What is the recommended workup for dementia?

Recommended Workup for Dementia

A comprehensive dementia workup should include standardized cognitive assessments, functional evaluations, informant reports, laboratory testing, and neuroimaging to accurately diagnose dementia and identify potentially reversible causes. 1, 2

Initial Cognitive Assessment

• Screening Tools: Begin with rapid screening instruments:

  • Mini-Cog or Memory Impairment Screen (MIS) + Clock Drawing Test 1, 2
  • Four-item version of MoCA (Clock-drawing, Tap-at-letter-A, Orientation, and Delayed-recall) 1
  • AD8 or GP Assessment of Cognition (GPCOG) 1

• Comprehensive Assessment: If screening indicates concerns or for more thorough evaluation:

  • Montreal Cognitive Assessment (MoCA) - preferred for mild cognitive impairment with 90% sensitivity 2
  • Mini-Mental State Examination (MMSE) - widely used but less sensitive for mild impairment 1
  • Modified Mini-Mental State (3MS) examination or Rowland Universal Dementia Assessment Scale (RUDAS) 1

Important caveat: The MMSE has limitations in detecting mild cognitive impairment and should not be used alone for diagnosis 2, 3. The MoCA is more sensitive for detecting mild cognitive impairment and should be used when MMSE scores are "normal" (24+ out of 30) but cognitive concerns persist 1.

Functional Assessment

• Assess Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADLs) using:
  • Pfeffer Functional Activities Questionnaire (FAQ) 1
  • Disability Assessment for Dementia (DAD) 1

Behavioral and Psychological Assessment

• Evaluate for behavioral changes and mood disorders:
  • Short version of the Neuropsychiatric Inventory (NPI-Q) 1
  • Mild Behavioural Impairment Checklist (MBI-C) 1
  • Patient Health Questionnaire-9 (PHQ-9) for depression screening 1, 2
  • Confusion Assessment Method (CAM) to rule out delirium 2

Informant Reports

• Obtain information from a reliable informant using standardized tools:
  • Ascertain Dementia 8 (AD-8) questionnaire 1
  • Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) 1

Key point: Combining cognitive tests with functional screens and informant reports significantly improves diagnostic accuracy 1, 2.

Laboratory Testing

• Standard laboratory workup to rule out reversible causes:
  • Complete blood count
  • Comprehensive metabolic panel
  • Thyroid function tests
  • Vitamin B12 levels 2

Neuroimaging

• Brain MRI (preferred) or non-contrast CT to evaluate:
  • Structural causes
  • Vascular disease
  • Patterns of atrophy 1, 2

Indications for neuroimaging include:

• Onset of cognitive symptoms within past 2 years
• Unexpected decline in cognition/function
• Recent head trauma
• Unexplained neurological manifestations
• History of cancer
• Risk for intracranial bleeding
• Significant vascular risk factors 1

Special Considerations

• High-risk populations requiring increased vigilance:

  • History of stroke or TIA
  • Late-onset depression
  • Untreated sleep apnea
  • Recent delirium
  • First major psychiatric episode at advanced age
  • Recent head injury
  • Parkinson's disease 1, 2

• Additional specialized testing in atypical cases (age <65, rapid onset, or unusual presentation):

  • Cerebrospinal fluid assays
  • Genetic testing 4
  • Consider FDG-PET or Amyloid PET in select cases 2

Follow-up Assessment

• Regular follow-up every 3-6 months to:
  • Evaluate effectiveness of interventions
  • Assess for risk factors for progression
  • Monitor cognitive, functional, and behavioral changes 2
  • Consider longitudinal serial cognitive assessments (e.g., QuoCo curves) to improve diagnostic accuracy 1

The diagnostic criteria for dementia require cognitive or behavioral symptoms that:

1. Interfere with ability to function at work or usual activities
2. Represent a decline from previous functioning
3. Are not explained by delirium or major psychiatric disorder
4. Include impairment in at least one cognitive domain (memory, reasoning, visuospatial, language, or personality/behavior) 2, 4