Overview

• Dementia → cognitive impairment that impairs with independence and ADLs.
• <65yo = early-onset dementia.

1. Alzheimer’s Disease
   • Cerebral atrophy due to neuronal loss. Amyloid plaque formation and tau protein tangles. Hippocampi in temporal lobe are affected.
   • Sx → insidious onset, slowly progressive cognitive decline over years with a gradual loss of function.
   • MRI → grey matter atrophy, wide ventricles and sulci, temporal lobe atrophy.
2. Vascular Dementia
   • Stroke related vascular dementia → dementia after infarction, CT scan will show lacunary infarcts.
   • Sx → sudden onset (may follow CVA), stepwise deterioration of cognitive function.
   • Mx → risk factor modification (aspirin + manage BP, cholesterol, glycaemic control).
     • Aspirin only if indicated due to previous CVA or AF risk.
3. Lewy Body Dementia
   • Lewy Bodies → α-synuclein.
   • Sx (TRIAD) → fluctuating cognitive impairments + hallucinations (haLEWYcinations) + parkinsonism.
     • Can be worsened by antipsychotics.
   • Mx → acetylcholinesterase inhibitors (donepezil or rivastigmine). Do NOT offer antipsychotics.
4. Frontotemporal Dementia
   • Atrophy of frontal and temporal regions.
   • Sx → changes in personality, lack of social awareness, aggression and disinhibition, lack of filter and empathy.
   • Mx → non-pharmacological (behavioural interventions and environmental modifications).

• Pseudodementia → global memory loss in severe depression (dementia will instead cause recent memory loss). Much quicker onset.

Making Diagnosis

Clinical Features

• Cognitive Impairment → memory (forgetfullness), orientation (disorientation to time, person or place), visuo-spatial (reading, writing, getting lost), language (reading, speech, comprehension), executive functioning (planning, problem solving, organising), social cognition.

• Non-Cognitive Impairment → behavioural symptoms (agitation, wandering, apathy), psychotic symptoms (delusions and hallucinations), affective symptoms (depression).

  <aside> 💡 If patient has sleep disturbance, stress triggers and normal mini-mental test score with global memory loss, consider depression rather than dementia.

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• 4A’s → amnesia (recent memories lost first), aphasia (can’t find right words), agnosia (can’t recognise things), apraxia (can’t do skilled tasks, eg. dressing).

Investigations

• Bedside → collateral history, physical exam, risk assesment, cognitive screen (AMTS, MMSE), urine dipstick (UTI and glucose - look for causes of delirium).
  • MMSE in Alzheimer’s (≥25/30 = normal) → 21-24 = mild, 10-20 = moderate, <10 = severe.
  • AMTS <8/10 = cognitive impairment.
• Bloods (rule out organic causes of memory loss and delirium) → FBC, U&Es, glucose, LFTs, calcium, TFTs (hypothyroidism), B12 + folate, septic screen.
• Brain Scan (organic pathology)