Dementia

Definition

Syndrome due to disease of the brain, usually of chronic or progressive nature, in which there are multiple disturbances of higher cortical function. Usually accompanied by changes in emotional control, social behaviour and motivation. These changes occur in clear consciousness.

Epidemiology

• 5% over 65, 20% over 80

• Commonest (~50%) is Alzheimer's disease

• Next commonest (~20%) is vascular dementia

Causes of Dementia

• Primary Cerebral Degenerations

  • Alzheimer's Disease

  • Pick's disease

  • Parkinson's Disease

  • Lewy Body dementia

  • Huntington's disease

  • Progressive supranuclear palsy

  • Wilson's disease

  • Spinocerebellar degeneration

• Space Occupying lesions

  • Tumours

  • Subdural haematoma

  • giant aneurysm

  • hydrocephalus

• Cerebral infection

  • Neurosyphilis

  • Encephalitis

  • meningitis

  • AIDS

  • cerebral abscess

• Prion disease

  • Creutzfeld-Jacob disease

  • Gerstman-Straussler disease

  • Kuru

• Storage diseases

  • Metachromatic leukodystrophy

  • adrenoleukodystrophy

  • cerebral lipidoses

• Inflammatory systemic diseases

  • multiple sclerosis

  • systemic lupus erythematosis

• Cerebrovascular disease

  • multi-infarct dementia

  • Binswanger's disease

  • Lacunar infarcts

• Trauma and anoxia

• Toxic

  • Alcohol

  • Drugs

  • Poisons

  • Heavy metals

• Metabolic

  • hypothyroidism

  • hypo/hyper calcaemia

  • hypoglycaemia

  • hyper/hypo natraemia

  • chronic hepatic encephalopathy

  • chronic uraemia

  • porphyria

• Nutritional

  • B₁₂ deficiency

  • Pellagra

  • Malabsorption

  • thiamine deficiency

Clinical Features

Early

• Mild memory impairment
• difficulties with ADLs
• personality changes
  • withdrawn
  • passive
• mood changes
  • depression
  • anxiety
• speech
  • word finding difficulties

Late

• marked memory impairment
• marked decline in ADLs
• Speech
  • paraphasias
  • nominal dysphasia
  • perseverative
• Behaviour
  • day/night reversal
  • repetitive requests
  • labile mood
  • aggression
  • wandering
  • hyperactivity
  • sexual disinhibition

Psychiatric symptoms

• delusions
• persecutory ideas
• hallucinations
• misinterpretations
• depressives syndromes

Diagnosis

• Clinical
  • history from informant
  • physical examination
  • mental state exam
• Bloods
  • FBC, U&E, ESR, LFT, TFT, glucose, Ca, PO₃, B₁₂ and folate, VDRL
• CXR
• ECG
• Possibly
  • EEG
  • CT / MRI
  • psychometric testing

Management

• Treat medical disorders & causes of disability
• Assess and maximise ADLs
• finances
  • Enduring Power of Attorney or Court of Protection
• early referral to social services
• most live at home
  • home alone
    • home care worker
    • meals on wheels
    • day centre
  • home with carer
    • ADS / age concern advice
    • respite
    • CPN for behaviour problems
    • high prevalence of depression in carers
• Assess dependency and risk
  • LA home
  • residential
  • nursing homes
  • NHS care

Drugs tried to treat dementia

• Improved blood flow
  • dihydroergotoxine
• Psychostimulation (monoamine receptors)
  • pentoxyfylline
• Enhanced mental performance (potentiation of glutamate)
  • piracetam
  • aniracetam
• Cholinergic replacement
  • cholinesterase inhibitors
    • Donepezil
    • tacrine
    • physostigmine
  • muscarinic agonists
    • arecoline
    • pilocarpine
  • nicotine

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