dementia

• Alzheimer's


  Plaques containing beta-amyloid peptide and neurofibrillary tangles containing tau protein, occur throughout the neocortex
• Alzheimer's risk factors


  • Age
  • Family history
  • Down's syndrome
  • APP (presenilin 1/2) mutation
  • History of hypertension
  • Dyslipidemia
  • Cerebrovascular disease
  • Altered glucose metabolism
  • Brain trauma
• Alzheimer's epidemiology


  Onset >60 years old if not familial
• Alzheimer's symptoms


  • Short-term memory impairment early and prominent
  • Variable deficits of executive function, visuospatial function and language
  • Memory impairment and difficulty remembering new information (early)
  • Behavioral/psychological symptoms (late/intermediate)
  • Incontinence (advanced)
• Alzheimer's MRI/CT findings


  Excludes other dementia causes, diffuse cortical atrophy especially in the hippocampus, gyri narrowing, sulci widening, ventricle enlargement
• Vascular dementia


  Multifocal ischemic changes
• Causes of vascular dementia

  • Cerebral artery atherosclerosis
  • Carotid artery/heart embolization
  • Chronic hypertension leading to cerebral arterioles sclerosis
  • Vasculitis
• Vascular dementia risk factors

  • Smoking
  • Hypertension
  • Diabetes
  • Insulin resistance
  • Hyperlipidemia
  • Hyperhomocysteinemia
• Vascular dementia epidemiology


  Increases with age, second most common cause of dementia
• Vascular dementia symptoms


  • Accumulation of cognitive defects associated with repeated strokes, frontal (executive dysfunction), left parietal (aphasia/apraxia/agnosia), right parietal (hemineglect, confusion, agitation, visuospatial, constructional difficulty), temporal (anterograde amnesia)
• Vascular dementia MRI/CT findings

  Shows multiple cortical, subcortical infarcts
• Lewy body dementia


  Alpha-synuclein-containing Lewy bodies (protein aggregation) occur in the brainstem, midbrain, olfactory bulb, and neocortex
• Lewy body dementia epidemiology

  Onset 50-85 years old
• Lewy body dementia symptoms

  • REM sleep behavior disorders - sleep walking, sleep talking
  • Autonomic nervous system dysfunction: orthostatic hypotension, syncope, urinary incontinence/retention, constipation, impotence
  • Repeated falls (parkinsonism)
  • Cognitive fluctuation
  • Hypotension
  • Neuroleptic sensitivity
• Lewy body dementia MRI/CT findings

  SPECT - dopamine transporter ligand ioflupane I-123 (DaTSCAN) shows decreased transporter perfusion
• Frontotemporal dementia


  Deficits in empathy, social comportment, insight, abstract thought, and executive function, speech issues delayed and apraxia symptoms later
• Lewy body dementia commonly presents with visual hallucinations