Neurology Book

http://www.fpnotebook.com/

DementiaAka: Alzheimer's Disease

Advertisement

  1. See also
    1. Delirium
    2. Altered Level of Consciousness
    3. Dementia Management
    4. Dementia Related Malnutrition
    5. Behavior Problems in Dementia
    6. Agitation in Dementia
    7. Sleep Problems in Dementia
    8. Wandering Behavior in Dementia
    9. Dementia Resources
  2. Definition
    1. Chronic loss of previously acquired mental function
  3. Epidemiology
    1. Prevalence
      1. Age over 65 years: 10%
      2. Age over 90 years: 50%
  4. Causes of Dementia
    1. See Dementia Causes
  5. Risks Factors for Alzheimer's Disease
    1. Age
      1. Risk increases with age over 65 years
    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. Myocardial Infarction
    9. Combined CV factors in middle age (odds ratio 3.5)
      1. Hyperlipidemia
      2. Hypertension (increased systolic Blood Pressure)
      3. Kivipelto (2001) BMJ 322:1447
  6. Types of Dementia
    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. Mixed Dementia (10-20%)
      1. Combined Cortical and subcortical
      2. Usually Alzheimer's with Multi-infarct Dementia
  7. Dementia Syndromes
    1. Alzheimer's Disease (60-70%)
    2. Dementia with Lewy Bodies (15-25%)
    3. Frontotemporal Dementia (5-15%)
    4. Vascular Dementia (5-20%)
    5. Creutzfeldt-Jakaob Disease (<1%)
  8. 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
  9. 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
  10. 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
  11. Evaluation
    1. See Mental Status Exam (lists all tests)
    2. Mental Status Screening (rapid clinic screening)
    3. Mini-Mental Status Exam
      1. Standard decline 3 points per 6 months
      2. Error is +/- 3 points
    4. Addenbrooke's Cognitive Examination (ACE)
      1. Differentiates Alzheimer's from other dementias
      2. Detect early dementia
    5. 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
  12. Dementia Diagnosis
    1. Amnesia (Wexler)
      1. Short Term Memory
      2. Long Term Memory
    2. One of the following (in addition to Amnesia Above)
      1. Aphasia (communication disorder)
      2. Apraxia (purposeful Movement Disorder)
      3. Agnosia (sensory interpretation deficit)
      4. Executive Function Disturbance (e.g. Serial 7's)
  13. Exacerbated by
    1. Illness
    2. Hospitalization
    3. Minor surgery
    4. Bereavement
  14. 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
  15. Labs and Diagnostics
    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. Metabolic screen (CCCD)
        1. Serum Electrolytes
        2. Serum Calcium
        3. Serum Glucose
    4. Evaluation only as indicated
      1. Erythrocyte Sedimentation Rate (ESR)
      2. Liver Function Tests
      3. Syphilis Serology (VDRL or RPR)
      4. Urinalysis
      5. Serum Magnesium
      6. Arterial Blood Gas (ABG)
      7. Medication Levels
      8. Chest XRay
      9. Electrocardiogram (EKG)
      10. Electroencephalogram (EEG)
        1. Seizure disorder
        2. Creutzfeldt-Jakob Disease (or other prion disease)
      11. Lyme Titer
      12. 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)
      13. Heavy metal screening
      14. Ceruplasmin for Wilson' Disease
      15. Arylsulfatase for metachromatic leukodystrophy
      16. Serum Protein Electrophoresis for Multiple Myeloma
      17. Human Immunodeficiency Virus (HIV)
      18. Connective Tissue Disease
        1. Antinuclear Antibody (ANA)
        2. C3 Complement
        3. C4 Complement
        4. Anti-DS DNA
      19. Urine Toxicologic screen
      20. Urine porphobilinogens
      21. Apolipoprotein E (not recommended)
  16. Imaging
    1. Imaging modalities
      1. Brain MRI (preferred): Especially coronal views
        1. Hippocampal atrophy is hallmark
      2. CT Head
    2. Imaging Indications
      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
      2. Dietch (1983) West J Med 138:835
  17. 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
  18. Differential Diagnosis
    1. See Altered Level of Consciousness
    2. Delirium
    3. Psychosis
    4. Major Depression
    5. Medications are a very common cause
      1. Polypharmacy
      2. Anticholinergic Medications (e.g. Elavil, Benadryl)
      3. Drug Toxicity (e.g. Digoxin, Phenytoin)
  19. Course
    1. Cases due to reversible cause: 10-20%
    2. High index of suspicion for reversibility in elderly
  20. Management
    1. See Dementia Management
  21. Neurology Consultation Indications
    1. Rapidly progressive dementia
    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
  22. Resources
    1. See Dementia Resources
  23. References
    1. Adelman (2005) Am Fam Physician 71:1745
    2. Daly (1999) J Am Board Fam Pract 12:375
    3. Santacruz (2001) Am Fam Physician 63:703
    4. (1994) Neurology 44:2203

Dementia (C0497327)

Definition (MSH)An acquired organic mental disorder with loss of intellectual abilities of sufficient severity to interfere with social or occupational functioning. The dysfunction is multifaceted and involves memory, behavior, personality, judgment, attention, spatial relations, language, abstract thought, and other executive functions. The intellectual decline is usually progressive, and initially spares the level of consciousness.
Definition (CSP)loss of intellectual functions such as memory, learning, reasoning, problem solving, and abstract thinking while vegetative functions remain intact.
ConceptsMental or Behavioral Dysfunction (T048)
ICD9290, 294.8
EnglishAmentia, Amentias, Dementia, Dementias
Spanishdemencia
CreditsDerived from the NIH UMLS (Unified Medical Language System)



Navigation Tree