Dementia is caused by various diseases and conditions, many with no cure. The table below shows the early symptoms, pathology, and prevalence of four main dementia subtypes, all progressive and irreversible.
| Type of Dementia | Early Symptoms | Pathology | Prevalence |
| Alzheimer’s Disease | impaired memory, apathy, wandering, getting lost; problem recognizing others; impulsiveness; difficulty communicating | Abnormal deposits of amyloid plaques and tau tangles; slow, insidious decline | 50 to 70% of all irreversible dementias; onset >60, sometimes younger with family predisposition |
| Vascular Dementia | Mood fluctuations; some forgetting; difficulty following direction and new learning; misplacing items | Blood clots disrupt blood flow, CV disease, single or multi-infarcts; stepwise decline | 20 to 30%; onset typically >65 |
| Dementia with Lewy Bodies | Concentration, attention and alertness; disorganized thinking, muscle rigidity, daytime sleepiness, loss of coordination | Abnormal deposits or aggregation of “lewy bodies” (alpha synuclein) affecting brain’s chemical signals | <5%; onset at 50mor older (also seen in Parkinson’s disease) |
| Fronto-temporal Dementia | Difficulty planning and organizing; personality and mood changes; difficulty with balance and walking, language | Abnormal amounts of tau and proteins in neurons in frontal and temporal lobes | 5 to 10%; typically younger onset (45-64) |
Closing
This article on dementia subtypes is referenced in the Living to 100 Club’s new publication. It is Better, Longer & Happier: A Guide to Aging with Purpose and Positivity. In the Guide, Module 08 is focused entirely on gaining a better understanding of depression, dementia, and delirium.