• Defined as a loss in previously attained intellectual abilities that is severe enough to affect everyday life.
  • Memory problems are the most common sign
  • Affects up to 11% of adults >65%
  • Most commonly caused by Alzheimer disease, dementia with Lewy bodies, and vascular dementia

Symptoms and Signs

  • Memory loss plus impairment in one of the following areas: language, perception, visuospatial function, calculation, judgement, abstraction or problem solving skills


  • Increased in people older than 65


  • A clinical diagnosis in most cases
  • Blood test to rule out reversible causes of dementia (such as B12 def)
  • Brain biopsy- normally reserved for a chronic progressive disorder with an unusual course


  • Dependent on underlying cause


  • Dependent on underlying cause

Differential Diagnosis

  • Alzheimers
  • Creutzfeldt-Jakob disease, AIDS encephalopathy
  • Brain tumor such as a low grade astrocytoma
  • Parkinson disease
  • B12, niacin, thiamine deficiency
  • Depression