Sponsors

You're browsing as an anonymous user. Join the community today to view notes at your university, edit pages, and share knowledge!

Alzheimer's Disease

From Mediwikis

Alzheimer's disease is the most common form of dementia, accounting for approximately 50% of cases. It is estimated to affect 496,000 people in the UK alone, and over 15 million worldwide.

Other causes include vascular dementia, Lewy body dementia, frontotemporal dementia, Parkinson's disease, alcoholic dementia and infections such as HIV and syphilis.

The onset of the disease is insidious and it usually progresses over 7-10 years. The mean survival of patients with Alzheimer's disease is 7 years from the clinical (overt) onset.

Pathology

  • Amyloid plaques
  • Neurofibrillary tangles
  • Reduction in brain tissue
  • Changes in neurotransmitter levels

Risk Factors

Stages

  1. Amnesia and spatial disorientation.
  2. Personality disintegration (eg with aggression, psychosis, agitation, depression) and focal parietal signs (eg dysphasia, apraxia, agnosia, acalculia). Parkinsonism and hyperorality may also occur.
  3. Neurovegitative changes with apathy or akathisia, wasting, immobility and incontinence. Seizures and spasticity may also occur.

General Clinical Features

  • Impaired cognition
  • Slow and muddle thinking
  • Poor memory
  • Delusions and hallucinations
  • Altered mood
  • Blunt affect
  • Emotional incontinence (eg excessive crying)
  • Altered speech: syntax errors, dysphasia, mutism

Diagnosis

There are various diagnostic criteria which may be used.

NICE recommends the use of the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS/ADRDA) diagnostic criteria.

Alternatives include the ICD-10 and DSM-IV criteria.

Management

  • Patient-centred care
  • Non-pharmacological:
    • structured group cognitive stimulation programme
    • memory enhancement strategies (eg reminder notes, lists, reorganisation of possessions)
    • cognitive behavioural therapy for those with anxiety or depression
  • Pharmacological:
    • acetylcholinesterase (AChE) inhibitor (eg donezepil, rivastigmine, galantamine)
      • for mild-moderate disease
    • NMDA antagonist (eg memantine)
      • as a second-line option
    • antidepressant
      • for those with depression
      • avoid tricyclic antidepressants - they may have an adverse effect on cognition

References

  1. Longmore M et al. Oxford Handbook of Clinical Medicine. 9th ed. Oxford: Oxford University Press, 2014.
  2. Coller J et al. Oxford Handbook of Clinical Specialties. 9th ed. Oxford: Oxford University Press, 2013.
  3. Patient. Alzheimer's Disease. Available at: http://patient.info/doctor/alzheimers-disease (accessed 12/12/2015).