highest quality study, which emphasizes the importance of a multi-tiered and individualized laboratory evaluation in the assessment of cognitive or behavioral symptoms 1. The lab workup should be tailored to the patient's medical risks and profile, and may include additional tests such as:
- Testing for syphilis (RPR or VDRL), HIV (in at-risk individuals), and hemoglobin A1c
- Checking vitamin D levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) to evaluate for inflammatory conditions
- Brain imaging with MRI or CT scan to rule out structural abnormalities
- Lumbar puncture to evaluate for inflammatory or infectious conditions affecting cognition
- Cognitive testing using standardized tools like the Mini-Mental State Examination (MMSE) or Montreal Cognitive Assessment (MoCA) to complement laboratory testing This comprehensive approach allows for the identification of reversible causes of cognitive impairment, such as anemia, electrolyte abnormalities, thyroid dysfunction, vitamin deficiencies, infections, and metabolic disorders, before considering neurodegenerative disorders like Alzheimer's disease. It is essential to note that the diagnostic evaluation of mild cognitive impairment due to Alzheimer's disease involves a combination of clinical criteria, cognitive assessment, and biomarkers, as recommended by the National Institute on Aging and the Alzheimer's Association 1. Additionally, the use of cerebrospinal fluid biomarkers, such as amyloid-β, tau, and phosphorylated tau, can provide valuable information in the diagnostic evaluation of mild cognitive impairment, as suggested by the international working group 2 criteria for prodromal AD 1. However, the most recent and highest quality study 1 prioritizes a comprehensive and individualized lab workup, which should be the primary approach in the diagnostic evaluation of forgetfulness.
From the Research
Lab Workup for Forgetful Patients
- The lab workup for forgetful patients may involve a range of tests to rule out underlying medical conditions that could be contributing to their symptoms.
- A Complete Blood Count (CBC) is a common test that may be ordered, as it can provide information on various components of the blood, including white blood cell count, hemoglobin, and platelet count 2, 3.
- Other tests that may be ordered include:
- These tests can help identify underlying conditions such as anemia, thyroid disorders, or vitamin deficiencies that could be contributing to the patient's forgetfulness.
- It's worth noting that the study by 4 found that POAG patients had decreased vitamin D levels, which could be relevant to patients presenting with forgetfulness.
- However, it's also important to note that the relationship between these lab tests and forgetfulness is not always straightforward, and a comprehensive evaluation by a healthcare professional is necessary to determine the underlying cause of the patient's symptoms.