There are three types of cortical dementia:
- Primary degenerative dementia (eg, Alzheimer dementia), accounting for about 50–60% of cases.
- atherosclerotic (multi-infarct) dementia, 15–20% of cases (this figure is probably low because of the tendency to overuse the diagnosis of Alzheimer dementia)
- Mixtures of the first two types or dementia due to miscellaneous causes, 15–20% of cases . Examples of primary degenerative dementia are Alzheimer dementia (most common) and Pick, Creutzfeldt-Jakob, and Huntington dementias (less common).
In all types, loss of impulse control (sexual and language) is common. The tenuous level of functioning makes the individual most susceptible to minor physical and psychological stresses. The course depends on the underlying cause, and the general trend is steady deterioration.
Pseudodementia is a term applied to depressed patients who appear to be demented. These patients are often identifiable by their tendency to complain about memory problems vociferously rather than try to cover them up. They usually say they can’t complete cognitive tasks but with encouragement can often do so. They can be considered to have depression-induced reversible dementia that remits when the depression resolves.
