What investigations should be done for agitation in dementia?

Investigations for Agitation in Dementia

The priority is to systematically rule out delirium and reversible medical causes before attributing agitation to dementia itself, as delirium is present in approximately 25% of hospitalized geriatric patients and is often superimposed on underlying dementia. 1

Initial Screening and Assessment

Cognitive and Delirium Screening

• Use validated screening tools to distinguish delirium from dementia, starting with a two-step delirium assessment: the highly sensitive Delirium Triage Screen followed by the Brief Confusion Assessment Method 1
• Perform dementia screening using validated instruments appropriate for the clinical setting to establish baseline cognitive function 1
• Document mental status formally, as this provides a baseline for future evaluations and guides directed interventions 1

Quantitative Behavioral Assessment

• Administer the Cohen-Mansfield Agitation Inventory (CMAI) or Neuropsychiatric Inventory Questionnaire (NPI-Q) to quantify baseline agitation severity and establish objective measures for monitoring treatment response 2, 3
• Use structured ABC (antecedent-behavior-consequence) charting to identify specific triggers and patterns of agitation 2, 3

First-Tier Laboratory Investigations

All patients with new or worsening agitation require comprehensive laboratory testing to identify reversible causes. 1

Essential Blood Work

• Complete blood count (CBC) to assess for infection or anemia 1
• Complete metabolic panel including electrolytes, glucose, calcium, and renal function to detect metabolic disturbances 1
• Thyroid-stimulating hormone (TSH) to exclude thyroid dysfunction 1
• Vitamin B12 and folate levels to identify nutritional deficiencies 1
• Urinalysis and urine culture as urinary tract infections are among the most common precipitants of agitation in dementia 1

Additional First-Tier Tests

• Medication review and measurable drug levels when applicable, with particular attention to anticholinergic medications, vasodilators, diuretics, antipsychotics, and sedative/hypnotics 1
• Oxygen saturation to ensure adequate oxygen delivery 1

Imaging Studies

Brain Imaging

• Obtain CT or MRI of the brain to exclude structural causes, particularly in atypical presentations, rapid progression, or when etiology remains uncertain 1
• Brain MRI without gadolinium is preferred when available; CT is acceptable if MRI is contraindicated or unavailable 1
• Imaging helps identify cerebrovascular disease, space-occupying lesions, or other structural abnormalities that may contribute to behavioral changes 1

Assessment for Common Precipitants

Infection Screening

• Actively investigate for infections, particularly urinary tract infections and pneumonia, as these are the most common infectious triggers of agitation in dementia 1
• Consider chest radiography if pneumonia is suspected clinically 1
• Obtain appropriate cultures based on clinical suspicion 1

Pain and Discomfort Assessment

• Systematically assess for pain, as untreated pain is a major contributor to behavioral disturbances in patients who cannot verbally communicate discomfort 1, 2, 3
• Evaluate for constipation, urinary retention, and dehydration as these commonly precipitate agitation 1, 2

Sensory and Environmental Factors

• Assess for sensory impairments including hearing and vision deficits that may increase confusion and fear 1, 3
• Evaluate environmental triggers and timing patterns (e.g., sundowning) 1

Second-Tier Investigations (Specialist Setting)

Reserve these investigations for atypical presentations, rapid progression, early-onset dementia, or when first-tier workup is unrevealing. 1

Advanced Laboratory Testing

• Homocysteine and methylmalonic acid (MMA) for more sensitive B12 deficiency assessment 1
• Rapid plasma reagin (RPR) or VDRL for neurosyphilis in appropriate clinical contexts 1
• HIV testing when risk factors present 1
• Antinuclear antibody (ANA), ANCA, and other autoimmune markers if autoimmune encephalopathy suspected 1
• Serum protein electrophoresis (SPEP) and urine protein electrophoresis (UPEP) for paraproteinemia 1

Specialized Studies

• Electroencephalogram (EEG) if seizure activity or specific encephalopathies are suspected 1
• Lumbar puncture with CSF analysis (cell count, glucose, protein, and potentially AD biomarkers including amyloid beta-42, tau, and phospho-tau) in rapidly progressive or atypical cases 1
• Sleep study for obstructive sleep apnea or REM sleep behavior disorder if Lewy body dementia suspected 1

Critical Pitfalls to Avoid

• Never assume agitation is simply "part of dementia" without systematically excluding delirium and reversible medical causes, as this leads to missed treatable conditions and worse outcomes 1
• Do not overlook medication-induced agitation, particularly from anticholinergic agents, which can worsen confusion and behavioral symptoms 1
• Avoid attributing agitation to dementia in patients with acute or fluctuating symptoms, as this pattern strongly suggests delirium requiring urgent investigation 1
• Remember that dementia and delirium frequently coexist, with delirium superimposed on baseline cognitive impairment 1