Types of Dementia
The 4 main types of dementia are-
Alzheimer’s dementia. This is the commonest type of dementia. The classic feature is progressive short term memory loss. As the disease progresses it affects the ability to think, plan, organise one’s day, language, communication and manage simple daily tasks.
Vascular dementia. Vascular dementia is dementia caused by a stroke or evidence of vascular brain injury on brain CAT scan or MRI scan (post-stroke dementia).
These patients with post-stroke dementia experience a stepwise cognitive decline after a stroke.
They usually have prominent impairment of executive functions (planning and getting daily activites done), sometimes with relative sparing of memory.
They may have other signs of stroke such as aphasia (comprehension and language impairment), dyspraxia (impaired co-ordination and planning of movements and activities), and apathy.
Many patients with Alzheimer’s dementia already have evidence of previous strokes or vascular disease on brain scans without symptoms of previous strokes.
The prevalence of vascular dementia is declining and is less than 10% of all dementia.
Most vascular dementia is in fact Alzheimer’s dementia.
Vascular dementia usually causes mild cognitive impairment only.
Frontotemporal dementia or frontal lobe dementia. This is the name given to dementia due to degeneration or damage to the frontal and temporal lobes of the brain.
These parts of the brain control mood, personality, social behaviour, attention, judgement, reasoning, language and speech, planning your day-to-day living and self-control.
Lewy Body dementia. This is a form of dementia similar to Alzheimer’s dementia, but with associated visual hallucinations and Parkinsonism (slowing of movement, stiffness, shuffling and upper limb tremors similar to that seen in Parkinson’s disease).
For more information read Dr Peter Lipski’s book “Your Elderly Parents Failing Health. Is It Ageing Or A Treatable Condition”.