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Dementia

Definition

(Show Disclaimer) Note: I copy the "definition" of something straight from the book. I find it's best to have an all-encompassing definition in order to better orient myself when I am studying.

Show Definition
  1. Neurocognitive disorders are characterized by deficits in cognitive function, with a significant decline from a previous level of function. Decline may be evident in one or more areas of function, including attention, language, memory, visuospatial skills, or executive function (e.g., complex tasks such as organizing, sequencing, judgment, and reasoning).
  2. Neurocognitive disorders include Alzheimer’s disease, vascular dementia, Lewy body dementia, and other dementias (frontotemporal dementia, Parkinson’s dementia, HIV dementia, neurosyphilis, and Korsakoff’s dementia).
  3. Clinical features that differentiate these disorders:
    1. Alzheimer's disease.
      1. Gradual onset and a course of progressive decline.
      2. Memory, language, and visuospatial deficits.
      3. Depressive symptoms, which may precede diagnosis.
      4. Delusions, hallucinations, agitation, and apathy.
    2. Vascular dementia:
      1. Abrupt onset and a stepwise course of progression.
      2. Aphasia.
    3. Lewy body dementia:
      1. Visual hallucinations and delusions.
      2. Extrapyramidal symptoms (muscle rigidity, Parkinsonism).
      3. Fluctuating mental status.
      4. Increased sensitivity to antipsychotic medications.
    4. Frontotemporal dementia:
      1. Change in personality.
      2. Hyperorality.
      3. Impairment in executive function, with relatively well-retained visuospatial skills.
      4. Loss of social awareness.
  4. Important to distinguish:

    The diagnosis of dementia must be differentiated from delirium, a disturbance in cognition that develops over a short period and is characterized by an alteration in attention that fluctuates in severity during the course of the day.

    Delirium may be the consequence of an acute medication condition, hospitalization, or medication/substance induced.

    Delirium typically may last weeks to months, with gradual improvement in cognition.

Incidence and Prevalence

Likely not important for the NAC OSCE exam.

(If you're a keener click here)

Pathogenesis

Likely not important for the NAC OSCE exam, but I think it helps with DDx.

(If you're a keener click here)

Predisposing factors

  1. Definite risks:
    • Advanced age.
    • Atrial fibrillation.
    • Depression.
    • Family history.
    • Down syndrome.
  1. Possible Risks:
    • Delirium.
    • Head trauma (e.g., sports, accidents, boxing).
    • Heavy smoking.
    • Chronic poor sleep (e.g., sleep apnoea, insomnia).

Common Findings

Copied the "findings" straight from the book, which are mostly cognitive. I would say Social withdrawal possibly related to depression in some cases.

  1. Disoriented to date and/or place.
  2. Naming difficulties (anomia).
  3. Impaired recent recall.
  4. Decreased insight.
  5. Impaired judgments.
  6. Social withdrawal.
  7. Problems managing finances, inability to pay bills and manage finances, spending money in unusual ways.
  8. Getting lost in familiar environments.
  9. Lack of safety awareness: leaving the stove on, taking medications incorrectly, increased vulnerability to strangers.

Impairment of remote memory carries a graver prognosis than the loss of recent memory alone.

History

  1. Use family members, learn onset and duration of sx.
  2. Question mood (also if anhedonia), ADLs: hygiene, safety, grooming, independent.
  3. STIs.
  4. Ask about Rx, esp. those w/ anticholinergic side effects, include OTC (e.g. diphenhydramine).
  5. New stressors: loss of loved one, new environment, loss of interest after retirement.
  6. (I added this): Esp. if delirium is suspected, ROS should include signs/sx related to possibly sepsis (UTI/PNA/Skin wound).

Physical Exam

Coming soon.

Diagnostic Tests

  1. Formal testing includes:
    1. Mini-Mental State Examination (MMSE).
    2. Montreal Cognitive Assessment (MoCA).
    3. The clock draw test (CDT) may also be administered and used as a screening tool.
  2. Rule out reversible causes:
    (I don't think you will order these tests, but this list really helps with DDx. Click to enlarge.)
    1. Thyroid function tests, to rule out either hypothyroidism or hyperthyroidism.
    2. Complete blood count (CBC).
    3. Vitamin B12 level: Anaemia or B12 deficiency.
    4. Serum chemistry profile: Hyponatraemia, hypomagnesia.
    5. Toxicology screen or serum drug screen: Toxicity or intoxication.
    6. Rapid plasma reagin (RPR), fluorescent treponemal antibody absorption (FTA-ABS), or microhaemagglutination assay for antibody to Treponema pallidum (MHA-TP; cerebrospinal fluid [CSF]) to confirm syphilis, if indicated.
    7. HIV-1 antibody titre, if indicated: AIDS–dementia complex.
    8. Liver function tests: Liver disease.
    9. CT scan or MRI: Vascular dementia, tumour, chronic subdural haematoma (SDH), normal pressure hydrocephalus, and AIDS–dementia complex.
    10. EEG: Creutzfeldt–Jakob disease, if indicated.
    11. Neuropsychological evaluation.

History is KEY in establishing diagnosis. Normal aging does NOT cause significant decreases in IQ.

DDx

  1. Completely reversible dementia (see diagnostic tests section for causes):
    1. Depression and adverse reactions to medications are the most common reversible causes of dementia .
    2. Use the DEMENTIA mnemonic:
      1. D: Drugs or depression.
      2. E: Emotional upset.
      3. M: Metabolic, for example, vitamin B12 deficiency or hypothyroidism.
      4. E: Ear or eye impairment or sensory impairment.
      5. N: Normal pressure hydrocephalus.
      6. T: Tumours or masses, for example, SDH.
      7. I: Infection or sepsis.
      8. A: Anaemia.
  2. Alzheimer’s disease.
  3. Dementia with Lewy bodies.
  4. PD with dementia.
  5. Vascular dementia.
  6. Frontotemporal dementia.

Plan

Follow-up

In one month to evaluate client's status, compliance/response to Rx, side fx.

Consultation/Referral

Multi-team approach to comprehensive care.

Individual Considerations

Pediatric (if present at young age) and geriatric care as per guidelines

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