Alzheimer's Dementia (AD)
- Profile: Insidious progressive course of cognitive disability, often many years; onset before or after age 65
- Diagnosis: proliferation of neural plaques and tangles at autopsy
- Subtypes:
- Sporadic (most cases) or
- Familial (5%-10% of cases)
- Communication: Language impairment common; semantic system most affected; progression to mutism
- Behavior: depression, insomnia, incontinence, delusions, agitation
Lewy Body Dementia (LBD)
- Profile: Periods of normal cognition alternate with abnormal cognition; progressive course, often rapid
- Diagnosis: Lewy bodies at autopsy
- Subtypes:
- Attentional impairment
- Visual hallucinations
- Parkinsonism
- Communication: Motor speech disorder with hypophonia
- Behavior: Periods of delirium (confusion); daytime drowsiness
Vascular Dementia (VaD)
- Profile: Abrupt deterioration; course may be stable, improving or worsening (stair-step decline)
- Diagnosis: varied, including multiple-infarcts, strategically placed single-infarct, small-vessel disease, multiple lacunes, hypoperfusion, or hemorrhage
- Subtypes:
- Predominantly cortical clinical signs
- Predominantly subcortical clinical signs
- Extent of brain lesions
- Communication: Motor speech disorder prominent; may have simplified grammar and writing; slowness and reduced initiation
- Behavior: Depression and mood changes
Frontotemporal Lobar Dementia (FTD)
- Profile: Insidious onset, more likely before age 65; progressive course, often slow
- Diagnosis: Focal cortical atrophy
- Subtypes:
- FTD-Frontal variant (executive dysfunction)
- FTD-Temporal variant (semantic deficits)
- FTD-nonfluent aphasia variant
- Communication: Varies with subtype
- Behavior: Wide range, especially frontal lobe variant
For a comprehensive discussion, see Horner, J., Norman, M. & Ripich, D. (2004, in press). Dementia: Diagnostic approaches and current taxonomies. In A.F. Johnson & B.H. Jacobson (eds.). Medical speech-language pathology: A practitioner's guide. New York: Thieme.
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