Chapter 58 Alzheimer’s disease
Dementia can be defined as an acquired global impairment of cognitive function (i.e. the intellectual abilities involved in thinking, learning and remembering) with no decrease in the level of consciousness. There are many causes (Table 3.58.1), but by far the most common in industrialized countries is the topic of this chapter, Alzheimer’s disease.
Table 3.58.1 Common causes of dementia
| Disorders | Examples |
|---|---|
| Primary neurodegenerative disorders | Alzheimer’s disease; Pick’s disease; Huntington’s disease; diffuse Lewy body disease |
| Secondary dementias | |
| Cerebrovascular disease | Multi-infarct dementia |
| Prion diseases (spongiform encephalopathies) | Creutzfeld–Jacob disease; variant Creutzfeld–Jacob disease |
| Microorganisms | Neurosyphilis, HIV |
| Gross structural abnormalities | Hydrocephalus; space-occupying lesions |
| Metabolic abnormalities | Hypothyroidism; liver failure |
| Repeated diffuse trauma | Dementia pugilistica |
| Toxins | Chronic alcoholism; lead poisoning |
| Demyelinating diseases | Multiple sclerosis |
| Vitamin deficiencies | B1, B2, B12 |
