Dementia

Aka: Dementia, Alzheimer's Disease, Alzheimer Disease, Alzheimers Disease

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II. Definitions

  1. Dementia
    1. Chronic loss of previously acquired mental function, including impaired memory, judgment, attention span and problem solving
  2. Alzheimer's Disease
    1. Progressive, uniformly fatal, neurodegenerative disease of the brain with gradual development of Dementia
    2. Typical onset after age 60 and associated with severe cortical atrophy, senile Plaques, neurofibrillary tangles

III. Epidemiology

  1. Prevalence (U.S.)
    1. Age 65 to 74 years: 5%
    2. Age 75 to 84 years: 13%
    3. Age >85 years: 33%

IV. Pathophysiology: Alzheimer's Disease

  1. Gradual accumulation of amyloid Plaques and neurofibrillary tangles (hyperphosphorylated Tau Proteins)
  2. Neurofibrillary Tangles lead to Neuron degeneration, cerebral atrophy, Memory Loss, overall functional decline

V. Causes

  1. See Dementia Causes

VI. Risks Factors: Alzheimer's Disease

  1. Age >65 years old (greatest risk factor)
  2. Apo E4 Allele
    1. Confers 8% risk if two Alleles
  3. Family History of Alzheimer's Disease
  4. FAD gene
  5. Female gender
  6. Low education
  7. Head Trauma
  8. Cardiovascular disease (e.g. prior Myocardial Infarction)
  9. Cerebrovascular Disease (e.g. prior Cerebrovascular Accident)
  10. Diabetes Mellitus
  11. Combined CV factors in middle age (Odds Ratio 3.5)
    1. Hyperlipidemia
    2. Hypertension (increased systolic Blood Pressure)
    3. Kivipelto (2001) BMJ 322:1447-51 [PubMed]

VII. Types: Presentations

  1. Cortical (e.g. Alzheimer's Disease): 60-70% of cases
    1. Short Term Memory loss
    2. Aphasia
    3. Apraxia
  2. Subcortical (e.g. Vascular Dementia): 10-20%
    1. Mental slowing
    2. Mood disturbance
  3. Metabolic Dementia (e.g. Vitamin B12 Deficiency)
    1. Similar presentation as subcortical Dementia
  4. Lewy Body Disease (7%)
    1. Parkinsonian symptoms with Dementia
  5. Frontotemporal Dementia
    1. Socially inappropriate and compulsive behaviors
    2. Empathy loss, change in political and religious beliefs
    3. Progressive Aphasia
  6. Mixed Dementia (10-20%)
    1. Combined Cortical and subcortical
    2. Usually Alzheimer's with Multi-infarct Dementia

VIII. Types: Dementia Syndromes

  1. Alzheimer's Disease (60-70%)
  2. Dementia with Lewy Bodies (15-25%)
  3. Frontotemporal Dementia (5-15% overall, but 60% in those 45-60 years old)
  4. Vascular Dementia (5-20%)
  5. Creutzfeldt-Jakaob Disease (<1%)

IX. Criteria

  1. Insidious, gradual onset (months) of deterioration
    1. Mild to severe fluctuations
    2. All higher cortical functions
  2. Long duration of symptoms
  3. Normal Level of Consciousness, but altered content
    1. Impaired memory and
    2. One higher cortical function (e.g. Judgement)
  4. Vital Signs typically normal

X. Presentations: Early

  1. New information is difficult to learn and retain
  2. Complex tasks are difficult to perform
  3. Unable to solve simple problems
  4. Getting lost in familiar surroundings
  5. Difficulty expressing oneself
  6. Irritable or aggressive behavior

XI. History

  1. Family members should accompany patient to appointment, sitting side-by side with patient
  2. First ask questions of patient "why are you here?"
    1. Do not spend much time on this aspect
    2. Establish relationship with patient and establish reliability as historian
  3. Ask family (and patient if mild Dementia)
    1. Baseline functional status (education level, work responsibilities)?
    2. When was the first time their thinking and memory was completely normal?
    3. Timeline of cognitive function loss since onset?
    4. Is there any time you thought they were having a stroke?
    5. Do they repeat? misplace? Forget names? Rely more on notes and calendars?
    6. Who is in charge of medications? Bill Paying? checkbook balancing (IADLs) ?
    7. Word finding difficulty?
    8. Get lost driving?
    9. Do you feel comfortable leaving them alone? Overnight? For a weekend? for a week?
    10. Can they perform Activities of Daily Living (ADLs)?
    11. Are they depressed? anxious? agitated or restless?
    12. Do they have Hallucinations?
    13. How is sleep? Do you sleep in the same bed? Nighttime Incontinence?
    14. Has there been Head Trauma?
  4. References
    1. McCarten (2009) UMN CME Internal Medicine Review, Minneapolis

XII. Findings: Signs and symptoms

  1. Normal alertness, awareness, attentiveness
  2. No Hallucinations or Delusions
  3. Disorientation
  4. Memory Impairment (short much more than long term)
    1. New forgetfulness
    2. Difficult word finding
  5. Impaired Executive, Social, or cognitive function
    1. Driving difficulties or getting lost
    2. Neglect of self care and household chores
    3. Difficult money handling
    4. Work mistakes
    5. Judgement and Language impaired
  6. Behavior changes
    1. See Behavior Problems in Dementia
  7. Personality change
    1. Inappropriately friendly or even flirtatious
    2. Affect shallow or blunted or social withdrwal
    3. Frustration to explosive spells
  8. Psychiatric symptoms
    1. Suspiciousness or paranoia
    2. Withdrawal or apathy
    3. Abnormal beliefs or Hallucinations
  9. Provocative Factors
    1. Acute illness
    2. Hospitalization
    3. Minor surgery
    4. Bereavement

XIII. Evaluation: Dementia Screening Tools

  1. See Mental Status Consolidated Screening
  2. Mini-Cognitive Assessment Instrument
    1. Patient repeats and recalls 3 unrelated words, and draws a clock face with a given time
  3. General Practitioner Assessment of Cognition (GPCOG)
    1. https://www.alz.org/documents_custom/gpcog(english).pdf
  4. Ascertain Dementia 8-Item Informant Questionnaire
    1. https://www.alz.org/documents_custom/ad8.pdf
  5. Early Detection and Screen for Dementia (NTG-EDSD)
    1. https://www.the-ntg.org/ntg-edsd
    2. Indicated in adults with Down Syndrome or other congenital intellectual disabilities

XIV. Evaluation: Dementia Diagnosis Tools

  1. See Mental Status Exam (lists all tests, history, exam)
  2. St. Louis University Mental Status (SLUMS)
    1. http://medschool.slu.edu/agingsuccessfully/pdfsurveys/slumsexam_05.pdf
  3. Addenbrooke's Cognitive Examination (ACE)
    1. Differentiates Alzheimer's from other Dementias
    2. Detect early Dementia
  4. Mini-Mental Status Exam (requires payment for use)
    1. Standard decline 3 points per 6 months
    2. Error is +/- 3 points
  5. Montreal Cognitive Assessment
    1. http://dementia.ie/images/uploads/site-images/MoCA-Test-English_7_1.pdf
  6. Psychometric Testing
    1. Test of higher cognitive functioning
      1. Logical, abstract, conceptual and verbal reasoning
      2. Identifies more subtle changes in cognition
    2. Indications
      1. Early Dementia
      2. Depression
      3. Alcohol Abuse versus Alzheimer's Disease
      4. Unusual Dementias
      5. Non-english speaker or patient with less education

XV. Evaluation: Depression Screening Tools

  1. Patient Health Questionaire 9 (PHQ-9)
  2. Zung Depression Rating Scale
  3. Cornell Scale for Depression in Dementia
  4. Geriatric Depression Scale (GDS, also in short version)

XVI. Diagnosis

  1. See Dementia Diagnosis

XVII. Associated Conditions

  1. Gait Apraxia
  2. Disinhibited behavior
  3. Slurred speech if Vascular
  4. Anxiety, mood, and sleep disturbance
  5. Delusions and Visual Hallucinations
  6. Speech rambling, irrelevant, and incoherent
  7. Personality change

XVIII. Labs: Secondary Cause Evaluation

  1. Goals: Rule out reversible cause (Delirium Causes)
  2. Guidelines vary based on organization
    1. American Academy of Neurology (AAN)
    2. Canadian Consensus Conference on Dementia (CCCD)
  3. Standard Evaluation
    1. Thyroid Stimulating Hormone (AAN, CCCD)
    2. Serum Vitamin B12 Level (AAN)
    3. Complete Blood Count (CCCD)
    4. Comprehensive Metabolic Panel
      1. Serum Electrolytes
      2. Serum Calcium
      3. Serum Glucose
      4. Liver Function Tests
      5. Renal Function Tests
  4. Evaluation only as indicated
    1. Syphilis Serology (VDRL or RPR)
    2. Urinalysis
    3. Serum Magnesium
    4. Arterial Blood Gas (ABG) or Venous Blood Gas (VBG)
    5. Medication Levels
    6. Chest XRay
    7. Electrocardiogram (EKG)
    8. Electroencephalogram (EEG)
      1. Seizure Disorder
      2. Creutzfeldt-Jakob Disease (or other Prion Disease)
    9. Lyme Titer
    10. Lumbar Puncture for rapidly progressive Dementia
      1. Systemic signs and symptoms
      2. Atypical presentation
      3. Cancer
      4. Hydrocephalus
      5. Infectious disease
        1. Neurosyphilis
        2. HIV Infection
        3. Cerebral Lyme Disease
        4. Creutzfeldt-Jakob Disease (or Prion Disease)
          1. Positive CSF for 14-3-3 Protein
    11. Heavy Metal screening
    12. Ceruplasmin for Wilson' Disease
    13. Arylsulfatase for metachromatic leukodystrophy
    14. Serum Protein Electrophoresis for Multiple Myeloma
    15. Human Immunodeficiency Virus (HIV)
    16. Connective Tissue Disease
      1. Erythrocyte Sedimentation Rate (ESR)
      2. C-Reactive Protein (C-RP)
      3. Antinuclear Antibody (ANA)
      4. C3 Complement
      5. C4 Complement
      6. Anti-DS DNA
    17. Urine Toxicologic screen
    18. Urine porphobilinogens

XIX. Labs: Alzheimer Disease Specific Testing

  1. Apolipoprotein E (not recommended)
  2. PrecivityAD
    1. Marketed for age 60 years old and older with Cognitive Impairment
    2. Combines 2 tests
      1. Apolipoprotein E (apoE) Genotype
      2. Amyloid-Beta (Abeta) Peptides: Abeta 42 to Abeta 20 ratio
    3. Generates a proprietary Amyloid Probability Score
      1. Low Likelihood <36
      2. Intermediate Likelihood 36 to 57 (consider Amyloid PET)
      3. High Likelihood >57
    4. References
      1. Anderson (2022) Am Fam Physician 105(1): 79-81 [PubMed]
  3. Lumipulse G
    1. Marketed for age 55 years old and older with Cognitive Impairment
    2. Measures multiple biomarkers for Alzheimer Disease in cerebrospinal fluid (CSF)
      1. Total and Phosphorylated Tau
      2. Amyloid-Beta (Abeta) Peptides: Abeta 42 to Abeta 40 ratio
        1. Low ratio <0.072 supports Alzheimer Disease diagnosis
    3. References
      1. Lau (2023) Am Fam Physician 107(5): 550-1 [PubMed]

XX. Imaging

  1. Imaging modalities
    1. Brain MRI (preferred): Especially coronal views
      1. Hippocampal atrophy is hallmark
    2. CT Head
      1. Poor Test Sensitivity in Dementia
      2. Evaluates for Intracranial Mass, Intracranial Hemorrhage, large CVA
    3. Amyloid Positron Emission Tomography (PET) Scan
      1. Indicated if definitive diagnosis will impact management
      2. Cost is $5000 in 2022 (may be covered by Medicare)
      3. Good efficacy in comparison with autopsy confirmed Alzheimer Disease
        1. Test Sensitivity: 91%
        2. Test Specificity: 92%
  2. Imaging Indications (indicated in most cases of Dementia)
    1. Age under 60 years old
    2. Dementia with duration under 1 month
    3. Rapid progression over months
    4. Recent Head Trauma
    5. History of Cerebrovascular Accidents
    6. History of cancer
    7. History of Anticoagulant use
    8. Seizure Disorder
    9. Urinary Incontinence of new onset
    10. Headaches
    11. Focal neurologic findings
    12. Visual Field Defects
    13. Papilledema
    14. Gait Abnormality or Ataxia
  3. References
    1. Chertkow (2001) Can J Neurol Sci 28:S28-41 [PubMed]
    2. Dietch (1983) West J Med 138:835 [PubMed]

XXI. Diagnostics: Special Tests (Research use only currently)

  1. Cerebrospinal Fluid for Alzheimer's specific Proteins
    1. High tau
    2. Low Beta-Amyloid
  2. Functional imaging
    1. SPECT scan
    2. Positron Emission Tomography (PET Scan)
    3. Functional Head MRI

XXII. Differential Diagnosis

  1. See Dementia Differential Diagnosis
  2. See Altered Level of Consciousness
  3. Delirium
    1. Especially if recent hospitalization or illness
  4. Psychosis
  5. Major Depression
  6. Medications are a very common cause
    1. See Drug Induced Altered Level of Consciousness Causes
    2. See Polypharmacy
    3. See Medication Use in the Elderly (Beers List, STOPP)
    4. Anticholinergic Medications (e.g. Elavil, Benadryl)
    5. Drug Toxicity (e.g. Digoxin, Phenytoin)

XXIII. Course

  1. Cases due to reversible cause: 10-20%
  2. High index of suspicion for reversibility in elderly

XXIV. Management

  1. See Dementia Management

XXV. Management: Neurology Consultation Indications

  1. Rapidly progressive Dementia (weeks to months)
  2. Dementia in a young patient
  3. Severe behavior psychiatric abnormalities
  4. Red Flags for uncommon Dementia
    1. Significant personality change
    2. Extrapyramidal signs
    3. Rapid progression
    4. Gaze Palsy
    5. Urinary Incontinence
    6. Gait Abnormality

XXVI. Management: Evaluate the Caregivers - Family journey phases

  1. Prediagnostic: Is there a real issue?
  2. Diagnosis: Tramua of the diagnosis
  3. Role changes: Taking away rights
  4. Chronic caregiving: Engulfment and exhaustion
  5. Shared care: Obtaining respites
  6. Long term care: Patient is moved to long-term care
  7. End of life: Prolonging life versus a good death
  8. Reference
    1. Caron (2000) Alzheimer's Disease - The Family Journey, North Ridge Press, Plymouth, MN

XXVII. Resources

  1. See Dementia Resources

XXVIII. References

  1. (1994) Neurology 44:2203-6 [PubMed]
  2. Adelman (2005) Am Fam Physician 71:1745-50 [PubMed]
  3. Daly (1999) J Am Board Fam Pract 12:375-85 [PubMed]
  4. Falk (2018) Am Fam Physician 97(6): 398-405 [PubMed]
  5. Santacruz (2001) Am Fam Physician 63:703-18 [PubMed]
  6. Jaqua (2024) Am Fam Physician 110(3): 281-93 [PubMed]

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