Initial Bloodwork for Dementia Evaluation

Core Laboratory Tests

The Alzheimer's Association recommends a comprehensive Tier 1 laboratory panel including CBC with differential, complete metabolic panel, TSH, vitamin B12, homocysteine, CRP, and ESR for all patients presenting with cognitive or behavioral symptoms concerning for dementia 1, 2, 3, 4
The American Geriatrics Society suggests assessing renal function, including BUN and creatinine, to evaluate for uremia 5
The American Academy of Neurology and the Alzheimer's Association recommend checking hepatic function, including AST, ALT, alkaline phosphatase, and bilirubin, as part of the initial dementia workup 5, 6
The Alzheimer's Association guidelines designate the use of CBC with differential to identify anemia, infection, or hematologic abnormalities that may contribute to cognitive symptoms as a Strength of Recommendation A 1, 2, 3, 4
The Mayo Clinic recommends assessing electrolytes, including sodium, potassium, chloride, and bicarbonate, to identify hyponatremia, a treatable cause of cognitive impairment 6
The Alzheimer's Association suggests evaluating glucose levels, as both hypoglycemia and hyperglycemia can cause cognitive dysfunction 1
The Journal of the American Geriatrics Society recommends checking calcium levels, as hypercalcemia from hyperparathyroidism is a reversible cause of cognitive impairment 5
The Alzheimer's Association guidelines recommend assessing magnesium and phosphate levels as part of the comprehensive metabolic panel 1, 2, 3, 4

The Mayo Clinic Proceedings suggest checking thyroid-stimulating hormone (TSH) levels, as hypothyroidism is a common reversible cause of dementia 6, 5, 1
The Journal of the American Geriatrics Society recommends evaluating vitamin B12 levels, as deficiency can mimic or exacerbate dementia symptoms 6, 5, 1
The Mayo Clinic Proceedings suggest checking folate levels, although it is less commonly causative, alongside B12 6, 7

The Alzheimer's Association recommends assessing C-reactive protein (CRP) to evaluate for systemic inflammation 1, 2, 3, 4
The Alzheimer's Association suggests evaluating erythrocyte sedimentation rate (ESR) as an additional inflammatory marker 1, 2, 3, 4

The Alzheimer's Association recommends checking homocysteine levels, as elevated levels may contribute to vascular cognitive impairment 1, 2, 3, 4

The Alzheimer's Association guidelines suggest that the multi-tiered laboratory approach serves to identify common comorbid conditions that rarely cause but often contribute to cognitive symptoms, allowing for treatment of reversible or exacerbating factors 1, 2
The Mayo Clinic Proceedings recommend integrating laboratory results with the patient's clinical history, cognitive testing results, and physical examination findings to identify treatable contributing factors 6

The Journal of the American Geriatrics Society suggests ordering syphilis serology (RPR/VDRL) only when clinical suspicion exists for neurosyphilis, not as routine screening 5
The Mayo Clinic Proceedings recommend ordering HIV testing in patients with risk factors or atypical presentations 6
The Journal of the American Geriatrics Society suggests ordering heavy metal screening only with specific exposure history 7
The Journal of the American Geriatrics Society recommends ordering urinalysis when urinary tract infection is suspected as a delirium trigger 7

The Alzheimer's Association guidelines suggest that the comprehensive panel is more extensive than older guidelines but reflects current understanding that inflammatory markers and homocysteine provide additional diagnostic value 1
The Journal of the American Geriatrics Society recommends considering the cost-effectiveness of the comprehensive panel, which can vary depending on comprehensiveness, but the clinical yield of identifying treatable conditions justifies the more thorough modern approach 5