03.Types of dementia
Dementia describes a broad range of symptoms and exists in many forms, each with its own cause.
One disease, many forms
Alzheimer’s disease, vascular dementia, dementia with Lewy bodies, Parkinson’s disease, fronto temporal lobar degeneration, Huntington’s disease, Korsakoff’s syndrome and Creutzfeldt-Jakob disease are all common forms of dementia.
Alzheimer’s disease is a progressive, degenerative illness and the most common form of dementia, accounting for about 60% of cases. The cause is unknown, but disease pathology in the brain is characterised by “tangles” of material inside brain cells and deposits or plaques of amyloid protein outside the cells, which interfere with brain messaging and lead to cell death and loss of function. The familial form of Alzheimer’s can be inherited from an affected parent, whereas sporadic Alzheimer’s disease can affect adults at any age, but usually after 65. This is by far the most common form of Alzheimer’s disease and affects people who may not have a family history of the disease.
Vascular dementia refers to dementia related to poor blood supply to areas of the brain and is the secondmost common form of dementia. Dementia with Lewy bodies is caused by the degeneration and death of nerve cells in the brain, which is thought to be linked to abnormal spherical structures inside nerve cells (Lewy bodies).
Mild cognitive impairment (MCI) refers to cognitive decline in older people that is beyond what is expected, but not sufficient for a dementia diagnosis. Those with MCI are still very functional but have a 45% chance of experiencing further decline and progressing to Alzheimer’s disease.